REDUCTION OF ATMOSPHERIC POLLUTION
FINAL REPORT ON RESEARCH ON
REDUCING EMISSION OF SULPHUR OXIDES,
NITROGEN OXIDES.AND PARTICULATES
BY USING FLUIDISED COMBUSTION OF COAL
Appendices: (Vol. 3 of 3)
4 -- Experiments with 12-in.
corrosion combustor
5 -- Experiments with 6-in.
corrosion combustor
6 -- Mathematical model of
sulphur retention
7 -- Coal studies
8 -- Limestone and Dolomite studies
9 -- Methods for determination of NOX
Environmental Protection Agency,
Office of Air Programs,
Research Triangle Park,
North Carolina 27711
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NATIONAL COAL BOARD
FINAL REPORT
JUNE 1970 - JUNE 1971
REDUCTION OF ATMOSPHERIC POLLUTION
APPENDIX 4. EXPERIMENTS WITH THE 12 IN CORROSION COMBUSTOR. (TASK IV)
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
All WEST CHAPEL HILL STREET
DURHAM, NORTH CAROLINA 27701
FLUIDISED COMBUSTION
REFERENCE NO. DHB 060971 CONTROL GROUP
SEPTEMBER 1971 NATIONAL COAL BOARD
LONDON, ENGLAND
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REDUCTION OF ATMOSPHERIC POLLUTION
Research on reducing emission of sulphur oxides,
nitrogen oxides and participates by
fluidised bed combustion of coal
Appendix 4. Experiments with the 12 in corrosion combustor. (Task IV)
Main objective
To obtain data on corrosion of evaporator,
superheater and reheater materials for
lower fluidising velocities.
Report prepared by: M.J. Cooke and E.A. Rogers
Report approved by: A.D. Dainton and H.R. Hoy
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FOREWORD
This Appendix describes experimental work carried out using
the 12 in corrosion combustor at CRE., between June 1970 and June 1971,
as Task IV of the joint N.C.B./O.A.P. research programme. The
objective of Task IV was to obtain data on corrosion of evaporator,
superheater and reheater materials for lower fluidising velocities,
with or without addition of limestone. Attention is drawn to the
main results obtained, but these are not discussed here. A summary
of the work is presented in the main report and the results are
discussed there, together with results from other pilot plants.
A4.v
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Page No.
Foreword
1. Description of Plant A4. 1
1.1 Coal feed system A4. 3
1.2 Fluidising air preheater A4. 4
1.3 Fluidised bed combustor A4. 5
1.4 Specimen tube assemblies A4. 6
1.5 Coarse ash collection hopper A4. 7
1.6 Cyclone gas de-dusting system A4. 7
1.7 Auxiliary sample equipment A4. 8
1.7.1 Bed sampling A4. 8
1.7.2 Dust sampling A4. 8
1.7.3 Gas sampling A4. 9
1.7.4 S0_/S0- sampling A4. 9
1.7.5 Volatilised alkali sampling A4.10
2. Operating Procedures A4.12
2.1 Coal and limestone preparation A4.12
2.2 Plant start-up A4.12
2.3 Throughput measurements and sampling A4.13
2.3.1 Coal feed A4.13
2.3.2 Product ash A4.13
2.3.3 Bed samples A4.14
2.3.4 Secondary fines A4.14
2.3.5 Dust A4.14
2.3.6 Offtake gas A4.14
2.3.7 Mass balances-data processing A4.14
2.4 Plant shut-down A4.16
2.5 Corrosion test specimens A4.16
2.5.1 Preparation before tests A4.18
2.5.2 Procedure during tests A4.19
2.5.3 Procedure after tests A4.19
3. Results A4.20
3.1 Test Series 1 A4.20
3.1.1 Description of Test Series 1 A4.20
3.1.2 Results A4.21
A4. vii
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Page No,
3,l,2ol Plant data A4o21
30lo2.2 Visual examination of corrosion A4,28
test specimens
3olo2»3 Chemical analysis of deposits A4»29
3ol02o4 Specimen weight loss . A4.32
3c,l»2»5 Metallographic examination A4o32
3o2 Test Series 2 A4»33
3,201. Description of Test Series 2 A4033
3,2,2 Results A4.34
3.2.2,1 Plant data A4.34
3.2,2.2 Visual examination of corrosion A4.42
test specimens
3,2.2.3 Chemical analysis of deposits A4,43
3,2.2,4 Specimen weight loss A4.46
3o2.2o5 Metallographic examination A4,46
3.3 Test Series 3 A4.47
3.3.1 Description of Test Series 3 A4,47
3.3,2 Results A4048
3.3.2,1 Plant data A4.48
3,3,2,2 Visual examination of corrosion A4,60
test specimens
3.3,2.3 Chemical analysis of deposits A4.60
3.3.2.4 Specimen weight loss A4.61
3.3.2.5 Metallographic examination A4.64
3.3.2,6 Electron probe microanalysis A4.64
4. References A4.66
5, Acknowledgement A4,67
Figs. A,4.1 - A.4.25
(Note that when referring to Tables and Figures in the text the prefix
A4 is omitted).
A4. viii
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DESCRIPTION OF PLANT
The 12 in. combustor (Fig. 1 & 2) at CRE was built specifically
to investigate whether fireside corrosion of steam generation,
superheater and reheater tubes is likely to be a problem. Corrosion
specimen tubes, which are comprised of rings of different alloys
clamped together, are installed in the fluidised bed combustor,
both within the ash bed itself and in the freeboard section. There
are also facilities to mount small plates (coupons) of different
alloys in and above the bed.
A gas fired fluidising air pre-heater is used for start-up
purposes in order to heat the ash bed to a temperature at which
combustion of coal takes over. The coal for a test is kept in a
10 ton storage bunker. It is then transported to the coal feed
system where it is metered through a calibrated rotary valve and
pneumatically fed to the fluidised bed. There it is burnt and much
of the heat generated is removed by the corrosion specimen tubes,
the walls of which are air-cooled to the required test temperature.
The remaining available heat is removed by other air-cooled tubes
immersed within the bed.
A constant bed height is maintained by using an over-flow pipe
down which the excess bed ash flows into a sealed coarse ash'collection
hopper. The fine carbonaceous material, elutriated from the bed before
being completely burnt, is returned to the bed by means of an internal
cyclone. Solids not collected in the internal cyclone are removed by
a higher efficiency secondary cyclone. Any remaining dust is then
discharged into the atmosphere with the gas.
Sampling equipment for obtaining both combustion data and
information regarding the corrosion environment is used.
Special control by safety devices is incorporated to enable
the plant to operate continuously and safely with minimum of staff.
Basically, the start-up of the plant, coal storage, handling of ash
products and sampling are carried out manually when required. For
the normal running of the cqmbustor, fluidising and transport air
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are metered at constant rates and the bed temperature is controlled
by the coal feed rotary valve speed. The air flow through the
specimen tubes is controlled to give constant specified tube
temperatures and the additional air passed through the control
tubes is set such that the desired combustion conditions are
obtained. For.example, if a lower oxygen content in the exhaust
gas is required, the air through the control tubes is increased,
causing an automatic increase in the coal feed rate to maintain
bed temperature.
If conditions within the combustor vary beyond specified
limits, the plant is shut down automatically. The coal feed,
fluidising.and transport air are stopped while the temperatures
of the specimen tubes are kept at or below their specified levels
until the plant cools down. Should the main air supply fail, there
is a standby diesel compressor operating continuously which is
capable of supplying sufficient air during the plant shutdown.
In the event of complete failure of air supplies, steam is passed
through the specimen tubes in order to keep their wall temperatures
below the test settings. In this way the corrosion test is "frozen"
until restarted. Automatic plant shutdown is affected by:
(a) Bed temperature, high or low
(b) Fluidising air flow rate, high or low
(c) Transport air flow rate, high or low
(d) Specimen tube temperatures, high
(e) Combustor pressure, high
(f) Main air pressure, low
(g) Power failure
For the following more detailed description, the plant is
divided as follows (Fig. 1).
1. Coal feed system
2. Fluidising air pre-heater
3. Fluidised bed combustor
4. Specimen tube assemblies
5. Coarse ash collection hopper
6. Cyclone gas de-dusting system
7. Auxiliary Sampling Equipment
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General information regarding instrumentation follows the descriptions
of each item of the equipment listed above.
1.1 Coal feed system
Coal required for the tests is stored in a 10 ton bunker. All
interior surfaces are coated with bitumen paint ("Hevikote'1) to prevent
scaling and to assist the discharge of coal. Prepared coal is fed
pneumatically from solids pumps at the coal preparation plant to the
bunker.
Coal is fed pneumatically from the 10 ton coal storage bunker
via a 5 in rotary valve and ejector to coal feed cyclones and thence
to the coal lock hopper. An alternative emergency method of supply
is also available from a drum tippler which feeds coal from drums.
The coal is pneumatically fed along lj in n.b. lines and enters the
coal feed lock hopper via primary and secondary feed cyclones
situated above a vibratory screen which removes oversize and tramp
material. The air is discharged to the atmosphere. The flow of
coal may be diverted to a duplicate set of cyclones for sampling.
The coal feed system first lock hopper has a capacity of
approx. 800 Ib and is lined with "Hevikote". It is used to supply
coal by gravity to a second feed hopper, situated vertically and
axially beneath the first. It operates under a positive pressure
without disrupting the coal feed to the fluidised bed. The second
coal feed hopper has also a capacity of approx. 800 Ib and is intern-
ally lined with "Hevikote".
Coal is metered from the lower hopper through a small stainless
steel rotary valve feeder into a i in n.b. pneumatic transport line.
The feature of this feeder is ease of access, for maintenance and for
changing the rotor if necessary. The pockets in the rotor are
shaped and sized to promote their filling and discharge. Two air
purges are used to keep the sides of the rotor clear in order to
prevent seizure by coal binding.
A balance line system is connected to the transport air supply
line so that the feed hopper pressure may be maintained the same as
A4.3
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the pressure beneath the rotary valve. The feed transport line to
the fluidised bed combustor contains a transparent section for a
visual check of coal flow.
Instrumentation
When coal is required to be fed to the combustor feed .hopper
the 5 in rotary valve is started manually from the main control
panel on the rig. At the same time, a magnetic valve opens to
supply the transport air to the coal transport line to the coal
feed cyclones above the combustor feed hoppers.
The lock hopper system is operated manually with Goring and
Kerr high and low level capacitance probe indicators on each
hopper. The coal feed rotary valve is driven by a 0 - 10 rpm
240 V d.c. electric motor and gearbox with a speed control. From
the drive a revolution counter also operates.
The transport air rate is automatically controlled and the
safety shut down system will operate if the flow rate falls below
or rises above set limits.
1.2 Fluidising air preheater
The hot gas generator burns town's gas or natural gas in air,
with excess air used for keeping the exit gas temperature below the
maximum of 1300 F. Gas and air are supplied to the burner, controlled
2
at pressures of 10 Ib/in gauge. Before the combustor bed tempera-
ture is reached (about 1110°F), the hot gas generator is shut off
2
and separate metered air from a 45 Ib/in gauge supply reduced from
2
the 80 - 100 Ib/in gauge main is used.
Instrumentation
The air supplies are metered through rotameters
while the gas rate is automatically controlled by the exit hot gas
temperature. Gas is ignited by a spark ignition system and a
safety system shuts off the gas if ignition is not achieved or if
there is a flame failure. This safety device will also operate
with an outlet gas temperature higher than a preset value and also
with low gas or air supply pressures.
A4.4
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1.3 Fluidised bed combustor
The mild steel vessel was protected by lining it with 4 in of
Amberex insulating blocks (ex Genefax Monolithics Ltd.)> followed
by a 3 in lining of Durax 1500 hard castable refractory (ex Genefax
Monolithics Ltd.) to protect the former. In the top of the combustor
are two 4 in diameter explosion relief discs of | in thick asbestos
millboard.
The fluidised combustor has been designed to operate at 2 to
4 ft/s fluidising velocity with bed temperatures up to 1650 F. It
contains an internal cyclone, which is described later, for returning
the elutriated fine coal and ash back to the bed.
The fluidising air distributor consists of a horizontal base
plate with nine vertical tubes spaced on a 4i in square pitch. Each
tube has six £ in holes drilled just below the closed ends, to
give operating pressure drops of about 4 in and 10 in w.g. at 2 and
3 ft/s fluidising velocities respectively. The tubes are connected
to a manifold which receives the fluidising air. The bed level,
emergency and sample ash offtake pipes also pass through the base.
Coal is fed into the reactor 3 in above the holes in the air
distributor. .In order to achieve uniform coal feed discharge in the
combustor, the $ in pneumatic coal feed transport line terminates
at the centre of the combustor. To provide a fluidised bed for
start up ash is fed in at the top of the vessel.
The fluidised bed depth is kept constant at 2 ft by an
adjustable | in n.b. stainless steel pipe which acts as an overflow
weir. Excess bed ash produced is discharged into an ash collection
hopper.
The specimen tubes, on which rings of different alloys are
tested, are described in more detail later. However four such
tubes form part of a 6 in triangular pitch of 2 in o.d. tubes four
rows deep (Fig. 2). The remainder of the tubes, which make up the
pattern, are used for bed control purposes. They are of bayonet
construction and are air cooled. An exhaust duct discharges the
A4.5
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cooling air outside the building and at the same time acts as a
silencer. Two specimen tubes are also situated in the freeboard 2 ft
above the top of a 2 ft bed.
Eight studs are situated within the bed on which specimen
'coupon' plates are attached for corrosion tests. In the freeboard
section is an assembly mounted from one of the bursting disc flanges
on which six coupons may be attached.
The combustor has a number of 3 in n.b. sockets for thermocouples,
pressure probes, gas sample probes etc.
Instrumentation
Pressure probes, purged by air, are used to give manometer
readings for pressure drops over the air distributor, a fixed depth
of fluidised bed, the total bed, the internal primary cyclone and
seondary cyclone. Bed height is obtained from the ratio of the
pressure drops across a fixed depth of bed and the total bed. A
pressure tapping is used for the safety shut down system if the
combustor pressure rises too high.
Thermocouples are situated in and above the fluidised bed. Bed
temperature is automatically held constant by the coal feed rotary
valve speed. High or low bed temperature will operate the shut
down system.
1.4 Specimen tube assemblies
There is provision for six 2 in o.d. specimen tubes, four in
the fluidised bed itself and two in the freeboard section (Fig. 2).
The specimen tubes consist of seventeen rings I" long and 2 in o.d.
of different alloys (Fig. 3). The rings are initially turned, then
lapped with their neighbours and finally the outside surfaces, which
are to be exposed to the bed environment, are ground to give a fine
surface finish with a minimum of work hardening. The procedures for
handling the rings are described in section 2.5.
A4.6
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The rings are clamped together and spring loaded to allow
for expansion. Air is passed through the tubes for cooling and
steam is available as a temporary coolant if the air supply fails
during a run. The central former is shaped so that wall temperatures
are as constant as possible throughout the length.
The four tubes in the bed can be removed together with the
door on which they are mounted. Similarly, the two tubes above the
bed are mounted on another door. A trolley device is used to carry
each door when they are being removed or refitted,
Instrumentation
When corrosion tests are conducted, three of the specimen rings
in each tube assembly have holes to accommodate 1/16 in bonded pyro-
tenax thermocouples. The thermocouples are used for control purposes
and to operate the high temperature alarm/shut down system.
Ii5 Coarse ash collection hopper
This receives ash from the overflow pipe in the combustor and
has an ample capacity of 500 Ib so that it can take ash for a 24 h
period and may therefore be emptied daily.
1.6 Cyclone gas de-dusting system
This consists of two cyclones in series which separate fine
ash and unburnt material from the hot effluent gases. The primary
cyclone is mounted internally in the combustor so that the coarser
fines may be returned to the bed. The dip leg (2 in o.d.) terminates
at a level 1 in above coal feed line and 2 in off centre. It is
shielded by a 2 in diameter stainless steel plate fixed 1 in beneath
the end of the leg. In this way the returned fines have a greater
chance to be burnt and so the overall combustion efficiency is
improved. The secondary cyclone, which has a higher efficiency, is
used for collecting as much of the escaping fine material as possible
before the gases are discharged into the atmosphere. A flow straight-
ener has been installed after the secondary cyclone for reducing the
swirl of the gases before the dust sampling is carried out.
A4.7
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The primary and secondary cyclones have been designed according
to Perry (1950) and based on inlet gas velocities of 50 and 100 ft/s
respectively for a fluidising velocity of 3 ft/s at 1470°F.
The secondary cyclone and the gas line from the primary cyclone
are electrically heated by three inconel sheathed heating elements,
each of 1000 W.
Instrumentation
The electrical heaters are controlled by Sunvic regulators and
thermocouples are used for measuring wall temperatures. Pressure
probes permit the measurement of pressure drops over the cyclones.
1.7 Auxiliary sample equipment
1.7.1 Bed sampling
Samples of the ash bed are taken through an adjustable vertical
stainless steel pipe mounted through the base of the combustor into
the fluidised bed. The other end has a I in Milliken valve and a
li in union which takes an 8 Ib capacity sample container. A sample
is taken by discarding the ash initially in the pipe and then
collecting the required quantity in the sample container. Care is
taken to keep the ash sample air tight until it has cooled
sufficiently to prevent the combustion of any carbon in it.
1.7.2 Dust sampling
The exhaust gases from the secondary cyclones are sampled
isokinetically. (See Fig.4). The essential features are a 5/16 in
i.d. stainless steel probe and a stainless-steel filter (Gallenkamp)
with stainless steel ball and socket joints (Size S19). The dust is
separated in the filter on a glass paper disc. The gases are cooled
in an acetone/solid carbon dioxide cold trap to remove moisture and
finally metered through a rotameter and dry gas meter.
Before operating, the system is tested for leaks and a weighed
filter paper is fitted into the holder. Gases are then withdrawn at
the isokinetic rate for a set time and the volume of gas sampled is
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recorded. The. dust sample is then taken and weighed with the filter
paper.
1.7.3 Gas sampling
(a) Batch sampling
A water cooled gas sample probe situated 56.5 in above the
air nozzles is used. When samples are not being taken, the probe
is kept clear by an air purge. Samples are taken using evacuated
250 ml glass pipettes after the probe has purged itself by
discharging combustion gases into the atmosphere for a few
seconds.
The gases are analysed on a Fisher-Hamilton gas partitioner,
Model 29, for C02> 02, CO and CH^.
(b) Continuous gas sampling
At the secondary cyclone outlet a continuous sample.is
withdrawn through an open-ended probe. A water ejector/
separator (Mines Safety Appliances Co. Ltd.) pumps the gas
to a Kent oxygen analyser, the output of which is continuously
recorded. Some of the carbon dioxide in the gases is absorbed
by the water but it is assumed that this is reasonably constant..
Thus the continuous record give a good indication of the
steadiness of the combustion conditions.
1.7.4 S00/SO, sampling
2. j
The SO^ and SO- content of the exhaust gases leaving the
secondary cyclone are determined by the 'Shell Condensation* Method.
(Goks*5yr,1962: Lisle, 1965). A diagram of the apparatus is given
in Fig. 5.
A continuous sample of the exhaust gas is withdrawn through a
3
silica glass probe at 6 ft /h for 10 min. The probe is followed by
a quartz wool filter to separate the dust and the temperature of the
gas at this point should be above the acid dew point, preferably
above 480 F. The gas sample passes to the condenser which has water
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coolant between 140 F - 190 F, so that the S0_ is condensed as
sulphuric acid while the other gas constituents remain in the gas
phase. After the condenser is a bubbler containing 100 ml of 3%
hydrogen peroxide solution to absorb the sulphur dioxide.
The condenser is washed out with 5% isopropyl alcohol
solution at pH 4.6 and sulphur is determined gravimetrically
as barium sulphate. The solution from the bubbler is trans-
ferred to a separate vessel using 5% isopropyl alcohol as wash
liquid and then boiled for 10 min to remove excess hydrogen
peroxide. The solution is made up to 250 ml with distilled water,
and an aliquot is titrated against N/50 sodium hydroxide to give a
rough estimate of sulphur emission while the run is being carried
out. The remainder is used to determine sulphur gravimetrically
as barium sulphate. Alternatively, the total sulphur content of
the flue gas during a run is determined by measuring the volume of
flue gas required to decolourise a solution containing a known
volume of iodine. This method uses the same sampling train
already described but the condenser is omitted. The bubbler
'contains 2-15 ml (depending on S02 concentration in the flue gas)
of 0.1 N iodine and 100 ml of 2% potassium iodide solution. Exhaust
3
gas is drawn through the bubbler at 2 ft /h. Sulphur emission is
then calculated from the volume of gas required to decolourise the
iodine solution.
1.7.5 Volatilised alkali sampling
The sampling procedure is based on the postulate that the
volatilised alkalis are present in the flue gas as alkali aerosols,
which are responsible for the formation of alkali rich deposits on
superheater tubes (Ounsted, 1958).
A metered bleed from the flue gas leaving the secondary cyclone
is sucked through a stainless steel probe and passes through two
electrostatic precipitators in series which remove the aerosols,
(Fig. 6). These precipitators are washed out with hot distilled
water and the alkali content (Na, K and Ca) of the washings is
estimated using standard flame photometry. The probe and precipitators
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are kept above the acid dew point of the gases (above 300°F) using
electrical heaters where necessary.
Chloride in the offgases is determined by totally the chloride
collected in the electrostatic precipitators and the remainder
absorbed in the hydrogen peroxide bubbler situated after the
precipitators.
The measurement of chloride in the offgas appears to be
satisfactory but there is doubt about the measurements of volatilised
alkali salt concentrations.1 This is because the temperature of the
sampling probe was only about 400°F making it possible for these
salts to be deposited before reaching precipitators. It has also
been found that, in addition to any condensed alkali salt, small
quantities of fine ash (dust) containing Na, K and Ca were
collected in the precipitators.
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2. OPERATING PROCEDURES
2.1 Coal and limestone preparation
Both the Pittsburgh coal and Limestone 18 were crushed to minus
1680 ym. The coal and limestone were prepared on the Fluostatic
dryer/sample house crusher system and the Atritor preparation plant
respectively. These are described in Appendix I, sections 1..4.1 and
1.4.2.
2.2 Plant start-up
Hot products of combustion from the fluidising air preheater,
to which excess air had been added to give a temperature of 1290°F,
' were passed through the air distributor into the empty fluidised
bed combustor. External heat to the offtake gas lines and secondary
cyclone was supplied by electric heaters controlled through three
Sunvic regulators.
When the temperature within the bed had reached 480 F, the
preheat gas was stopped while sufficient bed ash was introduced
through a funnel inserted at the top of the combustor to give a
2 ft bed height. The ash bed was- then fluidised with the hot gas
from the air preheater in order to increase the bed temperature
sufficiently for the combustion reaction to take over. At this
time the temperature controllers on each of the six specimen tubes
were set to operate on automatic control. The preheat gas flow rates
were adjusted regularly in order to maintain 3 ft/s fluidising
velocity as the bed temperature rose. When the bed temperature had
reached 720°F, the coal feed was started at approximately 25% of the
expected final rate. At 1110°F the fluidising air preheater was shut
off and the main fluidising air controller was used. The coal feed
was then increased to 50% and further increased to the final rate
by the time that the desired bed temperature of 1560°F had been
reached. The bed temperature controller was then switched to AUTO.
Any minor adjustments to the fluidising air and specimen tube
temperatures were then made.
The amount of air passed through the remaining control tubes
was then set to obtain the desired combustion conditions. When the
plant had stabilised on the required operating conditions and all
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alarms were correct, the safety shutdown system was switched on. The
plant then shut itself down automatically and safely as described
previously when any operating variable changed beyond preset limits.
Each test was commenced when the plant had-reached the required
bed temperature of 1560°F. The time taken from cold was about 5 h.
2.3 Throughput measurements and sampling
The coal feed and product rates were determined by the methods
described below. The sample procedures are also given. Sections 3.1.1,
3.2.1 and 3.3.1 give details of mass balance periods.
2.3.1 Coal feed
Before and after the tests the coal feed rotary valve was
calibrated to find the quantity of coal discharged per revolution.
The rate was then calculated from the product of the number of
revolutions of the rotary valve in a specified time, and thus, the
calibration figure in Ib/rev. An incremental coal sample over the mass
balance period was obtained by diverting the coal to a sample cyclone
for 10s every 10 min when the coal feed hoppers were being filled from
the main storage bunker. The resulting 70 Ib sample consisting of 20
increments of 3i Ib, was then subdivided using a rotary riffler to
provide a sample for analysis.
2.3.2 Product ash
Excess bed ash was discharged via the overflow weir into a hopper.
The ash collected over a mass balance period was then subdivided using
a rotary riffler.
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2.3.3 Bed samples
The samples were taken through a vertical pipe mounted through
the base of the combustor into the fluidised bed as already described.
Subdivision of the samples was carried out with a rotary riffler.
During the 500 h tests bed samples were taken at the start and conclusion
of each mass balance period.
2.3.4 Secondary fines
Most of the fine ash, which leaves the internal primary cyclone
with the offtake gases, was collected by the secondary cyclone and
discharged into a collection hopper. This material was also sampled
using a rotary riffler.
2.3.5 Dust
The sampling procedure used has already been described. About ten
samples of dust from the exhaust gases leaving the secondary cyclone
were obtained for each mass balance period. They were bulked for
chemical analysis. The chlorine content was high, probably because
of the condensation of HG1 from the flue gases. For mass balance
purposes the chlorine content of the dust was assumed to be similar to
that of the secondary fines.
2.3.6 Offtake gas
Sampling and analysis of the gaseous combustion products has
already, been described. Batch samples were taken at approximately 4 h
intervals through a water cooled probe and analysed for C02, 02, CO
and CH, .
The measurement of SOj, S0_, chloride and alkali aerosol (Na, K
and Ca) content of the exhaust gases leaving the secondary cyclone has
already been described. The frequency of sampling in each test is
indicated in sections 3.1.2.1, 3.2.2.1 and 3.3.2.1 where the results
are presented.
2.3.7 Mass balances - data processing
The feed rates, measured solids output rates and chemical
analyses of the input and output streams were used to calculate mass
balances which were carried out by computer.
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The major factor in the mass-balance", which: was not measured
was the flow rate of flue gas. It was necessary to estimate this.
Since the gas analysis was carried out. on a dry volume basis, the
dry volume rather, than mass flow rate of gas was estimated. This
was done by correcting the feed air flow rate for the volume changes
due to the reactions which occurred. These were:-
—9- 2H20 (liquid)
(i)
(ii)
(iii)
(iv)
(v)
4H (coal)
20 (coal)
2C
CaC03
CaO + $02
+ o2
+ 02
+ so2
The volume changes due to (i) and (ii) were calculated assuming
that all the hydrogen and oxygen in the coal were released.
The increase due to (iii) was calculated from the measured
concentration of CO in the flue gas. The net effect of (iv) and
(v) was small and this was neglected. Thus the flue gas flow rate
was calculated as
Flue gas flow-rate =
Air + 379X Coal Feed Rate. x(0 Content/32- H Content/4)
(1 - 0.5 x CO in Flue Gas)
SCFH
The following mass balances were carried out:-
(i) Total.
(ii) Ash.
(iii) Carbon.
In this the mass flow rate of dry flue gas was
calculated from the composition and a hydrogen
balance was assumed.
This was a balance for the inorganic solids, i.e. ash and
acceptor. No allowance was made for the weight changes due
to calcining of CaCO, and formation of sulphate.
This was a balance for the organic carbon in the coal
and is directly relevant to the combustion process.
(iv) Nitrogen. This balance served as a check on the accuracy of the
flue gas analysis.
A4.15
-------
(v) Oxygen. This is a balance for the oxygen in. the air and the
organic oxygen in the coal. It is directly relevant
to the combustion process.
(vi) Sulphur, calcium,, sodium, potassium and chlorine.
The following parameters were calculated from the flow rates
in the mass balance:-
(i) Excess air level, defined as
., . . Feed air - Stoiehiometric air for coal feed rate .--_
Excess air = ... . . t ——. :—7 r—=—3 x 100%.
Stoiehiometric air for coal feed rate
(ii) Carbon loss, defined as
„ , - Unburnt carbon output rate -inn*
Carbon loss = _ ^ , r —*— — x 100%.
Total carbon output rate
The carbon loss is based on the total measured carbon output
rate since this is considered to be a more accurate estimate of the
carbon input rate than that based on the coal feed rate and chemical
composition.
2.4 . Plant shut down
At the completion of each test the coal feed and fluidising
air were stopped and the bed was fluidised with nitrogen whilst
being discharged. The nitrogen supply was continued until the
combustor body had cooled to below 390 F.
Specific operational details of the individual tests are given
in sections 3.1.1, 3.2.1 and 3.3.1.
2.5 Corrosion test specimens
Seven steels were tested and their nominal compositions are
given in Table 1. They represent the range of steels used in
conventional coal and oil fired boilers with the exception of 12% Cr
ferritic steel and Nimonic PE 16 which are under consideration for
certain applications.
A4.16
-------
Table A.A.I Typical Analyses of Alloys Tested
Material
Type
Medium Carbon Steel
2J% Cr, 1% Mo Steel
12% Cr Steel
Austenitic 316
Austenitic 347
Esshete 1250
Nimonic PE 16
BSS
3059/5
3059/622
EN 56 A
EN 58 J
EN 58 G
AISI No.
410
316
347
Nominal Composition %
Cr
2.25
12
17
18
15
17
Ni
12
11
10
43
C
max
0.25
0.15
0.15
0.09
0.08
0.15
0.10
Mn
0.7
max
1.0
max
2.0
max
2.0
max
6.0
P
max
0.05
0.04
0.04
0.05
0.05
0.04
S
max
0.05
0.04
0.03
0.05
0.03
0.03
0.02
Si
max
0.5
1.0
0.2
1.0
1.0
0.3
Mo
1.00
2.5
1.0
3.0
Ti
1.2
Al
1.2
Fe
Bal
Bal
Bal
Bal
Bal
Bal
Bal
Other
Nb 10 :
C min
Nb 1%
-------
With the exception of Nimonic PE 16, the steels were obtained
as 2 in o.d. cold drawn tube in a fully heat treated condition.
The Nimonic PE 16 was supplied as 2 in diam. bar, fully heat
treated, for the manufacture of the rings and as 16 s.w.g. sheet
for the coupon plates.
2.5.1 Preparation before tests
The rings and coupons were manufactured according to Figs. 7
and 8 with the exception of coupons of Nimonic PE 16 (Fig. 9). All
faces of the specimens made to Figs. 7 and 8 were fine turned except
those indicated which were ground, with the minimum of work hardening
to a surface finish, expressed as centre line average, of less than
10 y in. The coupons of Nimonic PE 16 were cut from sheet and all burrs
removed. The specimens were stored in a dessicator.
Before the outer surface .of the rings were ground, they were
assembled in the required order into tubes. Each ring was ground in
with its neighbour using fine grinding paste in order to minimise
leaks between the rings during the corrosion test. At this stage the
thermocouple holes were drilled in three rings from each tube.
The identification-of position of each specimen (rings and
coupons) is given in Fig. 10. Rings f, 1 and p were fitted with thermo-
couples at the '9 o'clock' and '3 o'clock' positions for tubes 1, 3, 5
and tubes 2, 4, 6 respectively when viewed from the air inlet end.
After surface grinding the specimens were washed in Teepol
solution, rinsed, dipped in acetone, dried and weighed. The rings
were then assembled in the correct order and orientation into tubes
held together by spring tensioned centre bodies.. The assembled tubes
were leak tested by sealing off the end of each tube and noting the
flow rate of air required to maintain a constant pressure of 5 Ib in2
gauge. An acceptable leak rate was less than 30 s.c.f.h. In this
case the air weeped uniformly through the ground joints between the
rings. The tubes were next mounted in the combustor with the coupons.
The tubes were leak tested again to check that their alignment had not
been disturbed by the handling procedure.
A4.18
-------
2.5.2 Procedure during tests
Each tube was controlled to its required wall temperature using
air as coolant. There was no failure of the air supply so emergency
steam for cooling was not used at any time.
Tube wall temperatures were measured using thermocouples inserted
into three rings on each tube (section 2.5.1).
2.5.3 Procedure after tests
When the combustor had cooled to below 200 F the tubes were
withdrawn and photographed. The tubes and coupons were then removed
from the doors and examined visually. Deposits and scales were
sampled where they could be removed without damaging the metal
specimens. Rings and coupons were then selected for more detailed
microscopic examination of the fireside surfaces.
The majority of the test specimens were then descaled while some
were retained. The descaling was carried out by immersing the specimens
for 5 min in a bath of molten sodium hydroxide at 680 - 720°F
containing 2% of sodium hydride. They were then water quenched and
washed to remove all traces of scale.
The specimens were then re-weighed. A selection of both
descaled and undescaled rings and coupons were then sectioned for
metallographic examination.
A4.19
-------
3. RESULTS
3.1 Test Series 1
This preliminary run of 100 h duration was carried out to test
the operation of the rig when burning the strongly caking Pittsburgh
coal. The data on corrosion may be compared with the similar test of
longer duration (Test Series 2: 500 h) in order to determine the effect
of time on the steels when exposed to the fluidised combustion
environment. No limestone was added with the feed.
3.1.1 Description of Test Series 1
The combustor operated continuously from 5th - 10th October 1970
with the exception of one shut-down lasting 5.83"h caused by a coal
feed stoppage.
The initial bed was composed of minus 1680 ym burnt Newdigate
shale and the average conditions during the test are given in Table 2.
Table A.4.2 Operating conditions during Test Series 1
Coal Pittsburg
Coal size (upper limit),ym 1680
Acceptor None
Fluidising velocity, ft/s 3
Bed temperature °F 1560
Bed depth, ft. 2
Recycle Yes
Oxygen in flue gas, % 2
Because the original uncooled coal feed nozzle blocked frequently
by coking in the hot section when initially tested with Pittsburg coal,
a water cooled coal feed pipe was installed. It operated satisfactorily
throughout. However, it was apparent that it caused some ash bed
material to be occasionally transported up the dip leg of the internal
primary cyclone and be collected in the secondary cyclone. This
caused the secondary cyclone solids outlet to block.
A4.20
-------
For this reason it was not possible to measure the fines and
dust output rates accurately,,. ..Estimates of these^rates have been
based on the relatively short periods with no blockages. Minus
1680 ym Newdigate shale was added daily to maintain the required
bed height.
In order to allow for the 5.83 h shutdown the test was concluded
105.83 h after the start. The mass balance was commenced immediately
after the shutdown at 21 h from the start of the test and continued
to the end of the test. The length of the mass balance period was
84.83 h.
3.1.2 Results
3.1.2.1 Plant data
Chemical analysis and size distribution of the-coal feed are
given in Tables 3 and 4 respectively.
Table 5 gives chemical and size analyses of the bulk sample
of secondary cyclone fines for the whole mass balance period.' The
coarseness of these fines was probably the result of the internal
cyclone occasionally transporting ash bed material up the dip leg
through the secondary cyclone. This would account for the
slightly low carbon content of these fines compared with test
Series 2 (Table 18).
A4.21
-------
Table A.4.3 Chemical Analysis of coal feed in test series 1
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen + errors
Chlorine
Carbon dioxide
Ash analysis
CaO
Na20
K20
F6203
Ash fusion Temp.
Initial deformation
Hemisphere
Flow
Gross Calorific
value
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b,
°F
op
op
Btu/lb
d.a.f.
1.0
13.6
41.7
70.5
4.6
1.45
2.75
3.7
0.08
0.79
7.4
0.7
1.5
18.4
1886
2174
2228
15,120 |
Table A.4.4 Size distribution of coal feed in test series 1
Particle size
(ym)
+ 1680
+ 500 - 1680
+ 25.0 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
Packed density (lb/ft3)
% in grade by
weight
1.2
44.1
18.7
13.5
14.3
8.2
440
65.3
A4.22
-------
Table A.4.5 Chemical and size, analyses of secondary cyclone.fines,,from Test Series 1
Weight percentage, "as received"
•
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
Na20
K20
Fe203
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
Packed density (lb/ft3)
23.4
0.22
. 1.15
0.00
0.19
3.6
0.46
1.92
10.7
% in grade by weight
0.2
17.8
15.2
8.8
14.0
44.0
88
60.4
Chemical analysis of the. dust is given in Table 6.
Table A.4.6. Chemical analysis of dust from Test Series 1
Weight percentage, "as received"
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
Na20
K20
Fe2°3
27.3
0.33
1.55
0.18
0.26
4.1
0.46
1.32
13.3
'
*Carbon does not include carbon present as carbon dioxide
A4.23
-------
Table / gives the chemical and size analyses of bed material.
The initial ash bed was Newdigate shale which was also added daily
in order to maintain the required bed height. No product ash was
therefore obtained.
Table A.4.7 Chemical and size analyses of bed material from Test Series 1
Weight percentage, "as received"
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
Na20
K20
Fe203
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
Packed density (lb/ft3)
Initial
Ash Bed
1.33
0.33
0.30
0.03
0.04
0.78
0.57
3.94
6.3
Final
Ash Bed
0.03
0.03
1.05
0.01
0.10
4.5
0.58
3.21
7.5
% in grade by weight
0.0
60.2
18.2
8.1
4.4
8.1
750
93.8
0.3
87.5
9.8
1.8
0.4
0.2
850
83.3
*Carbon does not include carbon present as carbon dioxide
Figs. 11 and 12 present the off gas analyses taken during the test.
No CO-, Oo and CO measurements were made from 15 h to 21 h because the
plant was shut down. Methane was not found in any of the samples. Only
two determinations of chloride were made because the equipment was faulty
earlier in the test. Those made have been expressed as HC1 (p.p.m.).
The S02 and SO- content of the exhaust gases were determined by the
'Shell Condensation' method.
The mean gas analysis used in the mass balance was:
C02 %
°2 %
CO %
SO- p.p.m.
HCI p.p.m.
15.4
1.9
0.033
2270
57
A4.24
-------
«••
The alkali aerosol content
-------
Table A.4.9 Mass balance for test series 1
Rate: Ib/h
Coal
Air
Total Input
Ace. in bed
Offtake Ash
Secondary fines
Exhaust Dust
Flue gas
Total Output
Loss (In - Out)
Loss Percent
Rate: Ib/h
Coal
Air
Total Input
Ace. in bed
Offtake Ash
Secondary fines
Exhaust Dust
: Flue gas
• Total output
Loss (In - Out)
Loss Percent
Total
20.2
214.6 >
234.8
0.0
-0.9
3.9
1.0
229.6
233.6
1.2
0.51
Sulphur
0.556
0.000
0.556
0.008
-0.003
-0.044
0.015
0.511
0.575
-0.019
-3.42
Ash
3.0
0.0
3.0
0.0
-0.9
3.0
0.7
0.0
2.8
0.2
6.67
Ca
0.147
0.000
0.147
0.026
-0.005
0.100
0.029
0.010
0.160
-0.013
-8.8
Carbon
14.3
0.0
14.3
0.0
0.0
0.92
0.27
13.30
14.49
-0.19
-1.32
Na
0.014
0.000
0.014
0.000
-0.004
0.013
0.003
0.001
0.013
0.001
7.1
Nitrogen
0
165
165
0
0
0
0
167
167
-2
-1.21
K
0.035
0.000
0.035
-0.006
-0.029
0.059
0.011
0.000
0.035
0.000
0
Oxygen
0.7
49.6
50.3
0
0
0
0
47.8
47.8
2.5
4.97
Chlorine
0.016
0.000
0.016
0.000
0.000
0.000
0.000
0.016
0.016
0.000
0
Excess air is
Carbon loss is
2.5%
8.2% (Unburnt)
A4.26
-------
Table A.4.10 Pressure Drops through Plant in Test Series 1
Pressure drop, (in. water gauge)
Baseplate
10.5-12.5
Bed
17-23
Density (over 8$ in )
7.0-8.0
1° cyclone
1.2-1.5
2° cyclone
3.5-5.5
Bed height = A P' (Bed) x 8.5 + 3 in.
& P (density)
Table A.4.11 Temperature Distribution through Plant in Test Series 1
Position
In bed
In bed
In bed
In bed
In bed
In bed
1° cyclone
inlet
1° cyclone
exit
2° cyclone
exit
Probe
No.
Nl
N2
N2
N3
N3
N3
N9
-
-
Height above
air nozzles
(in)
3
6
11
21
21
21
88
-
.
Probe
length
(in)
3
9
6
3
9
6
3
2
2
Temperature
(°F)
1580-1600
1580-1600
1570-1590
1560-15.80
1580-1600
1560-1580
1400-1450*
1320-1380*
1180-1220*
t
* Excluding first 24 h.
A4.27
-------
3.1.2.2 Visual examination of corrosion test specimens
When the tubes and coupons were removed from the combustor
they were examined visually.
Tube 1 (in bed, 750°F)
There was a thin dark brown and slightly .blistered scale on the
rings of medium carbon and 2$%'Cr steel. The surfaces of the high
chromium alloy rings had a thin brown film. However, on the underside
of rings g - o there was a dark grey coke-like deposit approximately
0.02 in thick. This was probably the result of the close proximity
of the coal feed nozzle.
Tube 2 (in bed, 1110°F)
In general, there was a thin reddish brown film except on the two
rings of 2|% Cr steel which had scaled to a greater extent than the
same steel held at 750°F and 930°F.
Tube 3 (in bed, 930°F)
It appeared similar to tube 1 except there was no coke-like deposit
on any of the rings.
Tube 4 (in bed, 1290°F)
There was a very reddish brown scale or deposit on the rings.
Tube 5 (above bed, 750°F)
There was a band about 3/4 in wide on the top of the tube which
was protected by a layer of ash. On the underside of the tube was a
thin layer of buff coloured dust-like deposit. The surfaces not
covered by deposits had a thin oxide film which was slightly thicker
on rings of medium carbon and 2j% Cr steel.
Tube 6 (above bed, 1290°F)
It appeared similar to tube 5.
Coupons in the bed (1560°F)
The coupons had a red-brown oxide film.
Coupons above the bed (1440°F - 1560°F ) '
All coupons were covered with a fine buff deposit.
A4.28
-------
3.1.2.3 Chemical analysis of deposits
The deposits on the rings were in general very thin and adherent
except for the deposits from tubes 5 and 6. As a result in most cases
it was not possible to obtain a sample because the metal surface of
the rings would have been damaged. Chemical analyses of those
deposits and scale samples which were obtained are given in Tab.le 12.
Comparison with the analysis of bed ash given in Table 7 shows that
the deposits were predominantly ash with little enrichment of
potentially corrosive salts.
The chloride content of the deposits was low (<^ 0.1%) except
for the deposit from the 750 F tube 1 (1%) which was situated close
to the coal feed nozzle. This deposit contained 53% carbon and on
an ash basis there was three times more sulphur in the deposit than
in the bed ash.
There was only a small enrichment of up to about two times
the sulphur, sodium and calcium in the deposits from the tubes
situated above the bed when compared with the bed ash.
Table A.4.12 Chemical analyses of deposit and scale samples from Test Series 1
Description of sample .
Deposit from underside, tube 1
(750°F)
Scale from 2j% Cr steel ring,
tube 2 (1110°F)
Deposit from top, tube 5
(750°F)
Deposit from underside, tube 5
(750°F)
Deposit from top, tube 6
(1290°F)
Deposit from underside, tube 6
(1290°F)
Weight percentage, "as received"
C
53.3
—
—
—
—
S
1.6
0.3
2.3
1.1
2.5
1.3
Cl
1.0
0.07
0.03
0.10
0.02
0.08
CaO
1.03
1.06
6.2
3.9
6.3
4.1-
MgO
0.28
0.13
1.13
0.96
1.13
1.18
Na20
0.24
0.42
0.53
0.75
0.51
0.85
K20
0.39
1.02
1.9
1.9
1.9
2.5
Fe203
3.4
94
—
—
—
A4.29
-------
Table A.4.13 Summary of Corrosion Results; Rings and Coupon Weight Loss - Mg/cm h (Test Series 1)
>
tfe.
CO
o
"S
M
Freeboard
Tube
No.
1
2
3
4
5
6
Location
of Ring
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature ( F)
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature .( F)
a
S
**
S
**
S
**
S
**
S
**
S
**
b
MCS
74
S
6
MCS
125
S
9
MCS
63
S
3
c
F2
67
R
8
F2
153
R
10
F2
86
R
3
d
MCS
100
E
10
MCS
193
E
17
MCS
66
E
7
e
S
1
S
10
S
2
S
13
S
3
S
3
f
E
1
680
E
11
1150
E
3
940
E
21
1300
E
2
740
E
8
1330
g
MCS
90
± 13
F2
696
± 18
MCS
143
+ 27
S
13
± 27
MCS
62
± 9
S
3
+ 36
h
F2
83
R
7
F2
154
R
12
F2
68
R
5
j
MCS
***
E
***
MCS
***
E
***
MCS
***
E
***
k
F2
***
S
***
F2
***
S
***
F2
***
S
***
1
E
1
700
E
9
1050
E
3
940
E
24
1350
E
1
830
E
10
1350
m
MCS
101
+ 30
F2
462
± 13
MCS
190
± 27
E
24
±"36
MCS
57
± 13
E
10
+ 36
n
F2
109
R
7
F2
198
R
11
F2
65
R
6
o
F2
111
S
9
F2
210
S
11
F2
78
S
4
P
S
1
860
S
8
t
S
2
900
S
11
1220
S
1
660
S
5
1260
q
E
3
± 18
E
7
E
3
± 18
E
19
± 18
E
2
+ 18
E
16
+ 36
i
S
**
S
**
S
**
S
**
S
**
S
**
Coupons
Temperature (°F)
Location
Alloy
Weight Loss
Bed
1560
1
S
9
2
*
3
*
4
E
20
5
R
12
6
*
7
*
8
*
Freeboard
1440 - 1560
9
*
10
E
4
11
S
2
12
R
3
13
*
14
*
* Coupon not fitted
f Thermocouple defective
** Ring used as Spacer
*** Ring not descaled,
retained for further examination
MCS Medium Carbon Steel
F2 Ferritic 2\% Cr Steel
W Ferritic 12% Cr Steal
S Austenitic Type 316
R Austenitic Type 347
E Austenitic, Esshete 1250
N Nimonic PE 16
-------
Table A.4.14 Microscopic Examination of Specimens: Test Series 1
Alloy
f^^
Medium
Carbon
Steel
1
2|% Cr
1% Mo
Steel
AISI
316
i
AISI
347
Esshete
1250
PE 16
Temp.
750
750
750
750
930
930
750
750
750
750
930
930
1110
1110
750
750
930
1110
1290
1290
1560
1110
1290
1290
1560
750
750
930
1110
1290
1290
1470
1560
1560
Specimen +
position
lj
1m
5j
5m
3j
3m
Ik
lo
5k
5o
3k
3o
2g
2m
IP
5P
3p
2k
4k
6k
1
2h
4h
6h
5
11
51
31
2j
4j
6j
10
4
2
Wt. loss
(yg/cm2h)
*
101
*
57
*
190
*
111
*
78
*
210
696
462
1
1
2
*
*
*
9 '
7
12
5
12
1
1
3
*
*
*
4
20
8
Surface **
Texture
smooth
smooth
smooth
smooth
rough
rough
smooth
smooth
rough
smooth
Pits
(ym)
o.
0
0
0
0
0
0
0
0
0
rough ! 0
rough : 0
v. rough '. 0
v. rough 0
smooth 0
smooth
0
smooth ' 0
rough 0
v. rough 0
smooth 0
smooth f few 10
rough 0
rough 0
smooth ,| 0
rough ': few 15
smooth . 0
smooth ' 0
smooth
rough
rough
smooth .
smooth
0
few 20
0
few 8
0
rough few 15
smooth 0
j
Deposit (D)/
Scale (S) (ym)
20:S+50:D
-
8:S+30:D
-
30:S
-
Penetration (ym)++
Sulphide
Oxide
i
1
0 j 3
0
0
0
0
3
0 i
0
0
0 8
1
15:S+50:D 0
.
6:S+20:D
-
20:S
-
-
0
0
0
15?
18?
30
| 15
—
-
10:S+5:D
15:S i
2:S+10:D
0
0
0
0
20
0
1 15
-
-
-
—
-
-
-
10:S+5:D
18:S+10:D
3:S+10:D
-
—
-
0
0
0
0
0
0
0
0
10
0
0
0'
0
0
2
8
4
15?
18?
i
2
0
0
5
-
0
-
2
i
6
0
8
0
0
0
5
-
0
0
8
6
* Specimens not descaled and reweighed at end of test.
+ See Fig. 10.
** See Section 3.1.2.5.
++ Sulphide penetration was accompanied by oxide penetration.
A4.31
-------
3.1.2.A Specimen weight loss
Rings and coupons were weighed before the test and re-weighed
after descaling at the conclusion of the run. The difference or
n
weight loss results are given in Table 13 and expressed as yg/cnr
of exposed surface to the fluidised combustion environment per h.
Rings a and r on each tube were not used for corrosion
measurements because they were partly shielded by the combustor
walls. A few rings were not descaled. These were sectioned for
microscopic examination (section 3.1.2.5).
3.1.2.5 Metallographic examination
. Some of the specimen rings and coupons were sectioned, mounted
and polished. They were examined under a microscope and the
observations are given in table 14.
The surface texture of each specimen is described using three
.categories (Fig. 13).
a. Smooth: surface irregularities of up to 4 ym.
b. Rough: surface irregularities of up to 12 pm.
c. Very Rough: surface irregularities of greater than 12 ym.
Irregularities of greater magnitude than the average texture
have been, reported as pits-of specified~depth. Whilst the surface
-texture is broadly-indicative of the amount of "corrosion which has
taken place, caution should be applied, because a smooth surface does
not necessarily imply that corrosion:did not occur.
Where possible the maximum thickness^ of deposit and scale
observed on specimens that had not been descaled, has been reported.
Where penetration was found, the maximum depth of sulphidation
or oxidation has been given.
The results in Table 14 show that a small amount of sulphide and
oxide penetration occurred with medium carbon and 2i% Cr steels. There
was some oxide penetration of the high chromium steels, but little
sulphide penetration.
A4o32
-------
3.2 Test Series 2
This run of 500 h duration, was..carried out without limestone
addition. The effect of limestone dosage on corrosion may be
determined by comparing this test with Test Series 3 in which
limestone was added to the feed. Corrosion data from this test may
also be compared with the similar test of shorter duration (Test
Series 1: 100. h) in order to determine the effect of time on the
steels when exposed to the fluidised combustion environment.
3.2.1 Description of Test Series 2
The combustor operated continuously for 500 h from 4th -
25th November 1970 except for one short interruption of a few
seconds, which was the result of a power cut.
The initial bed was composed of ash .resulting from the
combustion of Pittsburg coal in Test Series 1 and the average
conditions for the test are given in table 15.
Table A..4.15 Operating conditions during Test Series 2
Coal Pittsburg
Coal size (upper limit), ym 1680
Acceptor None
Fluidising velocity, ft/s 3
Bed temperature °F 1560
Bed depth, ft 2
Recycle Yes
Oxygen in flue gas, % 2
In the previous 100 h test (Test Series 1), the water cooled
coal feed pipe caused the internal fines cyclone to function erratically.
It was modified for this test so that the coal was discharged away
from the cyclone dip-leg. The fines return system operated satisfactorily
and bed height was maintained throughout with some offtake ash being
produced.
A4o33
-------
Two mass balances were carried out as follows:
1. 0-115 h.
2. 283-383 h.
The coal, feed and product rates were determined and samples taken
by the methods already described.
3.2.2 Results
3.2.2.1 Plant data
Chemical analyses and 'size distributions of the coal feed for
both mass balance periods are given in tables 16 and 17 respectively.
Table A.4.16 Chemical analysis of coal feed in Test Series 2
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen .
Sulphur
Oxygen + errors
Chlorine
Carbon dioxide
Ash analysis
CaO
MgO
K20
F6203
Gross calorific
value
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
Btu/lb
d.a.f.
1st balance
period
0.9
12.7
41.0
72.7
4.5
1.45
2.75
3.9
0.10
0.70
7.9
1.3
0.7
1.6
17.2
15,240
2nd balance :
period
1.5
13.1
41.1
i
72.3
4.6
1.45
2.75
4.1
0.10
0.70
7.8
1.4
0.7
1.5
16.2
15,160
A4o34
-------
Table A.4.17 Size distribution of coal feed in Test Series 2
Particle size
+ 1680
+ 500
+ 250
+ 125
+ 63
- 63
Median
(ym)
- 1680
- 500
- 250
- 125
dia. (ym)
Packed density
(Ib/ft3)
% in grade by weight
1st balance
Period
0.4
33.4
18.9
16.2
29.6
1.5
290
55.2
2nd balance
Period
1.2
38.3
16.0
12.9
22.9
8.7
300
54.2
Table 18 gives chemical and size analyses of secondary cyclone
fines for both mass balance periods. Chemical analysis of dust is
given in table 19.
Table A.4.18 Chemical and size analyses of secondary.cyclone fines Test Series 2
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
K20
Fe2^3
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
Packed density (lb/ft3)
Weight percentage, "as received"
1st balance period
30.7
0.30
1.25
0.04
0.26
4.5
0.81
0.47
0.95
12.0
2nd balance period
31.6
0.30
1.55
0.04
' -
4.5
0.9
0.46
0.94
11.3
% in grade by weight
0.0
1.5
4.5
5.9
13.9
74.2
16
39.8
0.0
1.4
4.2
6.2
14.7
73.5
18
39.4
* Carbon does not include carbon present as carbon dioxide
A4o35
-------
Table A.4.19 Chemical analysis of dust from Test Series 2
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
Na20
K20
Fe2°3
i
Weight percentage, "as received"
1st balance period
11.9
0.20
1.40
0.18
0.11
4.8
1.11
0.70
1.57
12.7
2nd balance period
17.0
0.20
1.80
0.40
- •
10.9
1.56
0.61
1.94
8.2
* Carbon does not include.carbon present as carbon dioxide
A4.36
-------
Table 20 gives the chemical and size analyses-of bed material,
including the initial and final ash bed. At the start and conclusion
of both mass balance periods bed samples were taken.
Table A.4..20 . .Chemical and size .analyses of bed material from Test Series 2
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
Na20
K20
Fe203
Particle size
(ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia.
(ym)
Packed density
(lb/ft3)
Weight percentage, "as received"
Initial
ash
bed
0.03
0.03
1.05
0.01
0.10
4.5
0.58
3.21
7.5
1st balance period
Bed
sample
0.01
0.06
1.35
0.02
0.15
6.7
1.46
0.68
2.77
7.3
Product
. ' ash
0.50
0.06
1.70
0.05
0.17
8.1
1.43
0.69
2.40
7.9
Bed
sample
0.00
0.04
2.35
0.01
-
9.2
1.52
0.62
2.06
7.71
2nd balance period
Bed
sample
0.00
0.03
2.65
0.01
-
12.3
1.69
0.58
1.77
8.3
Product
ash
0.48
0.05
2.80
0.02
-
4.9
1.05
0.64
1.39
11.3
Bed
sample
0.00
0.03
2.95
0.02
-
11.1
1.59
0.60
1.87
8.3
Final
ash
bed
0.2
0.02
2.85
0.02
0.40
12.2
1.61
0.59
1.74
8.0
% in grade by weight
0.3
87.5
9.8
1.8
0.4
0.2
850
83.3
0.0 '
86.6
12.7
0.6
0.1
0.0
900
84.7
0.3
84.3
11.1
2.0
1.5
0.8
820
84.3
0.0
84.8
13.4
1.1
0.4
0.1
750
84.3
1.0
84.4
13.4
0.8
0.3
0.1
850
89.4
0.6
81.3
14.5
2.3
0.8
0.5
800
83.7
1.2
82.5
15.0
0.8
0.3
0.2
850
84.4
0.0
75.6
19.1
3.9
1.0
0.4
780
91.8
* Carbon does not include carbon present as carbon dioxide
A4.37
-------
Figs. 14-17 present the offgas analyses taken during the test.
Methane was not found in any of the samples. Chloride results are
expressed as HC1 (p.p.m.). The S02 and SO^ content of the exhaust
gases were determined by the 'Shell Condensation1 method. Some
measurements of..sulphur ..(SO.) were,also made using the iodine
bubbler method.
The mean gas analyses used in the mass balances were:
1st balance period'
co2
°2
CO
so2
HC1
% 15.2
% 2.3
% 0.066
p.p.m. 2090
p.p.m. 64
2nd balance
C02 %
02 %
CO %
SOo p.p.m.
HC1 p.p.m.
period
15.6
2.1
0.09
2050
63
Table 21 gives results of measurements of the alkali aerosol
content of the exhaust gas leaving the secondary cyclone. There is
some doubt in these results as has been discussed in section 1.7.5.
Table A.4.21 Concentration of sodium, potassium and calcium in the flue gas; Test Series 2
Elapsed time from
start of test
series (h)
Cone, in flue gas
p.p.m. (wt)
Na
K
Ca
1st balance period
2.17
1.1
0.7
18.0
47.0
1.4
0.9
17.4
47.4
5.5
2.2
14.0
2nd balance period
334.58
4.9
1.6
18.7
335.0
5.0
1.7
22.4
338.70
4.3
1.2
25.0
339.07
4.6
1.6
17.0
A4.38
-------
Table A.4.22 Mass Balance for test series 2: 1st balance period
; Rate: Ib/h
t
' Coal
Air
i Total Input
Ace. in bed
Offtake Ash
Secondary fines
Exhaust Dust
Flue Gas
Total Output
Loss (In - Out)
Loss Percent
Rate: Ib/h
Coal
Air
Total Input
Total
20.4
214.6
235.0 .
0.0
0.4
2.9
0.3
229.9
233.5
1.5
0.64
Sulphur
0.561
0.000
0.561
Ace. in bed 0.009
Offtake Ash '• 0.007
Secondary fines 0.036
Ash
2.7
0.0
2.7
0.0
0.4
2.0
0.2
0.0
2.6
0.1
3.70
Ca
0.147
Carbon
14.8
0.0
14.8
0.0
0.0
0.89
0.03
13.2
14.12
0.68
4.59
Na
0.014
0.000 0.000
0.147 0.014
0.016 0.000
0.024 0.002
0.092 0.010
Exhaust dust 0.004 0.009 0.001
i Flue gas ,0.470 ' 0.002 0.000
Total Output 0.526 0.143 0.013
Nitrogen
0
165
165
0
0
0
0
167
167
-2
-1.21
K
0.036
0.000
0.036
-0.005
0.008
0.023
0.004
0.000
0.030
Oxygen
0.8
49.6
50.4
0.0
0.0
0.0
0.0
48.2
48.2
2.2
4.37
;
:
Chlorine
<
0.020
0.000 1
0.020
0.000
0 .000
0.001
0.000
0.017
o.ois ;
Excess air is 6.3%
Carbon loss is 6.5% (Unburnt)
Loss (In - Out)
Loss Percent
0.035
1 6.24
i
0.004
': 2.7 !
0.001 i
7.1 1
i
0.006
16.7
0.002
10.0
A4.39
-------
Table.A.4.23 Mass Balance for test series 2; 2nd balance period
Rate: Ib/h
i Coal
Air
Total Inout
Ace. in bed
Offtake Ash
' Secondary Fines
j Exhaust Dust
' Flue Gas
Total Output
I
1 Loss (In - Out)
Loss Percent
Rate: Ib/h
Coal
1 Air
Total Input
Ace. in bed
Offtake Ash
' Secondary fines
Total
20.3
214.6
234.9
0.0
0.4
3.0
0.3
Ash
2.7
0.0
2.7
0.0
0.4
2.1
0.3
230.9 i 0.0
234.6
0.3
0.13
Sulphur
0.558
2.8
-0.1
-3.7
Ca
0.151
0.000 i 0.000
Carbon
14.7
0.0
14.7
0.0
0.0
0.96
0.05
13.5
14.51
0.19
1.3
Na
0.014
0.000
Nitrogen
0
165
165
0
0
0
0
167
167
-2
-1.2
K
0.035
0.000
0.558 ' O.lSli 0.014! 0.035
1 •
0.003 I -0.008
0.011 i 0.014
! 0.047 j 0.097
i Exhaust Dust j! 0.006 ! 0.025
0.000 i 0.001
Oxygen
0.8
49.6
50.4
0.0
0.0
0.0
0.0
48.9
48.9
i
1.5
2.98
Chlorine
0.020
0.000
0.020
0.000
0.002: 0.005 0.000
0.010 1 0.024 0.001
0.001' 0.005 ! 0.000
i Flue gas j -0.459 | 0.003 1 0.001; 0.000 '. 0.016
; Total Output
1
!
, Loss (In - Out)
1 0.526 ; 0.131
1
!
0.032 , 0.020
_ _ ' _ _
0.014 0.035 i 0.017
0.000 0.000
•i
0.003
4 1-
Loss Percent
5.7 i!3.2
0
0
15
Excess air is 4.2%
Carbon loss is 7.0% (Unburnt)
A4.40
-------
The mass balances for Test Series-,2 are-given in tables 22 and
23. The .method of calculation has been discussed-in-section 2.3.7.
Both balances are thought to be satisfactory.
The pressure drops and temperature distribution through the
plant are shown in tables 24 and 25 respectively. The normal
operating ranges, excluding start up and shutdown, are given.
Bed height,.. calculated from the pressure drops over 8^ in
bed and the-whole bed, was 21 in to 25 in throughout the test.
Table A.4.24 Pressure drops through plant in Test Series 2
Baseplate
7.0-9.0
Pressure drop, (in. water gauge)
Bed
18-23
Density (over 8$ in)
8.5-9.0
1° cyclone
1.5-2.0
2° cyclone
5.0-6.5
.. ..
Bed
A? (bed) x 8.5
AP (density)
3 in
A4.41
-------
Table A.4.25 Temperature Distribution through, plaat, in Test Series 2
Position
In bed
In bed
In bed
In bed
In bed
In bed
i O ,
1 cyclone
inlet
1° cyclone
exit
2° cyclone
exit
Probe
No
Nl
N2
N2
N3
N3
N3
N9
-
-
Height above
air nozzles
(in)
3
6
11
21
21
21
88
-
-
Probe
length
(in)
3
9
6
3
9
6
3
2
2
Temperature
(°F)
1540-1560
1530-1550
1540-1560
1540-1560
1530-1560
1540-1560
1450-1500*
1340-1420*
1220-1240*
* Excluding first 24 h.
3.2.2.2 Visual examination of corrosion test specimens
When the tubes and coupons were removed from the combustor they
were examined visually.
In general:the condition, of the surfaces appeared similar to
that found at the conclusion of Test Series 1 which was conducted
under similar operating conditions. However, on tube 1, there was
little deposit on the underside of the rings.
A4.42
-------
3.2.2.3 Chemical analysis of deposits
The deposits on the rings were in general very thin and adherent
except for the deposits from tubes 5 and 6. As a result in most cases
it was not possible to obtain a sample because the metal surface of
the rings would have been damaged. .Gheniieal .analyses of those
deposits and scale samples which-were obtained are given in table 26.
Comparison with the analysis of product ash given in table 20 shows
that the deposits were predominantly ash with little enrichment of
potentially corrosive salts.
Table A.4.26 Chemical analysis of deposit and scale samples from Test Series 2
Description of Sample
Scale from 2|% Cr steel ring,
tube 2 (1110°F)
Deposit from top, tube 5
(750°F)
Deposit from underside, tube 5
(750°F)
Deposit from top, tube 6
(1290°F)
Deposit from underside,
tube 6 (1290°F)
Weight percentage, "as received"
C
*
—
0.4
0.2
1.4
S
0.1
3.9
*
3.9
1.7
Cl
0.00
0.00
*
0.00
0.00
CaO
1.8
7.6
3.5
7.8
5.2
MgO
0.25
1.26
0.88
1.34
1.13
Na20
0.36
0.65
0.77
0.57
0.88
K20
0.14
1.7
1.3
1.7
1.8
Fe203
94
18
33
16
14
* insufficient sample
A4.43
-------
Table A.4.27 Stannary of Corrosion Results; Rings and Coupon Weight Loss - Mg/cm h (Test Series 2)
•o
-------
Table A.4.28 Microsopic Examination of Specimensi Test Series 2
Alloy
Medium
Carbon
Steel
2|% Cr,
1% Mo
Steel
12% Cr
Steel
AISI
316
AISI
347
Esshete
1250
Nimonic
PE16
Temp.
750
750
750
750
930
930
750
750
750
750
930
930
1110
1110
750
750
930
1110
1290
1290
1560
750
750
930
1110
1290
1290
1560
1110
1290
1290
1560
750
750
930
1110
1290
1290
1470
1560
1290
1290
1560
Specimen +
position
Id
1m
5d
5m
3d
3m
Ic
Ih
5c
5h
3c
3h
2g
2m
lo
5o
3o
2o
4o
60
3
IP
5p
3p
2p
4p
6p
1
2h
4h
6h
5
11
51
31
21
41
61
10
4
4m
6m
2
Wt. loss
(yg/cm2h)
*
36.4
*
18.4
*
132
34.0
*
29.4
*
81.2
*
793
365
2.4.
1.6
7.8
5.9
5.1
3.0
308
0.3.
0.1
1.2
3.0
3.6
1.8
5.4
1.8
3.4
1.1
6.6
0.4
0.1
1.7
4.6
9.2
5.2
3.4
7.3
4.6
2.1
2.9
Surface **
Texture
smooth
smooth
smooth
smooth
rough
rough
smooth
smooth
smooth
rough
rough
v. rough
v. rough
v. rough
rough
smoo th
smooth
smooth
smooth
smooth
v. rough
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
rough
smooth
smooth
smooth
smooth
smooth
Pits
(ym)
0
0
0
0
few 15
0
0
0
0
0
0
0
0
0
0
0
0
one 10
few 10
0
0
0
0
0
one 6
few 8
0
0
0
0
0
0
0
0
0
0
few 5
smooth i 0
smooth
smooth
few 10
0
smooth
smooth
smooth
. 0
0
0
Deposit (D)/
Scale (S) (ym)
S:70
-
S:16+D:15
-
S:65
—
-
S:24
-
S:23+D:30
-
S:50+D:18
-
—
-
-
-
-
-
-
—
-.
-
-
-
-
-
—
-
- '
-
—
-
-
-
-
-
-
-
-
-
-
—
Penetration (ym)++i
Sulphide
0
0
0
0
12
10
0
0
0
0
24
18
50
40
0
0
0
10
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Oxide I
0
0
2
3 1
-
- i
o
0
5
10 1
- i
_ i
-
—
6
0
3
•" •
i
2
0
™"
0
0
0 i
0
0
0
4
0
0
0
0
0
0
2
5
0
0
0
0
3
0
15
* Specimens not descaled and reweighed at end of test.
+ See Fig. A.4.10.
** See Section 3.2.2.5.
++ Sulphide penetration accompanied by oxide penetration.
A4.45
-------
3.2.2.4 Specimen weight loss
Rings and coupons were weighed before the test and re-weighed after
descaling at the conclusion of the run. The difference or weight loss
results are given in table 27 and expressed as yg/cnr of exposed surface
to the fluidised combustion environment per hour. The weight loss after
500h was only about double that in 100 h, indicating a marked decrease
in the rate of weight loss.
Rings a and r on each tube were not used for corrosion measurements
because they were partly shielded by the combustor walls. A few rings
were not descaled. These were sectioned for microscopic examination
(section 3.2.2.5).
3.2.2.5 Metallographie examination
Some of the specimen rings and coupons were sectioned, mounted
and polished; They were examined under-a microscope and the observations
are given in table 28, using the same categories as for Test Series 1,
section 3.1.2.5.
Comparison with table 14 shows that-for medium carbon and 2|% Cr
steels the amount of sulphide and oxide penetration in 500 h is slightly
higher than after 100 h". There was almost no sulphide or oxide
penetration of the high chromium steels during the 500 h test, although
this was found in the 100 h test and also in a 1000 h test with Newstead
coal (U.K.).
Carburisation, which can occur in steels subjected to strongly
reducing conditions at elevated temperatures, was not found.
A4.46
-------
3.3 Test Series 3
This run of 500 h duration was carried out with limestone
addition. The effect of limestone dosage on corrosion may be
determined by comparing this test with another of similar
duration (Test Series 2)in which no limestone was added to the
feed, the long term effect on the level of sulphur dioxide in
the exhaust gases when adding a constant proportion of limestone
with the coal feed may also be determined.
3.3.1 Description of Test Series 3
The test was carried out on 4th-23rd January 1971. It was
terminated at 465 h after a failure of the coal feed controller.
However, the run time was sufficient to enable a satisfactory
comparison to be made with the results of Test Series 2.
The initial bed was composed of ash resulting from the
combustion of Pittsburgh coal in Test Series 2 with which a trial
run of approximately 100 h duration with limestone addition was
carried out, immediately before this test. The average conditions
are given in table 29. ...',.,
Table A.4.29 Operating conditions during Test Series 3
Coal • v" Pittsburgh
Coal jize (upper limit), ym 1680
Acceptor Limestone 18
Acceptor size (upper limit)ym 1680
Stoichionetric ratio Ca/S 2
Fluidiiing velocity, ft/a 3
Bed temperature °F 1560
Bed depth, ft 2
Recycle Yes
Oxygen in flue gas, % 2
Limestone to give a stoichiometric (Ca/S) mol ratio of two
(21 Ib of limestone to 100 Ib coal) was mixed with the coal in 250 Ib
batches in a ribbon mixer. The mixture was stored in the 10 ton
bunker which supplies the coal feed to the 12 in combustor. The
usual method of coal feed was employed.
A4.47
-------
For three hours before the end of the run, while attempts were
being made to rectify the fault in the coal feed control unit, the
combustion conditions varied from reducing to oxidising. The total
time under reducing combustion conditions was about 1$ h.
Except for this period of unsteady combustion, the plant operated
satisfactorily. There were four minor interruptions each of several
minutes duration caused by (a) temporary shortage of compressed air,
(b) failure of instrument nitrogen supply, (c) false high specimen
tube temperature alarm, (d) coal feed control fault. On the first
three occasions the bed temperature did not fall below 1470 F. On
the other occasion, the bed temperature dropped to between 1440 and
1470 F for 25 min because the coal feed rate was low.
Two mass balances were carried out as follows:
1. 0-100 h, .
2. 334-434 h.
The coal feed and product rates were determined and samples
taken by the methods already described.
3.3.2 Results
3.3.2.1 Plant data
Chemical analyses and.size-distributions of the eoal plus limestone
feed for both mass balance periods are given in tables 30 and 31
respectively. Table 31 shows that the feed for the second mass balance
was much finer than in the first mass balance possibly the result of
segregation in the 10 ton coal storage bunker.
Table 32 gives the chemical analysis of the limestone 18 used in
this test. Six drums of mixed.coal and limestone from the ribbon
•mixer were analysed for calcium in order to determine the consistency
of mixing (Table 33). Each drum was subdivided using a rotary fiffler.
On each day during both mass balance periods, when the coal and
limestone mix was being fed to the feed hoppers, a sample was obtained
as described in section 2.3.1. For this test each day's sample
was split using a rotary riffler to give a daily sample and bulked to
A4.48
-------
give a combined sample for the mass balance period. The calcium analysis
of each day's sample is given in table 34. It should be noted that the
feed would start to be fed from the feed hopper into the combustor about
30 to 40 h from the time of sampling. This is because the lower feed
hopper was^.always operated nearly full (800 Ib capacity).
.The calcium analyses of the bulk coal feed samples for the first
and .second;mass balance periods were 9.25% and 7.55% CaO on an "as
received" basis. The calculated calcium content of the coal plus
limestone mix to give a stoichiometric ratio of two is 8.7% CaO,
(as received).
Table A.4^.30 Chemical analysis of coal feed + limestone in Test Series 3
Proximate analysis
Total moisture
Ash
Volatile Matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen + errors
Chlorine
Carbon dioxide
Ash analysis
CaO
MgO
Na20
F6203
Gross calorific
value
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
Btu/lb
d.a.f.
1st balance
period
1.2
22.9
46.8
57.8
3.7
1.15
1.95
3.6
0.07
6.70
39.9
1.2
0.6
0.7
6.5
14,260
2nd balance
period
1.1
20.4
45.2
61.6
3.8
1.30
2.05
3.7
0.06
5.10
36.6
1.2
0.6
0.8
7.3
14,540
A4.49
-------
Table A.4.31 Size distribution of coal + limestone feed in Test Series 3
Particle size
(ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia.
(ym)
Packed density
(Ib/ft3)
% in grade by weight
1st balance
period
0.6
44.9
19.7
14.2
9.2
11.4
440
66.1
2nd balance
period
0.3
23.0
18.1
17.2
25.7
15.7
180
55.0
Table A.4.32 Chemical analysis of limestone
Weight percentage, "as received"
CaO
MgO
Si 02
C02
45.5
0.91
15.0
36.7
A4.50
-------
Table A.4.33 Calcium analysis of coal + limestone feed for Test Series 3 (ex drums)
Weight percentage, "as received"
Drum
CaO
1
8.8
2
9.4
3
7.85
4
8.0
5
7.15
6
7.55
Table A.4.34 Calcium analysis of coal +.limestone feed for Test Series 3 (ex plant)
Weight percentage, "as received"
Elapsed time from start
of test series (h)
CaO
1st balance period
1
8.55
22
8.7
46
7.85
70
8.55
2nd balance period
310
8.25
334
7.3
358
7.15
382
7.85
406
8.55
A4.51
-------
Table A.4.35 Chemical, and size analyses of secondary cyclone fines Test Series 3
Carbon *
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
Na_0
K2 0
Fe203
Particle size
(ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (vim)
Packed density (lb/ft3)
weight percentage, "as received"
1st balance period
20.9
0.35
4.05
0.03
2.80
26.0
0.81
0.47
0.57
6.6
2nd balance period
5.80
0.13
6.30
0.06
3.25
27.3
0.96
0.53
0.75
9.3
% in grade by weight
0.0
1.8
5.0
12.0
16.9
64.3
38
60.3
0.0
0.4
1.1
4.3
9.8
84.4
12
46.3
* Carbon does not include carbon present as carbon dioxide
A4.52
-------
Table 35 gives chemical and size analysis of secondary cyclone
fines for both mass balance periods. Chemical analysis of dust is
given in Table 36.
It is noted that the carbon contents of the fines and dust from
the second mass balance period were markedly lower than those from the
first mass balance period. Jn addition the ash collected in the
secondary cyclone was finer in the second balance period. This
indicates that the internal fines return-cyclone was probably
working more efficiently towards the end of the test.
Table A.4.36 Chemical analysis of dust from Test Series 3
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
Na20
K20
Fe203
Weight percentage, "as received"
1st balance period
19.4
0.45
3.60
1.00
3.20
20.0
0.78
0.54
0.83
7.1
2nd balance period
6.5
0.24
5.30 ;
0.60
3.30
22.7
0.93
0.59
0.94
8.4
* Carbon does not include carbon present as carbon dioxide
Table 37 gives the chemical and size analyses of bed material,
including the initial and final ash bed. At the start and conclusion
of both mass balance periods bed samples were taken.
A4.53
-------
Table A.4.37 Chemical and size analyses of bed material from Test Series 3
Carbon*
Hydrogen
Sulphur
Chlorine
Carbon dioxide
CaO
MgO
Na20
K20
Fe20o
Particle size
(urn)
+1680
+ 500-1680
+ 250- 500
+ 125- 250
+ 63- 125
- 63
Median dia.
(ym)
Packed density
(lb/ft3)
weight percentage "as received"
Initial
ash
bed
0.4
0.08
6.9
0.02
2.77
31.0
1.11
0.47
0.84
4.1
1st balance period
Bed
sample
1
0.30
0.06
6.60
0.01
1.25
30.0
1.30
0.50
0.90
4.7
Product
ash
0.40
0.07
8.05
0.02
0.40
35.8
1.11
0.46
0.57
3.7
Bed
sample
2
0.09
0.06
9.05
0.02
0.41
38.0
1.11
0.44
0.46
3.1
2nd balance period
Bed
sample
1
0.15
0.07
9.20
0.02
0.29
39.0
1.13
0.46
0.39
2.8
Product
ash
0.40
0.09
9.40
0.03
0.36
36.8
1.06
0.46
0.39
3.4
Bed
sample
2
0.04
0.08
10.6
0.02
0.65
39.5
1.09
0.43
0.34
2.6
Final
ash
bed
0.50
0.05
9.85
0.04
0.60
37.2
1.10
0.42
0.43
3.29
% in grade by weight
0.1
40.4
32.1
21.5
4.2
1.7
490
98.1
0.9
46.5
32.8
18.2
1.3
0.3
490
94.7
0.6
35.6
38.2
22.3
2.2
1.1
400
85.3
0.2
41.9
43.8
13.7
0.3
0.1
455
91.7
0.2
29.8
42.7
22.8
3.6
0.9
380
99.5
0.1
22.6
29.8
25.2
11.9
10.4
265
109
0.1
37.9
44.5
15.3
1.8
0.4
420
93.4
1.5
33.7
22.3
18.8
9.8
13.9
340
103
*Carbon does not include carbon present as carbon dioxide
A4.54
-------
It is noted that there was an increase in calcium and sulphur
content of the bed material in the second balance period compared
with the first balance period. There was also an increase in the
amount of fine, material in the ash.. This evidence supports the
possibility already discussed that the internal cyclone was operating
more efficiently in the latter half of the test. Alternatively, the
fineness of the product ash may have been the result of the finer
feed in the second balance period.
Figures 18-21 present the offgas analyses taken during the
test. Methane was not found in any of the samples. Chloride
results are expressed as HC1 (p.p.m). No measurements of chloride
were made in the second balance period because emphasis was being
placed on obtaining SO- measurements. The S02 and S0« content of
the exhaust gases were determined by the 'Shell Condensation'
method. Some measurements of SO- were also made using the iodine
method. The mean gas analyses used in the mass balances were:
1st balance
rn 7
I-**-* — /e
2
0- %
2
CO %
SO- p. p.m.
HC1 p. p.m.
period
15.6
2.1
0.06
200
55
2nd balance
CO- %
2
0- %
2
CO %
SO- p. p.m.
HC1 p. p.m.
period
15.0
2.4
0.06
52
The SO- content in the flue gas averaged about 200 p.p.m. at
the start and fell towards 50 p.p.m. at the end of the test which is
equivalent to an improvement in SO- reduction from 0.90 to 0.97.
This improvement in the efficiency of S0_ removed from the exhaust
gas could have been caused by a change in the sulphur or calcium
content of the coal plus limestone feed. However, chemical analysis
of the feed indicates no marked change in composition that could
account for this reduction. This improvement in S02 reduction may
have been the result of the internal cyclone operating more
efficiently or the finer size of feed in the latter part of the test,
AA.55
-------
Table 38 gives results of measurements of the alkali aerosol
content of the exhaust gas leaving the secondary cyclone. There is
some doubt.in these results as has been discussed in section 1.7.5.
Table A»4.38 Concentration of sodium, potassium and calcium in the flue gas;
Test Series 3
Elapsed time from start
of Test Series (h)
Cone, in flue gas
(p. p.m. (wt) )
Na
K
Ca
1st balance period
51.05
3.9
0.7
100
51.48
3.3
0.5
91
92.67
5.1
0.8
100
93.03
6.0
0.9
100
2nd balance period
361.87
4.0
0.6
76
433.35
3.1
0.7
101
433.72
4.2
1.2
231
The mass balances for Test Series 3 are given in tables 39 and 40.
The method of calculation has been discussed in section 2.3.7. Both
balances seem satisfactory. Chlorine in the flue gas was not
determined in the second balance period because the emphasis was
being placed on obtaining SOo measurements.
The carbon loss dropped from 6.3% in the first balance period
to 1.2% in the second balance period, probably due to the increase in
efficiency of the internal cyclone in the latter half of the test as
already discussed.
A4.56
-------
Table A.4.39 Mass balance for test series 3; 1st balance period
Rate: Ib/h
Coal + limestone
Air
Total Input
Ace. in bed
Offtake ash
Secondary fines
Exhaust dust
Flue gas
Total Output
Loss (In - Out)
! Loss Percent
! Rate: Ib/h
i
i Coal + limestone
; Air
: Total Input
Ace. in bed
Offtake ash
Secondary fines
Exhaust dust
. Flue gas
Total Output
Loss (In - Out)
Loss Percent
Total
23.1
214.6
237,. 7
0.0
2.6
4.0
0.3
229.9
236.8
0.9
0.38
Sulphur
0.450
0.000
0.450
0.024
0.210
0.162
0.011
0.046
0.453
Ash
5.3
0.0
5.3
0.0
2.6
3.2
0.2
0.0
6.0
-0.7
-13.2
Ca
1.523
0.000
1.523
0.059
0.667
0.743
0.044
0.014
1.527
i
-0.003 -0.004
-0.7 [-0.26
Carbon
13.4
0.0
13.4
0.0
0.01
0.84
0.06
13.5
14.41
-1.01
-7.5
Na
0.022
0.000
0.022
0.000
0.009
0.014
0.001
0.001
0.025
-0.003
-13.6
Nitrogen
0
165
165
0
0
0
0
167
167
-2
-1.2
Oxygen
0.8
49.6
50.4
0.0
0.0
0.0
0.0
48.1
48.1
2.3 :
4.56 ;
i
( i
K
0.033
0.000
Chlorine
0.016
0.000
0.033 | 0.016
i
-0.004 ] 0.000
. 0.012 | 0.001
0.019
0.002
0.001
0.000
0.000 \ 0.015
0.029
0.017
0.004 !i -0.001
12.1
-6.25
Excess air is 5.5%
Carbon loss is 6.3% (Unburnt)
A4.57
-------
Rate: Ib/h
i
' Coal + limestone
Air
Total Input
Ace. in bed
Offtake ash
Secondary fines
Exhaust dust
Flue gas
Total Output
:
i Loss (In - Out)
Loss Percent
Rate: Ib/h
Coal + limestone
Air
Total Input
Ace. in bed
Offtake ash
Secondary fines
Exhaust dust
Flue gas
Total Output
Loss (In - Out)
Loss Percent
Total
21.0
214.6
235.6
0.0
Ash
4.3
0.0
4.3
0.0
2.6 2.5
1.9 1.8
0.5
229.1
234.1
1.5
0.64
0.5
0.0
4.8
-0.5
-11.6
Sulphur I Ca
i
0.431 1 1.134
0.000 I 0.000
0.431 \ 1.134
Carbon
12.9
0.0
12.9
0.0
0.01
0.11
0.03
13.0
13.15
-0.25
-1.94
Na
0.019
0.000
0.019
i
0.014
0.240
0.004! 0.000
0.670 0.009
0.120 0.372J 0.008
0.028 1 0.085
0.012
0.414
0.017
3.9
0.018
1.149
-0.015
-1'3
0.002
0.001
0.020
-0.001
-5.26
1
Nitrogen
0
165
165
0
0
0
0
168
168
-3
-1.8
K
0.030
0.000
Oxygen
0.8
49.6
50.4
0.0
0.0
0.0
0.0
46.9
46.9
3.5
6.94
Chlorine
0.013
0.000
0.030 0.013
0.000 0.000
0.008 0.001
0.012 0.001
0.004
0.000
0.000
-
0.024
0.006
20.0
Excess air is
Carbon loss is
12.0%
1.2% (Unburnt)
A4.58
-------
The pressure drops and temperature distribution through the
plant are .shown in tables 41 and 42 respectively. The normal
operating ranges, excluding start up and shutdowns, are given.
Bed height, calculated from the pressure drop over 8$ in bed
and over the-whole bed, was 21 in to 24 in throughout the test.
Table .A..4.-.41. Pressure drops through piaat in Test Series 3
Pressure drop, (in. water gauge)
Baseplate
10.5-11.0
Bed
16-18
Density (over 8^ in)
7.5-8.5
1° cyclone
1.4-1.8
2° cyclone
4.0-6.0
_ , . . , ^ A P (bed) x 8.5 + 3 in.
Bed height = •"-,;,— i N
6 A P (density)
Table A.4.42 Temperature distribution through plant, in Test Series 3
Position
In bed
In bed
In bed
In bed
In bed
In, bed
1° cyclone
inlet
1° cyclone
exit
2 cyclone
exit
Probe
No.
Nl
N2
N2
N3
N3
. N3
N9
- .
—
Height above
air nozzles
(in)
3
6
11
21
21
21
88
-
-
Probe
length
(in)
3
9
6
3
9
. 6
3
2
2
Temperature
(°F)
1540-1560
1530-1540
1530-1550
1540-1560
1530-1550
1550-1560
1400-1420*
1280-1320*
1170-1180*
* Excluding first 24 h.
A4.59
-------
3.3.2.2 Visual examination of corrosion test specimens
When the tubes and coupons were removed from the combustor they
were examined visually.
In general the fireside surfaces were in a similar condition as
those from Test Series 2.
The following differences were noted:-
(a) The surfaces of the tubes in the bed were darker in colour
which may have resulted from the relatively short period
of substoichiometrie combustion at the end of the test.
(b) There was more deposit (about 2 in. deep) on top of the
'above bed' tube 6. A similar deposit of fine particulate
material was found on top of the coupons situated above
the bed.
3.3.2.3 Chemical analysis of deposits
The deposits on the rings were in general very thin and adherent
except for the deposits from tubes 5 and 6. As a result in most
cases it was not possible to obtain a sample because the metal surface
of the rings, would have been damaged. Chemical analysis of those
deposit samples which were obtained are given in table 43. Comparison
with the analysis of product ash given in table 37 shows that the
deposits were predominantly ash with little enrichment of potentially
corrosive salts.
There was insufficient sample of deposit from the underside of
tube 1 for a complete analysis. However some enrichment of alkali
salt is indicated by the sodium content being three times that of
the product ash.
-------
Table A. 4.43 Chemical analysis of deposit and scale samples .-from Test Series 3
Description of sample
Deposit from underside, tube 1
(750°F)
Deposit from top, tube 5
(750°F)
Deposit from underside, tube 5
(750°F)
Deposit from top, tube 6
(1290QF)
Deposit from underside, tube 6
(1290°F)
Weight percentage, "as received"
C
*
1.8
, *
1.3
*
S
*
8.5
*
10.3
*
Cl
*
0.00
*
0.08
*
CaO
14
37
28
39
25
MgO
0.93
1.08
0.93
1.10
1.00
Na20
1.48
0.50
0.54
0.46
0.78
K20
1.08
0.45
0.54
0.35
0.69
Fe203
13
9.7
—
8.7
*
* insufficient sample
3.3.2.4 Specimen weight loss
Rings and coupons were weighed before the test and reweighed
after descaling .at-the.conclusion of.the .run. The difference or
weight loss results are given in table 44 and expressed as yg/cm^
of exposed surface to the fluidised combustion environment per hour.
There is little difference between the rate of weight loss in
this test and in the 500 h test without limestone, Table 27, indicating
that the addition of limestone to the bed does not effect the rate of
weight loss.
Rings a and r on each tube were not used.for corrosion
measurements because they were partly shielded by the combustor
walls. A few rings were not descaled. These were sectioned for
microscopic examination (section 3.3.2.5).
A4.61
-------
Table A.4.44 Stannary of Corrosion Results; Rings and Coupon Weight Loss - yg/cm h (Test Series 3)
u
to
Freeboard
Tube
No.
1
2
3
4
5
6
Location
of Ring
Alloy
Weight Loss
Temperature ( F)
Alloy
Weight Loss
Temperature ( F)
Alloy
Weight Loss
Temperature ( F)
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature (°F)
Alloy
Weight Loss
Temperature ( F)
a
S
**
S
**
S
**
S
**
S
**
S
**
b
MCS
340
F2
94.8
MCS
60.5
N
3.1
MCS
12.7
N
1.1
c
F2
40.3
R
2.1
F2
74.6
R
5.7
F2
16.1
R
1.4
d
MCS
***
W
3.4
MCS
***
W
4.6
MCS
***
W
1.7
e
S
1.4
S
2.9
S
2.2
S
5.7
S
0.2
S
1.2
f
E
1.1
720
E
2.6
1090
E
2.1
940
E •
8.2
1320
E
0.5
800
E
2.6
1300
g
MCS
42.8
± 13
F2
286
± 9
MCS
80.0
± 9
N
4.8
± 27
MCS
21.4
± 27
N
1.8
+ 9
h
F2
***
R
2.2
F2
***
R
6.1
F2
***
R
1.5
•
W
1.4
W
3.0
W
6.7
W
7.7
W
1.1
W
2.2
k
F2
36.2
S
1.7
F2
82.3
S
6.6
F2
18.0
S
1.4
1
E
0.9
740
E
2.6
1120
E
2.3
920
E
16.0
1320
E
0.6
730
E
5.4
1320
m
MCS
47.2
± 9
F2
285
± 9
MCS
112.0
± 13
N
5.8
± 27
MCS
18.8
± !8
N
2.7
+ 13
n
F2
50.7
R
1.8
F2
136
R
5.7
F2
20.8
R
2.2
o
W
1.8
W
1.6
W
4.2
W
9.1
.W
3.1
W
2.8
P
S
0.9
750
S
2.5
1100
S
1.6
905
S
4.8
1250
S
0.2
700
S
1.8
1240
q
E
1.2
± 36
E
2.4
± 9
E
1.8
± 9
E
13.8
± 13
E
0.5
± 54
E
8.6
+ 9
S
**
S
**
S
**
S
**
S
**
S
**
OS
Coupons
Temperature (°F)
Location
Alloy
Weight Loss
Bed
1560
1
S
2.2
2
N
2.1
3
W
475
4
E
3.4
5
R
2.8
6
*
7
*
8
*
Freeboard
1420 - 1560
9
N
2.3
10
E
11.6
11
S
2.8
12
R
1.5
13
W
1.6
14
*
* Coupon not fitted
** Ring used as Spacer
MCS Medium Carbon Steel
F2 Ferritic 2$% Cr Steel
W Ferritic 12% Cr Steel
*** Ring not descaled,
retained for further examination
S Austenitic Type 316
R Austenitic Type 347
E Austenitic, Esshete 1250
N Nimonic PE 16
-------
I
Temp.
Alloy (0F)
Specimen +
position
-Medium 750 Id
Carbon 750 i 1m
Steel 750 5d
750 5m
j 930 3d
2|% Cr
1% Mo
Steel
12% Cr
steel
AISI
316
AISI
347
930
750
750
750
750
930
930
1110
1110
3m
Ic
Ih
5c
5h
3c
3h
2b
2g
1110 2m
750 lo
750
5o
930 3o
1110 1 2o
1290
1290
1560
750
750
930
1110
4o
60
3
IP
5p
3p
2p
1290 4p
1290 6p
1560
1110
1290
1290
1560
Esshete 750
1
2h
4h
6h
5
U
1250 750 51
i 930 31
1110 21
i 1290
I 1290
' 1470
'• 1560
Nimonic 1290
41
61
10
4
4m
PE 16 1290 ! 6m
1560 1 2
•
Wt. loss
(yg/cm2h)
*
47.2
*
18.8
*
112
40.3
*
16.1
*
74.6
*
94.8
286
285
1.8
3.1
4.2
1.6
9.1
2.8
475
0".9
0.2
1.6
2.5
4.8
1.8
2.2
2.2
6.1
1.5
2.8
0.9
0.6
2.3
2.6
16.0
5.4
11.6
3.4
5.8
2.7
2.1
Surface **
Texture
smooth
smooth
smooth
smooth
rough
rough
smooth
smooth
smooth
smooth
smooth
v. rough
rough
v. rough
v. rough
smooth
smooth
rough
smooth
smooth
smooth
v . rough
smooth
smooth
smooth
smooth
smooth
smooth
smoo th
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
smooth
rough
smooth
smooth
rough
Pits
(ym)
0
0
0
0
few 26
0
0
0
0
0
0
0
0
0
0
0
0
0
few 8
0
few 13
0
0
0
0
one 8
0
0
few 15
0
0
one 13
0
0
0
0
0
0
0
few 20
0
0
0
0
IE
Deposit (D)/
Scale (S) (ym)
28:S
-
10:S+6:D
'enetration (ym)++
Sulphide! Oxide
0 3
0
0
0
100 : S+D 0
~*
-
15:S+20:D
-
10:S+6:D
-
50:S+30:D
—
-
—
—
-
-
-
-
-
—
-
—
-
-
-
—
—
—
- . -
-
—
-
-
-
-
-
-
-
-
-
-
-
10
0
0
0
0
20
10
16
26
40
0
0
0
8
26
0
100
0
0
0
12
8
0
40
0
16
0
28
0
0
0
0
10
0
0
20
18
0
0
2
0
0
0
—
4
0
0
0
-
-
_ j
i
—
0
0
10
-
.
0
—
0
0
6
-
-
0
—
0
-
0
—
2
0
0
2
-
0
0
—
-
0
20
Specimens not descaled and reweighed at end of test.
+. See Fig. A.4.10.
** See Section 3.3.2.5.
++ Sulphide penetration accompanied by oxide penetration.
A4.63
-------
3.3.2.5 Metallographic Examination
Some of the specimen rings and coupons were sectioned, mounted
and polished. They were examined under a microscope and the
observations are given in table 45, using the same categories as for
Test Series 1, Section 3.1.2.5.
Comparison of these results with Test Series 2, table 28, shows
that limestone addition did not increase the penetration of medium
carbon and 2j% Cr steels. The apparent increase for high chromium
steels is due to the surprisingly low penetration in Test Series 2
and the actual amount of penetration is little different from that
obtained using Newstead coal (U.K.) without limestone.
Carburisation, which can occur in steels subjected to strongly
reducing conditions at elevated temperatures, was not found.
3.3.2.6 Electron probe microanalysis
Three specimens from this test with limestone addition have
been examined at the University of Aston using an electron probe
micro-analyser. They were chosen in order to verify the sulphide
attack indicated by optical microscopy.
Two specimens from ring 2m (Ferritic 2$% Cr steel, 1110 F)
which had apparently suffered penetration to depths of up to 40ym
were examined and this type of attack was confirmed. Figures 22
and 23 show the optical photo-micrograph with corresponding X-ray
photographs of two of the areas examined. The lighter regions
in the X-ray photographs indicate higher concentrations of the
element being determined. Thus manganese and sulphur are associated
with the grey rounded particles forming the intergranular attack
with, in one case, a higher concentration of chromium. The rest of
the localised higher concentrations of manganese and sulphur are
inclusions of manganese sulphide present in the original steel.
This has been verified by electron probe micro-analysis at the centre
of one of the specimens. A line scan at right angles to the metal
surface showed a slight decrease in iron and chromium content to a
depth of about 50 ym (Fig. 24),
A4.64
-------
The other specimen examined was of ferritic 12% Cr steel held
at 1290 F (4o). Optical examination showed that sulphide attack was
apparent to depths of up to 26 ym. Electron probe microanalysis
confirmed this type attack (Fig. 25). It is also evident that there
was slightly less chromium in this region adjacent to the metal
surface.
A4o65
-------
4. REFERENCES
Goks/rfyr, H. and Ross, K., J. Inst. Fuel, (1962), 3_6, 177-179
Lisle, E.S. and Sensenbaugh, J.D., Combustion, (1965), 36, 12-16
Ounsted, D., J. Inst. Fuel, (1958), 3^, 474-479.
Perry, J.H., Chemical Engineer's Handbook, McGraw-Hill, (1950), 1024,
A4.66
-------
5. ACKNOWLEDGMENT
The authors acknowledge the contributions of their colleagues at
CRE in carrying out the work described in-this report. The work was
administered by Dr. A.D. Dainton and Mr. J. McLaren and the overall
experimental programme was devised in consultation~with Mr. D.C. Davidson.
Mr. B.J. Bowles was responsible for the operation of the plant; the
chemical analyses were carried out under the supervision of Dr. H.A. Standing
by .Mr. G.J. Corney, Mr. H.W. Harris and Mr. L.-Stanley; metallographic
examination of the corrosion test specimens-was carried out under the
supervision of Dr., G. Pitt by Mr. A. Page; maintenance of the plant was
carried out bythe CRE'engineering and instrumentation sections.
The electron probe microanalysis of corrosion test specimens was
carried out by Mr. R. Howell of the Metallurgy Department, University of
As ton.: in Birmingham.
The contribution made by Mr. E.L. Carls, the O.A.P. representative
in the U.K. is also acknowledged.
A4.67
-------
Coal and
i
transport air
Vibratory
sieve
Coal feed
cyclones
Coal
lock
hopper
Coal
feed
hopper
Internal
fines
return
system
Specimen tube
Specimen tubes
Control tube
Air—*
^J^4m+++
tttt
Y
Fines
collection
cyclone
Cooling air
Cool ing air
• Fluidised bed
—* Air
Gas pre-heater
T
Ash collection
hopper
Fig.A4.1. 12in combustor for corrosion experiments (CRE)
A4.68
-------
CD
NATIONAL COAL BOARD
i»e isiiiiiswciT
STOKI a»CK»BD. CmiJtMMOI
IZ'FUUIOISEO REACTOR
CORROSION BIG. MCI
Fig. A4. 2. 12in Combustor
-------
m«t ».*tt C**Hi*:t. w.t«o»mw ««. tu>tt ^t.t tu«« »t6>^*t» *«< PHU
NATIONAL COAL BOARD
1.1 0. UKIUSMMT
i': A4. 3. -12in Combustor: specimen tube assembly
-------
Gas sample
pipette
Rota meter
in SS. probe
Rotary valve
pump
S.S ball and
socket joints
Flow
regulator
Thermos
flask
F3ointer
Glass filter
paper
t
ol
From
secondary
cyclone
a
Filter holder
Cold trap
Acetone/solid
Fig. A4.4. Dust sampling equipment
-------
to
Quartz wool
filter
Sulphur
tri oxide
condenser
Thermocouple
(48C/F)
Hot water
(140-19O°F)
Ball and
socket joints
t
Hydrogen
peroxide
bubbler
Gas sample
pipette
From
secondary
cyclone
Wet gas meter
Rotameter
Diaphragm
pump
Cold trap
Acetone /
solid CO2
Fig. A4. 5. Sampling equipment for sulphur oxides
-------
lnSS probe
-3
CO
Electrostatic precipitators
/'
f ,
V,
7
Hydrogen ~=i
peroxide "Jr~
bubbler f::": dry ing tube
ifg
F
S.S. flexible
pipe A
From
secondary
r cyclone
•/^J?\.-^M-^
>ay-7
x' Flow
'an regulator
Fig. A4. 6. Sampling equipment for volatilised alkali
-------
Drill V16 india.
Hole to be square and
parallel to inner face
Detail of thermocouple socket
Outside surface ground
to finish of 10/ain or better
g
T3
d
'•6
c .c
N 0>
0000
ur/////fa
ijin
* *
7/8in
4 2 »
a
'•5
.£.£
'•6
00 00
Stamp code
on this face
All corners to have 0-005in rod.
Fig. A4. 7 Test rings
A4.74
-------
2 holes
drill Vain did.
Stamp code
on this face
-O--
A
"
Surface ground
to finish of
10u. in or better
Type 1
Material:- 2in O/dia.tube x 6SWG wall
Fig. A4.8. Coupons (not PE16)
A4.75
-------
Stamp code
on this face
2 holes
drill V4 in dia.
Type 2
Material :16SWG
Fig. A4.9. Coupons of PE16
A4.76
-------
Coupons
above bed '
Tubes
above bed — - *
in bed *~~
Face'B'
gu
an
a 12
aio
a 9
^ ®
J &
^ r\ c\ "*~"
2 3 ^
•— »J3 a
© a ©— --
i
AAirout A
[Face'D'J
9 / v
s
V
/ s
/ s
, s
/ • s '• '
•T T T
fFace'A'f
1 air in '
Side elevation
from air inlet
side (Face 'A')
~~^- Fluidised bed
^ Tubes
in bed
Plan
Face'C*
air — > abcdefghj klmnopqr — + air
inlet outlet
Ring positions on a tube
Not to scale
Fig. A 4.10. Position of tubes and coupons and position
of rings on a tube in 12in combustor
A4.77
-------
00
18
17
C0216
% 15
14
13
12
5
4
o2 3
°/0
2
1
0
0-5
CO o-4
°'" 0-3
0-2
0-1
O
.GO
o
O
oo
o
o
o
o o o
o
^ o OQ cxc
o
o
i_ «
10 2O
o o o
G
0 o
O o ° O o
Q o
J IQQ i n Q I Q
3O 40 50 60 70 8O
Time from start of test: h
9O 1OO
Fig. A4.11. Analysis of exhaust gas ys time for Test Series 1
-------
e.+j\j*j
2400
2300
^ 2200
SO2
ppm21 00
20OO
1900
180O
170O
9O
HCI 80
ppm 70
60
50
SO3 1°
ppm 5
0
i i i i i i ii i i
- ° § -
o &
o -
o o _
0 \
— —
- ' —
— • . ' —
8 ~
'- o I
i i i i 9 i ° i i i i
10 20 30 40 50 6O 70 80 9O 1OO
Time from start of test : h
Fiq. A4.12. Analysis of exhaust qas vs time for Test Series 1
-------
Photomicrograph (x480) of sectioned specimen.
Surface texture: smooth (<4um)
Photomicrograph (x480) of sectioned specimen.
Surface texture: rough (< 12pm)
Photomicrograph (x480) of sectioned specimen.
Surface texture:-very rough (,?12um)
Fiq. A4. 13. Surface texture of specimens after test
A4.80
-------
00
CO2
18
1^
16
14
13k
12
5
O2 4
% 3
2
1
O-
0-5-
03
0-2
0-1
0
I I I T
O
i t
i i
i I I T I i
0
<£> O
O
t t
t t
-i »-
8
0 40 60 SO
o o-
« <
0
-rQ
O
0
100 120 140 160 180
Time from start of testrh
a^^^-r-L-CMD-l
200 220 v 240
Fig. A4.14. Analysis of exhaust gas vs time for Test Series 2
-------
00
to
JO
17
16
CO2
o/ 15
/o
14
13
12
5
4
02
°/o 3
2
1
O
O-5
CO °«
°/c O-3
O-2
0-1
r\
ii i i i i i i
ooo o o
h ^ ° 0° ° ®E> r, nO
° ° oS °°
'••' ^^ O /~\
o o
o
-
-
„.
^ o °
0 CD> 9, « • 00 ° °n
- 0 £>0° ^^ °°n 0GOG0Oo^ 0
0 °g) 0 0 0
GV o 0 0 0
-
0
o
0 0 ^^0 0
0 ° § 0
1 1 II
o
* CU^^&XBOOo.
o
o o "
-
—
_
o
°o oOoo° o o o o °-
o °o
-
—
o
o o ~
oO oo o
01° 1° 0 IO 0,OO °
24O 26O 260 30O
32O 340 36O 36O 40O 42O 440 46O 48O 50C
Time from start of test: h
Fig. A 4.15. Analysis of exhaust gas vs time for Test Series 2
-------
SO
ppm
00
CO
2500
2400
2300-
2200-
21OO
2OOO
19OO
1800
170O
90
HCI 80
ppm 70
6O
50
S03
ppm 5
o
o
O
10
n
i
i
i
i
i
i
2O 40
6O 80 10O 120 140 160 18O
Time from start of test: h
200 22O 24O
Fig. A4.16. Analysis of exhaust gas vs time for Test Series 2
-------
00
2DW
2400
2300
2200
s°2 21OO
ppm
2OOO
19OO
180O
170O
90
HCI 80
PPm ^
60
50
SO3 1°
ppm 5
i i i i i i i ii i i i
- OH2Oz
_ x Iodine _
— (TJ) X j( _
™ v * * ,? * * \
-^xXXQOj^ -
o
-
0°
o
o
" ^ © 0 0 Q
I I i i ii i I I i ii
O 260 28O 3OO 320
34O 360 38O 4OO 42O
Time from start of test:h
44O 46O 48O 5OO
Fig. A4.17 Analysis of exhaust gas ys time for Test Series 2
-------
CO2
18
17
16
15-
14
13
12
0,
00
cn
3
2
1
O
0-5
% 0-3 -
O-2
O-1
-0
0
- 0
0
i 0 i
i i
°
°
oO
o o 0
°°°OO
H 1 1 h
o
0
H 1 1 1-
©
O
H 1 1 h
2O 4O
OQ
o
H h
I I
60 80 100 . 120 140 16O
Time from start of test: h
°
o 1
0 _
2OO 22O 24O 26O
Fig. A4.18. Analysis of exhaust gas vs time for Test Series 3
-------
00
a>
IO
17
16
CO2 15
0/0 14
13
12
5
4
O2 3
0/0 2
1
O
O-5
O-4
CO
% 0-3
O-2
O-1
§
i i i i i i i i i i
20 _
^.O o O o ^
_ r\O OO OO ®^O/-\_ O* O £)
- O^ u O O ^Oo °° °° °^ ™
O OOQ OQ G&°O o
o ° o 0 °o o "
•/
-
•• ' «™
O^
j^^\ ,^^\
_o°(9 OG°OOOOOO 0° OQO 00°^ o° o2)°(poo0o ^oo _
1 o o • • - ' -
_ .
o
o
-
-------
co
35O
300
250
15O
100
50
0
90
HCI 80
7O-
60
5O
S03 10
ppm 5
o
o
o
©
o
i
«
i
I l^
O H202
x lodrne
i
20 40
6O 8O 100 . 120 140 16O
Time from start of testth
18O 2OO 22O
Fig. A4. 2O. Analysis of exhaust gas vs time for Test Series 3
-------
00
oo
SO2
ppm
HCI
ppm
S03
ppm
«tvx\
-------
Ring K2m (Area 1)
(Ferritic 2|% Cr. l%Mo. steel)
(Specimen from tube at 600 C after 500h)
•''&«• '-"•«•>
' :*te- '
o.
1-
* .
« ..
Optical X600
Chromium x-rays
X600
Manganese x-rays
X600
Sulphur x-rays X600
Fiq.A4. 22. Optical photomicrcxjraph and electron probe micrographs of section*
A4. 89
-------
Ring KZtn (Area 2)
(Ferritic Zi% Cr. 15% Mo. steel)
(Specimen from tube at 600 C after BOOK)
Optical X600
Chromium x-rays X600
Manganese x-rays X600
Sulphur x-rays X600
Fiq. A4.23. Optical photomicrograph and electron probe micrographs of sectioned tube
A4. 90
-------
CO
1OO
90-
Rfng 2m
(Ferritic 21'4«/oCr,
1%Mo steel, 111O°F)
20
18O 2OO
4O 6O 80 1OO 12O 14O 16O
Distance from metal surface :jim
Ffg.A4.24. Electron probe microanalysis : elemental line traces
-------
Ring K4
-------
NATIONAL COAL BOARD
FINAL REPORT
JUNE 1970 - JUNE 1971
REDUCTION OF ATMOSPHERIC POLLUTION
APPENDIX 5. EXPERIMENTS WITH THE 6 IN COMBUSTOR. (TASK V)
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
411 WEST CHAPEL HILL STREET
, DURHAM, NORTH CAROLINA 27701
FLUIDISED COMBUSTION
REFERENCE NO. DHB 060971 CONTROL GROUP
SEPTEMBER 1971 NATIONAL COAL BOARD
LONDON, ENGLAND
-------
REDUCTION OF ATMOSPHERIC POLLUTION
Research on reducing emission of sulphur oxides,
nitrogen oxides and particulates by using
fluidised bed combustion of coal
Appendix 5. Experiments with the 6 in combustor. (Task V)
Main objective
To obtain data on sulphur retention for a
range of coals and limestones, in particular
to allow comparison to be made with the 6 in
rig at Argonne.
Report prepared by: D.G. Cox
B.C. Davidson
J. Highley
J.C. Holder
Report approved by: A.D. Dainton
H.R. Hoy
AS.iii
-------
FOREWORD
This Appendix describes experimental work carried out using
the 6 in eombustor at CRE, between June 1970 and June 1971, as
Task V of the joint NCB/OAP research programme, The main object-
ive of Task V was to obtain data on sulphur retention for a range
of coals and limestones, in particular to allow comparison to be
made with the 6 in rig at the Argonne National Laboratory (ANL).
Attention is drawn to the main results obtained, but, apart from
a comparison with the ANL data, the results are not discussed
here,, A summary of the work is presented in the main report and
the results are discussed there, together with results from other
pilot plantso
A5. v
-------
Table of Contents
Page No.
Foreword
1. Description of the Combustor A5. 1
1.1 General A5. 1
1.2 Air Distributor A5. 1
1.3 Coal Feeder A5. 1
1.4 Cooling Circuit A5. 1
1.5 Bed Height Control A5. 2
1.6 Flue Gas System A5. 2
2. Experimental Procedures A5. 2
2.1 Preparation of Feedstock A5. 2
2,2 Procedure for Start-up A5. 2
2.3 Test Procedure A5. 3
2.4 Shut-down Procedure A5. 4
2.5 Data Processing A5. 4
3. Results A5. 7
3.1 Test Series 1 A5. 7
3.1.1 Description of the test series AS. 7
3.1.2 Results of the test series . A5. 8
3.2 Test Series 2 A5. 9
3.2.1 Description of the test series A5. 9
3.2.2 Results of the test series A5.10
3.3 Test Series 3 A5.12
3.3.1 Description of the test series A5.12
3.3.2 Results of the test series A5.12
3.4 Test Series 4 A5.13
3.4.1 Description of the test series A5.13
3.4.2 Results of the test series A5.14
3.5 Test Series 5 A5.15
3.5.1 Description of the test series A5.15
3.5,2 Results of the test series A5.15
A5. vii
-------
Comparison with results from Argonne National Laboratory (ANL)
4.1 Illinois coal and Limestone 1359
4.2 Welbeck coal and U.K, limestone
Acknowledgement
Tables A5.1.1 to A5.1.16 Results of Test Series 1
Tables AS.2,,1 to A5.2.23 Results of Test Series 2
Tables A5.3.1 to A5.3.14 Results of Test Series 3
Tables A5.4.1 to A5.4.17 Results of Test Series 4
Tables A5,5.1 to A5.5.10 Results of Test Series 5
Figures A5.1 and A5.2 Details of plant design
Figures A5.3 to A5.9 Reductions of S02 emission obtained
(Note that when referring to Tables and Figures in the text
the prefix A5 is omitted).
Page No.
A5.16
A5.16
A5.17
A5.18
A5. viii
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DESCRIPTION OF THE COMBUSTOR
Id General
The general design of the combustor is shown in Fig. !„
The main reactor was in three sections, all fabricated from stain-
;
less steel, (a) a lower cylindrical section 6$ in diameter and
6 ft long, with the air distributor at the base, (b) a conical
expansion section leading to (c) an upper cylindrical section
1 ft 5 in diameter and 4 ft longo This upper section was terminated
by a flat plate,, The tptal internal volume of the combustor was
3 3
8,18 ft , of which the expanded head comprised 6«95 ft .
The whole combustor could be heated electrically by external
wall heaters embedded in a heat-conducting cement. The heaters
were intended to counterbalance heat losses, with the exception of
the first 12 inches in length of the 6 in diameter section which
had additional windings (bed heaters) to permit more rapid heating
of the bed material„ A layer, of insulation clad the whole exterior
of the combustor^
Io2 Air Distributor
Details of the bed section of the combustor are shown in
Fig* 2o This shows the air distributor which was a flat plate
with forty-five 3/32 in holes covered by three layers of J in
diameter alumina balls to prevent ash particles from falling
through the holes,
103 Coal Feeder
The feed hopper for the coal and coal/limestone mixtures was
of stainless steel and terminated in a rotary valve for metering
the feed to the combustorr The metered feed was pneumatically
injected into the bed tangentially to the combustor diameter through
a 5/16 in bore tube | in above the alumina pebbles, i»e. approximately
1| in above the distributor plate (see Figo 2). The feed pipe
terminated at the inner wall of the combustor.
1,4 Cooling circuit
The heat produced by combustion in the bed could be removed
by means of an immersed cooling coil of $ in Ood« stainless steel
A5ol
-------
tubing (see Fign 2) in which water was boiled and superheated.
The flow of water was controlled automatically in response to a
signal from a thermocouple in the bed. The steam from the coil
was condensed and the condensate recirculated=
1-5 Bed jiejlght control
The bed height was measured by means of pressure probes in
the vessel, and could be automatically maintained constant by
emptying surplus ash through a tube in the centre of the baseo
This was done using a vibrating trough on which the ash in the
tube restedo
1.6 Flue gas system
The gases leaving the reactor could be directed through two
alternative cyclone systems., Both contained twb cyclones of
diameter 3 in and 1| in respectively, in series„ In one system
the fines removed from the gas stream by the primary cyclone were
returned to the bed through a dip-leg ending 4j in above the base,
and the secondary cyclone fines were collected in a catchpot„ In
the other, both cyclones were fitted with catchpots, and fines were
not recycled to the bed, To ensure satisfactory flow of fines into
the catchpots, lines and valves of 1 in bore were used and the
catchpots wtre fitted immediately below the cyclones»
2, EXPERIMENTAL PROCEDURE
2ol Preparation of Feedstock
The coal feed was normally prepared to -10 B.S. mesh (1680 ym)
and screen analyses of the feed coals used in the runs are given in
the texto The feed for runs with limestone addition was prepared
by weighing and mixing the required quantities of coal and limestone,
2o2 Procedure for Start-up
The feed for a particular run was loaded into the feed hopper
which has a maximum capacity of 60 Ib of coalo The ash bed was re-
used from the previous run, where practicable, but, apart from
Test 408, a lime-enriched ash was not used for tests at a lower lime-
stone addition than that used to produce the ash. Thus, at the
-------
beginning of each run, a fluidised bed was established using either
ash from the previous run, or a fresh bed of ash from Welbeck coal,
from an earlier run made without limestone addition. The bed
temperature was raised initially using the combustor heaters and
/ . Q
electrically pre-heated fluidising air at approximately 1200 F,
At a bed temperature of J840 F, which was usually reached within
45 minutes, the coal feed was started at approximately half the
anticipated final feed rate,. The warming-up process then
continued for approximately one hour, by which time the bed
temperature had reached approximately 1100 F° The coal feed rate
was then increased to the anticipated rate for the run. Normally
a further one hour was then required for the bed temperature to
reach the run condition (usually 1470 F) at which temperature the
air preheater was switched off, the bed heaters were turned down,
and the cooling water circulated„ The bed temperature stabilised
within 30 minutes, after which ash was withdrawn to adjust the bed
height to the required level. The air flow rate was adjusted to
attain the chosen fluidising velocity as calculated for the empty
vessel at the temperature of the bed. The coal feed rate was set
according to the proportion of excess air at which the run was to
be carried out- The electrical supply to the freeboard heaters
was adjusted to maintain the freeboard at the same temperature as
the bedo Gas samples for chromatographic analysis were taken in
evacuated bottles at a gas sampling point downstream of the secondary
cyclone to confirm the oxygen analysis on the continuous analyser.
2c3 Test Procedure
Once the experimental conditions had been set, the ash
withdrawn from the bed and the cyclone fines were each collected
over successive periods of one hour and weighed0 Further gas
samples were taken to determine the flue gas composition*
The normal test period over which the above procedure was
carried out was six hours, and is referred to as the mass balance
period- Samples taken during this period, plus samples of feed-
stock, initial bed and final bed, were analysed for volatile
matter, carbon, calcium and sulphur„
A5,3
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Gas samples for sulphur dioxide determinations were taken
immediately downstream of the cyclones at one or other of the
points shown in Fig, 1, depending upon whether or not fines
recycling was being practised„
The sulphur dioxide determinations were made at least four
times during a mass balance period using N/10 iodine solution to
which 2% potassium iodide had been added to prevent loss of
iodine« Each determination was run to complete discolouration
of the iodine solution using thiodene as an indicator, and the
quantity of iodine initially used was adjusted to give 10 to 20
minutes sampling time at a sampling rate of approximately 2 litres/
min* The results sheets for each test show the mean value for SO.,
obtained with iodine»
In addition to iodine tests, samples were also taken by
absorption in hydrogen peroxide solution^ These solutions were
bulked over each half of the mass balance period and subsequently
analysed for sulphate, chloride, and ammonium ions-,
2.4 Shut-down Procedure
At the end of the run the coal feed was stopped and
simultaneously nitrogen was substituted for the fluidising air* To
assist in cooling the bed the flow of cooling water was increased.
When the bed temperature had fallen to 755 F the ash bed was emptied
into tins which were then sealed„ Samples of the bed were taken for
analysis after cooling down in the sealed tins,
2.5 Data processing
The measured feed rates, solids output rates and chemical
analyses of the input and output streams were used to calculate
mass balances o These were carried out by computer<,
The major factor in the mass balance which was not measured
was the flow-rate of flue gas, and it was necessary to estimate
thisc Since the gas analysis was carried out on a dry volume basis,
the dry volume rather than mass flow-rate of gas was estimated«
This was done by correcting the total ^ir flow-rate for the volume
changes due to the reactions which occurred,,
A5.4
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These were:-
(i) 4H (coal) + 02 - > 2H20 (liquid)
(ii) 20 (coal) - » - > 02
(iii) 2C + 02 - = - ^ 2 CO
(iv) CaC03 - ^ CaO + C02
(v) CaO
The volume changes due to (i) and (ii) were calculated
assuming that all the hydrogen and oxygen in the coal were
released,, The increase due to (iii) was calculated from the
measured concentration of CO in the flue gas,, The net effect of
(iv) and (v) was small and this was neglected o Thus the flue gas
flow rate was calculated as:
Flue gas flow-rate = Air + 379 x Coal Feed Rate x (0 Content/32- H Content/4) SCFH
(1 - 0,5 x CO in Flue Gas)
The following mass balances were carried out:-
(i) Total
In this the mass flow-rate of dry flue gas was calculated from
its composition and a hydrogen balance was assumed,
(ii) "Ash*
This is a balance for the inorganic solids, i0e. ash and acceptor.
No. allowance was made for the weight changes due to calcination of
CaCO, and formation of sulphate o Because it was not possible to
determine directly the bed weight at the beginning and end of the mass
balance period, the following procedure was used to find the amount of
ash accumulated in the becL The bed weight at the beginning of the
balance was obtained from:- the weight of bed initially fed to the
combustor plus the ash in the feed up to the start of the balance
minus (ash offtake + ash in fines make) up to the start of the balance,
The bed weight at the end of the balance was obtained from:-
the weight of the bed from the combustor after shut down plus ash in
the fines collected during the shut down procedure „ The ash content
of the fines produced during start-up and shut-down was taken as 50% o
-------
The bed weight at the end of the balance was then subtracted from
the bed weight at the beginning and divided by the period of the
mass balance in hours to give the accumulation rate per hour,
(iii) 'Carbon'
This is a balance for the organic carbon in the coal and is
directly relevant to the combustion process. No allowance was made
for the CCL in the flue gas arising from calcination,,
(iv) Nitrogen
This balance serves as a check on the accuracy of the flue gas
analysis,
(v) 'Oxygen'
This is a balance for the oxygen in the air and the organic
oxygen in the coal» It is directly relevant to the combustion
process.
(vi) Sulphur
This is a balance for the total sulphur content of the coal,
using the mean S0_ concentration obtained by the iodine method.
(vii) Calcium
This is a balance for the total calcium in the coal and
acceptor/
The following parameters were calculated from the flow rates
in the mass balance:-
(i) Excess air level, defined as:-
Feed air - stoichiometric air for coal feed rate ,__„
bxcess air = Stoichiometric air for coal feed rate x X
(ii) Carbon loss, defined as:-
„ , - Unburnt carbon output rate ,»-.„
Carbon loss = Total carbon outpi;t rate * 10°*
A5,6
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(iii) Sulphur retention, defined as:-
Sulphur retention - ,( 1 - fffi" ?" f lu? KM. > x 100%
( Total sulphur input )
(iv) Ca/S mol ratio, defined as:-
mols of Ca in additive
Ca/S mol ratio =
mols of S in coal
3. Results
The programme of work on the 6 in combustor can conveniently
be divided into five test series„ The actual tests were not carried
out in strict chronological order, as delivery of the Illinois coal
for Test Series 1 was delayed, and Test Series 2 with UoKo raw materials
was therefore completed first, However, all data are presented in
serial order, ignoring chronology,,
3.1 Test Series 1
To obtain data on sulphur retention for the coal used
at Argonne National Laboratories (ANL) to 'compare'with
ANL jiata
3olol Description of the test jsgrigs
The combustor was operated in the manner described in Section 2«
The nominal conditions for the series were as follows:
Coal: UoSo Illinois (ex ANL), - 1680 urn
Acceptor; U,S0 Limestone 1359, - 1680 ym
UoK. Limestone, - 1680 ym
Ca/S mol ratio: 0, 1, 2 & 3
Fluidising velocity: 3 ft/s
Bed temperature: 1470°F
Bed height: 2 ft
Flue gas 0^ 2o5 to 3.5%
Recycle: None
The Illinois coal was supplied prepared to -J" by ANL, and it
was suggested that the required -1680 ym feedstock could be obtained by
scalping off the coarser fractiono As this coarse fraction constituted
A5,7
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some 40% of the coal, it was agreed with OAF that the coal would be
crushed to give the required top size. This was done using the
hammer mill in the "Fluostatic Plant" which is described in
Appendix 1, Section 3»1?
The UoSo limestone 1359 was supplied prepared to minus
1/16 in by ANL and it was passed through a 1680 v-m sieve before
being used for the coal/limestone blends.
Bed ash from Welbeck coal produced in early experiments
without limestone addition was used for the first test of the
series. Table 1.1 indicates the source of the ash beds for the
subsequent tests=
The U.Kc. limestone was delivered as ~J in + i in graded
material and this was processed to pass 1680 urn, using the
hammer mill in the "Fluostatic plant','
3.1=2 Results of the test series
';
Table Id gives the details of the operating conditions for
L • e>
the eight tests carried out in this series. It should be noted
that as all tests on the 6 inch combustor occupy the same time
scale, running hours are not given in the tables.
Tables 1»2 and 1.3 present the analyses of the coal and
limestones used to make up the feed blends- Analyses of the
individual blends are given in Table 1-43
Solid product analyses of cyclone fines and of bed materials
are given in Tables 1U5 and lc.6* It should be noted that the primary
and secondary cyclone fines were bulked for analytical purposes„
The flue gas analyses are given in Table 1*7,
Tables 1,8 to Id5 give the mass balances and calculated
operating parameters for each test in the series„
The carbon balances were good and the excess air levels were
within the specified range0 The combustion efficiency, without fines
recycle, was about 96%. The ash balances here, and in subsequent test
series, are not very satisfactory, This is thought to be due to the
difficulty in determining the weight of ash accumulated in the bed,
A5o8
-------
which had to-be estimated by the indirect method given in Section 2o5»
The sulphur balances were satisfactory and the agreement between the
two runs without limestone addition was goods In general the S0_
concentration in the offgas, as measured by the H_02 method was in
reasonable agreement with but slightly lower than the value obtained
by taking the mean of the results of the iodine method„ The values
used for comparisons and in compiling graphs are the mean iodine
results unless otherwise stated *
The reductions in SO. emission, with the addition of limestone
1359 and U<,K» limestone, are given in Table l,16o These results are
plotted against the added Ca/S mol ratio in Figo 3o The graph shows
that the U»K0 limestone is significantly more effective at reducing
SO „ than is limestone 1359. The same effect was noted at ANL.
3o2 Test Series 2
To substantiate previous sulphur retention data,, Also to
obtain data for a high-rank U0K» coal and on the effect of sub-
stoichiometric operation
3«2ol Description of the test series
The combustor was operated in the manner described in Section 2»
The nominal conditions for the series were as follows: .
Coal: UcKc (a) Welbeck, and (b) Park Hill, -1680 um
Acceptor: UoK» Limestone, -1680 Um
Ca/S mol ratio: 0, 1, 2 and 3«
Fluidising velocity: ' 2 and 3 ft/s
Bed temp: 1470°F
Bed height: 2 ft
Flue Gas CU: 2C5% to 3°5% and substoichiometric
Operation both with and without recycle.
The Welbeck coal was supplied processed to -1680ym by BCURA,
It formed part of the batch of Welbeck coal that was used for Task II,
and the manner of processing of this material is described in Appendix 2,
Section (1.5).
The Park Hill coal was delivered as Ij in - 0 untreated smalls and
A5-9
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was processed in the Fluostatic Plant in a similar manner to the
coals used in Task I (see Appendix 1, Section 3ol)0
The proposal had been to use a U0K0 coal of high rank to
contrast with the other UoK« coal (Welbeck-low rank) and to compare
with the UoS, Pittsburgh coal (high rank)„ It was also proposed to
use a coal of comparable sulphur content to the Pittsburgh coal.
However, the coal received did not possess the expected qualities,
in particular the Gray-King coke number, which for the purpose of
the comparison should be G4 or higher, was determined as D<, It
was found on enquiry that the coal supplied was Park Hill, and not
Park Mill, and in addition that the Park Mill Colliery was not
currently producing a coal of sufficiently high rank to provide
the desired comparison,, As the sulphur content of the Park Hill
coal to hand was satisfactory (2<-45%) it was decided to use this for
the tests„
Considerable difficulty was experienced with the S0_
determinations using iodine, during the first tests with Park
Hill coal (Tests 2<,9,2<,10 and 2011), The subsequent analysis of
the hydrogen peroxide solutions from these tests gave better
results, but it was f.elt desirable to carry out further tests,
(2o12,2o13 and 2ol4)o These gave consistent results for SO-
using iodine solution, and the results were confirmed by the
analyses of the hydrogen peroxide solutions„
3o2o2 Results of the test series
Table 2nl gives the operating conditions for the 15 tests
carried out in this series„ Tables 2,2 and 2°3 present the
analyses of the coal and limestone used to make up the feed blends,.
Analyses of the individual blends are given in Table 2o40
Chemical analyses and size distributions of cyclone fines
and bed materials are given in Tables 2,5 and 2°6° It should
be noted that the primary and secondary cyclone fines were bulked
for analytical purposes„ The flue gas analyses are given in
Table 5o7,
Tables 208 to 2»22 give the mass balances and calculated
operating parameters for each test in the seriesc
A5olO
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The carbon balances were good throughout the test series.
Without fines recycle, the combustion efficiency for Welbeck coal
was about 93%, i.e., 3% lower than with Illinois coal in Test Series 1.
With recycle the efficiency increased to about 97%, The change in
fluidising velocity from 2 to.3 ft/s did not significantly effect the
combustion efficiencies obtainedo The run under sub-stoichiometric
conditions (run 2<=7) gave a carbon loss of 13,5% which is typical for
these conditions. In general, for the runs using Park Hill coal, the
oxygen concentration in the flue gas was slightly below the nominal
condition of 2=5% - 3o5%, with the result that the combustion
efficiencies averaged about 90%„
The sulphur balances in this series were generally satisfactory,
but there were some exceptions; for example in Tests 2.9 and 2.10
where experimental difficulties were experienced in determining S0_
using the iodine method. The reduction in SO. emission from Welbeck
and Park Hill coals using UoK. limestone are given in Table 2.23.
A separate S0« datum level was calculated for the sub-stoichiometric
run, test 2.7, to allow for the increase in coal burnt. Fig. 4
shows the effect of Ca/S mol ratio on SO^ reduction for U.K. lime-
stone with four different coals, at a fluidising velocity of 3 ft/s.
Some results from Test,Series 1, A and 5 are included in addition to
those from the present test series, The graph shows that the SO-
reduction is about 10% higher with-Welbeck coal than with the other
three coals„ Also, the S0_ reduction with Pittsburgh coal may be
slightly below that with Park Hill and Illinois„ Since the Welbeck
and Park Hill coals used almost identical properties, apart from
sulphur content, (18o2% and 16c.5% volatiles, both had a swelling
Number of 1, Gray King coke types C and D), the differences between
the coals cannot be ascribed to differences in rank. Possible
differences for the better S0_ reduction with Welbeck coal are
discussed in the Main Report.
The effect on SO- reduction of changing the fluidising velocity
is shown by Figo 5,, The results suggest that a decrease in S0_
reduction of about 10% results from increasing the fluidising velocity
from 2 ft/s to 3 ft/s»
Recycle of primary fines and running under sub-stoichiometric
conditions, did not significantly effect the S02 reductions obtained.
A5.ll
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3o3 Test Series 3
To investigate the effect of bed depth and temperature:
and the effect of fine grinding of limestone
3o30l Description of the test-series
The combustor was operated in the manner described in Section 2.
The nominal conditions for the series were as follows:-
Coal: UoS= Illinois, -1680 ym
Acceptor: ( U«,S<, Limestone 1359, -1680 ym and -125 ym
Ca/S mol ratio: 1,2 and 3
Fluidising velocity: 3 ft/s
Bed temperature: 1290° and 1470°F
Bed height: 2 and 3 feet
Flue Gas 02: 2,5 - 3,5%
Recycle: None
The coal and limestone for this test series were from the same
batches prepared and supplied by Argonne National Laboratory for test
series 10 The fine limestone (-125 um) was prepared on site from the
supplied material using a laboratory swing hammer mill, in batches of
approxo 1 Ib; each batch being hand sieved through a 120 B»S, sieve
(125 ym) and the coarse product returned to the mill with some fresh.
limestonec
303o2 Results of the test series
Table 3d gives the operating conditions for the six tests
carried out in this series„ Tables 3»2 and 3»3 present the analyses
of the coal and limestone used to make up the feed blends. Analyses
of the individual blends are given in Table 3«4<=
Chemical analyses and size distributions of cyclone fines and
bed materials are given in Tables 3=5 and 3°6, It should be noted
that the primary and secondary cyclone fines were bulked for
analytical purposes„ The flue gas analyses are given in Table 3»7o
Tables 3=8 to 3o13 give the mass balances and calculated
operating.parameters for each test in the series»
A5012
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The carbon balances were good, with the exception of Test 3»6o
The combustion efficiencies at 1470°F of about 96% confirm the
result of Test Series 1. At 1290°F the combustion efficiency was
about 93%, The sulphur balances for this series were good,, The
reductions in SO,, emission are given in Table 3ol4»
The results at 1290°F clearly show, that operation at this
temperature is unsatisfactory. The chemical analysis of the ash
and fines from these tests show that little calcination had taken
place. The reductions in S02 emission using 2 ft and 3 ft deep
beds (taken from Test series 1 and 3) with -1680 ym limestone 1359
and a 2 ft bed with -125 ym limestone 1359 are plotted against the
Ca/S mol ratio in Figo 6» The graph shows a 12-15% improvement in
S0_ reduction with the increase of bed height. The results using
-125 ym limestone are not so clear cut, at the low Ca/S mol ratio
a marked improvement in SO^ reduction is shown, but at the higher
level of addition the result is close to that obtained with -1680 ym
limestone. The latter finding is in agreement with the results in
Task 1, where using fine limestone had no significant effect on S0_
reduction,,
3o4 Test Series 4
To obtain sulphur retention data on the U.S,
(Pittsburgh) coal using U,S, Limestone No. 18
and U.K. Limestone
3.4.1 Description of the test series
The combustor was operated in the manner described in
Section 2, The nominal conditions for the series were as follows:-
Coal: U,So Pittsburgh, -1680 ym
Acceptor: U,S, Limestone 18 and U.K» Limestone,-1680 urn
Ca/S mol ratio: 0, 1 2 and 3
Fluidising velocity: 3 ft/s
Bed temperature: 1470°F
Bed height: 3 ft
Flue Gas 02: 2,5 - 3,5%
Recycle: None
The Pittsburgh coal and the limestone 18 used for this test series
A5.13
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were part of the batches used for Test Series 1 on the 36 inch
combustor (Task I) and the preparation procedures for the two
materials are described in Appendix 1, Section 3»lo The ILK,
limestone was from the same batch as was used for Test Series 1
and 2 in the present tasko
3.4.2 Results of the test series
Table 4,1 gives the operating conditions for the tests carried
out in this series,, Tables 4,2 and 403 present the analyses of the
coal and limestone used to make up the feed blends„ Analyses of the
individual blends are given in Table 4o4c
Chemical analyses and size distributions of cyclone fines and .
bed materials are given in Tables 4»5 and 4°6° It should be noted
that the primary and secondary cyclone fines were bulked for
analytical purposes. The flue gas analyses are given in Table 4o7«
Tables 4*8 and 4«16 give the mass balances and calculated
operating parameters for each test in the series„
The carbon balances obtained were satisfactory for this series.
The combustion efficiency for Pittsburgh coal without fines recycle
was about 91%.
The sulphur balances were satisfactory, with two exceptions,
Tests 4,8 and 4»9. Both these balances had quite high sulphur
losses of 18% and 25% respectivelyo Examination of these balances
and comparison with other tests at similar conditions suggest that
the error lies in the underestimation of the sulphur retained in the
bed and offtake ash,
The reduction in SO- emission with the addition of UoKo limestone
and limestone 18 are given in Table 4»17c These results are plotted
against the added Ca/S mol ratio in Fig* 7» The graph shows that
higher reductions of S0_ emission are obtained when using limestone 18
as additive,, This result in conjunction with the comparison of U,K.
stone and U.So 1359 carried out in Test series 1, shows that limestone
18 was about 15% more effective in reducing the SOj emission than was
the UcKo stone and the UoK, stone in turn was again about 10% more
effective than the U0S., 1359 limestone,,
A5.14
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As described in section 2^2, the normal test procedure was to
start with either a fresh ash bed or a bed from a previous test which
had been carried out at a lower Ca/S ratio than that to be used* In
order to demonstrate that an adequate time was being allowed for
equilibrium to be reached, Test 408 was carried out using a bed from
a test in which a higher Ca/S ratio had been used. The SO,, reduction
obtained was not significantly different from those obtained in
Tests 4o5 and 409 in which beds of fresh coal ash and shale were used,
respectively,
3.5 Test Series^ 5
To check sulphur retention data using a_ fresh batch
of U,K. (Welbeck) coal using U'.So No. 18 and UoKo
j. lines tones
3.5»1 Description of_the test series
The combustor was operated in the manner described in Section 2«
The nominal conditions for the series were as follows:-
Coal: U.K. Welbeck II, -1680 urn
Acceptor? IKS., No, 18 and U.Ko Limestones, -1680 'j
Ca/S moi ratio: 2
Fluidising velocity: 3 ft/s
Bed temperature: 1470°F
Bed height: 3 ft
Flue Gas 02: 2.5 - 305%
Recycle: None
3o5o2 Results of the test series
Table 5ol gives the operating conditions for the tests carried
out in this series„ Tables 5=2 and 5=3 present the analyses of the
coal and limestone used to make up the feed blends <> Analyses of the
individual blends are given in Table 5«4c
Chemical analyses and size distribution of cyclone fines and
bed materials are given in Tables 5o5 and 5.60 It should be noted
that the primary and secondary cyclone fines were bulked for
analytical purposes„ The flue gas analyses are given in Table 5o7»
A5,15
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Tables 5.8 and 5»9 gives the mass balances and calculated
operating parameters for each test in the series»
The carbon and sulphur balances were satisfactory in both
tests. The combustion efficiencies were similar to those
obtained in Test Series 2»
The reductions in SO^ emission are given in Table 5.10.
The result from Test 5»1 using U,Kn limestone is plotted in Fig, 59
and agrees well with the results using the same materials from Test
series 2, the use of a bed temperature 30 below that desired, did
not appear to affect the result„
The SO- reduction obtained in test 5.2, using U0So limestone 18,
was the same as in Test series 2, where UrKo limestone was used as
additive*, This result is a little surprising as the previous tests
with Pittsburgh coal had shown the UnS, stone to be the more effective;
however, as no other tests were carried out using Welbeck coal and UoSr
limestone, the result could not be checked0
4. COMPARISON WITH RESULTS FROM ARGONRE NATIONAL LABORATORY (ANL)
4nl Illinois coaland Limestone 1359
Preliminary results from Test Series 1 and results from runs
at ANL were compared in the ANL monthly progress report, No* 27,
Jano 1971 n The materials and operating conditions used were the
same at both centres, namely, Illinois coal, limestone 1359, bed
o
temperature 1470 F, fluidising velocity 3 ft/s, and bed height
2 ft, A graph of the results showed the points to fall on a smooth
curve and it was concluded that the results from the two centres
were the same, Figo 8 of this report is a re-plot of the same
work but using the final results from test series !„ The parameter
sulphur retention has been used instead of % SO,, reduction since the
level of S02 emission without limestone addition is not known for
the ANL work,. Sulphur retention is defined as the retained sulphur
expressed as a percentage of the total sulphur input,,
'Fig.. 8 confirms the ANL conclusion that there is no
significant difference between the results, However, there is a
tendency tor the ANL results to be above the curve and the CRE results
below. This difference corresponds to about 200 popom0 of SO^ in the
flue gas, the ANL results being the lowern
-------
4o2 Welbeck coal and U.Ks limestone
In a similar manner to Test Series 1, some of the preliminary
results from test series 2 had been compared to work at ANL and
this was reported in ANL monthly progress reports, Nos« 24 and 25„
The conditions and materials used were Welbeck coal, UoK0 limestone,
1470°F, 3 ft/s and a 2 ft deep bed. The results were plotted as SO.
in the flue gas p<,poino against Ca/S mole ratio (including calcium con-
tent of the coal) and showed the S0« concentrations from the ANL work
to be about 100 - 300 p»p.mi higher than the results from the NCB,
This difference is of the same order, but of opposite sign, to that
found with the test series 1 results,, Since, for Welbeck coal, the
S0~ emission without limestone is only about 1100 p.pom., there is a
significant difference in SO- reductions between the two plants, as
shown in Fig* 9»
Although there are several design differences between the ANL
and NCB 6 in combustors (listed in the Main Report) none of them
would account for a difference with one coal and not with another,,
Thus it must be concluded that at the present time it is not
possible to duplicate results on the two plants to an accuracy
greater than + 200 p.poih,, of S0_<,
A5d7
-------
ACKNOWLEDGEMENT
The authors acknowledge the contributions of their
colleagues at CRE in carrying out the work described in
this report„ The work was administered by Dr0 ACD, Dainton
and Mr0 J0 McLaren; the overall experimental programme was
devised by Mrn D»Co Davidson and Mr. A0Wo Smale, who was
also responsible for the operation of the plant; the shift
team leaders were Mr, R., Dryburgh, Mro J^C. Holder, Mr,, M;.
Powell and Mr* LoCo Stephens; the chemical analyses were
carried out under the supervision of Dr-, HC.AC Standing by
Mr* GoJn Corney, Mr» HoW, Harris and Mr0 L0 Stanley;
maintenance of the plant was carried out by the CRE
Engineering and Instrumentation Sectionsc
The contribution made by Mr,, E0L. Carls, the OoAoPo
representative in the U«Ko, is also acknowledged.
A5.18
-------
Table A.5.1.1 Operating conditions during Test Series 1
Constant Parameters
1
Coal: Illinois (ex A.N.L.) |
Coal Size: - 1680 ym ]
Acceptor Size: - 1680 ym \
Fluidising Velocity: 3 ft/s
Bed Temperature: 1470°F
Bed Height: 2 ft
Recycle: None
Test No.
Date
Acceptor
Ca/S mol
ratio
Ash Bed
1.1
17/7/70
None
0
Fresh
1.2
21/7/70
US 1359
1.5
ex 1.1
1.3
22/7/70
US 1359
2.2
ex 1.2
1.4
23/7/70
US 1359
3.3
ex 1.3
1.5
28/7/70
UK LST.
1.1
Fresh
1.6
29/7/70
UK LST.
2.2
ex 1.5
1.7
30/7/70
UK LST.
3.2
ex 1.6
1.8
31/7/70
None
0
Fresh
A5.19
-------
Table Ao5*lo2 Chemical analyses of coalo Test Series 1
Test Number
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen & errors
Chlorine
Carbon Dioxide
Ash analysis
CaO
MgO
Na20
K20
A12°3
Fe2°3
s,o,,
! 1 2
Calorific value (gross)
Swelling No,,
Gray King coke type
% a.r.
% a.ro
% d,a.f»
% d.b.
% dob.
% dob.
% dobc,
% d.bo
% dobo
% d »b «
%' d.bc
% dob.
% d0b0
% dob.
% dob.
% dobn
% d.b.
Btu/lb
1.1 - 1.8
9o8
11.8
46.6
67o8
4o45
1«=29
4o38
8,5
Oo22
1.05
ioa
1.0
1.7
1.8
12.2
20.6
40,8
14290
4i
D
A5.20
-------
Table A.5.1.3 Chemical and Size Analyses of Acceptor
Test Series 1
Test No.
Chemical Analysis
CaO a.r.
MgO a.r.
C02 a.r.
O i f\ n •*•
O J-wO a. • i. •
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
1.1-1.4
(US 1359)
55.5
0.3
43.3
0.8
1.5-1.8
(UK LST.)
54.9
0.2
42.0
1.6
% in grade by weight
0.1
36.7
24.8
16.6
8.7
13.1
353
0.5
52.1
19.1
10.1
7.2
11.0
537
A5.21
-------
Table A, 5,1.4 Chemical and Size Analyses of Feed Blends, Test Series 1
Test No.
Moisture a or.
Ash a.r.
Carbon d.b.
CaO d.b.
Sulphur dob.
C02 d.b,
Particle size (urn)
+ 1680
+ 500 - + 1680
+ 250 - + 500
+ 125 -+ 250
+ 63 - + 125
- 63
Median dia. ym
1.1
9o2
11 o 3
67.8
1.15
4.6
Oo72
Io2
7.8
19,4
55.5
10,22
3*9
60 54
1.3
7o2
21o7
52.0
13.71
3o35
10 06
1 = 4
5,2
26... 1
45.7
17,5
2»85
13,65
1.5
8o5
18o6
57.0
8o25
3*9
6o29
1.6
7.2
-
51.4
13,4
3o35
10 ,,45
1.7
6o5
27.2
43.7
18,47
3.15
14.12
1.8
8.7
11.4
68.0
0,96
4.45
0.59
% in grade by weight
0,3
49.2
25 .1
13.9
6.1
5,4
494
1.2
44.9
22o4
15o8
609
808
453
Oo6
51,9
19o9
12o8
7.2
7c6
543
0,6
53 ol
20.0
'11.8
6n4
8.1
551
1.7
53o7
19 = 4
11.9
5.9
7o4
577
Oo7
53o7
•18.1
12.0
7.2
8.3
566
0.2
48.1
21.3
14.4
7.6
8.4
478
0.1
60.4
18.6
10 . 1
5.2
5.6
655
A5.22
-------
< . .L . ./ vjitctuxcaj. cum oxae
ui oyciuue f .lues
Test Series 1
Test No.
Chemical Analysis
Carbon % a.r.
Sulp.hur % a.r.
C02 % a.r.
CaO % a.r.
Size Analysis
Particle size (ym)
+ 500
+ 250 - 500
+ 125 - 250 ?
+ 63 - 125
1-63
] - -
1.1
33.5
1.75
0.82
3.92
1.2
21^7
2.75
3.09
10.63
1.3
18.1
3.09
5.5,
16.0
1.4
15.0
3.09
8.54
21.65
1.5
24.6
2.86
3.66
12.6
1.6
19.4
2.76
6.6
17.05
1.7
16 4 1
2.60
11^80
23.40
1.8
24:4
1.90
10.80
0.56
% in grade by weight
0
0
£ 0.3
11.1
88.6
0
0
0.1
8.8
91.1
0
0
1.5
7.8
90.7
0
0
1.7
7.4
90.9
0
0
0.2
8.8
91.0
0
3.0
1.1
7.9
88,. 0
0
0.1
0.3
5.8
93.8
0.1
0.1
0.4
11.2
88.2
A5.23
-------
.Table A.5.1.6(a) Chemical and Size Analyses of Bed Material
Test Series 1
Test No.
Sample
Chemical Analysis:
Sulphur Z a.r.
O>2 I a.r.
CaO I a.r.
Size Analysis
Particle size (urn)
+ 1680
+ 500 - 1680
+ 250 - 500
.+ 125 - 250
+ 63 - 125
- 63
Median diam. (vim)
1.1
Initial
0.35
0.25
2.1
Final
0.95
0.39
3.08
Offtake
0.8
0.23
2.66
1.2
Initial
2.2
2.0
10.5
Final
•
4.15
4.58
21.2
^Offtake
3.15
4.32
15.4
1.3
Initial
4.2
4.84
22.4
Final
4.95
6.4
31.8
Offtake
5.55
5.9
25.6
1.4
Initial
6.0
6.68
32.2
Final
7.9
7.11
49.5
Offtake
7.35
8.68
43.0
% in grade by weight
0
52.0
35.6
10.7
1.2
0.5
516
0
49.5
36.4
12.1
1.8
0.2
496
0
47.7
37.5
12.2
2.3
0.3
483
0.1
48.3
37.7
10.3
3.4
0.2
488
0.1
47.8
36.0
9.8
5.4
0.9
483
0
50.3
35.7
10.8
3.1
0.1
502
0
41.8
39.1
14.3
4.6
0.2
442
0
31.7
33.7
23.4
10.6
0.6
349
0
53.2
35.0
10.2
1.5
0.1
526
O
38.0
32.9
18.5
9.5
1.1
401.
0
55.2
30.6
11.7
2.4
0.1
549
0
36.9
28.6
21.1
12.1
1.3
378
en
to
-------
Table A.5.1.6 (b) Chemical and Size Analyses of Bed Material
Test Series 1 (cont'd).
Test No.
Sample
Chemical Analysis:
Sulphur % a.r.
C02 % a.r.
CaO Z a.r.
Size Analysis
Particle size (pm)
+ 1680
+ 500 - 1680
+ 250 - 5OO
+ 125 - 250
+ 63 - 125
- 63
Median diam. (vim)
1.5
Initial
0.9
0.43
4.48
Final
4.25
1.41
18.6
Offtake
1.25
1.72
6.85
1.6
Initial
4.55
1.49
18.2
0
49.6
43.9
5.5
0.6
0.4
497
0
63.6
14.6
14.6
6.3
0.9
739
0
52.1
39.7
6.2
1.2
0.8
515
0.1
50.6
37.9
7.3
3.6
0.5
505
Final
6.7
1.79
31.6
Offtake
5.6
2.33
22.4
1.7
Initial
1.45
0.39
5.3
Final
3.0
0.71
11.6
Offtake
-
2.0
0.55
6.6
1.8
Initial
0.9
0.21
3.78
Final
0.9*
0.34
3.64*
Offtake
0.85
0.41
3.64
% in grade by weight
0
47.2
36.5
11.7
4.3
0.3
478
0
41.5
35.6
10.2
11.4
1.3
434
0
44.8
38.3
10.9
5.5
0.5
462
0.1
51.5
31.9
12.0
4.3
0.2
514
0
35.7
31.6
15.2
15.8
1.7
379
0
57.0
38.5
3.6
0.5
0.4
553
0
47.6
41.7
7.5
2.7
0.5
484
0.1
53.9
41.3
3.8
0.6
0.3
528
CJ1
CO
01
* Estimated
-------
Table A.5.1.7 Flue Gas Analyses
Test No.
Operating Conditions
Ca/S Mol Ratio
Fluidising Velocity ft/s
Bed Temperature °F
Bed Height ft
Chromatograph
Mean C02 Vol % Dry
Mean 02 "
Mean CO "
Mean CH4 "
S02 by Iodine
Sample 1. p. p.m. Dry
Sample 2. "
Sample 3. "
Sample 4. "
Sample 5. "
Sample 6. "
Mean S02
By Iodine p. p.m. Dry
By H202 p. p.m. Dry
Cl p. p.m. Dry
NH3 p. p.m. Dry
1.1
0
3
1470
2
14.5
2.9
0.04
0
4016
4057
3997
4023
3240
134
20
1.2 ! 1.3
1.5
3
1470
.2
14.8
2.8
0.05
0
2045
1910
2504
1974
2157
2118
2225
•
2.2
3
1470 '
2
15.3
2.6
0.03
0
1431
1494
1417
1458
•
1450
1380
126 { 150
90 | 9
|
1.4
3.3
3
1470
2
15.4
2.9
0.04
0
672
944
1163
845
831
870
504
145
23
1.5
1.1
3
1470
2
15.2
2.6
0.06
0
1766
1863
1733
1783
1781
1785
1703
179
34
1.6 ] 1.7
2.2 ! 3.2
3
1470
2
15.8
2.2
0.05
0
1148
1393
1376
1306
751
182
25
3
1470
2
16.0
2.3
0.05
0
228
232
266
265
218
219
229
1.8
0
3
1470
2
15.4
2.6
0.08
0
4032
4032
3961
3734
3720
3896
130 1 3670
152 .
17
160
26
A5.26
-------
Table A.5.1.8 Mass Balance for Test No. 1.1
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of Input
Total
4.31
0
45.94
1.9
52.15
-0.16
0
0.54
51.54
51.92
0.23
0.44
'Ash'
0.56 -
0
0
0
0.56
-0.16
0
0.41
0
0.25
0.31
55.36
'Carbon'
2.92
0
0
0
2.92
0
0
0.12
2.82
2.94
-0.02
-0.68
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37.6
37.6
-0.4
-1.08
'Oxygen'
0.37
0
10.64
0
11.01
0
0
0
10.74
10.74
0.27
2.45
Sulphur
0.189
0
0
0
0.189
0.014
0
0.009
0.193
0.216
-0.027
-14.28
t
Calcium ;
0.041
i
0
0
0
0.041
0.017
0
0.015
0
0.032
0.009
21.4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
12.6%
4.2% (Unburnt)
0%
0
-------
Table A.5.1.9 Mass Balance for Test No. 1.2
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.40
0.89
45.94
1.9
53.13
-0.14
0.67
0.52
51.65
52.70
0.43
0.81
'Ash'
0.58
0.89
0
0
1.47
-0.14
0.67
0.41
0
.0.94
0.53
36.05
'Carbon'
2.98
0
0
0
2.98
0
0
0.11
2.88
2.99
-0.01
-0.34
Nitrogen
o
0
35.3
1.9
37.2 .
0
0
0
37.5
37.5
-0.3
-0.81
'Oxygen'
0.37
0
10.64
0
11.01
0
0
0
10.88
10.88
0.13
1.19
Sulphur
0.193
0
0
0
0.193
0.059
0.021
0.014
0.102
0.196
-0.003
-1.7
I
Calcium '
0.041 I
0.354
0
0
0.395
0.231
0.074
0.040
0
i
0.344
0.051
12.9
i
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
12.1Z
3.75% (Unburnt)
47%
1.5
A5.28
-------
Table A05ol<,10 Mass Balance for Test No0 1»3
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed j
Offtake Ash i
Fines i
Flue Gas
Total Output .
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.41
1.32
45»94
1.9
53o57
-Oo22
1.0'9
0,57
51o79
53c23
Oo34
Oo63
'Ash1
Oo58
1.32
0
0
1»90
-Oo22
Io09
Oo47
0
Io36
Oo54
28o42
'Carbon'
2o99
0
0
0
2o99
0
0
OolO
2o97
3o07
-Oo08
-2,68
Nitrogen
0
0
35,3
•1.9
37o2
0
0
0
37=4
37o4
-Oo2
-0.54
'Oxygen'
Oo38
0
10064
0
11.02
0
0
0
11.04
11.04
-0.02
-0.18
Sulphur
Ool93
0
0
0
0.193
Oo023
Oo061
0B017
0,070
0.171
0,022
Calcium |
0=041 '
Oc522
0
0
Oo563
Oo204
0,200
0.063 '
0
0.466
0.097 1
\
11.8 |-17.2 j
Excess Air
Carbon loss
Sulphur Retention
Ca/S Mole Ratio
11.1Z
3.31% (Unburnt)
64%
2,2
A5.29
-------
Table A.5.1.11 Mass Balance for Test No. 1.4
Rate Ib/h i
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.40
1.99
45.94
1.90
54.23
0
1.38
0.69
51.82
52.03
2.2
4.1
'Ash1
0.58,
1.99
0
0
2.57
0
1.38
0.58
0
1.96
0.61
23.7
'Carbon1
2.98
0
0
0 '
2.98
0
0
0.10
2.99
3.09
-0.11
-3.7
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37.2
37.2
0
0
'Oxygen'
0.37
0
10.64
0
11.01
0
0
0
11.24 •
11.24
-0.23
-2.1
Sulphur
0.193
0
0
0
0.193
0.049
0.101
0.021
0.042
0.212
-0.019
-10.1 .
Calcium^
0.041
0.789
0
0
0.831
0.312
0.423
0.103
0
0.838
-0.007
-0.9
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
12.6%
3.3% (Unburnt)
78%
3.3
A5.30
-------
Table Ao5<,l°12 Mass Balance for Test No, 1,5
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Input
Unaccounted,
input-output
Unaccounted,
% of input
Total
4,37
0,66
45.94
1.90.
52,87
0,29
0
0,61
51,72
52o62
0025
Oo5
'Ash'
0.57
0»66
0
0
1.23
0,29
0
0.47
0
0,76
Oo47
38o2
'Carbon1
2.97
0
0
0
2.97
•o
0
0/14
2.96
3.10
-0,13
j
-4,4
Nitrogen ; 'Oxygen'
i
0 ! 0.37
0 i 0
35,3 j 10.64
1,9 \ 0
|
37.2 \ 11.01
o I o
0 1 0 :
o | o
37,4 10,98
37,4 | 10,98
1
-0.2 [ 0,03
-0.54 1 0,27
,i
i
Sulphur
0,192
0
0
0
0/192
0,087
0
0.017.
0,087
0,190
0,002
0.7
Calcium f
I1 f
0.041
Oo257
0
0
0,298
0,261
0
0,052
0
0,314
-0,016
-5.3
1
Excess .Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9,8%
4,59% (Unburnt)
55%
1,1
A5. 31
-------
Table Aola.5,1,13 Mass Balance for Test No, 1.6
Rate lb/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.25
1.28
45.94
1,9
53,37
-0,07
0.94
0.57
51.79
53,23
Ool4
0,26
'Ash'
0,56
1.28
0
0
1.84
-0.07
0,94
0.46
0
1,33
0=51
27 = 72
'Carbon'
2,88
0
0
0
2.88
0
0
0.11
3.07
3ol8
-0,30
-10,42
Nitrogen
0
0
35.3
Io9
37,2
0
0
0
37,3
37.3
-0.1
-0.27
'Oxygen'
0.36
0
10,64
0
11.00
0
0
0
11,04
11.04
-0 =04
-Oo36
Sulphur
0.186
0
0
0
0,186
0.066
0,053
0,015
0.063
0 , 1.97
.-0.011
-5,9
Calcium i
0,040
0,501.
0
0
0.541
0,,294 !
0,150
0.068
0
0.513
0,028
5,3
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole Ratio
8o5%
3,42% (Unburnt)
66%
2,2
A5. 32
-------
Table A.5.1.14 Mass Balance for Test No. 1.7
- •- -1
Rate Ib/h
Coal
Acceptor
Total Air
_
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.47
2.00
45.94
1.9
54.31
-0.29
1.43
0.75
51.99
53.88
0.43
0.79
'Ash'
0.59
2.00
0
0 ,
2.59
-0.29
1.43
0.63
0
1.77
0.82
31.66
'Carbon'
3.03
0
0
0
3.03
0
0
0.12
3.11
3.23
-0.20
-6.60
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37.2
37.2
0
0
'Oxygen'
0.38
0
10.64
0
11.02
0
0
0
11.27
11.27
-0.25
-2.27
Sulphur
0.196
0
0
0
0.196
•
0.050
0.111
0.019
0.011
0.192
Calcium
0.042
0.784 ;
0 ;
t
0 I
i
0.826 j
jl
,
0.317 ',
0.349
0.125
0
0.791
1
0.004 ; 0.035
2.0
4.2
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
8.5%
3.73% (Unburnt)
94%
3.2
A5.33
-------
Table A.5.1.15 Mass Balance for Test No. 1.8
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.35
0
45.94
1.9
52.19
-0.11
0
0.58
51.77
52.24
-0.05
-0.09
'Ash'
0.57
0
0
0
0.57
-0.11
0
0.44
0
0.33
0.24
42.1
'Carbon'
2.95
0
0
0
2.95
0
0
0.14
3.00
3.14
-0.19
-6.44
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37.3
37.3
-0.1
-0.27
' Oxygen '
0.37
0
10.64
0
11.01
0
0
0
11.08
11.08
-0.07
-0.64
Sulphur
0.191
0
0
0
0.191
0
0
0.011
0.188
0.199
-0.008
-4.5
Calcium
0.041
0
0
0
0.041 j
-0.003
0
0.045
0
0.042
-0.001
2.4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
9.7%
4.53% (Unburnt)
1%
0
A5.34
-------
Table A.5.1.16 S09 concentrations and % reductions
Test No.
Limestone Type
Fluidising Velocity, ft/s
Bed Temperature, F
Ca/S mol ratio
1.1
-
3
1470
0
SC>2 concentration, p. p.m. ] 4023
SOn reduction, %
0
1.2
U.S. 1359
3
1470
1.5
2118
46.5 .
1.3
U.S. 1359
3
1470
2,2
1450
63.4
1.4
1
U.S. 1359
3
1470
3.3
(680)
'
-
83
i
Test No. . 1 1.5 1 1,6
t
Limestone Type j U.K. ' U.K,
i
Fluidising Velocity, ft/s | 3 3
Bed Temperature, °F 1470 j 1470
Ca/S mol ratio 1.1 i 2.2
1
S07 concentration, p. p.m. 1785 , (1000)
1 i
1 !
S00 reduction, % j 55 i 75
^ ! '
1.7
U.K.
3
1470
3.2
229
94
1.8
-
3
1470
0
3896
0
( ) Mean of iodine and hydrogen peroxide methods,
S02 reductions are based on a datum level of 3960 p.p.m.
A5.35
-------
Table A.5.2.1 Operating Conditions During Test Series 2
en
CO
O3
Constant Parameters:
Co.al size : - 1680 micron
Acceptor : U.K. Limestone
Acceptor size : - 1680 micron
Bed Temperature : 1470°F
Bed Height : 2 ft
Test No.
Date
Coal
Ca/S mole ratio
PI. Vel. ft/s
Ash Bed
Excess Air %
Recycle
2.1
8.6.70
Uelbeck
(W)
0
2
Fresh
+10
Yes
2.2
9.6.70
W
0.8
2
ex 2.1
+10
Yes
2.3
10.6.70
W
0.8
2
ex 2.2
+10
No
2.4
15.6.70
W
0.8
3
ex 2.3
+10
No
Test Mo.
Date
Coal
Ca/s mole ratio
PI. Vel. ft/s
Ash Bed
Excess Air %
Recycle
2.9
23.6.70
Park Hill
(P.H.)
0.5
3
Fresh
-HO
No
2.10
24.6.70
P.H.
1.3
3
ex 2.9
+ 10
No
2.11
25.6.70
P.H.
2.7
3
ex 2.10
+10
No
2.12
3.8.70
P.H.
0
3
Fresh
+ 10
No
2.5
16.6.70
W
1.8
3
ex 2.4
+ 10
No
2.6
17.6.70
W
2.9
3
ex 2.5
+ 10
No
2.7
18.6.70
W
0.8
3
ex 2.6
-10
No
2.13
4.8.70
P.H.
1.1
3
ex 2.12
+ 10
No
2.14
5.8.70
P.H.
2.6
3
ex 2.13
+ 10
No
2.15
22.10.70
V
0.8
3
Fresh
+10
Yes*
2.8
19.6.70
W
1.8
2
Fresh
+10
No
* 2.15. Despite repeated attempts it was not possible to sustain recycle in this test.
-------
Table A.5.2.2 Chemical analyses of coal
Test Series 2
Test Number
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen + errors
Chlorine
Carbon Dioxide
Ash analysis
CaO
MgO
Na20
K20
A12°3
Fe2°3
Si°2
Calorific value (gross)
Swelling No.
Gray King coke type
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b.
% dob.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
Btu/lb
2.1 - 2.8
& 2.15
4.2
18.2
38.3
67.5
4.26
1.47
1.3
5.08
0.55
0.41
1.77
1.39
1.81
3.21
17.8
7.28
57.5
14600
•
2.9 - 2.14
2.1
16.5
39.2
68.2
4.43
1.33
2.45
5.3
0.14
0.6
2.25
1.66
0.75
3.62
21.1
15.0
46.0
14750
1
D
A5.37
-------
Table A,5.2.3 Chemical and Size Analyses of Acceptor
Test Series 2
Test No,
Chemical Analysis
CaO a.r.
MgO a.r.
CO a.r.
S.02a.r.
Size Analysis
Particle size (ym)
' + 1680
2,1 - 2,15
1
54,9
0.2
42,0
1.6
% in grade by weight
0.5
+ 500 - 1680
t
I + 250 - 500
i+125 - 250
{ + 63 - 125
!- 63
52.1
19.1
10.1
7,2
11.0
I Median diam. (ym)
537
A5.38
-------
Table A.5.2.4 (a) Chemical and Size Analyses of Feed Blends
Test Series 2
1 Test No,
i
] Moisture a,r ,
Ash a,r.
Carbon d.b.
i
CaO d,b.
Sulphur d^b.
C02 d.b.
Particle size (ym)
2,1
4,9
16 o 3
67.9
Oo38
1.26
0.37
2,2
4.4
18,9
65e6
2o06
Io31
1-73
2,3
4,7
19,0
65.5
2.2
1.26
1,88
2,4 J 2,5
. 5,0
19,5
63.9
2.07
1,26
1,82
4.7
j
19,6
63.2
3,61
1,31
2»88
2.6
3 c- 6
22.3
59.3
6.64
1.09
5.0
2-7
5,1
21 »8
61.9
2 = 14
1.27
1,79
t
2,8
4-4
21,4
61.5
3.84
1.15
2.9
% in grade by weight
+ 1680 0
+ 500 - 1680 29.4
+ 250 - 500 37,1
Ool
32,8
37.2
+ 125 - 250 17,3 i 15o4
1,
+ 63 - 125 6,4
- 63 9o8
Median dia. urn 364
5,5
9-0
376
o
30,9
37.9
16.0
5.6
9.6
380
:
0
25,0
37.7
17,8
7.5
i
0 ; 0
34,4 31,4
36,9 i 36,0
i'
15*5 |! 16,0
4.9 ! 5.8
12,0 j 8.3 ? 10.8
; j ;!
1 336
386 375
0
29,8
38,1.
0
30.3
38 . 1
15.9 16,0
6.5
9-7
374
6,1
9', 5
377
A5. 39
-------
Table A.5.2.4 (b) Chemical and Size Analyses of Feed Blends
Test Series 2
!: Test No.
2-
i
1 Moisture a.r. 2.
i !
1
i Ash a.r.
16.
i
Carbon d-b. 64.
. CaO d.b. 12.
', Sulphur d.b. 2.
• C02 d.b.
Particle size (um)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
63
Median dia. urn
2.
0
47.
22.
13.
7.
9.
9
4 i
2
8
72
35
35
3
3
2
9
3
467
2,
2
20
61
5
2
4
0
50
21
12
7
8
10
o
.8
,5
.81
.2
.48
.1
.8
.4
.2
.1
.4
512
2.1
1.
23.
56.
9.
1.
7.
% in
0.
56.
18.
10.
; 5,
8-
(cont'd)
1 !
9 1
6 |
f
I.
6 ?
59
95
75
2.12 !
2,5 i
i
15.4
69,6
0,48
2.35
0.44
grade by
1
1 |
6
7
5
9
2
598
0
63.5
16.7
8,9
4-9
6.0
716
2.
2
21
60
5
2
4
13
.4
|
.6
.1
.19
.30
.21
2-14
2.0
25.0
54,0
10,21
2,10
8.15
2.15
i
3.8
21.4
1 62.6
: 2.28 :
1.20 j
1.80
weight
0
53
21
12
6
6
.1
.7
.5
.4
,0
"4
549
0
54,7
18.2
12.1
6.6
8.4
570
: i
, o
i
33.5
35-9
15.3
6.5
; 8.8
376
A5.40
-------
Table A,5-2.5 (a) Chemical and Size Analyses of Cyclone Fines
Test Series 2
• Test No. 2.1* 2.2* i 2»3
' . :
! Chemical Analysis
Carbon % a.r.
26.9
Sulphur % a.r. 0,8
C02 % a.r.
CaO % a.r.
0,13
2,58
' 24.6
1,50
0.19
5,82
Size Analysis |
40,2
. 2,4. | 2,5
42.6
41.9
1.1 0.95 j 1.15
0,18
3.33
0,18 : 0,62
2.41 l 5,79
2.6
33»8
1,41
2»38
'2,7
54,2
0.9
2,8 f
i
33.8 ;
1,3
0.23 : 0.43 i
10.6 i 2.49 5,82 i
I ;
% in grade by weight
Particle
-t-
+
+
+
500
250 -
125 -
63 -
size (urn)
500
250
125
- 63
0.3
1.4
1.7
3.1
93.5
I
i °
i 0
i
1 0
1
| 2
1 97
.2
-2
,4
,1
,1
! o
0
1
14
83
,3
,2
« 1
.7
.7
i,
I
; 0.2
0,2
1.4
13,5
84,7
|
0.
0
1.
14 ,
83 c
2
3
9
i |
0 j 0 1 0 ,
0 [ 0 ! 0 j
Oo5 [ 1.7 j 1.2 i
11,6 19.4 , 12.5 .
6 87.9 ! 78.9 ' 86,3 ';
* Note: Tests 2-1 & 2,2 used recycle- Fines collected in secondary cyclone
only-
A5.41
-------
Table A.5.2.5.(b) Chemical and Size Analyses of Cylone Fines
Test Series 2 (cont'd).
Test No.
Chemical Analysis
Carbon % a.r.
Sulphur % a.r.
.C02 Z a.r.
CaO % a.r.
Size Analysis
Particle size (ym)
+ 500
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
2.9
37.9
0,95
0.43
2.5
; 2.10
34.8
1.0
1.31
4.3
2.11
37.0
1.4
4.0
6.94
2.12
42.0
0,82
0.11
13.1
2.13
39.7
1.04
1.07
5.84
2.14
2.15*
:
.i
33.6
1.38 -
2.96
9,32 I -
i 1
1
% in grade by weight
0
0
2.0
22.5
75.5
0.2
0.2
1.6
19,0
0.1
0.4
1.1
15.2
79.0 | 83.2
0
0.2
2.0
24.6
73.2
0
0.1
0.9
17.9
81.1
:
i
o 1 -
1.1
1.4
17.3
80.2
-
-
-
* Test 2.15 was unsatisfactory - attempted recycle .'.no representative
fines.samples.
A5.42
-------
Table.A.5.2.6 (a) Chemical and Size Analyses of Bed Material
Test Series 2
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
CO- % a.r.
CaO % a.r.
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median diam. (ym)
2.1
Initial
0.55
0.08
1.99
Final
0.55
0.31
1.99
Offtake
0.5
0.31
1.99
2.2
Initial
0.55
0.12
2.21
Final
0.95
0.18
3.54
Offtake
0.6
0.11
2.52
2.3
Initial
0.8
0.13
3.32
Final
1.2
0.23
4.45
Offtake
0.85
0.24
3.28
2.4
Initial
1.0
0.27
4.03
Final
1.65
0.17
5.48
Offtake
1.45
0.33
5.46
% in grade by weight
0
53.2
35.8
9.0
1.4
0.6
526
0
44.3
36.8
11.3
3.5
4.1
457
0
47.8
37.9
10.1
2.3
1.9
484
-*
-
-
-
-
-
-
0
40.4
36.8
13.8
5.6
3.4
428
0
45.7
36.1
12.2
3.7
2.3
467
0
39.0
39.4
13.4
5.1
3.1
423
0
44.1
33.7
15.1
6.0
1.1
451
0
40.1
39.9
13.6
4.6
1.8
431
0
45.2
35.2
13.8
4.9
0.9
462
0
33.9
39.4
20.8
5.6
0.4
389
0
34.9
33.0
15.5
13.4
3.2
377
Ol
^
CO
* Sample lost; Test 2.1 'Final Bed* is similar
-------
Table A.5.2.6 (b) Chemical and Size Analyses of Bed Material
Test Series 2 (cont'd)
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
CO 2 % a.r.
CaO % a.r.
Size Analysis
Particle size (pm)
+ 1680
+ 500 - 1680
+ 250 - 500
+125 - 250
+ 63 - 125
- 63
Median diam. (pm)
2.5
Initial
1.65
0.24
5.42
Final
2.65
0.30
9.4
Offtake
1.85
0.42
6.95
2.6
Initial
2.8
0.75
13.6
Final
3.06
0.36
15.9
Offtake
2.65
0.80
11.3
2.7
Initial
2.96
0.46
14.7
Final
2.97
0.29
11.6
Offtake
3.10
0.80
13.8
% in grade by weight
0
43.7
37.1
13.7
4.9
0.6
452
0
38.9
36.7
17.8
6.4
0.2
417
0
35.1
33.2
17.4
13.0
1.3
379
0.1
38.9
37.5
16.9
6.4
0.2
419
0
37.3
37.0
18.8
6.7
0.2
406
0
29.9
32.5
20.5
16.0
1.1
336
0
37.1
36.3
18.6
7.8
0.2
403
0
31.0
37.4
21.8
9.4
0.4
366
0
33.8
31.3
19.3
14.2
1.4
361
2.8
Initial
0.45
0.21
2.56
Final
1.45
0.39
6.38
Offtake
0.55
0.22
2.68
0
69.4
38.6
10.1
1.3
0.6
652
0
45.3
38.9
12.4
3.1
0.3
466
0
52.6
34.8
8.4
3.3
0.9
521
CJ1
-------
Table A.5.2.6 (c) Chemical and Size Analyses of Bed Material
Test Series 2 (cont'd).
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
C02 % a.r,
CaO % a.r.
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median diam. (ym)
2.9
Initial
0.7
0.16
3.26
Final
1.55
0.27
5.92
Offtake
0.65
0.19
2.8
2.10
Initial
1.25
0.48
5.04
Final
2.6
0.85
11.8
Offtake
1.7
1.32
6.74
2.11
Initial
2.15
0.6
9.5
Final
4.05
0.9
21.6
Offtake
3;4
2.05
14.4
2.12
Initial
1.55
0.52
5.31
Final
1.95
0.02
5.73
Offtake
1.35
0.53
4.9
% in grade by weight
*
-
-
-
"-
-
0
47.1
37.8
11.7 .
3.1
0.3
478
0
49.0
39.2
10.5
1.2
0.1
493
0.1
48.0
38.0
11.4
2.2
0.3
486
0.1
45.6
37.1
13.1
3.8
0.3
467
0
42.5
37.0
13.1
6.3
1.1
444
0
47.1
37.0
12.1
3.4
0.4
478
0
46.4
34.8
13.4
5.0
0.4
471
0.1
40.4
33.4
15.5
9.3
1.3
422
0.1
54.5
38.3
4.7
1.9
0.5
535
0
50.3
39.6
6.8
3.0
0.3
502
0
55.9
37.8
4.4
1.4
0.5
545
01
Sample lost : Test 2.1 Initial bed is similar
-------
CJl
^
Oi
Table A.5.2.6 (d) Chemical and Size Analyses of Bed Material
Test Series 2 (cont'd)
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
C02 % a.r.
CaO Z a.r.
Size Analysis
Particle size (vim)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
* 63
Median diam. (ym)
2.13
Initial
1.45
0.39
2.03
Final
3.0
0.71
4.2
Offtake
2.0
0.55
2.8
2.14
Initial
3.2
1.89
15.7
Final
4.45
1.61
23.4
Offtake
4.95
2.7
20.4
2.15
Initial
2.85
1.33
9.9
Final
2.70
0.44
9.2
^Offtake
-
% in grade by weight
0
49.3
41.1
6.5
2.7
. 0.4
495
0
46.5
39.4
9.0
4.5
0.6
475
0
52.0
37.2
6.1
3.9
0.8
515
0
45.3
39.8
9.6
4.6
0.7
467
0
50.1
32.6
12.4
4.4
0.5
501
0
37.4
31.6
15.3
13.6
2.1
392
0
62.6
27.3
6.9
2.2
1.0
634
0.1
75-7
22.1
1.8
0.3
0
828
—
—
_
_
—
-
Test 2.15. Unsatisfactory recycle test - no representative offtake ash sample obtained.
-------
Table A.5.2.7 (a) Flue Gas Analyses
• Test No.
Operating Conditions
Ca/s Mol ratio
Fluidising velocity ft/s
Bed temperature F
Bed height ft
Chromatograph
Mean CO Vol % dry
] Mean 02 Vol % dry
' Mean CO Vol % dry
Mean CH^ Vol % dry
S00 By Iodine
Sample 1 p. p.m., dry
Sample 2 p.p.m, dry
Sample 3 p-p.m, dry
Sample 4 p.p.m, dry
Sample 5 p. p.m. dry
Sample 6 p.p.m. dry
Mean S00
By Iodine p.p»m0 dry
By HO p-p.m, dry
Cl p.p,m. dry
NH- p.p.m, dry
'2.1
0
2
1470
2
14.6
3.1
0,2 j
0
1054
1088
1118
1087
1088
438
11
2,2
0,8
. 2
1470
2
14,6
3,1
0.2
0
422
502
540
488
564
408
10
2,3
0.8
2
1470
2
14.2
3.1
0.1
0
560
528
472
492
513
493
456
6
2.4
0.8
o
1470
2
14,4
3.1
0.2
0
585
591
621
599
604
267
ND
2o5
1.8
3
1470
2
15.2
2.3
0,12
0
219
202
: 199
207
223
:' 411
51
2,6 ; 2,7
2.9 0.8
3 3
1470 1470
2 2
15,7 16.7
2.2 0.3
0,1 0.4
0 0
27 589
38 ; 623
34 623
i
,
33 612
30 875
289 ! 325
ND ND
2.8 j
1.8 ;
2
1470
2 ;
I
15.0
2.6 !
0.1
0
160
144
158
177
161
149
158
146 •
1 410
16
ND - Not determined
A5.47
-------
Table A.,5.,2,7 (b) Flue Gas Analyses
Test No, 2,9
Operating Conditions.
-
Ca/s Mol ratio 0«,5
Fluidising Velocity ft/s 3
Bed temperature F 1470
Bed height ft 2
Chromatograph
Mean C0_ Vol % dry 15 .5
Mean 02 Vol % dry 2.0
Mean CO Vol % dry 0,12
Mean CH^ Vol % dry 0
S00 By Iodine
Sample 1 p,p,m, dry 2034
Sample 2 p,p,m, dry 2275
Sample 3 p,p.m. dry 2063
'
Sample 4 p.p,m, dry 2180
Sample 5 p,p,m, dry
Sample 6 p,p,m, dry
Mean S00
By Iodine p»p,m, dry 2138
By HJ39 p,p-m, dry 1690
Cl p.p.m, dry 136
NHL p.p.m- dry , 15
2,10
1,3
3
1470
2
15,5
2,5
0,11
0
1793
1753
1322
1514
1483
1596
1576
1045
89
25
2.11
2,7
3
1470
2
15,6
2.0
0,06
0
452
554
422
443
.
:
468
237
'
68
60
2,12
0
3
1470
2
15,4
2,3
0
0
2163
2145
2055
2002
2094
2091
2045
175
31
2.13 | 2,14
! t
\
1.1 | 2,6
3 ! .3
1470 i 1470
1
2 i 2
1
i
15.7 15,6
2.1 ; 2,5
0,1 \ 0.09
0 ! 0
:
1187 ' 340
1200 : 298
1230 ' 340
1220 311
1210 320
1210 322
1024 354
149 132
36 30
2.15 ;
Oo8 |
3 :
1470 |
2
15.4 '.
2.0 :
!
0.16 !
i
0
I
i
563 .
511
519
597 .
547
544
337
7
A5.48
-------
Table A05o2080 Mass Balance for Test No. 2,1
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
2089
0
30.59
1.9
35,38
0.15
1,65
0,19
34,81
36n79
-1.41
-4.0 -
'Ash'
0,55
0
0
0
0,55
0.15
1,65
0,14
0
1,94
-1 „ 39
52o7
'Carbon'
1,95
0
0
0
1.95
0
0
On05
1.95
2,00
-0_05
-2.56
Nitrogen
0
0
23.5
1 = 9
25,4
0
0
0
25,4
25.4
0
0
'Oxygen'
0.15
0
7.09
0
7.24
0
0
0
7o29
7n29
-Oo05
-0,69
Sulphur
0*038
0
0
0
0.038
0
0.008
0,002
0C035
Oo045
-0.007
-19.6
Calcium
0,007
0
0
0
0,007
0
0,023
0.004
0
0.027
-0,020
-290.5
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
14.7%
2.62% (Unburnt)
7%
0
A5.49
-------
Table A.5.2.9. Mass Balance for Test No, 2.,2
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
2 ,,88
0,09
30.59
1.9
35,46
-0,27
1.46
0.21
34^82
(36,22
-0.76
-2,14
'Ash'
. 0,55
0,09
0
0
0,,64
-0,27'
1.46
0,16
0
1.35
-0.71
-110.9
'Carbon'
1,94
0
0
0
1,,94
0
. 0
0.05
1.95
2.00
-0U06
-3.09
Nitrogen
0
0
23,5
1,9
25,4
0
0
0
25 „ 4
25 .,4
0
0
"Oxygen1
0015
0
7.09
0
7,24
0
0
0
7.29
7.29
-Or,05
-0069
Sulphur
0,037
0
0
0
0,,037
0,012
0,009
0.003
0.016
0.040
-0.003
-8.11
Calcium
0,,007
0.035
0
0
0.042
0,028
0,026
0,009
0
0,063
-0,021
-50.0
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
14 .,7%
2o61% (Unburnt)
58%
A5.50
-------
Table A.5.2.10„ Mass Balance for Test No. 2,3
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted ,
input-output
Unaccounted,
% of input
Total
3^01
0.09
30.59
Io9
35,59
-0.02
0,34
0.34
34,82
;35o48
0.11
0.31
'Ash;'
0.57
0.09
0
0
0.66
-0.02
0,34
O.,21
0
0,53
. 0.13
19.70
"Carbon1
2.03
0
0
0
2o03
0
0
0.14
1.88
2002
0.01
0«49
Nitrogen
0
0
23.5
1.9
25.4
0
0
0
25*6
25*6
-Oo2
-0.79
X| Oxygen'
0.15
0
7.09
0
7,24
0
0
0
7.16
7,16
0.08
1.1
Sulphur
0.038
0
0
0
Oo038
0U012
0.003
0,004
0,016
0.035
0,003
7.5
Calcium
0..007
0.037
0
0
0,044
0.022
0,,008
0.008
0
0.038
0,006
13.4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
11,1%
6., 85% (Unburnt)
56%
0.8
A5.51
-------
Table A.5.2.11 Mass Balance for Test No. 2A
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input- output
Unaccounted ,
% of. input
Total
4.99
On 16
45.94
1.9
52-99
-0,16
0.59
0.57
51,22
52.22
Oo77
Io45
'Ash'
0.95
0016
0
0
1.11
-0.16
0.59
0.32
0
0,75
0036
32.4
'Carbon'
3.37
0
0
0
3.37
0
0
0.24
2o82
3.06
0031
9o20
Nitrogen
0
0
35.3
1.9
37»2
0
0
0
37.3
37,3
-0.1
-0.27
"Oxygen'
0,25
0
10.64
0
10,89
0
0
0
10.84
10 ,,84
0^05
4.59
Sulphur
0,062
0
0
0
0,062
0.018
0,,009
0.005
0.029
0..060
0,002
3.4
Calcium
0.012
0,061
0
0
0.073
0,028
0.023
OoOlO
0
0.061
0,012
16.6
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9.3%
7.9% (Unburnt)
54%
0.8
A5. 52
-------
Table A,5 2 JL2 Mass Balance for Test No. 2.5
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4,32
0,31
45.94
1,9
52,47
Ooll
0.79
0,54
51.34
52 ,78
-0.31
-1.22
"Ash*
0,82
0.31
0
0
l.,13
0..11
0,79
0.31
0
1.21
-0,,08
-7o08
'Carbon*
2,92
0
0
0
2 ,,92
0
0
Oo22
2U97
3.19
-0U27
-9.25
Nitrogen
0
0
35.3
1,9
37.2
0
0
0
37,5
37 .,5
-0.3
-0,81
"Oxygen"
0,22
0
10 ,,64
0
10 = 86
0
0
0
10.61
10,61
0,25
2,30
Sulphur
0,054
0
0
0
0.054
0.027
0..015
0,006 .
0.010
0.058
-0.004
-7, .41
Calcium
0,010
0.123
0
0
0.133
O.Q76
0-039
0,022
0
0.137
-0.004
-3.01
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
7 07% (Unburnt)
82%
1.8
A5.53
-------
Table A.,5,, 2^,13, Mass Balance for Test No .2^6
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4,81
0.55
45,94
1,9
53.20
-0-11
0,87
0,50
51^48
52.74
0.46
0,86
'Ash'
0091
Oo55
0
0
1«46
-0,11
0 87
0,33
0
1<,09
0,37
25.34
"Carbon1
3,25
0
0
0
3,25
0
0
Oo'l7
3,05
3.22
0..03
0.92
Nitrogen
0
0
35*3
1,9
37 ,,2
0
0
0
3702
37,2
0
0
u Oxygen '
0,25
0
10,64
0
10,,89
0
0
0
10,96
10,96
-Oo07
-0.64
Sulphur
0,060
0
0
0
0,060
0..006
0.023
0..007
0,001
0..037
0,023
38U33
Calcium
0.012
0,215
0
0
0-227
0,040
0..071
0,038
0
0.149
0,078
34.36
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
6,5%
5n28% (Unburnt)
98%
2,,9
A5.54
-------
Table A,.5.2 140 Mass Balance for Test No. 2.7
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
. % of input
Total
5.92
0.19
45094
Io9
53.95
0
1,10
0.94
51.85
53,89
0,06
0.11
'Ash'
1.12
Ool9
0
0
1.31
0
1.10
0,43
0
Io53
-0..22
-16.79
'Carbon'
4.00
0
0
0
4,00
0
0
0.51
3028
3.79
Oo21
5,25
Nitrogen
0
0
35.3
1,9
37, ,2
0
0
0
37.3
37.3
-0,1
-0,27
'Oxygen*
0»30
0
10.64
0
10.94
0
0
0
10.92
10.92
0,02
0018
Sulphur
0..074
. 0
0
0
0..074
0
0,034
0.008
0.029
0,071
0,003
4«0
Calcium
0.014
0.072
0
0
0,086
-0.058
0-108
0,017
0
0.067
0,019
22 ,,4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
-10,9%
13,42% (Unburnt)
61
0,8
A5. 55
-------
Table A.5,2.15 Mass Balance for Test No. 2.8
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted ,
% of input
Total
2,78
0,20
30.59
1,9
35,47
0.13
0,50
0.31
34.85
35-79
-0,32
-0,90
'ASh«
0,53
0,20
0
0
0,73
0,13
0,,49
0,20
0
0.82
-0.09
-12,3
'Carbon9
1,88
0
0
0
1,88
0
0
0,10
1,99
2,09
-0.21
-11.17
Nitrogen
0
0
23o5
1.9
25.4
0
0
0
25,5
25 ,,5
-0.1
-0039
"Oxygen"
0,14
0
7,09
0
7,23
0
0
0
7.20
7.20
0-03
0.41
Sulphur
0,035
.0
0
0
0.035
0,029
0,003
0,004
0,005
0.041
-0.006
-17,14
Calcium
0,007
0.080
0
0
0,087
0-078
0,010
0,013
0
0,101
-0,014
-16.09
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9-5%
5.12% (Unburnt)
86%
1.8
A5.56
-------
Table A.5.2.16 Mass Balance for Test No. 2.9
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total
A. 93
0.21
45.94
1.9
!
Total Input 52.98
i
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
-0.02
0.30
0.97
51.54
52.79
0.19
0.36
'Ash'
0.83
0.21
0
0
1.04
-0.02
0.30
0.60
0
0.88
0.16
15.38
'Carbon'
3.36
o
0
0
3.36
0
0
0.37
3.01
3.38
-0.02
-0.60
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37.3
37.3
-0.1
-0.27
' Oxygen '
0.26
0
10.64
0
10.90
0
0
0
10.88
Sulphur
0.121
o
0
0
Calcium
0.013 i
0.082 I
t
o !
° 1
i
0.121 0.095
! !
.
0.022
0.050
i
0.002
0.009
0.102
10.88 0.136
0.02
0.18
-0.015
1
-12.2
0.006
0.017
0
0.073
0.022
23.2
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mol ratio
0.2%
10.87% (Unburnt)
15%
0.5
A5. 57
-------
Table A.5.2.17 Mass Balance for Test No. 2.10
Rate Ib/h
1
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.59
0.47
45.94
1.9
52.90
-0.34
0.58
0.9
51.56
52.70
0.20
0.38
'Ash'
0.77
0.47
0
0
1,24
-0.34
0.58
0.58
0
0.82
0.42
33.87
'Carbon'
3.13
0
0
0
3.13
0
0
0.31
3.. 02
3.33
-0.20
-6.39
Nitrogen
•
0
0
35.3
1.9
37.2
0
0
o
37.2
37.2
0
0
'Oxygen'
0.24
0
10.64
0
10.88
0
0
0
11.03
11.03
-0.15
-1.38
Sulphur
0.112
0
0
0
0.112
0.036
0.010
0.009
0.078
0.133
-0.021
-18.7
,
Calcium ;
i
0.012
0.184
0
'
0
.
0.197
•
0.134
0.028
0.028
0
0.189
0.008 i
4.0
Excess Air 4.1%
Carbon Loss 9.43%
Sulphur Retention 30%
Ca/S Mol ratio 1.3
(Unburnt)
A5.58
-------
c. 2,, 18 Mass Balance^ for Test No,
Rate Ib/h
. Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted 5,
% of input
Total
4,42
0,9
45-94
1,9
53.16
-0,04
0,86
0-95
51,50
53.27
-0,11
-0,21
'Ash'
0,74
0.90
0
0
1.64
-0,04
0.86
0*60
0
1,42
0.22
13.41
'Carbon'
3,02
0
0
0
3,02
0
0
0.35
3,03
3,38
-0.36
-11.92
Nitrogen
0
0
35 3
1 = 9
37,2
0
0
0
37,4
37r4
-0.2
-0,54
'Oxygen'
0,23
0
10,64
0
10,87
0
0
0
10,75
10 , 75
0.12
1.10
Sulphur
0,106
0
0
0
0.106
0-050
0,029
0.013
0,023
. 00104
0.002
1-9
Calcium
0,012
0.352
0
0
0.364
0,226
0,088
0,047
0
0.362
0,002
On7
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
0,8%
10,39% (Unburnt)
79%
2,7
A5. 59
-------
Table A.5.2.19 Mass Balance for Test No. 2,12
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4,66
0
45.94
1.9
52,51
-0,07
0,39
0,82
51..49
52U63
-0.12
-0,23
'Ash"
0 , 78
0
0
0
0.78
-Oo07
0.39
0-49
0
Oc.81
-0,,03
-3.85
'Carbon1'
3,18
0
0
0
3.18
0
0
0.34
2.99
3»33
-0.15
-4.72
Nitrogen
0
Q
35,3
1.9
37,2
0
0
0
37 3
37.3
-0,1
-0C27
'Oxygen'
0.25
0
10,64
0
10,89
0
0
0
10,89
10.89
0
0
Sulphur
0.114
0
0
0
0,114
0,010
0.005
0^007
0.101
0.123
-0.009
-7,6
Calcium
0,013
0
0
0
0.013
0.007
0.014
0.007
0
On028
-0.015
-127,5
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
2,'6%
10.10% (Unburnt)
12%
0
A5.60
-------
Table A, 502,20 Mass Balance for Test No. 2.13
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.69
0»40
45.94
Io9
52.93
0,06
0.56
0091
51.54
53.07
-0.14
-0.26
'Ash'
0.79
0«40
0
0
1.19
Q.,06
0.56
0.56
0
1.18
0.01
0.84
'Carbon'
3.20
0
0
0
3.20
0
0
0,35
3.05
3.40
-0.20
-6.25
Nitrogen
0
0
35.3
1.9
37o2
0
0
0
37.2
37o2
\
0
0
'Oxygen1
Oo25
0
10.64
0
10«89
0
0
0
10.96
10.96
-0.07
-0,64
Sulphur
On115
0
0
0
0.115
0.046
OoOll
0,009
0.058
Ool24
-0.009
-8.2
Calcium
0.013
0.158
0
0
0.170
0.134
0.026
0.037
0
0.197
-0.027
-15.4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
Io2%
10.28% (Unburnt)
49%
1.1
A5.61
-------
Table A.5,2.21 Mass Balance for Test No, 2,14
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input .
Total
4,42
0.90
45^94,
1,9
53ol6
-0.27
0.96
0.94
51.56
53,19
-0..03
-0,06
'Ash'
0074
0.90
0
0
1.64'
-0.27
0.96
0.63
0
1,32
0,32
19.5
'Carbon1
3U01
0
0
0
3,01
0
0
0.31
3,03
3o34
-0,,33
-10«96
Nitrogen
0
0
35o3
1,9
37.2
0
0
0
37.2
37.2
0
0
'Oxygen'
0.23
0
10 .,64
0
10.87
0
0
0
11.02
11.02
-0.15
-Io38
Sulphur
0.108
0
0
0
0.108
0.037
Oo048
0.013
0,015
0.113
— OoOOS
-4.4
Calcium
0*012
0.353
0
0
0*365
0,164
0.140
0,061
0
0,366
r-0.001
-0.2 .
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
4.3%
9o23% (Unburnt)
86%
2,6
A5.62
-------
Table A05°2o22 Mass Balance for Test No0 2,15
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen.
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input- output
Unaccounted,
% of input
Total
4,96
0,16
45,94
1,9
52o96
Oo26
0
1.71
51,43
53c40
-Oo44
-0,83
'Ash1
0,94
0016
0
0
lolO
6o26
0
Ic43
0 .
1,69
-0,59
-53,64
'Carbon'
3 = 35
0
0
0
3.35
0
0
0,28
3oOO
3.28
0007
2,09
Nitrogen
0
0
.35.3
Io9
3702
0
0
0
37o4
. 37n4
-0,2
-Oo54
'Oxygen *
Oo25
0
10o64
0
10089
0
0
0
10,76
10,76
0,13
1.19
Sulphur
Oo062
0
0
0
0,062
-0 ,004
0
0,033
0,029
0,058
0,004
6.9
Calcium
0,011
0.061
0
0
0,073
j
-0.015
0
0.075
•
0
0,061
;
0,012
16.5
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
8,65% (Unburnt)
54%
0,8
A5.63
-------
Table A.5.2.23 SO^ concentrations and I reductions
Test No.
Coal Type
Fluidising Velocity, ft/s
Bed Temperature, °F
Ca/S mol ratio
S02 concentration, p. p.m.
S02 reduction, %
2.1
Welbeck
2
1470
0
1087
0
.2.2
Welbeck
2
1470
0.8
488
55
2.3
Welbeck
2
1470
0.8
513
52
2.4
Welbeck
3
1470
0.8
599
45
2.5
Welbeck
3
1470
1.8
207
81
2.6
Welbeck
3
1470
2.9
33
97
2.7
Welbeck
3
1470
0.8
612
48
2.8
Welbeck
2
1470
1.8
158
85
Test No.
Coal Type
Fluidising Velocity, ft/s
Bed Temperature, F
Ca/S mol ratio
SO. concentration, p. p.m.
SO- reduction, %
2.9
Park Hill
3
1470
0.5
(1690)
19
2.10
Park Hill
3
1470
1.3
(1045)
50
2.11
Park Hill
3
1470
2.7
(237)
89
2.12
Park Hill
3
1470
0
2091
0
2.13
Park Hill
3
1470
1.1
1210
42
2.14
Park Hill
3
1470
2.6
322
84
2.15
Welbeck
3
1470
0.8
547
50
OJ
( ) Hydrogen peroxide results.
S02 reductions for Welbeck runs (except 2.7) are based on a datum level of 1087 p.p.m.
S02 reduction for Park Hill runs are based on a datum level of 2090 p.p.m.
S02 reduction for Test 2.7 based on calculated datum level of 1190 p.p.m.
-------
Table A,5.-.3»1 Operating Conditions During Test Series 3
Constant Parameters:
Coal :
Coal Size :
Acceptor :
Fluidising Velocity :
Recycle :
Illinois (ex A,NoL,)
- 1680 micron
U.S. Limestone 1359
3 ft/s
None
Test No,,
Date
Acceptor Size ym
Ca/S mole ratio
Bed temp, F
Bed height ft
Ash bed
3,1
6,8,70
-1680
1.1
1290
2
Fresh
3,2
7o8.70
-1680
2.2
1290
2
ex 3,1'
3,3
25=8.70
-1680
1.1
1470
3
Fresh
3.4
2608.70
-1680
2.1
1470
3
ex 3.3
3.5 3-6
27,8,70 28,8,70 •
-125 -1.25
1,1 3-6
1470 1470 |
2 2
Fresh ' ex 3-5
A5.65
-------
Table A.5.3.2 Chemical analyses of coal
Test Series 3
Test Number
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen + errors
Chlorine
Carbon Dioxide
Ash analysis
CaO
MgO
Na20
K20
A1203
Fe203
Si02
Calorific value (gross)
Swelling No,
Gray King coke type
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b .
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
Btu/lb
3.1-3.6
9.8
11.8
46.6
67.8
4.45
1.29
4.38
8.5
0.22
1.05
10.1
1.0
1.7
1.8
12,2
20.6
40.8
14,290
4J
D
A5.66
-------
Table An5..3o3 Chemical and Size Analyses of Acceptor
Test Series 3
Test No- .
Chemical Analysis
CaO a-r.
MgO a . r -
C02 a,r-
S.00
i 2 a.r.
3,1 - 3,4
55.5
0,3
43,3
0,8
;
3-5 & 3.6
55.5'
0,3
43-3
0,8
Size Analysis % in grade by weight
Particle size (ym)
1
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
63
0,1
36.7
24.8 .
16.6
8,7
13.1
E
Median diam,- (ym) | 353
Particle
Size(ym)
+ 125
+ 90 - 125
+ 75 - 90
+ 63 - 75
+ 45 - 63
- 45
8.8
9,3
19,8
11.8
30,3
20.0
62
A5.67
-------
Table A.5.3.4 Chemical and Size Analyses of Feed Blends
Test Series 3
Test No.
Moisture a.r.
Ash a.r.
Carbon d.b.
CaO d.b.
Sulphur d.b.
C02 d.b.
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
3.1
5.8
19.0
56.4
9. '09
3.85
7.01
3.2
7.1
22.7
49.8
13.86
3.30
11.42
3.3
-
-
-
-
-
-
3.4
8.1
22.3
49.7
14.85
3.40
12.05
3.5
7.5
17.4
58.6
7.71
3.80
5.96
3.6
5.6
27.3
43.9
18.25
2.90
14.15
% in grade by weight
1.0
50.5
22.3
13.6
6.0
6.6
519
0.5
50.0
21.4
12.6
7.0
8.5
506
-
-
-
-
-
-
0.8
54.9
19.1
12.9
5.7
6.6
582
0.8
49.7
17.6
9.1
8.4
14.4
508
0.9
48.2
18.9
14.7
7.3
10.0
487
NOTE Test 3.3 Feed Blend sample not taken - operator error.
A5. 68
-------
A,oo,3 Uhemicai ai:d Size Analyses of Cyclone Fines
Test Series 3
ji Test No, .
I Chemical Analysis
] Carbon % a,r.
!
1 Sulphur % a.r,
j
| CO % a.r.
i ^
] CaO % a.r,
i
J Size Analysis
i
1 Particle size (utn)
1 + 500
3.1
28,8
2,05
5,05
10,20
0,1
.!
5+250-500 0,3
1 + 125 - 250 1.0
| + 63 - 125 10.7
j - 63 87,9
3.2
23,6
2.58
8-21
15,6
3,3
29,0
2,82
1,99
9,06
3,4 3,5 j 3-6
i
24,1 16.8 ! 13.3
2o84 4.15? 3.67
4.70 9,41 | 13-0
13.62 22,38 j 26,9
[
% in grade by weight
0
0»2
0,4
0.2
|
0 00
0,2 JO 0 | 0,2
2,0 | 0,4 0.9 j 0,5
! i
8,4 16-0 ! 8.4 7.2 i 5,3
it !?
91.0
81o6
91,2 ! 91.9 \ 94,0
I
A5.69
-------
Table A.5.3,6 (a) Chemical and Size Analyses of Bed Material
1
Test No. !
|
Sample j Initial
j
!
Chemical Analysis
Sulphur % a, re : 1.6
CO % a.r. 0,33
1
CaO % a.r. • 6.15
•
t
'
Size Analysis
Particle size (urn) 1
i + 1680 0
" i
+ 500 - 1680 \ 41.6
+ 250 - 500 j 41.1
+ 125 - 250 14.1
+63-125 2.1
f
- 63 I 0.1
Median diam» (ym) j 443
3,1
Final
2,05
9,31
18.2
0.1
43.5
39.0
14.4
2o8
0,2
454
Test
Offtake
2,05
2.22
9.65
0.1
34.1
37o9
18.5
7.7
1.7
387
Series 3
Initial
1.9
6.95
14,41
% in gr
0.1
41e2
40.3
. 15.3
2.7
0,4
440
3.2
Final
1.9
20.23
29.6
ade by
0
44.5
37.6
15.0
2,8
0,1
459
Offtake
2.5
13.59
23.39
weight
0.1
34.3
31.0
22o3
11.3
1.0
j 356
Initial
1.6
0.35
6.1 i
0
50.6
37.0
10.2
1.3
0.9
505
3,3
Final
3.1
2.74
13,43
0
47- .0
38,1
11.9
2,7
0.3
478
Offtake !
1.75 i'
0.9
7,12 1
1
0 j
46.4
40.0
11.5
1.6 :
0.5 ,
474
A5.70
-------
Table A.5.3,6 (b) Chemical and Size Analyses of Bed Material
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
CO % a.r.
CaO % a.r.
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
, + 250 - 500
! + 125 - 250
+ 63 - 125
i
Initial j
i
2,15 !
1,46 1
8.67 I
Test Series 3 (cont'd)
3.4
Final
4.45
5.15
23.5
Offtake
•
1.85
1.0
7.26
3.5^*'
Initial
1.55
0.17
5.46
Final
3»5
0.89
10,35
Offtake
1.55
0.36
5.46
3,6
Initial Final
3.25 5,0
0.83 2.83
10.09 29-0
•
i
Offtake
5.7
3.02
22.82
% in grade by weight
0
45.0
37.8
12.1
4.0
- 63 Id
; Median diam. (um) i 463
0
46.9
36.9
12.7
0
54.0
34.1
9.6
3.2 1,8
Oo3 0.5
476 534
0
54,8
33,6
7.3
2,1
0
51,0
32.2
9.6
6,7
2.2 | 0.5
0
59,2
32.3
6.7
1.2
0.6
541 j 509 j 583
;
0 [ 0
54.5 ' 48.8
31.5 | 34.2
8.4 ' 10.5
5.0 :• 6,0
0.6 i 0.5
541 i 490
f
0
34.4
26.8
12.9
! 22.3
' 3.6
.
356
A5.71
-------
Table A.5.3.7 Flue Gas Analyses
Test No.
Operating Conditions
Ca/S mol ratio
Fluidising Velocity, ft/s
Bed Temperature, F
Bed Height, ft
Chromatograph
Mean C02 Vol % Dry
Mean 02 Vol % Dry
Mean CO Vol % Dry
Mean CH4 Vol % Dry
S02 by Iodine
Sample 1. p. p.m. Dry
Sample 2. p. p.m. Dry
Sample 3. p. p.m. Dry
Sample 4. p. p.m. Dry
Sample 5. p. p.m. Dry
Sample 6. p. p.m. Dry
Sample 7. p. p.m. Dry
Mean S02
By Iodine p.. p.m. Dry
By H202 p. p.m. Dry
Cl p. p.m. Dry
NH-j p. p.m. Dry
3.1
1.1
3
1290
2
15.3
2.7
0.11
0
3438
3409
3326
3375
3335
3376
3587
141
34
3.2
2.2
3
1290
2
15.2
2.4
0.12
0
3126
3121
3379
3347
3337
3162
3245
3130
161
23
3.3
1.1
3
1470
3
15.4
2.7
0.03
0
1693
1853
2041
1984
2004
2007
1930
1980
126
12
3.4
2.1
3
1470
3
15.6
2.6
0.05
0
1082
1117
1120
1160
1190
1146
1136-
1228
125
11
3.5
1.1 .
3 .
1470
2
15.5
2n4
0.07
0
1418
1328
1362
1527
1708
1689
1630
1523
1502
139
21
3.6
3.6
3
1470
2
t
16.0
2.5 ;
0.05 i
0
236
258
296
321
281
278
298
97
9
A5. 72
-------
Table A.5,.3.,8 . __M;ass Balance for Test No., 3d
Bate JLb/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
5.11
0,71
45o94
1,9
53.72
-0.23.
0.77
0.83
51.87
53.24
0,48
0,89
'Ashv
0,,67
0,,77
0
0
1.44
-0U23
0^77
0,60
0
1.14
0»30
20U83
'Carbon1
3.46
0
0
0
3.46
0
0
0023
2,97
3..20
0,26
. 7,51
Nitrogen
0
0
35.3
1.9
37 „ 2
0
0
0
37.1
37 ol
0.1
0.27
' Oxygen "
0043
0
10.64
0
11.07
0
0
0
11,36
11U36
-0.29
-2n62
Sulphur
0.224
0
0
0
0..224
0.-013
0.016
0.017
0,170
0,216
0,008
3.7
1
Calcuim
0-048
0 , 304
0
0
0.352
0.252
0.053
0.059
0
0.364
-0.012
-3,5
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
7,2%
7o29% (Unburnt)
24%
1,1
-------
Mass Balance tor Test No. 3.2
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
5.05
1.52
45.94
1.9
54.41
-0.13
1.39
0,90
51.85 '
54.01
0.40
0,74
'Ash'
0.66
1.52
0
0
2.18
-0,13 '
1.39
0.69 .
0
1.95
0.23
10.55
'Carbon'
3.42
0
0
0
3.42
0
0
0.21 '
,2.96
3.17
0.25
7.31
Nitrogen
0
0
35,3
1.9
37.2
0
0
; o
37.3
37.3
-0.1
-0.27
'Oxygen'
0.43
0
10.64
0
11.07
0
0
0 '
11.13
11.13
-0.06
-0.54 ,
Sulphur
0*221
0
0
0_ ' '
0.221 •'
0
0.035
0.022
0.164
0,221 •
0
0
Calcium
0.047
0,602
• o""
' '0 '
0,649
0.327
0.232
0-097
0
0.656
:'-0.007
-1.1
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
6.5%
6.51% (Unburnt)
26'% '
2.2%
-------
Table A.b.3.10 Mass Balance tor Test No, 3.3
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.37
0.66
45.94
1,9
52,87
0,03
0,58
6,55
5l<79
52,95
-0,08
-o as
'Ash'
0.57
0.66
0
0
1,23
0,03
Oo58
0,40
0
loOl
0,22
17*89
"Carbon'
2.97
0
0
0
2,97
0
0
0,16
2,99
3.15
-0.18
-6 ,,06
Nitrogen
0
0
35,3
1.9
37.2
0
0
0
37,3
37.3
-0.1
-0,27
'Oxygen'
0,37
0
10.64
0
11.01
0
0
0
11,13
11.13
-0.12
-1.09
Sulphur
00192
0
0
0
0*192
00065
0.010
0,015
0..097
0.188
0:,004
2.1
Calcium
0,041
0,260
0
0
0,301
0,230
0.030
0.035
0 •
0 295
0,006
2,0
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9.9%
4.99% (Unburnt)
49%
1.1
-------
Table Ao5o30ll Mass Balance for Test No. 3,.4
Race Ib/h
Coal
Accepcor
Total Air
Bleed Nitrogen
Total input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4 ,,40
1,29
45.94
1.9
53.53
0.01
1.02
0,67
51,80
53.50
0.03
0,06
'Ash'
0.58
1..29
0
0
Io87
0,01.
1.02
0051
0
1.54
0.33
17..65
'Carbon'
2.99
0
0
0
2*99
0
0
0.16
3.03
3.19
-0,20
-6.69
Nitrogen
0
0
35,3
1 = 9
37.2
0
0
0
37,2
37.2
0
0
'Oxygen*
0,37
0
10,64
0
11.01
0
0
0
Ilol9
11.19
-0.18
-1,63
Sulphur
0.193
0
0
0
0.193
0.100
0.019
0-018
0.057
0,195
-0.002
-1.0
Calcium
0.041
0,509
0
0
0.550
0.461
0.053
0.063
0
0.577
-0.027
-4.7
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9,2%
4.9% (Unburnt)
70%
2.1
-------
Table A.5-3.,12. Mass Balance for Test No . 3 5
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input -output
Unaccounted,
% of input
Total
4.42
0;66
45.94
1,9
52o92
-0.36
0,55
0/76
51.75
52-70
0.22
0.42
'Ash'
0,58
Oo66
0
0
in24
-0»36
0,55
0,64
0
0..83
0.41
33,06
'Carbon1
3.00
0
0
0
3nOO
0
0
0,13
3,02
3,15
-0.15
5.0
Nitrogen
0
0
35.3
1,9
37.2
0
0
0
37.3
37,3
-D.I
~0;27
'Oxygen'
0,38
0
10.64
0
Ilo02
0
0
0
11..05
11.05
-0.03
-0.27
Sulphur
0 .194
0
0
0
0, 194
0.059
0.009
0,031
0..076
0.175
0.019
9.9
Calcium
0-042
0 263
0
0
0 305
0-105
0 021
0.120
0
0 247
0-058
18.8
Excess Air
Carbon Loss
Sulphur Retention
Cal/S Mole ratio
9 .,0%
4,07% (Unburnt)
61%
1,1
A5. 77
-------
Table_A.503o-13 Mass Balance J[or.Test No0. 36
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
3.98
U97
45.94
1..9
5 3., 79
0.06
1,27
0,88
51,88
54,09
-0..03
-0,,06
'Ash'
0.52
1,97
0
0
2,49
0.06 ,
1,27.
0,77
0
2. 10
0,39
15.66
' Carbon '
2.69
0
0
0
2o69
0
, 0
0,11
3.12
3,23 ,:
-0,54
-20.07
Nitrogen
0
:o '
35.3
1.9
37.2 .
0 ,
0
0
37.2
37.2. •
0
0
•'Oxygen'
. 0,34
0
10.64
0
10.98
0
. 0
• 0 ;
11.20
11.20 '
-Q.,22 .':
.-2.00 •
Sulphur
On 174
0
0
0
0.174
.0.058 ::
0.073
0,032
0..014
0.176
-0.002 .
-1.1
Calcium
0-037
0..781
0
0
0,818
0.449
0,208'
0,166
0
0*822
-0.004
-0.5
Excess Air :
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9.8%
3,59% (Unburnt)
'92% '••'•' ''
376
FS 78.
-------
Table A.5.3.14 SOo concentrations and % reductions
!
Test No.
Fluidising Velocity, ft/s
Bed Temperature, °F
Bed height, ft
Acceptor Size, ym
Ca/S mol ratio
SC>2 concentration, p. p.m.
I S02 reduction, %
i . ...
.
3.1
3
1290
.
2
-1680
1.1
•
3376
.
15
3.2
3
1290
2
.
-1680
2.2
3245
18
. .
3.3
3
1470
3
-1680
1.1
1930
51
3.4
3
1470
3
-1680
2.1
1136
72
3.5
3
1470
2
-125
1.1
1523
61
3.6
. 3
1470
2
-125
•
3.6
273
93
S02 reductions are based on a datum level of 3960 p.p.m.
A5. 79
-------
Table A.5.4.I Operating Conditions During Test Series 4
01
•
00
o
Constant Parameters:
Coal Pittsburgh
Coal Size -1680 micron
Acceptor Size -1680 micron
Fluidising Velocity 3 ft/s
Bed Temperature 1470 F
Bed Height 2 ft
Recycle None
Test No.
Date
Acceptor
Ca/S mole ratio
Ash bed
4.1
5.10.70
None
0
Fresh
4.2
6.10.70
U.K. Lst
1.0
ex 4.1
4.3
7.10.70
U.K. Lst
2.1
ex 4.2
4.4
8.10.70
U.K. Lst
3.1
ex 4.3
4 .5
13.10.70
U.S. Lst
18
0.9
Fresh
4.6
14.10.70
U.S. Lst
18
1.7
ex 4.5
4.7
15.10.70
U.S. Lst
18
2.6
ex 4.6
4.8
16.10.70
U.S. Lst
18
0.9
ex 4.7*
4.9
21.10.70
U.S. Lst
18
0.9
Newdigate
shale
Run 4.8 : Lime-rich ash bed ex- run 4.7 used to provide comparison with run 4.5.
-------
Table A.5..4.2 Chemical analyses of coal
Test Series 4
1
Test Number
Proximate analysis
Total moisture
Ash
Volatile matter
Ultimate analysis
Carbon
Hydrogen
Nitrogen
Sulphur
Oxygen •*• errors
Chlorine
Carbon Dioxide
Ash analysis
CaO
MgO
Na20
K20
A12°3
Fe203
Si02 ,
Calorific value (gross)
Swelling No.
Gray King coke type
:,
% a.r.
% a.r.
% d.a.f.
% d.b.
.% d.b.
% d.b.
% d.b.
t d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b .
% d.b.
% d.b.
% d.b.
% d.b.
Btu/lb
4.1-4.9 ;
1.4
12.7
41.8
72.9
4.55
1.43
2.75
4.3 .
0.11
0.64
7.6
1.3
0.7
1.6
18.3
17.3
45.8
15,320
8
G7
A5.81
-------
Table A.5.4.3 Che'mjcal, and Size Analyses of Acceptor
Test Series 4
Test No.
Chemical Analysis
CaO a.r.
MgO a.r.
C02 a.r.
Si02 a.r.
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- , 63
Median diam. (pm)
4.1-4.4
54.9
0.2
42.0
.1-6
4.5-4.9
45.9
;0.9 .
34.7
14'. 7
% in grade by weight
0.5
52.1
19.1
10. 1
7.2
11.0
537
0.1
21.0
22.0 ;
22.5
. 1.2,2
22.2 ; -
207
A5.82
-------
Table A.5.4.4 Chemical and Size Analyses of Feed Blends
Test Series 4
Test No.
Moisture a.r.
Ash a.r.
Carbon d.b.
CaO d.b.
i
; Sulphur d.b.
i •
1 C02 d.b.
4.1
1.3
12.4
72.9
0.90
2.75
0.6
4.2
0.9
17.3
65.4
5.45
2.45
4.28
4.3
0.9
18.3
62.3
9.25
2.40
7.08
4.4
1.0
23.5
54.7
13.44
2.20
10.41
4.5
1.2
18.0
65.2
4.61
2.60
3.7
4.6
1.1
22.5
59.3
7.96
2.35
5.80
4.7
.1.2
25.9
54.0
11.08
2.05
8.75
4.8
1.1
17.3
65.9
4.61
2.50
3.55
'•',
1.1
17.1
66.6
4.76
2.45
3.0
Particle size
(ym)
% in grade by weight
] + 1680
i
: + soo - 1680
' +• 250 - 500
, :+ 125 - 250
i
; + 63 - 125
63
i Median dia.
(pm)
0
36.6
23.5
17.0
12.8
10.1
340
0
47.3
21.9
12.8
8.5
9.5
466
0.1
43.2
22.6
14.3
8.9
10.9
420
0.2
46.6
20.0
13.0
8.5
11.7
457
0.7
45.2
•
19.7
14.2
9.5
10.7
444
0.2
45.7
21.0
14.4
8.8
9.9
447
0.1
43.2
20.3
13.2
9.8
13.4
412
0.2 i 0.1
i
65.2 I 50.3
(
16.1 ! 20.1
1
7.3 11.7
i
4.7 ; 7.8
i
6.5 10.0
•
752 505
A5.83
-------
Table Ar5,4,5 (a) Chemical and Size Analyses of Cyclone Fines
Test S.eries 4
Test NOn
Chemical Analysis
Carbon % a.r.
Sulphur % a. r^-
CO _ % a.r,
CaO % a, r0
4,1
40.95
1=45
0 . 64
3,77
4.2
40.60
1.80
2.59
7.05
4;3
47.9
2o01
4.20
8,62
4.4
36,6
1.95
6.85
14.1
4,5
40,4
1.91
3.09
7,79
4,6
.39 ,0
1,96
5.87)
f
10,25 j
Size Analysis t % in grade by weight
4 '
Particle Size (ym)
+ 500
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
.
0
Ool
0,6
16.4
82-9
0
0
1-1
12.9
86.0
0
0
0..2
10, 1
89.7
0
0
0,4
9.7
89.9
0
0
0,9
13,4
85.7
0,1
0,1 ;
1.0
11.0
87o8
A5.84
-------
Table A,5,4,5 (b) Chemical and Size Analyses of Cyclone Fines
Test Series 4 (Cont'd)
Test No,
Chemical Analysis
Carbon % a.r.
Sulphur % a,r0
CO. % a.r,
2.
CaO % a,r.
Size Analysis
Particle size (ym)
+ 500
+ 250 - 500
+ 125 - 250
-
+ 63 - 125
:
j - 63
I
' 4.7
33.3
1,88
9-68
16,2
4,8
40.5
2.11
4.67
9,78
4.9 |
1
1
43.4
2.11
2.57
.,.«
% in grade by weight
0,1
0,5
0,3
6,7
92-4
0
0
0 0.1
0.1
9*8
90.1
0,7 |
!
14o5 !
'
84,7
i
A5. 85
-------
Table A.5.4.6(a) Chemical and Size Analysis of Bed Material
Test Series 4
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
C02 % a.r.
CaO % a.r.
Size Analysis
Particle size
(jam)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
4.1
Initial
0.75
0.26
3.64
Final
1.0
0.31
3.64
Offtake
1.0
0.45
3.64
4.2
Initial
1.2
0.39
5.45
Final
2.45
2.53
10.62
Offtake
1.55
0.41
5.17
4.3
Initial
2.55
2.13
10.22
Final
3.75
6.9
20.35
Offtake
2.85
2.62
12.10
4.4
Initial
3.45
5.82
18.95
Final
4.8
8.08
29.81
Offtake
4.5
9.3
24.4
% in grade by weight
0
57.4
32.6
7.5
1.5
1.0
566
0.1
62.9
29.6
6.2
1.1
0.1
628
0.1
56.2
31.9
8.4
2.6
0.8
557
0
59.1
30.0
7.3
2.4
1.2
588
0
53.4
32.3
10.1
3.8
0.4
530
0
59.9
30.3
6.4
2.5
0.9
595
0.1
54.5
33.6
8.9
2.5
0.4
539
0.1
54.9
28.5
11.2
4.8
0.5
550
0
50.8
32.5
9.9
5.7
1.1
507
0
57.2
29.2
9.7
3.5
0.4
571
0.1
54.2
29.9
11.6
3.9
0.3
541
0.1
60.9
24.9
7.2
5.2
1.7
626
-------
Table A.5.4.6(b) Chemical and Size Analyses of Bed Material
Test Series 4 (cont'd)
Test No.
Sample
Chemical Analysis
Sulphur % a.r.
C02 % a.r.
CaO % a.r.
Size Analysis
Particle size
(ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median dia. (ym)
4.5
Initial
2.0
0.48
7.0
Final
3.5
1.23
11.51
Offtake
2.05
0.66
7.29
4.6
Initial
2.85
1.05
10.65
Final
4.25
2.61
16.12
Offtake
4.35
2.46
14.45
4.7
Initial
2.95
3.03
11.09
Final
5.10
3.96
21.75
Offtake
5.45
5.38
21.41
4.8
Initial
5.3
4.01
21.0
Final
5.4
4.92
20.7
Offtake
5.1
3.87
20.9
% in grade by weight
0.3
62.9
26.9
5.7
2.2
2.0
642
0
57.1
30.1
9.0
3.4
0.4
568
0.1
71.5
21.7
3.6
1.6
1.5
780
0
68.5
26.0
4.5
0.6
0.4
707
0
48.3
33.7
13.1
4.3
0.6
486
0.1
47.4
27.7
12.4
10.2
2.2
475
0.1
51.1
34.2
8.6
5.4
0.6
510
0
52.4
30.0
13.7
3.5
0.4
523
0
30.1
25.3
20.3
19.6
4.7
290
0
63.9
27.3
7.3
1.2
0.3
648
0
51.8
30.7
12.4
4.5
0.6
517
0
36.3
33.3
20.8
8.3
1.3
389
-------
Table A,5-4,6 (c) Chemical and Size Analyses of Bed Material
Test Series 4 (cont'd)
Test No,
Sample
Chemical Analysis
Sulphur % a. r<>
CO % a.,r.
CaO % a. TO
4.9
Initial
0,3
0 c 12
0,74
Final
Io25
Oo42
5»32
Offtake
0.45
0,37
Io96
Size Analysis % in grade by weight
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
-63
Median diam, (ym)
0
91,0
6n9
0,2
Oo4
1,5
1184
0
82.1
11,6
4o6
1.7
0
1042
0
72-9
19eO
8.1*
•" -
826
* - 250 ym
A5.
-------
Table A.5.4.7 Flue Gas Analyses
i Test No,
Operating Conditions
Ca/S Mol Ratio
Fluidising Velocity ft/s
o
Bed Temperature F
Bed Height ft
Chromatograph
Mean C02 Vol % dry
Mean 02 Vol % dry
Mean CO Vol % dry
Mean CH4 Vol % dry
' S00 By Iodine
Sample 1 p. p.m. dry
Sample 2 p. p.m. dry
Sample 3 p. p.m. dry
Sample 4 p. p.m. dry
Sample 5 p.p.m. dry
Sample 6 p. p.m., dry
Mean S00
By Iodine p.p.m, dry
By H202 p-p,m. dry
Cl p. p.m. dry
NH3 p,p.m, dry
4.1
0
1470
2
14.9'
2.3
0.08
0
1941
1946
2052
1945
2013
1980
2120
121
ND
4,2
1.0
3
1470
2
15.0
2.4
0.06
0
1395
1408
1307
1457
1292
1372
1415
75
ND
4,3
2.1
3
1470
2
15,2
2.2
0.06
0
963
928
911
960
931
938
1000
89
ND
-
4,4
3,1
3
1470
2
15,5
2,4
0.06
o
285
245
228
205
241
275
95
ND
4.5
0,9
3
1470
2
14.5
2.5
0.08
0
1135
1077
1131
1165
1177
!
1137
1180
83
0
4,6
1.7
3
1470
2
15.3
2.2
0.06
Q
566
571
598
579
573
581
604
581
640
69
ND i
4.7
2,6
3
1470
2
15,3
2.3
0.06
0
194
223
193
170
175
159
185
217
65
21
! 4,8
i
1
0,9
3
1470
2
14,6
2.1
0.06
0
1158
1250
1268
1276
1238
1185
69
22
4,9
i
0,9
3
1470
2
14,8
2.5
0,08
0
890
1014
996
1028
1089
940
990
1115
•47
24
ND - Not Determined
A5. 89
-------
Table A,5o4.8. Mass Balance for Test No, 4.1
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
3.82
0
45.94
1,90
51.66
-0.96
0.50
0.49
51.21
51.24
0,42
Oc8
'Ash'
0.49
0
0
0
0.49
-0,96
0.50
0.30
0
-Ool6
0.65
133
'Carbon1
2.79
0
0
0
2.79
0
0,01
0.20
2.90
3oll
0*32
llcl
Nitrogen
0
0
35.3
1,9
37,2
0
0
0
37.6
37.6
-0,4
-1.2
'Oxygen*
Ool6
0
10.64
0
10,80
0
0
0
10.41
10.41
0.39
3.6
Sulphur
OolOS
. 0
0
0
0.105
0.005
0.005
0.007
0.099
0.116
-0.011
-10.4
Calcium
0,027
0
0
0
0;027
0
0.013
0,013
0
0.026
0.001
3o9
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
6.7%
6,3% (Unburnt)
5%
0
A5.90
-------
Table A.5,4.9. Mass Balance for Test Nou 4,2
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted
% of input
Total
4.22
0.38
45.94
1.90
52,44
-0.11
0.36
0077
51n36
52.38
0 = 06
0.1
'Ash'
Oo54
0U38
0
0
0_92
-0.11
0.36
0347
0
0.72
Oo20
>1.7
'Carbon'
3o08
0
0
0
3o08
0
0.01
Oo31
2 = 91
3.23
.-0,15
-5.0
Nitrogen
0
0
35.3
1.9
37.2
0
0
0
37*5
3705
-0,3
-0.7
'Oxygen'
0.18
0
10.64
0
10,82
0
0
0
10o65
10,65
0,17
1.6
Sulphur
0.116
0
0
0
0-116
0.036
0.006
0.013
0.069
0*124
-0.008
-6P4
Calcium
0,030
0,147
0
0
0.177
0,105
0,013
0.038
0
0.156
0,021
11.6
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
4.0%
9.5% (Unburnt)
41%
1.0
A5.91
-------
Table AJK4..10 Mass Balance for Test No. 4.3
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4o04
0,73
45.94
L,9
52.61
-0.06
0,76
0,76
51..33
5 2, .79
-0,18
-0 34
'Ash'
0052
0,,73
0
0
1.25
-0.06
0..76
0.41
0
1,11
0/14
11,2
'Carbon'
2, ,94
0
0
0
2, -94
0
0
0 , 35
2,95
3,31
-0,37
-12 ,,59
Nitrogen
0
0
35 ,,3
1.9
37 ,2
0
0
0
3702
37. .2
0
0
'Oxygen'
0U17
0
10 ,,64
0
10 ,.81
0
0
0
10..58
10 ,,58
0,13
1 . 20
Sulphur
0,111
0
0
0
0.111
0,.034
0.022
0,015
0,047
0.118
-0,007
-6,5
Calcium
0 028
0 285
0
0
0-313
0.206
0,,066
0,046
0
0,317
-0 -004
-1.3
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
1,. 7%
10,74% (Unburnt)
57%
2,1
A5. 92
-------
Table A.,5o4.11 Mags Balance for Test No 4.4
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
4.33
1,16
45,94
1,9
53.33
-0.02
0,90
0-80
51,46
53.14
0,19
0^36
'Ash1
0.55
1..16
0
0
1.71
-0,,02
On90
0..52
0
1.40
0,31
18.1
'Carbon'
3 1 15
0
0
0
3.15
0
0
0,29
3-00
3.29
-0,14
-4,4
Nitrogen
0
0
35,3
1.9
37,2
0
0
0
37 c 2
37;, 2
0
0
"Oxygen1
0,19
0
10.64
0
10..83
0
0
0
10,94
10,94
0..11
1.02
Sulphur
0,119
0
0
0
0.119
0,036
0.041
0,015
0,012
0,105
O.,014
12.1
Calcium
0.030
0,455
0
0
0.485
0.210
0.157
0.079
0
0.446
0.039
8,0
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
4,4%
8.7% (Unburnt)
90%
3,1
A5. 93
-------
Table A.5,4,12 Mass Balance for Test No. 4.5
Race Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted ,
% of .input
Total
4,11
0,37
45,94
1,90
52.32
0,01
Oo34
0-67
51.24
52,26
0,,06
Ool
'Ash'
0,53
0,37
0
0
0,90
o;oi
0U34
0.41
0
0.75
0.15
16 , 7
'Carbon'
3,0
0
0
0
3,0
0
OcOl
0.26
2, ,82
3o08
-0,,08
-2,7
Nitrogen
0
0
35«3
Io9
37,2
0
0
0
37 ,7
37,7
-0,,5
-1,2
' Oxygen "
0,,18
0
10.64
0
10.82
0
0
0
10o41
KK41
0,41
3.8
Sulphur
0,113
0
0
0
0.113
0,042
0.007
0,012
0.-057
0.118
-0.005
-4.8
Calcium
0.029
0.121
0
0
0,150
0,,090
0.018
0,036
0
0.144
0.006
3.7
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
5,8%
8 ,,6% (Unburnt)
50%
0,9
A5.94
-------
Tab le
13 Mass Balance for Test No, 4 6
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
Z of input
Total
4,28
0.77
45.94
1.90
52. ,89
-0,01
0.76
0=79
51,41
52,,95
-0.06
-0 , 1
'Ash'
0,55
0.77
0
0
1,32
-o,'oi
0,76
0,49
0
i.,24
0,08
6,1
'Carbon*
3ol2
0
0
0
3,12
0
0
0,30
2,97
3,27
-0,15
-4,8
Nitrogen
0
0
35,3
1-9
37(2
, 0
0
0
37 ,4
37.4
-0,2
-0,5
'Oxygen'
0.18
0
10,64
0
10.82
0
0
0
10,72
10.72
0.10
1,,0
Sulphur
0,118
.. 0
0
0
0.118
0,040
0.036
0,015
0,029
0.120
-0.002
-2,2
Calcium
0,030
0.253
0
0
0,283
0.112
0.085
0.057
0
0.254
0.029
10,1
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
9,2% (Unburnt)
75%
1-7
A5. 95
-------
Table A,5..4,14 Mass Balance for Test No. 4.7
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted ,
% of input
Total
4 ,,36
U18
45.94
1.90
53* 38
-0.19
0,95
0,76
51.37
52,89
0,49
0,92
'Ash9
0,56
1.18
0
0
1.74
-0.19
Oo95
0.51
0
1.27
0,,47
27.0
'Carbon*
3ol8
0
0
0
3d8
0
0^01
0,24
2t>96
3.21
-0,03
-1.0
Nitrogen
0
0
35.3
1,9
37o2
0
0
0
37^3
37,, 3
-Onl
-Oo3
'Oxygen*
0.19
0
10.64
0
10083
0
0
0
10o80
10.80
0.03
003
Sulphur
0.120
0
0
0
Ool20
0,063
0»052
0,014
0.009
Ool38
-0..018
-14.8
Calcium
0,031
0.386
0
0
0.417
0.223
0.146
0*084
0
0,453
-0.036
-8.7
Excess-Air 5„2%
Carbon Loss 7,6%
Sulphur Retention 92%
Ca/S Mole ratio 2,6
(Unburnt)
A5. 96
-------
Table Ao5o4015 Mass Balance for Test No, A.8
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
' Unaccounted ,
%- of input
Total
4.27
Oo38
45,94
1.90
52-49
-0.06
0.50
0.75
51.25
52.44
0,05
0.1
'Ash'
0.55
0038
6
0
0.93
-0,06
0,50
Oo45
0
On89
0004
4o3
'Carbon'
3n10
0
0
0
3,, 10
0
0
0,30
2.83
3.13
-Oo03
1,0
Nitrogen
0
0
35.3
1,9
37.2
0
0
0
37.8
37o8
-0.6
-1.5
'Oxygen'
0,18
0
10.6
0
10,78
0
0
0
10.30
10o30
0,48
4o5
Sulphur
0.117
0
0
0
0.117
00003
0,026
0^015
0.052
On097
0.020
17,8
Calcium
0.029
0*125
0
' 0
0^154
-0.006
0.075
0.051
0
0.120
0,034
12,4
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
2,8%
9,4% (Unburnt)
55%
0.9
A5. 97
-------
Table A,564ol6 Mass Balance for Te.st No0 409
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted j
input-output
Unaccounted,
% of input
Total
4o57
Oo41
45c94
Io90
52.82
-0.69
0,43
0,85
51.33
51092
0.90
1.7
'Ash1
0058
0041
0
0
0.99
-0=69 '
Oo43
0049
0
Oo23
10.76
76
'Carbon1
3c33
0
0
0
3.33
0
0
0036
2.87
3o23
0.10
3=0
Nitrogen
0
0
3.5.3
1.9
37o2
0
< 0
0
37.4
37.4
-0.2
-006
'Oxygen'
0.2
0
10.64
0
10.84
0
0
0
10.72
10.72
0.12
1.1
Sulphur
0.126
0
0
! 0
0.126
0,026
0.002
0,017
0.050
0,095
0.031
24.6
Calcium
0.032
0.134
0
0
0.166
0.089
0.006
0.045
0
0.140
0.026
16.1
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
3oO%
11.1% (Unburnt)
60%
0,9
A5. 98
-------
Table A.5.4.17 . SO? concentrations and % reductions
Test No.
Limestone type
Fluidising Velocity, ft/s
Bed Temperature, F
Ca/S mol ratio
S0» concentration, p. p.m.
S02 reduction, %
4.1
-
3
1470
0
1980
0
4.2
U.K.
3
1470
1.0
1372
31
4.3
U.K.
3
1470
2.1
938
52
4.4
U.K.
3
1470
3.1
241
88
4.5
U.S. 18
3
1470
0.9
1137
43
4.6
U.S. 18
3
1470
1.7
581
71
4.7
U.S. 18
3
1470
2.6
185
91
•4.8
U.S. 18
3
1470
0.9
1238
38
4.9
U.S. 18
3
1470
0.9
(1115)
43
yi
to
to
SO2 reductions are based on a datum level of 1980 p.p.m.
( ) Hydrogen peroxide result.
-------
Table A~5>5,1 Operating Conditions During Test Series 5
Constant Parameters;
Coal
Coal Size
Acceptor Size
Fluidising Velocity
Bed Height
Welbeck II
(ex Task I)
- 1680 micron
- 1680 micron
3 ft/s
2 ft
! Test No,
i Date
,
Acceptor
1
Ca/S mole ratio
Bed Temp, F
Ash Bed
5,1 • \ 5,2
31,12:70 | l.'K
U,Ko Lst UoSo Lst
1,6 1,9
1440 * 1470
ex 2 15 ! ex 5 j 1
71
18
* Test 5,1 Bed temperature accidentally maintained
30°F below test 5-2=
A5.100
-------
Table A.5.5.2 Chemical analyses of coal
Test Series 5
Test Number
Proximate analysis
Total moisture
Ash
Volatile Matter
Ultimate analysis
Carbon
i Hydrogen
Nitrogen
Sulphur
Oxygen + errors
Chlorine
Carbon Dioxide
Ash analysis
CaO
MgO
Na20
K20
A1203
Fe2°3
Si02
Calorific value (gross)
Swelling No.
Gray King coke type
% a.r.
% a.r.
% d.a.f.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d.b.
% d,b.
% d.b.
% d.b.
Btu/lb
5.1 & 5.2
2,8
25.6
36.9
60.5
3.5
1.27
1.39
3.9
0.58
1.0
3.1
2.1
1,67.
3,3
21.4
8.7
54.8
14390
1 i
B
A5.101
-------
Table A.5.5.3 Chemical .and Size Analyses of Acceptor
Test Series 5
Test No.
Chemical Analysis
CaO a . r .
MgO a.r.
C02 a.r.
SiC>2 a.r.
Size Analysis
Particle size (ym)
+ 1680
+ 500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
63
Median dia. (ym)
5.1
54.9
0.2
42.0
1.6
5.2
45.9
0.9
34.7
14.7
% in grade by weight
0.5
52.1
19.1
10.1
7.2
11.0
537
0.1
21.0
22.0
22.5
12.2
22.2
207
A5.102
-------
Table A.5,5 A Chemical and Size Analyses of Feed Blends
Test Series 5
Test Noo
Moisture
Ash
Carbon
CaO
Sulphur
co2
Particle
I
. j 5.1
a or- | 3o5
a.r.
d.b.
d.b.<
d.b.
dob.
size (um)
+ 1680
+ 500 -
+ 250 -
I •
+ 125 -
+ 63 -
1680
500
250
125
28.1
55,6
4,48
1,35
1 5,2
2,7
30.8
52.7
4,76
1,25
3.75 4.20
% in grade by weight
0.1 ; 0.1
39,8 , 35.3
|
18,3 18o5
12,7 • 13.7
10.1 | 11.5
1-
i - 63
19,0
20,9
Median dia. ym
347
292
A5.103
-------
Table A.5.5.5 Chemical and Size Analyses of Cyclone Fines
Test Series 5
Test No.
Chemical Analysis
Carbon % a.r.
Sulphur % a.r. <
C02 % a.r.
CaO % a.r.
Size Analysis
Particle size (ym)
+ 500
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
5.1
39.95
1.4
0.52
6.39
5.2
34.1
1.33
0.53
7.55
% in grade by weight
0
0
0.6
11.0
88.4
0
0.2
0.5
9.5
89.8
A5.104
-------
Table A ,5,5,6 Chemical and Size Analyses of Bed Material
Test Series 5
Test No,
Sample
Chemical Analysis
Sulphur % a.r.
CO- % a.r.
CaO % a.r.
Size Analysis
Particle size (um)
+ 1680
+500 - 1680
+ 250 - 500
+ 125 - 250
+ 63 - 125
- 63
Median diam. (um)
5.1
Initial
2.9 !
0.64
,9 ,,94
Final
3,15
1,19
11,91
Offtake
2,9
0,69
9,8
!
5.2 (
Initial
2.8
0»96 j
11.05
? i
Final ', Offtake ;
i
t
3.1 3.45 :
0,72 0.43
12,89 13,04
% in grade by weight
0
69,1
26o8
3.1 '
0.7
0,3
709
0,1
66n4
25.3
5,1
2,9
0.2
689
0
67.1
21,6
6,7
0
62,1
26o9
6,0
4,1 4.7
;
0,5 j Oo3
f
723
630
I . ;
0 j 0
47o8 j 49,4 i
32.5 j 25,4 '
11.7 10.3
i
7,7 1 13,5 ,
i,
0.3 | 1,4
481 ! 493
1
A5.105
-------
Table A.5.5.7 Flue Gas Analyses
Test No.
Operating Conditions
Ca/S Mol Ratio
Fluidising Velocity, ft/s
Bed Temperature F
Bed Height, ft
Chromatograph
Mean C02 Vol % Dry
Mean 02 Vol % Dry
Mean CO Vol % Dry
Mean CH4 Vol % Dry
S02 By Iodine
Sample 1. p. p.m. Dry
Sample 2. p. p.m. Dry
Sample 3. p. p.m. Dry
Sample 4. p. p.m. Dry
Sample 5. p. p.m. Dry
Mean SO?
By Iodine p. p.m. Dry
By H202 p. p.m. Dry
Cl~ p. p.m. Dry
NHg p. p.m. Dry
5.1
1.6
3
1440
2
14.8
2.8
0.2
0
361
390
352
315
291
342
355
303
12
i
5.2 .
1.9
3
1470
2
15.4
2.6
0.18
0
225
229
232
246
250
236
255
363
3
A5.106
-------
Table A05o508 Mass Balance for Test No0 5,1
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
Total
5.69
0.41
45.94
1.9
53*94
-0.07
1.10
1,22
51,27
53.52
0,42
0.8
'Ash'
1.50
0.41
0
0
.1, 91
-0007
1.10
0.75
0
1,78
Ool3
608
'Carbon'
3.44
0
0
0
3,44
0
0.01
0,47
2.90
3.38
0.06
1.7
Nitrogen
0
0
35.3
Io9
37.2
0
0
0
37.3
37,3
-0,1
-0.3
'Oxygen'
0»22
0
10.64
0
10.86
0
0
0
10,79
10.79
0.07
0.6
Sulphur
0,079
0
0
0
0.079
OoOOS
0.032
0.018
0,017
0,074
0.005
5.9
Calcium
0.033
Oc.160
0
0
0.193
0.044
0.077
0.054
0
0.175
0,018
9.6
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
1.3%
14,,0% (Unburnt)
79%
1.6
A5.107
-------
Table A.5.5-9 Mass Balance for Test No. 5,2
Rate Ib/h
Coal
Acceptor
Total Air
Bleed Nitrogen
Total Input
Accumulated in Bed
Offtake Ash
Fines
Flue Gas
Total Output
Unaccounted,
input-output
Unaccounted,
% of input
total
5.71
0,56
45.94
1.90
54.11
-0.18
Io30
1.21
51,49
53o82
0.29
0.5
'Ash*
1.50
0.56
0
0
2»06
-0.18
1.30
Oo80
0
Io92
0.14
6U8
'Carbon'
3.45
0
0
0
' 3o45
0
OoOl
0040
3.01
3,42
0.03
0.9
Nitrogen
0
0
35.3
1 = 9
37.2
0
0
0
37o2
37,2
0
0
'Oxygen'
Oo22
0
10.64
0
10.86
0
0
0
11.00
. 11.00
-0,14
-1.3
Sulphur
0.079
0
0
0
0.079
0.009
0.045
0.016
0.012
0.082
-0.003
-3.8
Calcium
0.033
0.184
0
0
0.217
0.040
0.121
0.064
0
0.225
-0.008
-3.9
Excess Air
Carbon Loss
Sulphur Retention
Ca/S Mole ratio
2.0%
11.9% (Unburnt)
85%
Io9
A5.108
-------
Table A.5.5.10 SO? concentrations and % reductions
Test No.
Coal Type
Limestone Type ,
Fluidising Velocity, ft/s
Bed Temperature F
Ca/S mol ratio
S02 concentration, p. p.m.
SCL reduction, %
5.1
Welbeck
U.K.
3
1440
1.6
342
71
5.2
Welbeck
U.S. 18
3
1470
1.9
236
80
S02 reductions are based on a datum level of 1170 p.p.m.
A5.109
-------
Sampling Analyser
02
Analyser Sampling
Fines
Catchpot
Fines Return Line
1
S02
Cooling
Water
Reservoir
Vibrator
Ash
Fig. A 5.1. General Design Of The Gin Combustor
A5.110
-------
Inches
Cooling
Water
In and out
Coal (or Limestone)
Feed
Fluidising Air
Ash Offtake
Fig. A 5.2. Detail Of Bed Section Of 6in Combustor
A5.111
-------
100
90
80
70
60
Coal
Acceptor
Acceptor
Illinois
US 1359
UK Limestone
Symbol
V
o
Operating Conditions
Fluidising Vel.
Bed Temp.
Bed Depth
ft/s
°F
ft.
3
U70
2
0123
Ca/S Mol Ratio
Fig. A5.3. Test Seriesl. SO* Reduction v Ca/S mol ratio
A5.112
-------
100
90
80
70
c
T3
0)
o:
30
20
10
Coat
Illinois
Welbeck
Park Hill
Pittsburgh
Symbol
O
A
V
0
B
A
Welbeck
Park Hill, Illinois
8, Pittsburgh
Operating Conditions
Fluidising Vel.
Bed Temp.
Bed Depth
ft/s
°F
ft
3
U70
2
Ca/S Mol Ratio
Fig. A5./;. Test Series 1,2,4 &5. S02 Reduction vs Ca/S Mol Ratio
for Different Coals with U.K.Limestone
A5.113
-------
100
90
80
70
80
o
•a
a>
OH
50
30
20
10
Coal
Acceptor
Welbeck
UK Limestone
Operating Conditions
Fluidising Vel. ft/s
Fluid ising Vel. ft/s
Bed Temp °F
Bed Depth ft
2
3
U70
2
Symbol
O
A
0 1 2 3
Ca/S Mo I Ratio
Fig. A5.5 Test Series 2 & 5. Sulphur Reduction vs Ca/S Mol Ratio
A5.114
-------
100
90
80
70
60
§ 50
T3
0)
-------
90
70
60
30
20
10
Coal
Acceptor
Acceptor
Pittsburgh
US 18
UK Limestone
Symbol
A
0
Operating Conditions
Fluidising Vel. ft
Bed Temp. °F
Bed Depth ft
3
U70°
2
Ca/S Mol Ratio
Fig A 5.7 Test Series I*. SO Reduction vs Ca/S Mol Ratio for Two Acceptors
A5.116
-------
100
90
80
70
60
e*
C
O
•• 50
0)
4->
0)
a:
c?
30
20
10
Coal
Acceptor
Illinois
Limestone 1359
Operating Conditions
Fluidising Vet. ft/s
Bed Temp. °F
Bed Depth ft
3
U70
2
ANL
NCB
data
data
Symbol
A
0
0123
Ca/S Mot Ratio
f:igA5.8 S02 Retention vs Ca/S Mol Ratio. Comparison of Data from ANL and NfcB.
A5.117
-------
100
90
80
70
^ 60
o
I 50
30
20
10
G
Coal
Acceptor
Welbeck
UK Limestone
O
1
0
Operating Conditions
Fluidismg Vel
Bed Temp
Bed Depth
ft/s
°F
ft
3
U70
2
ANL data
NCB data
Symbol
A
O
Ca/S Mo I Ratio
Fig A5.9 S02 Reduction vs Ca/S Mol Ratio Comparison of Data of
from ANL and NCB.
A5.118
-------
NATIONAL COAL BOARD
FINAL REPORT
JUNE 1970 - JUNE 1971
REDUCTION OF ATMOSPHERIC POLLUTION
APPENDIX 6. MATHEMATICAL MODEL OF SULPHUR RETENTION. (TASK VI)
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
411 WEST CHAPEL HILL STREET
- DURHAM, NORTH CAROLINA 27701
FLUIDISED COMBUSTION
REFERENCE NO. DHB 060971 CONTROL GROUP
SEPTEMBER 1971 NATIONAL COAL BOARD
LONDON, ENGLAND
-------
REDUCTION OF ATMOSPHERIC POLLUTION
Research on reducing emission of sulphur oxides,
nitrogen oxides and particulates by using
fluidised bed combustion of coal
Appendix 6. Mathematical model of sulphur retention. (Task VI)
Main objective
To complete the development of a mathematical
model of sulphur retention and to compare its
predictions with the results of laboratory
and rig experiments, and to up-date it as
appropriate.
Report prepared by: F.V. Bethe11
D.W. Gill
B.B. Morgan
Report approved by: A.D. Dainton
H.R. Hoy
A6. iii
-------
Page No,
SUMMARY AND CONCLUSIONS
1. INTRODUCTION A6. 1
2. DESCRIPTION OF MODEL A6. 2
2.1 Absorption Calculation A6. 8
2.2 Input Data A6. 8
2.3 Initial Calculations A6. 8
2.4 Calculation of Elutriation Constants A6. 9
2.5 Adjustment of mass fractions of ash and limestone A6.ll
2.6 Calculation of bed composition A6.ll
2.7 Calculation of particle residence times A6.12
3. FORM OF INPUT DATA FOR MODEL A6.12
3.1 Bed voidage A6.12
3.2 Densities of ash and limestone A6.12
3.3 Attrition coefficients A6.13
3.4 Constants in reactivity equation A6.13
3.5 Recirculation cyclone efficiency A6.13
4. GENERAL OBSERVATIONS ON PERFORMANCE OF MODEL A6.13
4.1 Elutriation A6.14
4.2 Attrition A6.14
4.3 S02 generation pattern A6.15
4.4 Absorption of S02 in the gas space above the bed A6.15
5. COMPARISONS WITH RESULTS FROM THE CURRENT CONTRACT PROGRAMME A6.16
5.1 Task I A6.16
5.2 Task II A6.17
5.3 Task III A6.19
5.4 Task V A6.20
5.5 Pope, Evans and Robbins Data A6.20
6. DISCUSSION A6.21
7. COMPUTER PROGRAMME A6.26
ACKNOWLEDGEMENTS A6.27
ADDENDUM ON ACCURACY OF THE REACTION RATE DATA A6.27
REFERENCES
NOMENCLATURE
TABLES A6.1 - A6.6
FIGURES A6.1 - A6.19
(Note that when referring to Tables and Figures in the text the
prefix A6 is omitted).
A6. v
-------
SUMMARY AND CONCLUSIONS
There were two main objectives in developing the model of the
sulphur absorption process, firstly, to assist in understanding the
performance of the experimental-plant.and secondly to develop a
technique to assist in extrapolating the results to other plants
and feed materials.
The model broadly comprises two sections. The first calculates
from the input data the terminal velocities of particles in up to ten
size groups, and thence 'the bed composition as regards the weights of
ash and limestone particles in the selected size groups. The
calculation procedure also gives the mean residence time of each
group of particles. The second part calculates the absorption of SOo
in and above the bed. To do this a mean S02 concentration is
calculated using an assumed mean reactivity for the bed. This mean
S02 concentration is used to calculate.the.utilisation of each size
group of particles. The procedure involves solving equations
relating reactivity to utilisation and the equation for the sulphur
balance over the bed. The utilisation values that, result enable an
improved estimate to be calculated for the mean reactivity of the
bed and thence the calculation procedure is repeated until a
satisfactory degree of convergence is obtained.
The model uses semi-empirical constants to compute the rate
of reduction of particle size in the bed due to attrition and the
residence time of fines in the bed; constants are also applied to
express the mode of evolution of S02 in the bed. Subsequent to
the initial testing of the model a computational procedure was
introduced to allow for the exposure of fresh unsulphated lime by
abrasion of the sulphated layer i.e. to compensate for 'regeneration'
by attrition.
Agreement between the predictions from the model (summarised
at the end of Section 6) and plant performance is in general good
where.the acceptor does not contain.a.large fraction of material
fine enough to be elutriated. In circumstances where it does the
predicted retention is lower than that achieved. The general shape
-------
of the curves of retention vs Ca/S mole ratio obtained from plant
experiments is more consistent with SC>2 evolution occurring
throughout the bed rather than solely at the bottom of the bed.
The attainment.of closer representation of plant performance
where there is a high proportion of elutriable fines would most likely
be achieved by rigorous experimental determination of elutriation indices
for each rig. The factors that affect elutriation and attrition in
plant need to be more fully characterised before general extrapolation
of the results beyond the current range of process and design conditions
can be attempted with confidence.
Further development of the model should include the effect of
bubble growth and its effect on the contact efficiency between gas
and solids. Nevertheless, the existing model provides a valuable
guide as to the effects of changes in process conditions.
A6. viii
-------
1. INTRODUCTION
The development of a mathematical model had been started before
the present contract was negotiated. It seemed appropriate that the
work should continue and form a part of the programme of work under
the terms of the contract, and it was accordingly written into the
contract proposals.
Simultaneously with this development, similar work was in
progress at ANL (Argonne National Laboratories)by L B Koppel. It
is interesting to compare the approach used in the two models. Both
postulate a well-stirred reactor in respect of the solid particles,
but the ANL model stipulates that all of the solids are removed by
overflow from the bed, whereas the British model assumes that
solids removal is partly by overflow and partly by elutriation,
depending on particle size. Both models assume plug flow of gas
and allow of an SO generation function, so that it is possible to
simulate the case in which S0_ is released at the bottom of the bed,
or various cases in which the SO„ is formed in various patterns
throughout the bed depth. (The difficulty in testing the models
here lies in the absence of reliable information about SO^
generation patterns). Both models assume a uniform temperature
throughout the bed and uniform SO- concentration across any
horizontal plane, and both make the assumption that the rate of
reaction is proportional to the SO^ concentration in the surrounding
gas. The assumption that the reaction rate coefficient is the same
in the plants as in the laboratory measurements of reactivity is
common to both, but the ANL model is more complete than the British
model in that it allows for the presence of two phases, a parti-
culate phase and a bubble phase, with continuous exchange of gas
between them. Incorporation of this facility in the model,
described in this appendix, is considered to be desirable, if any
future work were to be done in development of the model.
The British model is capable of taking into account the
actual measured reactivity of limestone particles of different
sizes, whereas the American model is believed to apply a mean
reaction rate coefficient to all sizes of particle. The measure-
ments of reaction rate coefficients made in Task VIII of the
present contract indicate that for stone of zero utilization, the
A6.1
-------
reactivity is about the same for all sizes, but as the degree of
utilization increases, the reactivity of the coarser particles
drops off more rapidly.
A further assumption of the present model is that gas/solids
contact time does not play any part in controlling the reaction
rate, which is presumed to be governed by processes taking place
within the limestone particle.
Support for this assumption-is given by Table 2 of reference 6,
which records the results of experiments in which air containing S0~
was passed through shallow fluidised beds of limestone particles.
For gas velocities in the range 0.5 to 5 ft/s and bed depths of
about 1 to 2 inches, practically 100% removal of SO,, was noted
with fresh limestone in the majority of cases.
2. DESCRIPTION OF MODEL
The core of the mathematical model lies in the procedure for
calculating S02 absorption by limestone in the bed. Steady-state
operation is assumed and the rate of absorption is calculated by
solving, for each of a number of particle size groups, equations
relating the rate of sulphur take-up by the limestone to the
rate of .sulphur removal from the bed due to passage of 'stone
through the bed. There are two unknowns, limestone utilization
and SO2 concentration,. To solve the equations the relation between
these two is also usedo
The rate of sulphur take-up is dependent on the mass of stone
of the particular size group present in the bed, on its extent of
utilization, on the identity of the stone, and on the SO.
concentration throughout the bed. Since, for a first order gas/
solids reaction, the SO. concentration decreases exponentially
with height above the air distributor, solution of the equations
is simplified by using an equivalent mean concentration, which bears
a known relation to the concentration at the top of the bed. The
model permits the use of an S0« generation function so that, either
the case in which all the S0_ is formed very close to the air
distributor, or cases in which SO- is formed throughout the bed,
A6.2
-------
may be simulated. Details of the sulphur balance and of the S0_
generation function are given in the next section,,
The remaining parts of the model serve the purpose of
providing, in suitable form, information required to solve the
equations in the SO absorption calculation. This includes rates
of flow of limestone of the different size groups into and out
of the bed, and weights and residence times in the bed.
All the comparisons described were obtained using the final
version of the model„
A flow chart of the mathematical model computer programme is
shown in Fig. 6.1, and the programme itself, in ALGOL, is re-
produced at the end of this appendix.
Each of the steps will be discussed in detail, starting with
the main S0« absorption calculation.
2.1 Absorption Calculation
The validity of this calculation is crucial to the whole
model. The assumption has to be made that the rate at which S09
is taken up by the limestone in the bed is equal to that measured
at the same utilization under the conditions of the laboratory
experiments performed as part of Task VIII under the contract.
It is apparent on studying the results obtained in this
laboratory programme, that the reaction rate falls off in most
cases to a negligibly small value well before 100% utilization of
the limestone has been achieved. With limestone 1359, in parti-
cular, less than 25% utilization is indicated for 180 ym particles
at limiting sulphation, and only just over 10% for 55 ym particles.
On comparing this with some of the results from plant
experiments using the same limestone it became apparent that, in
the plant, a greater degreee of utilization was being achieved
than seemed possible on the basis of the laboratory measurements.
There seemed to be only one likely explanation of this behaviour*,
that is that attrition of the partly-sulphated particles in the
bed was exposing fresh surfaces to the SO- laden gas.
* It has since been learned that ANL have suggested that the higher
than expected degree of utilization may be due to exposure of the
stone alternately to oxidising and reducing conditions in the bed.
A6.3
-------
It was therefore considered imperative to take this factor
into account in some way in the mathematical model, even though
the time available would permit of only a fairly crude treatment.
The way this has been done is as follows :-
It is assumed that the sulphated particles consist of
completely unsulphated cores surrounded by shells of
completely sulphated material.
The effect of attrition on particle size is taken into
account according to the following equation:-
In - - - K .t /3600 (1)
v o
where x is the characteristic size in the feed material
o
x is the size after attrition of the sulphated layer
K, is the attrition coefficient, h
d
t is the time required to regenerate the particles, s
a 7
If the limiting utilization (i.e. the utilization at which the
reactivity falls to zero) is denoted by U , then the ratio of thickness
of the sulphated shell to particle radius, at utilization U is
1/3 C
(1 - (1 - U ) ) : 1. Thus X/X in equation 1 may be replaced by
(1 - U//^-
ta (1 - D)1'3 (2)
C
The rate of 'regeneration' will be proportional to the chances
that a particle will stay in the bed for a time t , i.e. exp (-t /T),
a a
where T is the mean residence time of particles in the bed. It will
also depend on the weight of unused limestone, of each size group in
"the.bed i.e. W. (1 - U.). The rate of regeneration (FR) is therefore
given by:-
F . = exp(- t /T.) W. (1 - U.)/t (3)
K, i ail i a
A6.4
-------
and the mean utilization of the particles remaining in the bed (U.)
to be used for calculating the reaction rate is:
Ui ' FiV (Fi + FR,i> ^
The regeneration procedure is only applied to non-elutriated
particles. Since the abraded stone is sulphated, it is recom-
mended that when applying this calculation procedure the adjustment
of input limestone sizes, to allow for attrition (as described in
section 2.3) should not.be used in calculating F.; otherwise
there will be an error in the absorption calculation. For
calculating bed composition and residence times the adjustment
of input sizes can still be used.
The relation between reaction rate and utilization is:-
dt
- k. (a . + a. . U. + a_ . U.2 + a, . U.3). c . W. (5)
i 0,1 l,i i 2,i i 3,i i i
where — Jt ^s t^e rate of S02 absorption by particles in size
group i, kg/s
3
k. is a basic rate constant for size group i, m /kgs
a, .. are coefficients derived from laboratory experiment,
D, i
3
c is SO™ concentration, kg/m
The priciples of the absorption calculation procedure have been
described in detail by Morgan . The outline principles only will be
given here. In the method of calculation employed, the reactivity of
a limestone size group is assumed to be the same as that of limestone
with a utilization equal to the mean utilization of all particles of
that size group in the bed. In fact, of course, there is quite a
wide spread of utilizations, due to the fact that there is a wide
spread of residence times of particles in the bed. Investigation
of a few examples indicated that in most cases the error introduced
by this simplification was small - a few percent only. Use of a
A6.5
-------
more exact method, in which reaction is integrated over the range
of utilization for each size group-would have made the total
computing time very much longer.
The mass balance of sulphated limestone in the bed at
equilibrium is represented by the set of N simultaneous non-linear
equations:
Tkc
0 (6)
where f(U). = (a . + a. «.U. + a0 .U.2 + a« .U.3)
i 0,1 l,i i 2,i i 3,i i
U = mean utilization of recycled limestone.
In Equation (6), the first term on the left-hand side represents
the rate of absorption of S0_ by group i; the second term represents
the rate at which S0_ is eliminated from the bed by removal of
sulphated limestone from the bed, and the third term represents
the rate which SO- is returned to the bed in the form of recycled
stone.
The calculation permits the solution of this equation for
assumed values of (a) the mean reactivity of all the limestone in
the bed, and (b) the amount of SO,, absorbed by limestone dust in
the gas space above the bed. (a) is necessary, because the value
of U depends on the mean S02 concentration, which in turn depends
on the mean reactivity of the bed. The procedure used is to input
a trial value for mean bed reactivity; calculate the mean S0_
concentration corresponding to this value; solve Equation (6),
by the Newton-Raphson method, using an assumed value for S02
absorption above the bed (initially assumed to be zero) in order
to obtain U , and so obtain a revised estimate for mean bed reactivity.
The process is repeated until satisfactory convergence has been
obtained. The S0_ concentration at the top of the bed is then used
to calculate a more exact value for absorption above the bed,
assuming plug flow in the gas stream (Equation (7)), and the whole
process is repeated again and again until satisfactory convergence
is obtained.
k . £ (U). . c (7)
dt
A6.6
-------
In practice, it was found that absorption above the bed is very small,
and only one iteration is normally required.
Some instability of the solution procedure may arise if K,,
(Equation 1), is greater than 0.03. There has not been time to
correct this fault, but it only occurs at values of K, which are
appreciably higher than are likely to occur in practice.
In calculating c, the mean SO^ concentration in the bed, an
S0_ generation function is input. This is of the form:
c = c +
o
/ <|>(z) . dz (8)
where c is the concentration resulting from S0? formation at the
bottom of the bed, and <|>(z) is a function giving the rate of
concentration increase with height (in the absence of absorption)
up to a height z1 above the air distributor (^ bed depth), at
which SO- generation ceases.
The form of function used is:
* (z) = 2B(z' - z)/(z')2 (9)
3 is a constant »
The use of this function means that the rate of S02 generation
decreases linearly from a maximum value at z = 0 to zero at z = z1.
When absorption of SO^ is occurring, the concentration at
height z is given by:
+ KC -
-------
In the solution procedure, K is an initially unknown parameter.
A value is. guessed and the true value approached by an iterative
process. A formal definition of K, however, is:
N
K =
F T k
'U,
p (U) f (U).dU
(ID
where X is the mass of S02 equivalent to unit mass of calcined limestone
M is the volume flowrate of gas
p(U) is probability of particle of utilization U (in range
of U corresponding to residence time distribution)
Solution of Equation (10) gives for ce, the concentration at the top
of the bed:
z
ce = c0 exp (-KzJ +
- z)
4 (z) dz (12)
It can also be shown that c, the mean concentration, averaged over the
height of the bed is:
c -
; - ce)/Kze
(13)
where c' is the concentration that would be found at the top of the
e
bed in the absence of absorption.
2.2 Input Data
A typical set of input data, as used in simulation of Test Series 4
of Task II, is shown in Table 6.1. This is largely self-explanatory,
but where appropriate further details are given in discussion of the
following steps.
2.3 Initial Calculations
Volume flow-rates are calculated assuming a fixed gas density of
3
1.236 kg/m at 273 K and 1 atm pressure, and the weight of bed
material is calculated from overall bed volume, voidage (input as
data) and a mean -density of bed material derived from relative input
rates of coal ash and limestone. It is assumed that the carbon content
of the bed. is. negligibly small. The effect of particle attrition on
A6.8
-------
size distribution is taken .into account by reducing the median and
bottom sizes according to the following equation:
x = XQ exp (- Kd.T/3600) (14)
A more complete treatment of attrition in the bed has been
2
developed , but in order not to complicate the present model unnecessarily
during its development stage, this simple treatment has been used. The
general principle behind its adoption is that because of the spread of
residence times in the bed (well-stirred- reactor principle), some
particles will be subjected to very little attrition, while others will
be subjected to considerable attrition. Thus the actual spread of sizes
will be widened. This has been done in the model by altering the median
and bottom sizes of the feed mixture, and keeping the top size the same.
The allocation of the ash and limestone into N groups of sizes res-
N+l N+2
pectively 4 to 8 ym, 8- to 16 urn .". 2 to 2 2048 to
4096 ym is done using the assumption that the distribution fits a relation of
the type:-
log (weight % undersize) = m log (size) + C (15)
2.4 Calculation of Elutriation Constants
The treatment of elutriation from the bed is based on the postulate
that the elutriation constant, Ke is a function of the ratio of gas
velocity to the terminal velocity of the particles.
Ke is defined as rate of elutriation divided by the mass of particles
in the bed, and has units s . Experimental work on elutriation from
3
a cold 12 inch bed at CRE yielded a relation .
_ 0.00732 /vf _ ,V-7 (16)
« «y
e ze
where ze is the bed depth, m
vf is superficial gas velocity, m/s
Vt is the terminal velocity of the particle, m/s
3
Work by Field and Littlejohn suggested that Ke may vary widely
according to the design of reactor and the manner of feeding the solids.
An empirical constant, n, has therefore been introduced into the model to
A6.9
-------
allow for'this uncertainty:-
(17)
The significance of Kg in the computations of sulphur retention is
that its reciprocal is equal to the mean residence time of the particles
in the bed, before they are elutriated. -A low value of Ke is therefore
associated with better .utilization of that particular size group of
particles.
Terminal velocity (v^) is calculated by applying corrections
recommended by Davies to the Stokes velocity(v).
vt
[Re]t / JRe]v (18)
where Re
and Re
t is the Particle Reynolds number for the terminal velocity
v is the Particle Reynolds number for the Stokes velocity.
The corrections differ according to whether the (Stokes velocity)
Reynolds number, |Rel v is greater than or less than about 5.
For [Re]y ^5:
r I 2 3 * '
|_ReJ t = Y,B - Y2 IT + Y3 B - YI+ B .............. (19)
3
(log B) ... (20)
log
and for
Mt •
where B =
Y 1 "
Y =
2
Y. =
LReJv
- Y5 + Y6
24 [Re] v
1/24
2.3363 x
2.0154 x
> 5:
log (B) -
-4
10 *
-6
10 b
2
YV (leg B) + Yn
7 °
Yc - 1.29536
5
Yc = 0.986
'6
Y, = 0.046677
YI+ = 6.9105 x 10"9 Y8 • 1.1235 x 10~3
In calculation of the gas velocity, the volume occupied by the bed
particles is ignored, because it is the velocity in the free gas stream
above the bed which determines whether or not a particle will be elutriated.
A6.10
-------
The value of gas viscosity used in calculation of the terminal
( T)
velocity is taken to be the same as that of air at the same temperature ,
and an approximation is made to a linear relation for temperatures within
100 to 150°C of 800°C:
y = 10~5(4.33 + 0.0024(T -1073) ) Ns/m2 ............... (21)
The mean particle size for each size group used in calculations
1/2
of terminal velocities is x = (x-.x2) where x-.x- are the lower and
upper particle sizes in the group.
2.5 Adjustment of mass factions of ash and limestone
This adjustment was found to be necessary because of the extreme
sensitivity of the model to very small changes in gas velocity under some
circumstances.
The sensitivity was due to the fact that whether or not a whole size
fraction was elutriated (in the model) depended on whether the gas
velocity was greater or less than the terminal velocity .corresponding to the mean
particle size. for the group.
The exact value of the critical velocity, for,, elutriation is
calculated,, and the mass of the size groups in the feed size distribution,
on either side .of. -this critical velocity is adjusted in proportion. The
effect of the adjustment is that the mass fraction, of .the two groups can
be increased or decreased by as much as 50%, depending on the ratio of
the critical., size, for -elutriation to the geometric mean particle size
of the groups.
2.6 Calculation. of... bed composition
(a) . Particles small enough to be elutriated:
In the general case, when solids recycling is being practised, at
equilibrium, the rate of escape of solids through . the .cyclone is equal to
the feed rate. The loss of fines by overflow is ignored, because it is
small compared with the elutriation. If a^ is the cyclone efficiency for
particles of size group i, then:
+Rr>i
Rr>i
hence Gi=7i/(l-ai) ...... ............... (22)
A6.ll
-------
where G. is the total mass flow of limestone of size i reaching the cyclone,
F. R . are the feed rate and recycle rate respectively of limestone in
1 r»1
size group i.
The weight, W., of particles of group i.in the bed is given by the
elutriation equation: .
G, = Ke , W• . (23)
Summation of W. for all groups of elutriable size gives the total weight
of elutriable particles in the bed.
(b) Particles not elutriated;
Subtraction of the weight of elutriable particles from the total bed
weight gives the weight of non-elutriable.particles. This is allocated
between-, the various .size groups in the .same' ratio as ^exists in the feed.
2.7 Calculation of particle residence times
For elutriable particles, this is the reciprocal of-the elutriation
constant, otherwise it is the same for.all size groups, and is the weight
of non-elutriable particles in the bed, divided by the feed rate of non-
elutriable particles.
3. FORM OF INPUT DATA FOR MODEL
Most .of. the data required...(-Table 6.1) can be derived easily from .
knowledge of the plant construction, limestone analysis and plant
operating conditions. Items;requiring.further explanation are as follows:-
3.. 1 i Bed voidage; Precise inf ormation.,is, no.t available for each test.
The value 0.7 has been used throughout, as being a: fairly ..representative
figure for fluidised-bed combustors.
3 3
3.2 Densities of ash and limestone; The value 2920 kg/m (182 Ib/ft )
has been taken for the particle density of ash throughout, and a constant
value 1578 kg/m3 (98.5 Ib/ft ) for. calcined limestone. It might be
argued that there is a case for using:, the density of,, limes tone before
3
calcination (176 Ib/ft ), since the time,, taken-for calcination is not
.negligible compared with the residence time of fines in the bed.
However, some runs using the higher density value did not show a signi-
ficant difference in the results, so the matter was not pursued.
A6.12
-------
3.3 Attrition coefficients; There.are no.reliable data for these,
and a range of values have been tried in order to discover the sensitivity
of results to this parameter. It had" keen hoped to obtain some informa-
tion on values of attrition coefficients by study of the size distribution
of sulphated:stone leaving the . comhustors^b-y .various routes, but there
was insufficient time to do this.
3.4 Constants in reactivity equation;,. These are listed, together with
values of Uc, the limiting utilization, in Table 2. The curves of
reaction rate coefficient vs utilization corresponding to the values of
these constants used are compared with the experimentally determined
. curves in Figs. 2 to 5.
3.5 Recirculation cyclone efficiency; The test series for which model
simulations were performed, which used solids recycle were: Task II,
Test Series 1, 2 and 4, and Task III, Test Series 2.
On the basis of the cyclone design data,.the.cyclone efficiencies
for the various particle size groups were assumed to be as shown in
Table 3.
In addition, to show the,.general effect..upon retention, some runs
of the model.were made for Task I, assuming the same cyclone efficiency
for.each particle size group, at a range of efficiencies. Results are
shown in Fig. 6.
There is no proof in any test.that .the cyclones were functioning
..as they were intended. Any failure.of the.diprleg.system for returning
the collected particles to the bed would reduce the efficiency of the
cyclones.
4. .GENERAL. OBSERVATIONS. ON ..PERFORMANCE OF MODEL
Early experience in running a simpler version of the model not
incorporating regeneration by.attrition,.with-input data derived from
operating conditions and plant geometry.appropriate to Tasks I, II, III
and V.in;, the current contract, showed that, in most cases, the predicted
retention was equal to or less than the measured':retention. Closer
examination of the results, particularly of the utilization of each
size fraction, showed that there were .two .principal reasons for the
low predicted retentions:
A6.13
-------
(i) When using previously reported values for elutriation constants,
the model predicted that the fine particles would be elutriated from the bed
so quickly that they would not have time.to.react to.any great extent.
(ii) As mentioned before, the low values determined in the
laboratory for the limiting utilization of the limestones, particularly
1359, meant that if there were no attrition of the sulphated layer,
the retention measured on the plant could not possibly be attained. An
example of,.this is in the tests in Task V;,>using limestone 1359. The
size distribution of this limestone was such that only 70% of it would
Sul^W
be.retained in the bed, yet the actuaL retention measured at a Ca/S mol
ratio of 1 was 44%, in spite of the-faet^that the laboratory experiments
indicated zero reactivity at less than 15% utilization for particles of
non-elutriable size. It was because of this fact (which was also
apparent..in other tasks, to.a. lesser extent) .that the procedure for taking
into account the exposure of fresh surfaces..by attrition.was introduced.
4.1 Elutriation
The two items in the input to the, mathematical model which might be
expected to.have a bearing on the.residence time of fines in the system,
and about which there is some uncertainty....regarding the actual figures
to be inserted.when preparing the input data, are the elutriation
constant, K , and the grade efficiencies.of the recirculation cyclones -
especially when these are internal cyclones. The cyclone efficiency is
dependent upon effective functioning of' the;.diprrleg, for, return of the
collected solids to the bed, and. these .have..been a'frequent source of
trouble in the running of fluidized-bed combustors.
Fig. 7 shows the effect of variation in n, (the exponent applied
in the calculation of K1 (Equation (16) ),„ on. predicted retention, and
Table 4 shows how increase in ncau**s an increase in the utilization
of particles not quite large enough to be retained in the bed.
4.2 Attrition
, The..effect, of -attrition..of .aa^outer sulphate layer is most striking
in,those cases where the limestone: reactivity falls off rapidly with
increase in sulphation, as in Limestone 1359. Fig. 8 shows how increase
in K, from 0 to 0.025 brings the predicted retention up very markedly to
values approaching those found on the plant,.. The..shapes of the
A6.14
-------
predicted and measured curves in Fig. 8 are not alike. As mentioned
later (Section 4.3) formation of S02 above the bottom of the bed, and
gas bypassing in bubbles may be responsible for this difference in shape.
With limestone 18, however, the effect of variation in K^ is not
nearly so pronounced (Fig. 9). This is because this limestone is more
reactive in a partially sulphated state than is Limestone 1359. The
way in which attrition allows fuller utilization of the limestone is
illustrated in Table 6. The limiting, utilization of this limestone,
in the absence of attrition, is 57.4%.
4.3 S02 generation pattern
In a few runs with the model, it was assumed that the SC>2, instead
of being all generated at the bottom of the bed, is all generated between
the bottom and the top.of the bed, the.rate, of generation falling linearly
from a maximum at the bottom to zero at. the top of the bed. The constants
in the generation equation were chosen so that all the sulphur in the coal
is converted to S02-
One set of results., (Fig. 10) shows that the evolution of S02
throughout the bed makes little difference to predicted retention at
retentions of less than about 80%, but above this it can account for
substantial differences in the shape of the retention curve.
It is impossible to guess at the form of the S02 generation function
occurring.in practical combustors; it will probably depend on the chemical
reaction.mechanism by which S02 is formed from the sulphur compounds in
the coal and coal ash, on the vertical profile, of:oxygen concentration in
the bed, and possibly also on the physical behaviour of coal in the bed -
swelling or. breakage. It is probable, however, that the two cases tried,
viz. generation only at the bottom of the bed,: and generation throughout
the bed represent extremes in between which all the practical systems lie.
4.4. Absorption of S02 in the gas, spaee above the bed
In all cases this was found to be negligibly small, because of the
short residence times of particles above the bed compared with the times
needed for significant amounts of reaction.
A6.15
-------
COMPARISONS. WITR RESULTS FROM • THE CURRENTirrCQNTRACT PROGRAMME
The retentions predicted by the mathematical model are expressed
as a percentage of sulphur in the coal fired. There is. an implicit
assumption that all the sulphur would..(in the absence of limestone) be
converted to S02 and appear in the combustion gases. It is therefore
more appropriate to compare the predicted retentions with experimental
S02 reductions rather than with experimental,:sulphur retentions since
any inaccuracies of the model due to the assumptions of complete
sulphur release in the absence of.limestone.will then be eliminated.
This course has been adopted in comparisons for all the Tasks.
5.1 Task I
5..L..1 Test Series 1
This test series used Pittsburgh.coal, sized -1/16 in to zero,
and Limestone 18 similarly sized. The allocation to particle size groups
by the mathematical model gave a good agreement with the actual size
distribution in the case of the coal, but not quite so good in the case
of the limestone (Fig. 11). The input data to the model were: ash
top size 1300 ym, ash median size 460 vim; limestone top size 1200 yn,
median size 200 ym and bottom size zero.
It was learned-shortly before this Appendix was prepared that the
actual bed depth in most of the tests.in-this series was 2.2 ft, whereas
the nominal: depth of 2 ft had been used: in the: computations. The result
of.; ,thi&.,.input, error -would, be .the,,, s.light. underestimation of retention.
Some idea of the magnitude of the error may.be gained by comparing curves
A and B in Fig. 12.
The measured SOo retention on the plant is higher than the model
predicts when using values of n close.to-1 especially at a Ca/S mol ratio
of about 1 (Curve A, Fig.^t*). Reasons for this.have been discussed
(4.1 and 4.2), but even when using values for n and K^ which are almost
outside.the probable ranges, the retention:is not predicted correctly.
There is obviously some factor which is not correctly simulated in the
model. Possibilities are, (a) greater sulphation of the fines in the bed
than is predicted by the model and (b) inaccuracies in the procedure used
by the model for taking into account, the,effect of particle attrition.
A6.16.
-------
With regard to the first of these possibilities, it was not possible,
for practical reasons, to measure in the laboratory the reaction rate
coefficients of very fine particles. However, simple calculation shows
that.the rates would have to be several orders of magnitudes higher to
compensate for the much shorter residence time of the.fines as compared
with.the. material which is too coarse.to.be elutriated. Fig. 13 shows
how the residence time varies with mean particle diameter, and also
illustrates the effect that variation;.in n has on the residence time of
the fines.
Possible reasons,for the different shapes .of. the retention vs Ca/S
mol ratio curves in plant and model, in: Task..I. have already been discussed.
They are, (a) the generation of 862 throughout the bed, and (b) gas
bypassing in bubbles passing up through the bed.
5.1-..2.... Test Series 2
This differed from Test Series 1 in that -1/8 inch to 0 coal and
limestone were used, and fluidizing velocities of 8 ft/sec and 4 ft/sec.
The comparison shown in Fig. 14 is for an 8 ft/sec test.
A reasonably true fit to the measured retentions is obtained by
inserting K
-------
The curves used to represent,.the reactivity of.the stone (Fig. 3)
are. the least satisfactory fits to the laboratory data of all the stones..
The reason for choosing cubic equations to represent reactivity vs
utilization, rather than linear onces,.as would appear at first sight
to be best, is that it is known that dolomites.in general can be
sulphated to a much greater extent than limestones, even though the
reaction rate may fall to a very low level at high utilizations. The
equations for calculating reactivity..used-in running the model will
over-estimate.retention, because of the positive error they introduce
in the 20-40% utilization range.
The effect of C02 partial pressure-has been ignored because it
was shown in earlier work (Ref. 6, p..2) that, partial:pressures encountered
in fluidised combustion, under these conditions of temperature and pressure,
did not.seriously affect the reaction rate when, using dolomite.
,5...Z..2. : Test Series 2 ;
These tests used Pittsburgh coal and dolomite 1337, again without
fines,,and having a top size 1588 ym, median size 930 ym and bottom size
400 ym. Once again, therefore, the value taken for the elutriation
constant n was not particularly critical.
In choosing the constants a to a., in the reactivity equation, a
similar device was used as in the case of U.K. dolomite, and it was
assumed that U had values approaching unity (Fig. 4).
Results predicted by the model for the two cases in which all the
S02 is generated at the bottom of the bed, and all is generated between
the bottom and the top of the bed are shown in Fig. 10. As in the
previous test series, good agreement is obtained without using high values
of the exponent n, but as pointed out above, little of the coal feed was
of a size small enough to be elutriated . (without breakage)-from the bed.
The.experimental measurements show that the case in which SO^ is evolved
throughout the bed gives the best-fitting curve.
5.2.3 Test Series 4
This series again used Pittsburgh coal and dolomite 1337. The
dolomite had a wide size distribution -1600 ym to zero - and the
A6.18
-------
procedure used by the model for allocating mass fractions to size groups gave
a close agreement with the actual size distribution.
In contrast to the earlier test series in Task II, the model in this
case underestimated the retention (Fig. 16). Since the main difference
between this test and Test Series 2,is in the size distribution of the
limestone, it may reasonably be inferred that the discrepancy lies in
the fact that the model predicts that the fines will be elutriated from
the, bed ..before they have had time to react to any great extent. Fig. 16
shows how an increase in n brings the predicted retention up towards the
measured values.
.5.3 Task III
Only one comparison has been made for Task III, namely with Test
Series 2, in which a range of Ca/S ratios was used in the course of a
run of long duration, using Pittsburgh coal and Limestone 18, both sized
3200 ym to zero. The combustor incorporated an internal recirculation
cyclone, designed to collect particles larger than 50 Urn in size; and
the assumed values of a appropriate to the different size groups are
shown in Table 3.
The predicted retentions for two cases are shown, together with
measured S02 reductions in Fig. 17. The solid line represents the case in
which all the S02 is formed at the bottom of the bed, and n = 1; the
broken line represents the case in which the S02 is all formed between
the bottom and the top of the bed, and n = 0.6. It should be noted that
3
it was on this combustor that Field and LittleJohn determined elutration
rates using a radioactive labelled tracer in the coal feed. The values
they found corresponded to a value for n of only about 0.6, but these
values were determined when firing a coarse coal (1/4 in to zero), which
required a high velocity in the transport air. It was suspected that
this air,initiated bubbles which caused the elutriation of a lot of the
fines before they mixed in with the bed.
When putting n equal to 0.6 the model predicts very closely the
retention that was found in practice. The only two tests which fall
appreciably off the line given by the model are 2.16.1 and 2.16.2,
neither of which used recycle of fines, so that the input data for the
model was not strictly applicable to these two tests.
A6.19
-------
5.4 Task V
The only comparison made for. Task,,V was with the experiments in
Test Series 1 which used 10 mesh to zero coal and limestone (1359) and a
fluidizing velocity of 3 ft/s. The comparison is shown in Fig. 8 which
well illustrates the importance of attrition when using this limestone.
There.is little doubt that the better retention achieved later in
tests 3,5 and 3.6 using -120 mesh limestone was due to the higher limiting
utilization possible with fine particles, although because the laboratory
method for measuring reaction rates.could .not be used for very fine
particles this cannot be confirmed. The model would predict an opposing
effect due to increased elutriation of the finer limestone, so once again
there seems to be something that requires further clarification, i.e.
how the fines are able to pick up so much S0£ in the limited time available.
5.5- -Pope, Evans and Robbins Data
In an attempt to reduce this data to a form more suitable for
comparison with the mathematical model, a statistical treatment of the
a
results was carried out. This showed that over the range.of experimental
conditions,.retention data could be fitted (for one size of .a particular
limestone) by an equation containing only temperature ,and.stoichiometric
ratio as variables.
.Comparisons were made for the cases in which (a) coarse and
(b) fine Limestone 1359 were used with unwashed coal (10.7% ash), and
(c) fine Limestone 1359 was used with washed coal (7.2% ash). The top,
median and bottom sizes respectively for coarse limestone were estimated
to be 1400 ym, 1200 ym and 1000 ym respectively (-14 + 18 U.S. mesh),
and for fine limestone 432 ym, 216 ym and 0 ym respectively (-325 U.S.
mesh).
Rate data, the same as determined in the present Task VIII experiments,
was used; K for coal ash and limestone was taken as 0.02, and n as 1.0.
A6.20
-------
The statistical correlations indicated the following equations for
retention:
Case (a):
R = exp (- 2.8603 +• L. 180. In y + 5920/T)
-Cases (b) and (c):
R = exp (2.4312 + 0.562 In y + 0.194 In t + 1797/T)
where R is percentage retention;
y is Ca/S mol ratio
t is gas residence time (seconds)
T is bed temperature (K)
Retentions predicted by the model (n = 1 and K, = 0.02) and as
given by the above two equations are plotted in Fig. 18.
There is no similarity at all between the predicted retentions
and those derived from the statistical analysis. In particular,
whereas the plant gave better retention when using fine limestone,
the model predicts very low retention. No explanation can be
offered for these differences. Lack of familiarity with the PER
plant and experimental techniques prevents any helpful speculation.
6. DISCUSSION
Probably the most outstanding feature that has come to light in
application and testing of the model against plant data is that whereas
agreement is in general good when the limestone fed to the bed does not
have a very large fraction of material fine enough to be elutriated; the
predicted retention is lower than measured when there are significant
amounts of fines. This is well illustrated by comparing Test Series 2
and 4 of Task II (Figs. 10 and 16) and also by the Pope, Evans and
Robbins results.
This indicates a serious lack of knowledge, at present, concerning
the mechanism by which fine particles are elutriated from the bed. The
procedure used in the model to calculate terminal velocities is well-
established, and has been tested independently and shown to give values
that agree well with practical experience. Published data on elutriation
A6.21
-------
3 9
constants shows a wide scatter ' , but to account for the utilization
of the fines in some of the plants, for example the 36 in x 18 in
combustor used in Task I, requires the use cf elutriation constants well
outside the scatter of existing data.
Amongst possible explanations, neither of which.can be strongly
argued on technical grounds,are (a).that the particles become sticky
when in the combustor, so that the fines tend to adhere to larger particles,
and (b) that the fines adhere to refractory or metal surfaces above the bed
and remain there for long enough to absorb appreciable amounts of S02 before
breaking away again. More detailed study of the mass balances made in the
experimental programmes, and of the distribution of sulphur between the
various particle sizes in the effluent might throw more light on this
question, but. lack of time has not allowed a systematic analysis of the
results with this objective.
The other major result of the comparisons made between the model
and the plants was the development of a fairly simple procedure for
incorporation in the model to allow for the exposure of fresh limestone
surfaces by attrition. Inspection of the plant measurements, alongside
the laboratory reactivity measurements, shows that a higher degree of
utilization is often achieved in the plant than would seem possible from
the laboratory experiments.
It has been suggested recently that exposure of the limestone
alternately to oxidising and reducing conditions might.lead to greater
penetration of sulphur than under continuously oxidising conditions.
It cannot be said, at present, whether this is the true explanation, or
whether attrition by itself, or a combination of the two is the cause.
The simple expedient adopted in the model works satisfactorily, however,
and any further development of the model should include an attempt to
correlate K2 evolution pattern (i.e. all at the bottom
of the bed or all within the bed) shows that the case in which the SC^
is assumed to be all evolved within the bed gives curves closest in shape
to the experimental ones (Figs. 10 and 17).
A6o22
-------
The curves fitting the experimental results in Figs. 9, 12, 14
and 16 also show a steeper gradient close to the origin and a less
steep gradient at high Ca/S ratios than the curves given by the model when
assuming S02 evolution all at the bottom of the bed. A better fit could
probably be obtained by assuming evolution.throughout the bed, but there
has not been time to do the computing required.to.verify this.
When the construction of a mathematical model was first undertaken,
it was visualized that benefits would result in two directions: firstly,
by throwing light on the relative importance of the various mechanisms
entering into the process the direction in which further effort might be
most profitably employed would be indicated; and secondly, the model
could be used, in conjunction with laboratory measurements to predict the
performance of a new plant or limestone, e.g. for.purposes of an economic
assessment.
The first of these aims can be said to have met with a fair measure
of success, in that aspects of plant behaviour which have a marked effect
upon retention have been shown up. The second aim cannot yet be regarded
as having been fully achieved. Whilst the performance of individual
plants can be satisfactorily explained by the model, there are differences
between one plant and another that.can best be explained by differences in
.the rate of elutriation of fines and in the rate of particle attrition
between the various plants. The reasons for these differences, and how to
predict-them from a knowledge of plant.design.is not yet clear, and it is
recommended that any future work should include attempts to gain a better
understanding of these aspects.
The following summarises the general predictions given by the
model of the effects of major input variables on retention:
.(i) Bed height
Increase in bed height causes an increase in retention for given
firing rate and ratio of Ca/S in the feed. (Fig. 12). This increase in
retention is due mainly to the increase in residence time of limestone
in the bed, allowing greater sulphation of the particles. An alternative
way of looking at it is that the gas has a greater opportunity of coming
into contact with limestone particles during its passage through the
A6.23
-------
bed, because there is a greater weight of limestone in the bed.
The two explanations are not inconsistent, but the mathematical model
approach concentrates on the former.
(ii) Calcium; sulphur ratio
The model is not constructed in such.a way that the effect of
Ca/S ratio can be reduced to a simple analytical equation. The general
shape of most of the curves of retention .against Ca/S ratio is a
progressively diminishing gradient, but whereas in some cases (e.g.
curve B in Fig. 12) the gradient is steep up to over 90% retention, in
others.(e.g. curve C in the same figure) a more gradual decrease in
gradient occurs. The model predicts 100%.retention, when there is a
sufficiently high Ca/S ratio, and when it is assumed that all the S02
is formed at the bottom of the bed. When it is assumed that S02 is
formed throughout the bed however, 100% retention may not be reached
at all. This mode of SQ2 release appears.the more likely.
The effect of increasing Ca/S ratio, other conditions being
unchanged, is to increase the weight of limestone in the bed, and to
decrease the utilization of the stone, at the same time decreasing
the mean S02 concentration in the gas stream. The interrelation of
these quantities is determined by the reactivity function, f (U),
and solution requires an iterative process.as in the model.
(iii) Gas velocity
Alteration of gas velocity is difficult in practice without
at the same time altering other variables. For example, when doubling
the air flowrate, the coal rate must also be doubled in order to keep
combustion conditions comparable. This means that the SO- generation
pattern may be altered. Also, the limestone .addition rate has to be
doubled in order to keep the Ca:S ratio the same.
The model predicts two effects, both acting in the same direction.
Firstly, because the limestone throughput is doubled for the same bed
capacity, its residence time will be halved, and the time available
for its sulphation will be halved. Less efficient use of stone will
result, and retentions will be lower (compare curves A and C, B and D
in Fig. 12). The second effect is that because of the higher velocities a
A6.24
-------
greater proportion of the limestone feed will be elutriated, and
the residence time of these particles will be reduced very greatly.
The importance of this will depend upon the size distribution of the
acceptor.
As stated earlier, the model contains the assumption that
gas/solids contact time is not a rate-controlling factor. The
reduction in contact time on increasing gas velocity does not therefore
have any effect upon retention.
Fig. 12 predicts that the fall-off in retention caused by increasing
fluidising velocity can be recovered by increasing the bed depth approximately
in proportion to the increase in velocity. This may not be economic with
operation at atmospheric pressure, but may be acceptable in pressurized
combustors.
(iv) Particle size
Reduction in particle size, other conditions being the same, results
in more elutriation of the stone. Indications from laboratory measurements
of reaction rate are that the increase in reactivity with decrease in size
is not sufficient to compensate for the decreased residence time, and a
reduction in retention is predicted, (Fig. 18). It might be expected that
with very fine particles a minimum retention might be reached, beyond which
increase in specific surface area outweighs decrease in residence time, but
laboratory rate data for such fine particles are not available.
(v). Temperature
Temperature can be expected to influence sulphur retention mainly
via its effect on the rate of reaction between lime and SC>2. Feeding
the data from laboratory measurements of the effect of temperature on
reaction rate for limestone 18 into the model led to predictions which
showed the correct trends, but under-predicted the magnitude of the
effect, Fig. 19.
(vi) Recycle
The model predicts that efficient recycling of elutriated fine
particles should improve the sulphur retention (Fig. 6).
A6.25
-------
Confirmation of this prediction by the plant experimental results
is not positive, because the number of comparisons made was not as great
as was originally hoped, and there is some uncertainty also as to
whether or not the experimental recycle systems were always operating
as intended. This may be the reason why two tests showed no improvement
in retention when using recycle, while others (Table 7) showed a sub-
stantial improvement. For example in Task I, Test Series 4 at 2 ft/s
the sulphur retention was increased from 86% at a Ca/S mol ratio of 2.2
to 99% at a ratio of 1.6 by recycling of fines, whereas in Task III, two
comparisons showed an improvement in retention after adjusting for Ca/S
ratio, one showed little difference, and one showed an adverse effect.
Table A6.7 Effect of recycling fines
Test No.
I
I
III
III
III
III
III
III
III
III
Test No.
4.5
4.6
2.9
2.4
2.16
2.1
3.3
3.1
3.4
3.2
Acceptor
size, ym
-1680
-1680
-150
-150
-3175
-3175
-3175
-3175
-3175
-3175
Velocity
ft/s
2.1
2.2
8.1
8.1
8.1
8.1
6.6
6.4
10.9
10.8
Ca/S mol
ratio
2.2
1.6
1.5*
1.9
2.2*
1.6
2.8
2.7
2.6
2.7
Recycle
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
SO? reduction !
% i
86
99
50*
32
60 *
55
82
3
85 1
77
77 |
* Average of results for two tests.
7. COMPUTER PROGRAMME
The following four pages contain a print-out of the programme finally
developed, in Elliott-Algol code, for running the mathematical model on an
/Elliott 4120 series computer.
A6.26
-------
"FOR "I :=CONSTB"STEP"1"UNTIL"COUNT"DO""BEGIN"
UF:=2t(2#I+3)/«l2;VEL(K2,UF,RHOG,MU,UTL);
"IF"LI/UTL<1"THF.N""B£GIN"KAPPALCI]:=0;"GOTO"AVOID2"END";
KAPPALCI3:=(Y*(LI/UTL-1)T.7)TFF;
AVOID2:"IF"KAPPALCI]>10-4"THEN"KL[ID: = "TRUE""ELSE"
"BEGIN""IF"KLCI-l]"THEN"IA:=I-l;KLCI]:="FALSE""ENDH;
"IF"KAPPALCI]>RT"THFN"KAPPALCI J:=RT;
"END";
FRED: UF:=2M2*IA + 3)/,ol2*(l + G/10);
"IF"G=31"THEN""GOTO"MILLIE"ELSE"VEL(K2,UF,RHOG,MU,UTL);
"IF"LI/UTL<1"THFN""REGIN"KAP:=0;"GOTO"AVOID4"END";
KAP:=(Y»(LI/UTL-l)t.7)tFFi
AVOID4: "IF"KAP>l.-4"THEN""BEG!N"G:=G + l;"GnTO"FREp"END";
MILLIE:FRLCIA]:=FRLCIA3/2*.016667*G»(FRLEIAI+FRLCIA+1]);
"COMMENT" CALCULATIONS OF BED COMPOSITION;
BWNE:=BW; WAOFC03 : =WLOFC03 : =0 ;
"FOR" I :=CONSTA"STEP"1"UNTIL"COUNTA"DO""8EGIN"
"IF"KACI]"THEN"
"BEGIN"NACO[I3.:=FRA[I3*ASHR/(1-CYCCI3); WABC ID : =WACOC I ] /KAPPA AC I 3 ;
WAOFCI]:=0; BWNE:=BWNE-WABCI3 "END" "ELSE"
MBEGIN"WACOd3:=0; WAOFC 13 : =FRAC I3*ASHR "END"; " .
WAOF [ 0 ] : = WAOF C 0 ] +W AOF C I D I " END" ;
"FOR"I :=CONSTB"STEP"1"UNTIL"COUNT"DO""BEGIN"
"IF"KLC I] "THEN"
"BEGIN"WLCOCI]:=FRLCn*VARC3.]/(l-CYCCn).;
*L8C 13 :=WLCO[I3/KAPPALCI3; WLOFC I 3 : =0 ; BWNE : =BWNE-WLBC I ]
"ENn""ELSE""BEGTN"
WLCOCI]:=0; WLOFCI]:=FRLCI]*VARC3] "END";
WLOFCO]:=WLOFCO]+WLOFCI3JFRCID:=FRLCI3»VARC33
"END";
OFR:=WAOFCO]+WLOFCO]; TB : =BWNE/OFR; CONST : =COUNT;
"FOR" I :=CONSTA"STEP"1"UNTIL"COUNTA"DO"
" IF" "NOT "K AC ID "THEN "WABC I ] : = WAOFC I ]*TB ;
"FOR "I : =CONSTB" STEP" 1" UNTIL" COUNT" DO11" IF" "NOT" KLC I] "THEN"" BEG IN"
WLBCID:=WLOFCI]«TB;
CONST:=CONST-1 "END";
"IF"KEY(5)"THEN""8EGIN"P(KAPPAA);PL(KAPPAD ; P ( WAS ) ; PL ( WLB ) ;
P ( WACO ); PL ( WLCO);P(WAOF); PL (WLOF); "PRINT1" 'L* » , FREEPO I NT ( 6 ) ,DIGITS<2) ,
BW , BWNE , OFR , TB . CONST "END" ;
"COMMENT" CALCULATIONS PRELIMINARY TO SOLUTION OF
ABSORPTION EQUATIONS;
"FOR" I : =CONSTB."STEP"1"UNTIL"COUNT"DO"
TBARC I ]:="IF"KL[I 3 "THFN"1/KAPPALC I ] "ELSE"TB ;
"FOR" I :=CONS TB" STEP"! "UNTIL "CONST" DO "UFACCI3:=l;
"FOR" I : = (CONST + D" STEP"! "UNTIL" COUNT "DO" "BEG IN"
RE: = (l-UCCI])t .3333;"IF"KDL>i.-6"THEN""BEGIN"UFACCI]:=-LN(RE)/KDL»3600;
UFACCI ]:=FRC I ]/(FRC ID + WLBC I D/UFACC I D«EXP(-UFACC I 3/TBARC I D ) );
"IF"KEY(6)"THEN""PRINT"' 'L* * , FREEPO I NT ( 6 ) , UFACC I ] "END" "ELSE"UFACC I 3 : =1"END" ;
"FOR" I :=CO'NSTB"STEP"1"UNTIL"COUNT"DO"
"BEGIN"
"IF""\'OT"KLCI3"THEN"CYCCI3:=0; GR[ I 3 : =FRC I 3/ ( 1 . 0-CYCC I 3 ) ;
XX:=TRAR[ I3*KSC 13; RMT : =BMT + WLBC I 3 ; FRT : =FRT + FRC I 3 ;
GRT:=GRT + GRCIJi RA T I OC I 3 : =SR*GRC I 3/CVR ; UCI3: = .2J
QQC I ] :=XX; FPSC 13 : =0 . 0 ; KGC I 3 : =GR[ I 3*XX*SR*RHOG/ ( MFR»Z ) ;"END";
A6.27
-------
"COMMENT" WITH FIXED CORRECTION, SOLVE BY APPROXIMATE METHOD;
DONJ"PRINT""L'TYPE TRIAL VALUE Of KK ' ; MREAD"READER<3»KK J
CYCLE:MEP:=MEZ;
NELLY: EMS llTHEN''"PRINT"''L'SFREEPOINm)>UP.FU;FUl,FO.Fi;
UN:="IF"ABS(F1)>»-6"THEN"UP-FO/F1"ELSE"UP;
"IF"UN>l"THEN"UN:=l;"IF'1UN<0"THENnUN: = 0;
"IF"ABS(UN-UP»i.-4"THEN""BEGIN"UP:=UN;"GOTO"ROOT"END";
"COMMENT" REVISE ESTIMATE OF K;
UCn:=UN;"IF"UCI]>l"THEN"UCI]:=UN:=i;UFUN(UN*RE) ;PORTCI]:=KGCI]*FU;
MF"'UN*RE>UCI"THEN""BEGIN"Um:=UCI/RE;PORTCI]:=0.0*END'1;
XX:=XX + PORT[n"END";
"COMMENT" TEST CHANGE IN K ; " I F"KEY < 4 ) "THEN"
"PRINT""LK ' ,FRFEPOINT(6) ,ME,MBAR,XX;
HIF"KEY<3)"THEN"WAIT;MIF««KEY<3)"THENH
"BEG IN" "PR I NT"' 'L' s , FREEPO I NT ( 6 ) , XX ; "GOTO" DON" END" ; " If " ABS( ( MEP-ME)
/(MEP+ME) )>»-4"THEN""BEGIN"
MEP:=ME;KK:=XX; "GOTO -NELLY "END";
"PRINT"FREEPOINT(6),CVR»UCI"THEN""BEGIN"UN:=UCI;DEL:=UCI-UP"END";
XX:=XX-DEL*RATIOCI];ULCI]:=UN"END";M:=XX"END";
"PR1NT""LX %,FRFEPOINT(6),M,' ' L2 * * ;
"COMMENT" TEST CHA.NGE AT CYCLONE;
"IF"ABS(MC-M)/»-4"THEN""BEGIN"MC:=M;
"FORM :=CONSTB"«;TEP"1"UNTIL"CONST"DO"EPSCI]:=ULCI]-UCI];
"IF"KEY(3)"THEN"WAIT;"IF"KEY(3)"THEN""GOTO"DON"ELSE"I1GOTOMCYCLE
"END ""ENID" J
"COMMENT" OUTPUT RESULTS;
PUNCH(l) ;"PRINT"' 'R50L* '. FREEPO INT ( 5 ) ,
"LXAIR RATE = »,VARCll,' KG/S'L»COAL RAJE = ',
VARC2D, 'KG/S'L*LIME RATE = s , VARC3] , ' KG/S' LI * * ,
"L'MASS FLOW OF SO? IN ABSENCE OF ABSORPTION = %,
FREEPOINT(6) ,MFS, ' KG/S*,
"L* AT EXIT FROM BED = S,ME*CVR,
"L^ AT CYCLONE = SM»CVR,
"L'EFFECTIVE RATIO OF FLOWS, CAO/S02 = * , SR*FRT/MFS,
' 'L'PERCENTAGE RETENTION OF S02'S15*= * , ( MFS-M»CVR) *100/MFS,
"L2SPARTICLE GROUP UTILISATION IN BED UTILISATION AT CYC. *
"FOR "I : =CONSTR " STEP" 1" UNTIL" COUNT "DO"" BEG IN"
"PRINT""LS5^,OIGITS(2),I,"S19^,ALIGNED(1,3).UC-I];
"IF"I"LF"CONST"THEN""PRINTM/ 'S15' * , AL I GNEDd , 3 ) , ULCI 3 "ELSE"
"PRIMT""S17%-» ;" END"; "PR I NT"' 'LH% *;
VARC3D:=VARC3] + ZZZ;tlIF"SR*FRT/MFS<3.0"THEN""GOTOuRAT;
"END""END";
A6.28
-------
KORANGAR6 DWG EX FVB AND BBM;
"BEGIN""INTEGER"CONST,CONSTA,CONSTB,CONSTG,COUNT,COUNTA,G,IA,
I,J,JJ,NG;
"REAL"ASH,ASHR,B2,BEDD,BEDR,BETA,BMT,BSA,BSL,BSLR,BW,BWNE,CAO,CFR,CVR,
DB,DEL,DT,DVOL,DZ,FO,F1,FF,FRT,FU,FU1,GRT,INT,K1,K2,KAP,KDA,KPL,KK,LI,
M,MO,M8AR,MC,ME,MEP,MEZ., MFR,MFS,MSA,MSAR,MSL»MSLR»MT,MU,OFR,PA,PN,PP,RE,
RHOA,RHOG,RHOL,RT,RTAB,S,SFR,SR,TB,TSA,TSL,UCI,UF,UN,UP,UTA,UTL,V,VB, •
V.C,VG,YOID,VpL,WS,Xl,X2iXX,YiYY,ZiZH,ZZ»ZZZfBETAl.Mi;
BINTEGER""ARRAY"NEi:53;
••REAL"'" ARRAY" A ACI: 10,0:33, CYC ;EPS.FR,GR,KAPPAA,KAPPAL,
KG,KS,PORT,QQ,RATIO,TBAR,U,UC,UFAC,UL,WAB,WACO,WLB,WLCO[J.:l03,Ei:i:63,
lNC»VARCi:53fFRA.FRL.MAOFfWLOFCO:113;
"800LEAN""ARRAY"KA,KLCi:i03; PREFIXC V);PUNCH(3);
"BE.GIN"
"PROCEDURE" P(A); "ARRAY"A;
"BEGINnuPRINTa"Li%,DIGITSC2),CONSTA,SAMELINE,' - VCOUNTA,
' 'L v ';"FOR"I:=CONSTA"STEP"1"UNTIL"COUNTA"DO""BEGIN""PRINT"
SAMELlNE,SCALED<3>,ACI3;nIFllI=5"THEN"uPRINT>" 'LS6' '"END""END";
"PROCEDURE" PL(A); "ARRAY"AJ
"BEGIN""PRINT""L^,DIGITS(2),CONSTB,SAMELINE,' - \COUNT,
"L% VJ"FOR"I :sCONST8MSTEP"lwUNTILl>COUNTnDO'"1BEGIN'l"PRINT11
SAMELINE,SCALED(3),AC I]J"IF"I=5"THEN""PR INT"''LS6' %"END""END";
"BOOLEAN""PROCEDURE"KEY(N)J
"VALUE"N;HI-NTEGER"N;
"BEGIN""BOOLEAN"BOO:
"CODEM5SDECS$N
%LDK$N
%CTOM
%SMRL
%AND:L$I
%STSBOO
;KEY:="NOT"BOO"END«;
"PROCEDURE" WEIGHT(A,B»C,D);
"ARRAV'A; "REAL"B,C,D;
"BEG I N"" INTEGERS; "RE AL"L;
L:=LN(2);Kl:=L/LN(B/C);K2:=-Kl»LN(B);X:=4096;
nFORHI:=0"STEP"l"UNTlL"ll"DO"ACI3:=0;I:=11;
TRYT:"IF"B"LE"X"THEN""BEGIN"I:=I-1;X:=X"DIV"2;
"GOTO"TRYT"END"; X:=4;COUNT:* I;AC I 3:=1;I: = I-1;CONSTB;=0;
TRYB:"IF"D"GE"X"THEN""BEGINHCONSTB:=CONSTB+i;X:=X*2;
"GOTO"TRYB"END";
"FOR"I:=CONST9"STEP"1"UNTIL"COUNT-1"DO"ACI3:=EXP(K1»L*(I+2)+K2);
"FOR"I:=COUNT"STEP"-1"UNTIL"CONSTB"DO"ACI3:=ACI3-ACI-1];
"IF"KEY(6)"THEN"PL(A) ;
"END" OF PROCEDURE FOR ALLOCATING PARTICLE SIZE GROUPS;
"PROCEDURE"VEL(A,B.C.D,E);"REAL"A,B,C»D,E;
"BEGIN"E:=A*B;KE:=C»E*SQRT(B)/D;RE:=24«RE;
MlF"RE<120"THEN"MEP:=RE/24+RE*RE*(-2.3363»-4+RE*
(2..0l54»-6-RE»6.9105..-9) )"ELSE"
•"BEGIN"XX:=LN(RE)/2.30258;MEP:=EXP(2.30258«(-1.29536+
XX»(.9'86-XX«( . 046677-1.1235i«-3*XX») )"END";
E:=E*H£P*24/RE; "IF"KEY(2>"THEN""PR INT"''L4 ' ,FREEPOI NT(6),E
"END"OF PROCEDURE FOR TERMINAL VELOCITY;
A6.29
-------
" urUNlUj; "VALUE"U; "KfcAL"U;
"8EGIN"FU:=AACI,0]*U*{AACI,1]*U*(AACI,23*U*AACI,3]));
FUl:=AACI 11] + U*(2.0*AACI,2D + U*3.0*AACI,3]);
"END";
"REAL""PROCEDURF"GEN(ZZ); "VALUE"ZZ; "REAL"ZZ;
GEN:="IF"ZZ "ELSE" 0.0;
"PROCEDURE" EMS(KK); "VALUE"KK; "REAL"KK;
"BEGIN"INT:=0,0;PP:=GEN(0.0);Xl:=KK*Z;
"FOR"I :=1"STEP"1"UNTIL"JJ"DO""BEGIN"ZZ:-I*DZ;X2:=EXP(-KK«ZZ);
PN:=GEN(ZZ)/X2;INT:=INT+.5*(PP+PN)*DZ;PP:=PN;
"END";
ME:=(MO+INT)»EXP(-X1>; MBAR:=(MEZ-ME)/X1J
"END" OF PROCEDURE FOR ME AND MBAR;
"COMMENT" INPUT DATA AND PERFORM INITIAL CALCULATIONS,
"READ11PA,DB.ZiVOL.VniD,FF,ASH.S,TSA.,MSAR,TSL.MSLRiBSLR.RHOAfRHOLi
KDA,KDL,CAO,M1,ZH,BETA1/VARC1],VARC23,VARC3],VARC43,ZZZ,.NG,JJ;
"FOR"I:=1"STEP"1"UNTIL"10"DO"
" RE AD " UC [ I ] , KS [ I ] , C YC C I D , A A [ 1, 0 ] , A A C 1,13 , A A [ I , 2 ]., A A [ 1, 3 ] ;
RAT:"BEGIN"PREFIXC M;PUNCH(3);
VC:=.7854*DB*D3*Z; VG:=VC*VOID;
VB:=VC-VG; MFR:=VARC1]+VARC2]»(1-ASH/100);
CVR:=MFR*VARC4]/337.8/PA; RHOG:=MFR/CVR;
ASHR:=VARC2]*ASH/100J SFR : =2*S»VARC2]/100 ;.
MT:=SFR/CVR; BEDR!=ASHR+VARC3];
BEDD:=BFDR/(ASHR/RHOA + VAR[3VRHOL>;
BW:=VB*BEDD; TB:=BW/BEDR;
MSA:=MSAR*EXP(-KDA/3600«TB);
MSL;=MSLR*EXP(-KDL/3600*TB);BSL:=BSLR*EXP(-KDL/3600»TB);
"IF"BSL<4"THEN"BSL:=4;
HS:=CAO/100; BSA:=4;
HEIGHT(FRA,TSA,MSA,BSA); CONSTA:=CONSTB;COUNTA:=COUNT;
WEIGHT(FRL,TSL,MSL,BSL);
SR:=1.14286*WS; MO:=M1*MT; BETA:=BETA1*MT; B2:=2.0*BETA;
MEZ:=MO+BETA; BMT:=FRT:=GRT:=0.0; MFS:=CVR*MEZ;
RTAB:=VOL/CVR; DT:=RTAB/NG; MC:=MEZ; DZ:»Z/JJ;
"COMMENT" CALCULATION OF ELUTRIATION CONSTANTS;
MU: = (4.33+..0024*(VARC4]-1073) )*,.-5; L I : =CVR*Z/VC;
Y:=.0073/Z;Ki:=(RHOA-RHOG)*9.81/l8/MU;K2:s(RHOL^RHOG)
•9.81/18/MU; RT:=CVR/VG;G:=i;
"FOR"I:=CONSTA"STEP"1"UNTIL"COUNTA"DO"MBEGINH
UF:=2t(2#I+3)/i.l2;VEL(Klf UF.RHOGtMU.UTA);
"IF"LI/UTA,,-4"THEN"KACI]:s"TRUEH"ELSE"
"8EGIN""IF"KACI-i:"THFN"IA:=a-l;KACI]:="FALSE""END";
"IF"KAPPAACn>RT"THEN"KAPPAACn:=RT;MENDM;
JOE:UF:=2t(2*IA+3)/»12*(l+G/10);
" I F"G = 31" THEN"" GOTO" JENNY"ELSE"VEL<:K1,UF, RHOG, MU,UTA);
"IF"LI/UTA<1"THEN""BEGIN"KAP:=0;"GOTO"AVOID3"END";
KAP:=(Y«(LI/UTA-l)t.7)tFF;
AVOIDS: " IF "KAP >,.-4" THEN ""BEGIN "G:=G*i;" GOTO "JOE "END" !
JENNY:FRACI A3:=FRACIAD/2+.oi6667*G*(FRACiA3+FRACiA+i]);
FRA[lA+i]:=FRACIA+i:+FRAClAD/2-.016667»G»(FRAClA3+FRACIA+13);
G:=i;
A6. 30
-------
ACKNOWLEDGEMENTS
The authors are grateful to Mr. D. Stockwell for checking the
presentation of the mathematics in this report, and for suggestions
for its improvement, and to Dr. A.D. Dainton, Mr. H.R. Hoy,
Mr. E.L. Carls and Mr. J. Highley for helpful comments on the
earlier drafts.
ADDENDUM
Further examination of the results of the reactivity measurements
(reported in Appendix 8, section?), has shown that the experimental
method used could have led to underestimation of the rate constants
for stone of low utilization and fine particle size, especially in
the case of Limestone 18.
It is not possible to estimate the magnitude of the error, but
it is believed that it could account for the discrepancies between the
predictions of the model and the measured values of sulphur retention
effected by the small, elutriable particles .(e.g. in Task I). A note
explaining how this error arises is included in Appendix 8.
A6. 31
-------
REFERENCES
(1) Argonne National Laboratories.
Document No. ANL/ES/CEN-F 025, November 1970, Appendix B.
(2) Merrick, D. 'A mathematical model of the behaviour of ash in a
fluidized bed combustor and recycle system1. . CRE F.C. Section
Report 60; August 1970.
(3) M A Field and R F Littlejohn: 'Measurement of the residence
time of fine particles in a pilot-scale fluidized-bed
combustor', BCURA Report to NCB, Doc.DIB/35, June 1970.
(4) C N Davies: Proc.Phys.Soc., Lond., 57, 259. (1945).
(5) B B Morgan: 'Calculation of Retention of Sulphur Dioxide by
Limestone in a Fluidized Bed', BCURA Report to NCB. Doc.No.
CT/19, March 1971.
'Addition of Recycling to Calculation of Retention of
Sulphur Dioxide by Limestone in a Fluidized Bed',
BCURA Mathematics Note No. 112, March 1971.
(6) F V Bethell: 'The Absorption of Sulphur Dioxide by Eleven
British Limestones' BCURA Document No. FCP 5, October 1969.
(7) Pope, Evans and Robbins, reports to NAPCA on development
work on fluidized bed combustion, Nos. 42, 43, 47-54
inclusive.
(8) F V Bethell: 'Retention of Sulphur in Fluid-Bed Combustion:
Analysis of Pope, Evans and Robbins Data'. BCURA Document
No. CT/13/1, November, 1970.
(9) D Kunii and 0 Levenspiel: 'Fluidisation Engineering1,
J Wiley and Sons Inc., 1968, pp 312-324.
A6.32
-------
NOMENCLATURE
Note: All limestone weights are expressed as calcined
stone.
a^ ^ Coefficient in reactivity polynomial, f(U), for i th
' particle size group.
c Concentration of S0« )
c Concentration of SO? at top of bed \ , / 3 ,, ,,. 3
e • *• ) kg/nr Ib/ft
Cg Concentration of S02 at top of bed in the absence of )
absorption )
c0 Concentration of S02 at bottom of bed *
c Concentration of S02 averaged over height of bed
C Constant in equation 15.
F Feed rate of limestone )
FR Regeneration rate of limestone due to attrition \
G Flow rate of limestone entering cyclone kg/s tori/h
k Utilization rate constant for particle size group m^/kgs ft-Vlb h
K Constant characterising the absorptive capacity
of the bed m ft
Kj Coefficient of attrition h
Kg Elutriation constant )
K1 Corrected value of Ke {
e )
M Volume flowrate of gas m^/s ft^/s
m Coefficient used in size distribution equation 15 -
n Empirical,-exponent in equation 17.
R Percentage retention
Rr Recycle rate of limestone kg/s ton/h
Particle Reynolds number calculated for the
tenniminal velocity
Particle Reynolds number calculated for the -
Stokes velocity
Absorption of S02 particles (Eq 5) kg Ib
Gas residence time s
Characteristic time for regeneration (defined by
equation 2)
Temperature K
[Re],
A6. 33
-------
NOMENCLATURE (Cont'd.)
U Fractional utilization of particles
U1 Fractional utilization of particles:remaining in the
bed after attrition.
Uc Limiting utilization of particles
Ur Fractional utilization of recycled limestone
v Stokes velocity of particles )
V£ Superficial gas velocity ^ m/s ft/s
vt Terminal velocity of particles )
W Weight of particles in bed kg
x Particle diameter )
xo Characteristic size in the feed material !
-. • \ \ ym B. S. S.
xj Lower size ) )
„ .... ) in the i th size group )
X£ Upper size ^ e r /
y Ca/S mol ratio
z Height, .above air. distributor )
\
z' Height above air distributor at which S02
generation ceases
z Height above air..distributor of bed surface )
(Bed depth) )
a Cyclone efficiency
6 Constant in equation 9
Y Constant used with equation 17
A Mass of SO2 equivalent to unit mass of
calcined limestone
y Dynamic viscosity of gas Ns/nr
T Mean.residence time of solids in the bed s
«5(z) SC>2 generation function
Subscript in general use
i Referring to property of particle size group i
generation ceases { m ft
A6. 34
-------
Table A6.1 Input Data for Test Series 4, Task II
Identifier
PA
DB
Z
VOL
VOID
FF
ASH
S
TSA
MSAR
TSL
MSLR
BSLR
RHOA
RHOL
KDA
KDL
CAO
MO
ZH
BETA
VAR(l)
VAR(2)
VAR(3)
VAR(4)
ZZZ
1 NG
I
i
Input
4.9
0.97
1.144
1.37
0.7
Various
12
2.7
1588
300
1588
400
0
2920
1578
0
0
53.0
1.0
1.0
0
0.6615
0.05635
0.00345
1068
0.00345
10
20
Value represented
Pressure
Bed equivalent diameter
Bed 'depth
Volume of freeboard
Bed voidage
Exponent in elutriation equation (n)
Ash content of coal
Sulphur content of coal
Top size of ash (coal)
Median size of ash (coal)
Top size of limestone
Median size of limestone
Bottom size of limestone
Density of ash
Density of calcined limestone
Attrition coefficient of ash
Attrition coefficient of limestone
CaO content of calcined limestone
Fraction of S02 released at bottom
of bed
Depth of bed in which S02 is released
(dummy value)
Fraction of S02 released above bottom
of bed
Air feed rate
Coal feed rate
Feed rate of calcined limestone
Bed temperature
Step increase in VAR(3)
No. of sections into which freeboard
is divided
No. of sections into which bed is
divided.
Units
Atmospheres
m
m
m3
-
-
%
%
ym .
ym
ym
ym
ym
kg/m3
kg/n>3
- '
-
%
-
m
-
kg/s
kg/s
kg/s
°K
kg/s
continued.
A6.35
-------
Table A6.1 (contd.)
Size
Fraction
I
1
2
3
4
5
6
7
8
. 9
10
UC.
i
1
1
1
1
1
1.
0.9
0.8
0.8
0.8
KS .
i
1
1
1
1
1
1
1
1
1
1
End of input data
CYC.
0
0.1
0.3
0.5
0.7
0.8
0.9
0.95
0.95
0.95
a .
0,1
0.15
0.15
0.15
0.15
0.15
0.15
0.14
0.14
0.14
0.14
al,i
-0.45
-0.45
-0.45
-0.45
-0.45
-0.45
-0.466
-0.525
-0.525
-0.525
32,i
0.45
0.45
0.45
0.45
0.45
0.45
*3,i
-0.15
-0.15
-0.15
-0.15
-0.15
-0.15
0.518 ,: -0.192
0.656 1-0.2735
0.656
0.656
-0.2735
-0.2735
•
Notes:
The rate equation used is:
= K.(a /+ a. . U. + a, . U? + a, . U?).c.W.
dt i 0,1 l,i i 2,i i 3,i i i
. H
where c is S02 concentration, kg/m"
U. is fractional utilisation of limestone
i
o is mass of limestone of size i in bed
i
d(SO?)i
dt
is rate of SO- absorption by size i, kg/s
UC- is the limiting utilisation - i.e. the value of U. at
which the rate falls to zero.
A6.36
-------
Table A6.2 Constants in Reactivity Equation
Stone
Lime-
stone
18
Lime-
stone
1359
U.K.
Dolomite
Dolomite
1337
Tempera-
ture °C
700
800
900
800
800
800
Size range
ym
4-4096
4-4096
4-4096
4- 64
64- 128
128- 256
256- 512
512-1024
1024-4096
4- 32
32- 64
64- 128
128- 256
256- 512
512-1024
1024-2048
2048-4096
4- 256
256- 512
512-4096
a
o
0.062
0.075
0.0736
0.061
0.061
0.061
0.061
0.061
0.061
0.117
0.116
0.115
.0.1145
0.113
0.1095
0.108
0.106
0.15
0.14
0.14
al
0
0
-0.03786
-0.001875
-0.00495
-0.0829
-0.004545
-0.03333
0.1824
-0.351
-0.348
-0.345
-0.3435
-0.339
-0.3285
-0.324
-0.318
-0.45
-0.466
-0.525
a2
0
-0.228
0.7575
-0.261
-0.973
-1.624
-5.0
-8.05
-17.25
-0.351
-0.348
-0.345
-0.3435
-0.339
-0.3285
-0.324
-0.318
0.45
0.518
0.656
S3
-2.125
0
-5.05
0
0
0
0
0
0
0.117
0.116
0.115
0.1145
0.113
0.1095
0.108
0.106
-0.15
-0.192
-0.2735
U
c
0.308
0.574
0.29
0.48
0.24
0.17
0.11
0.085
0.065
1.0 i
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1
0.9
0.8
A6.37
-------
Table A6.3 Tasks II and III - Assumed Recirculation Cyclone Efficiencies
Particle Group No.
1
2
3
4 . • '
5
6
7
8
9
10
Size range
ym
4- 8
8- 16
16- 32
32- 64
64- 128
128- 256
256- 512
512-1024
1024-2048
2048-4096
Efficiency, a
Task II
0
0.1
0.3
0.5
0.7
0.8
0.9
0.95
0.95
0.95
Task III
0
0
0
0.5
0.8
0.9
0.95
0.95
0.95
0.95'
A6.38
-------
Table A6.4 Effect of variation in n
Task I, Test Series 1 - Ca/S mol ratio 1.75
Size group, i
1
2
3
4
5
6
7
8
9
Retention, %
Utilization of particles in size group
n - 1.0
0
0
0
0
0.001
0.002
0.006
0.540
0.540
27.2
n = 1.5
0
0
0
0.002
0.008
0.060
0.531
0.531
0.531
46.1
n = 2.0
0
0
0.001
0.004
0.037
0.361
0.528
0.528
0.528
50.7
n = 2.5
0
0
0.001
0.012
0.163
0.524
0.524
0,524
0.524
57.9
n = 3.0
0
0
0.002
0.031
0.519
0.519
0.519
0.519
0.519
64.4
Table A6.5 Effect of variation .in q (assumed same for all i)
Task I - Test Series 2 - Ca/S mol ratio 1.84
Size group, i
1
2
3
4
5
6
7
8
9
Retention, %
Utilization of particles in size group
a = 0
0
0
0
0.005
0.102
0.543
0.543
0.543
0.543
61.4
a = 0.75
0
0
0.001
0.021
0.299
0.538
0.538
0.538
0.538
63.5
a = 0.95
0.001
0.001
0.007
0.101
0.499
0.513
0.513
0.513
0.513
66.4
a - 0.98
0.003
0.004
0.017
0.229
0.503
0.508
0.508
0.508
0.508
68.1
a = 0.99
0.012
0.013
0.049
0.390
0.497
0.501
0.501
0.501
0.501
70.4
A6.39
-------
Table A6.6 Effect of Attrition on Utilization of
Size Groups (appirox. Ca/S mol ratio = 1)
Size jGroup i
•
1
2
3
4
5
6
7
8
9
Utilization, %
Kd = 0
0
0
0
0.001
0.002
0.006
0.553
0.553
K, = 0.0175
Q
0
0
0
0.001
0.002
0.006
0.710
0.710
0.553 , 0.710
K, =0.02
d
0
0
0
0.001
0.002
0.006
0.734
0.734
0.734
K, = D.025
d
0
0
0
0.001
0.002
0.006
0.774
0.774
0.774
A6.40
-------
Input plant operating conditions
and limestone reactivity data
Perform initial calculations of
throughput rates, bed weight, etc.
Calculate elutriation constants
for each size fraction of ash + limestone
Adjust Baas fractions on either side
of critical site for elutriation
Calculate mass of each fraction of ash
and limestone in bed, and mean residence
time of each fraction of linestone
Braluate correction factor for effect of
attrition on mean particle reaction rate coefficient
Input trial value, KK, for mean
reactivity of limestone in bed, and
set absorption above bed to zero
Calculate o and c corresponding to
reactivity XX
Solve equations for sulphur balance
and SO, absorption rate, to give nean
utilization for each particle size group
Use these utilization values to
calculate a revised approximation to KK
Is
chance in
SO, concentration
since previous estimate
of KK less than
set
Calculate now approximation to
absorption above bod, appropriate
to £0, concentration at top of bed
No
Is
change in
SO, cor.ccntratioB •
at cyclone lc» than
cot licit?
Ten
Outrut recults and increase
li=estor.e rate to next higher
level
1
Is
Ca/S ool
ratio greater
than 3?
Fiq.A6.1. Flow chart of mathematical model of sulphur retention
A6.41
-------
Curves given by input data
for model
o 1292°F(700°C) '
Laboratory
x 1472 F(800°C)
measurements
A 1652°F(900°C)
•£004-
20 40
Utilisation :%>
Fig. A6.2. Rate coefficients for Limestone 18
A6.42
-------
0-12
Laboratory measurements:
D 180pm particles
x 1400 urn particles
o 2400 u.m particles
128-512 fil
4 - 128 fi
40 60
Utilisation: %>
10O
Fig.A6.3- Rate coefficients for U.K.Dolomite
A6. 43
-------
0-14
Laboratory measurements:
D 180 u,m particles
A 550 pm »
x 1400pm
o 2400pm "
256-512pm
4 - 256 urn
40 60
Utilisation: %>
80
100
Fig. A6-4. Rate coefficients for Dolomite 1337
A6.44
-------
0-10
0-08
20
I I
Laboratory measurements
o 180 ^m particles
D 550\irr\ particles
Curve 1
" 2
/. 3
.. 4
.. 5
" 6
4- 64 (im
64-128u,m
128-256 u,m
256-512 ^im
512 -1024u.m
1024-4096 u,m
40 60
Utilisation: %
100
Fig.A6.5. Rate coefficients for Limestone 1359
A6.45
-------
100
TJ
£80
4)
c.60
D
1=
a
D
•5
SS40
c
4)
t
_ a=-99 a = -98
a.95
-2
-1
Cyclone efficiency: log(1-a)
Fig A6.6. Predicted effect of altering recirculation
cyclone efficiency
Note: a assumed the same for all i
n = 3
A6.46
-------
100
90
80
o
o
0 70
c
L.
60-
0)
o:
30
20
10
Model predictions
o Plant results (Test Nos.)
1-0
2-0 3-0
Ca/S mo I ratio
4-0
Fig. A6.7 Task I. Test Seriesl. Effect of variation in n (Kd=0)
A6.47
-------
100
90
o Measured retention (Test Nos.)
I
Kd=0'025
Kd=0
1-0
2-0 3-0
Ca/S mol ratio
4-0
Fig.A6. 8. TaskY. Tests 1.2 to 1.4
A6.48
-------
100
Kd* -025
Kd* '02
Kd= -0175
o Plant results
2 3
Ca/S mol ratio
Rg.A6.9.Task I. Test Series!. Effect of variation
in Kd ( n = 1)
A6.49
-------
100
90
60
•o
-------
100
— Actual distributions
-— As computed by model
I
I
400
800 1200
Size:
1600 2000
p
Fig. A6.11. Size distributions. Task I. Test Series'!
A6.51
-------
100
Plant measurements: o
Model predictions:-
KD = '025
n = 3
A - 2ft deep bed: 4ft/s
D ~ 4 n ii it : it a
C-2n .. „ :8 „
D-4
iE - 6 •• n i " • " "
Ca/S mol ratio
Fig.A6.12. Taskl.Test Series 1
A6.52
-------
o
CD
CD
V)
r>
CD
£•
3'
CD
> Of) «
P CD 2
s 8
a
01
& o
HI
n = /-0
50O 1OOO
Mean particle size:^im
15OO
Fig. A6.13. Task I. Test Series 1. Mean residence time of particles m bed
vs particle size, for various values of n
-------
100
"S 80
o
o
u
•: eo
.c '
a
40
c
o
c
0)
0)
a:
Mathematical
model
o Experimental data
Model (Kd r»0«2: n = 3)
2 3
Ca/S mol ratio
Fig. A6.14. Task T. Test Series 2
A6. 54
-------
TUU
80
"o
o
u
c
L.
5 60
a.
D
H_
0
o
0*
^ 40
g
c
or
20
• /
'/
/
it
1
— fol
/ 1
1
1 1
i
1
- 1
II
>'
-I
II
li
I
o Measured retention
Model predictions
(Kd =-025: n = '
Model predictions
(Kd = 0 : n = 1 )
j i
1 2
Ca/S mol ratio
Fig. A6.15. Task IL Test Series 1
A6. 55
-------
100
90
i80
§70
u
c- 60
3
5°
40
o
i30
0)
•H
0)
* 20
10
o Experimental results
Mathematical model
n r 1-25
n= 1-0
0-5
1-0 1-5
Ca/S mol ratio
2-0
2-5
Fig.A6.16.Task n. Test Series 4
A6. 56
-------
100
90
_ 80
o
O
u
c 70
L.
•&60
b 50
o
30
20
10
2.2
Model: n = 1: SC>2 evolved at
bottom of bed
Mode I: n = 0-6: SO2 evolved
throughput bed
o Measured reduction
I
1-0 2-0 3-0
Ca/S mol ratio
4-0
Fig. A6.17 Task JE. Test Series 2. Coarse stone
A6. 57
-------
100
x Plant,
fine stone
coarse stone
coarse stone
•^1.-. — x—I •»""*i
x_ Model,
' ~ fine stone
i i
2 3
Ca/S mol ratio
Fig. A6.18. Pope, Evans and Robbins' Fluid Bed Mcxjule
A6.58
-------
o
0
o
~)
0>
a
c
c+
o'
3.
5"
to
p>
en T
co 3
OJ
O
3
•a
o
^^
#IUW
* "
1 — xX x*^*««»
/ Model, 4ft/s
/ Ca/S r 2-2
/Plant, 4ft/s
/ Ca/S r 2-2
x° .
- . . -
— . —
i i ii I i i i
125O 1300 1350 1400 145O 1500 1550 160O 165O 17C
Bed temperature : °F
Fig.A6.19. Temperature effect. TaskJ. Limestone 18
-------
NATIONAL COAL BOARD
FINAL REPORT
JUNE 1970 - JUNE 1971
REDUCTION OF ATMOSPHERIC POLLUTION
APPENDIX 7. COAL STUDIES. (TASK VII)
APPENDIX 8. LIMESTONE AND DOLOMITE STUDIES. (TASK VIII)
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
- 411 WEST CHAPEL HILL STREET
DURHAM, NORTH CAROLINA 27701
REFERENCE NO. DHB 060971
SEPTEMBER 1971
FLUIDISED COMBUSTION
CONTROL GROUP
NATIONAL COAL BOARD
LONDON, ENGLAND
•J1
-------
REDUCTION OF ATMOSPHERIC POLLUTION
Research on reducing emission of sulphur oxides.
nitrogen oxides and particulates by using
fluidised bed combustion of coal
Appendix 7. Coal studies. (Task VII)
Main objectives
To investigate the distribution of sulphur in
a range of coals and in the residue from the
rigs.
Report prepared by: B.C..Davidson and
J. Highley
Report approved by: A.D. Dainton and
H.R. Hoy
AT.iii
-------
Table of Contents
Page No.
1. Introduction A7. 1
2. Background A7, 1
3. Determinations of forms of sulphur A7. 2
4. Sulphur release studies A7. 3
4.1 Objective A7» 3
4.2 The furnace design A7. 3
4.3 The experiments A7. 3
4.4 The results A7. 4
5. Acknowledgement A7. 7
(Note that when referring to Tables and Figures in the text the
prefix A.7 is omitted).
A7.V
-------
INTRODUCTION
In early work on fluidised combustion, prior to the present contract,
it was observed that there were small but significant differences in the
sulphur retention obtained with coals of different types when burned
under similar operating conditions. It was established that these
differences could not be accounted for in terms.of the calcium contents
of the mineral matter. Consequently, the objective of the present task
was to seek further information on the role played by the type of coal
and its associated mineral matter on sulphur retention. Because the
effects were small compared to those of operating parameters such as
Ca/S ratio and fluidising velocity, only a small effort was to be
expended in these studies.
BACKGROUND
Comparison of results from experimental work at CRE and at
the Argonne National Laboratories, before the programme began, had
shown differences in the efficiency of sulphur retention under equivalent
conditions of particle size, bed temperature, and fluidising velocity.
Taken at face value, the differences in design between the two combustors
did not appear sufficient to account for the different performance.
Further, experiments at CRE on several coals in the same plant revealed
differences which appeared to be attributable to the nature of the feed
coals themselves, although the property responsible had not been
identified.
To explain these differences, two main approaches were followed.
On Task V? raw materials were exchanged between CRE and the Argonne
laboratory, in order to check on factors arising from differences in
plant design. The programme for Task VII provided, for measurements
on coals to see whether the form in which the sulphur was present
was an important factor affecting the efficiency of retention.
In Task V, all four coals used..in the programme were burned.
It was found that, for any given Ca/S ratio, the S0» retention was
significantly better with Welbeck coal than with the other three,
Illinois, Pittsburgh and Park Hill. Of these last three coals, S02
retention with the Pittsburgh was marginally worst.
* See Appendix 5.
A7.1
-------
Welbeck is a low-rank coal with poor caking and swelling
properties (See Table 1). In the other three coals, these properties
covered a wide range, but in one of the group, Park Hill, they were not
significantly different from those of Welbeck. It was therefore
possible to discount the swelling properties of coals as a possible
factor.
Table A7.1 Caking and Swelling Properties of coals
Coal
Welbeck
Illinois
Park Hill
Pittsburgh
Swelling Number
1
M
1
8
Gray-King Coke Type
C
D
D
G9
3. DETERMINATIONS OF FORMS OF SULPHUR
The forms of sulphur in the four coals used for the various
tasks were determined by standard methods as described in British
Standard 1016.11.1939. The results are given in Table 2.
Table A7.2 Forms of sulphur in coals
Illinois
Pittsburgh
Welbeck
Park Hill
Sulphur % as received
Total
3.95
2.75
1.25
2.40
Organic
2.45
1.44
0.73
1.01
Pyritic
1.35
1.25
0.50
1.35
Sulphate
0.15
0.06
0.02
0.04
Ratio
Org./Pyr.
1.8
1.1
1.4
0.7
Welbeck coal has the lowest total sulphur content, having
about half that of Pittsburgh and Park Hill, and about a third that
of Illinois. The relative proportions of organic to pyritic sulphur
range from 0.7 in Park Hill to 1.8 in Illinois, with Welbeck having
on intermediate value.
A7.2
-------
4. SULPHUR RELEASE STUDIES
4.1 Objective
In view of the findings described in Section 3, an attempt was
made to measure the rate of release of sulphur in laboratory
apparatus. The little which could be done in the time available
is described below.
4.2 The furnace design
The experiments were carried out using a reaction rate furnace
developed at Leatherhead. The furnace was designed originally for
studying the devolatilisation and combustion of pulverised coal,
and consisted of a vertically mounted silicon carbide tube which
could be controlled at any temperature between 1100 and 2700°F.
The tube length between the injection and collection points for the
reacting particles was isothermal.
The gas with which the particles were to be reacted was
pre-mixed .in the required concentration with argon as a diluent.
This gas was heated to the same temperature as the furnace by a
plasma arc and the heated gas flowed downwards through the
furnace tube. The flow in the furnace tube was laminar, which
ensured that particles were not lost to the walls.
The closely sized graded feed particles were introduced
slowly as a dilute stream into the gas along the axis of the
furnace through a feeder tube purged with argon. The feeder tube
was water cooled to prevent premature..reaction of. the particles.
4.3 The experiments
The coals chosen for the experiments,.were U..S. Pittsburgh
and U.K. Welbeck.
The feed material was produced by crushing.and sieving the
coals to give closely graded fractions between,75 and 53 ym particle
diameter. This feedstock was analysed for total and pyritic
sulphur before use.
The coal.,was fed to the furnace, .using .a vibration feeder at
approximately 0.1 g/min.
A7.3
-------
It was intended to measure the sulphur content of the gas
and to calculate the sulphur release from the coal from this. An
E.E.L. instrument for the measurement of SC>2 in the atmosphere was
available and this was used after modification to allow higher SC>2
concentrations to be measured. The instrument gives a photo-electric
indication of.the extent of de-colourisation of a continuous flow of
iodine solution. Since the' sulphur was to be determined as S02, it
was necessary to add oxygen to the argon carrier gas. Unfortunately,
it was found that it was not possible to feed the coal steadily at
the low rate required. Hence the SC^ concentration varied widely
and unpredictably throughout a test and could not be used to assess
the sulphur released from the coal.
The experiments were then repeated without adding oxygen and
the solid products were collected and analysed for total and pyritic
sulphur. This procedure was successful, but there was insufficient
time to make other than a simple comparison between the coals with
the furnace maintained at 1470 F and the collector located to
give a solids residence time of approximately 100 ms.
4.4 The results
The experimental results are given in Table.5... In both coals
almost.all of the pyritic sulphur was released in 100 ms, but less
than half of the organic sulphur was released. This confirms the
difference in release rates between the forms.of.sulphur, indicated
in Section.3. The amount of organic sulphur released in 100 ms from
Welbeck coal is 30% more than from Pittsburgh,./live.. 46%. in comparison
to 35%. There was a 20% greater releasevof total sulphur from Welbeck
coal during the experiment.
The. ratio of ..organic, to pyritic sulphur, fpr the Pittsburgh char
in the experiment (13) is in very good agreement.with that for the
cyclone fines from the combustor when burning this coal (a mean
value of 12, see Table 3). However, for Welbeck coal there is a
considerable difference between the ratios for the char (17.5) and
the cyclone fines (2,5, see Table 4)., Although there were oxidising
conditions in the combustor and reducing conditions in the experiment,
it is surprising.that there should be agreement for one coal and not
for another.
A7.4
-------
Selected solids samples from the 36 in combustor (Task I)
were also examined for forms of sulphur. These samples were of
primary cyclone fines from Test Series 2 (Pittsburgh coal) and
Test Series 3 (Welbeck coal). The analyses are given in
Tables 3 and 4.
Table A7.3 Forms of sulphur in cyclone Fines ; 3 ft combustor; Pittsburgh Coal
Test 2.1
Test 2.2
Test 2.3
Test 2.4
g
Sulphur % as received
Total
2.13
2.50
2.62
2.47
Organic
0.4
0.3
0.25
0.30
Pyritic
0.03
0.05
0.02
0.02
Sulphate
1.7
2.15
2.35
2.15
Ratio
Org./Pyr.
13
6
12
15
Table A7.4 Forms of sulphur in cyclone fines; 3 ft combustor; Welbeck Coal
Test 3.4
Test 3.5
Sulphur % as received
Total
1-.31
1.57
Organic
0.15
0.15
Pyritic
0.06
0.07
Sulphate
1.10
1.35
Ratio
Org./Pyr.
2.5
2.1 . .
The data in Tables 3 and 4 show that the ratio of organic
to pyritic sulphur in the cyclone fines is considerably higher
than in the coal, being about 10 for Pittsburgh and about 2.5
for Welbeck. This indicates that in both coals the rate of
release of pyritic sulphur was higher than that of organic, the
difference in rates being greater for Pittsburgh coal than for
Welbeck. The large amount of sulphate in the fines is the sulphur
retained as calcium sulphate.
A7.5
-------
Table A7.5 Results of laboratory, furnace... experiments
Test conditions:
Carrier gas
Furnace Tube Temps. °F
Gas temperature
Feed particle size '
Residence time
Coals
Argon
1470°F
1470°F
53-75 urn
100 ms
(a) Pittsburgh
(b) Welbeck (II) see Tasks
I & V
Decomposition;
Coal feed g
Char yield g
II II OT
n
Total sulphur:
In coal %
In char %
In char % of coal
Retention %
Pyritic sulphur:
In coal %
In char %
In char % of coal
Retention %
Organic sulphur*
In coal %
In char %
In char % of coal
Retention %
Ratio, Organic/Pyritic
Pittsburgh
5.5
2.35
42.4
2.79
2.41
1.02
37
1.34
0.17
0.072
5.4
1.45
2 ..24
0.95
65
13.
in char
1
Welbeck j
i
5.43
2.30
42.5
1.54
1.12
0.47
30.5
0.70
0.06
0.025
3.6
Q. 84
1.06
0.45
54
17.5
* Calculated by difference between total and pyritic sulphur.
A7.6
-------
At the present time it can be concluded.that there are
differences between the rates of release of the pyritic and organic
forms of sulphur, with the pyritic being released more rapidly.
However the actual release rates vary from coal to coal and may also
be affected by the operating conditions, in particular by whether the
surrounding gas is oxidising or reducing.
5. ACKNOWLEDGEMENT
The experimental work described in Section 4 was carried out at
BCURA by Mr. R.F. Littlejohn.
A7.7
-------
REDUCTION OF ATMOSPHERIC POLLUTION
Research on reducing emission of sulphur oxides.
nitrogen oxides and particulates by using
fluidised bed combustion of coal
Appendix 80 Limestone and dolomite studies, (Task VIII)
Main objectives
To investigate the pore structure and related
factors that affect sulphur retention by lime<
Report prepared by: FoV0 Bethel1
AoAn Herod
Gc McDonald
BrAc Napier
DoH,Tr Spencer
Report approved by: AoD. Dainton and
Hr.Ro Hoy
-------
FOREWORD
This Appendix describes laboratory experimental work carried
out at BCURA between June 1970 and June 1971 as Task VIII of the
joint NCB/OAP research programme. The objective of Task VIII was
to obtain information on the limestones and dolomites selected for
the pilot plant work, as follows:
(a) the development of their pore structures on
calcination, both with and without sulphation, and
(b) their rates of reaction with S0«, for use in the
Mathematical Model, Task VI„
A summary of the investigations is presented in the Main
Reports
A8. iii
-------
TABLE OF CONTENTS
Page No,
1, INTRODUCTION AND PRESENT POSITION A8, 1
2. POROSITY MEASUREMENTS: MERCURY POROSIMETRY AND DISPLACEMENT DENSITY A8» 6
2.1. Introduction.. . . .. . , ,: A8, 6
2.2 Preparation of Samples A8, 6
2.2,1 Exploratory samples A8. 6
2,2»2 Samples treated in controlled atmospheres A8, 7
2.3 Experimental Techniques Used for Measuring the Porosity A8, 8
2o3,l Helium density measurement A8» 8
2.3.2 Mercury density measurement A8. 9
2,3.3 Helium and mercury density A8, 9
2=3.4 Mercury injection porosimetry A8.10
2*4 Results and Discussion A8ol3
2,4,1 Exploratory experiments ' A8<.13
2c4o2 Controlled atmosphere experiments A8°14
2°4o2ol Linear relation between i/p and TTH and between
1/p Re and TT . < - Hg Hg- A8.16
2.4o2=,2 Evidence that the calcined and calcihed-sulphated
stones have little or no open porosity behind '" '
entrances <00014 ym in diameter, with possible
exceptions A8-.17
2<,4.2,3 Increase of pore volume with increase of extent
of calcination . A8ol7
2,4.2.4 Estimate of porosity development in stone, from
mercury density. A8ol8
2.4o2o5 Comparison of the distribution of pore volume with
respect to entrance diameter for the different
stones •"'•--• 'A8.19
2.4o2»6 Effect of sintering on pore size A8-20
2.4o2o7 The effect of sulphation on pore structure : A8.21
2.4»2.8 Sulphur fixation •• A8-29
2.5 Conclusions A8^30
3. MERCURY POROSIMETRY ON PARTIALLY SULPHATED PARTICLES BEFORE AND AFTER
BREAKAGE • A8,34
3.1 Method and Samples A8*34
3»2 Results : • : : A8»35
4. STUDIES OF POROSITY AT ELEVATED TEMPERATURE A8-38
4,1 Introduction A8o38
4o2 Principles A8,38
4.2ol Types of pore involved A8»38
4»2.2 Experimental procedure for measurement A8,38
4.3 Experimental A8,39
4.3»1 Description of apparatus A8»39
4,3,2 Calibration of apparatus A8,40
4.4 Results A8,42
4»4,1 Pore closure experiments A8,42
4,4o2 Pore penetration experiments - A8,42
4.5 Discussion and Conclusions A8,44
4.5.1 Pore closure A8,44
A8.v
-------
TABLE OF CONTENTS (cont'd)
Page No
4o5r,2 Pore penetration A8o44
4,5,2,1 Helium A8,44
4,,5o2,2 Xenon A8.44
4,5.3 Incidental observations in the pore penetration experiments A8.-47
5. THE EFFECT OF THERMAL CYCLING ON S02 UPTAKE A8.49
5«1 Introduction A8.49
5,2 Apparatus and Procedure A8;49
5,3 Results and Cot).clusions A8,50
60 MISCELLANEOUS - A8,51
6ol Optical Microscopical Examination A8o51
6o2 Surface Area A8,51
7, MEASUREMENTS OF SO REACTION RATE CONSTANTS A8.54
7.1 Description of Apparatus and Experimental Procedure A8,54
7.2 Mathematical Procedures AS,,57
7,3 Results A8.59
7o4 Discussion A8-60
8, ADDENDUM A8^62
9, GLOSSARY OF TERMS A8,65
10, REFERENCES A8r69
11. ACKNOWLEDGEMENTS A8.71
Tables A8ol to A8.24
Figures A8ol to A8.63
Mercury porosimetry data
(Note that when referring to Tables and Figures in the text the prefix A8
is omitted,)
AS.vi
-------
INTRODUCTION AND PRESENT POSITION
The removal of sulphur oxides from gaseous combustion products by
limestones or dolomites is of the basis of several projected methods for the
reduction of' atmospheric pollution* The use of such stones is particularly
attractive because reaction occurs at elevated temperatures, e<,g0, 1500°F,
and sulphur oxide removal can be effected in the combustion zone* In the
stone-injection process for-fluidised-bed combustors, with which the present
work is concerned, the atmosphere is oxidising and the overall reaction is:
CaO + \Q + SO- -»• CaSO,
However, it is well known1that laboratory Studies show that stones differ
widely in their capabilities to remove SO- at elevated temperatures, and this
complicates the choice of a stone for plant use* Reasons for these differences
are not well understood, but it is generally accepted that they are ascribable
12
to differences in physical structure rather than in chemical,composition ' ,
Certainly, porosity formation on calcination has been established as an
important factor, for example by Potter » However, it is not known why various
• 5 *
types of stone calcined under the same conditions should give calcines having
markedly different pore structures„ Potter's work was aimed at the correlation
of the physical properties of eighty six carbonate rock samples with their
•\ *.
capacity to remove S0~ from a simulated flue gas stream., the reactor for
sulphation was a 30 mesh screen, preheated to sulphation temperature, on to
. • ; 1; •
which the sample was dumped as a static bed. Normally samples were
precalcined at 1800 F and then sulphated at that temperature, but supplementary
tests were made with two stones, one a limestone and the other a dolomite, as
the hydrate and carbonate, as well as the oxide (prepared at 1800 F), with
sulphation over a wide temperature range„ For each stone the hydrated form
showed the best retention characteristics up to 1830 F, whilst the precalcined
stone was better than the uncalcined onen A series of calcinations at 2400 F
indicated a loss in B.E»To nitrogen adsorption surface area and (from mercury
porosimetry) a loss in total pore volume and an increase in mean pore-entrance
diameter, compared with calcination at 1800 F; also the shift in volume of
pores with entrances larger than 0,3 um diameter on calcination for the two
temperatures parallelled the shift in SO™ capacity at 1800 F= In his analysis
of data for the samples calcined and then sulphated at 1800 F, Potter calculated
correlation coefficients (each correlation coefficient was an index of the
probability of there being a valid correlation between SO- capacity and some
other variable): with the exception of iron content, the chemical composition,
A8.1
-------
e,g,, carbonate content, had no significant relevance to SO- capacity, and a poor
correlation coefficient between BnE=T, nitrogen adsorption surface area and S0_
capacity was taken to indicate the unimportance of pores with entrances of a
few tun diameter; the .importance of largerpores was indicated, through mercury
porosimetry, by (equally) good correlation between either volume in pores with
entrances greater than 0,3 urn diameter, or total pore volume, and the SO-
capacity,
Classification by Potter of stones according to SO- capacity showed
that Iceland Spar, comprising large crystallites, was the worst stone - even
Magnesite, MgCO-, was better. Chalk and oolitic samples, typically fine
grained materials, had the greatest SO- capacity; dolomites were better than
calcites, which were slightly better than marble samples„ In summary, Potter
considered that iron content, and mean pore-entrance diameter and total pore
volume both measured by mercury porosimetry, are the "most fundamental variables
for explaining differences in the SO- capacities of samples"o
Also, the fact that the SO- capacity of a limestone particle may be
well below that expected from purely chemical considerations is believed to
be due to the formation of a layer ( 'shell1 )of sulphate, presumably involving
thickening of pore walls, which impedes the further ingress of SO- towards
the centre of the particle<• The presence of such a shell has been observed
3 3,4
by optical microscopy and by electron microprobe analysis »With dolomites,
such a shell is either not formed, or formed to a much less marked extent than
with limestone, so that the interior of a dolomite particle is the more readily
available for SO- sorption* The reason for this difference in behaviour between
limestones and dolomites is not clear, but it is probable that the presence of
the magnesium oxide in calcined dolomite exerts a modifying influence,
particularly as: (a) the pores formed in the decomposition of the magnesium
carbonate, which occurs before that of the calcium carbonate, may facilitate
the subsequent egress of CO,, from the latter, resulting in a different final
pore structure from that of calcined limestone; (b) MgO remains unchanged
during the sulphation, and pores bounded by MgO, as well as CaO, in their surface
would seem to be less likely to become blocked by CaSO, than those bounded by
CaO alone-
It is clear therefore that basic studies aimed at obtaining further
understanding of the retention of sulphur oxides by stones should include
measurements of the pore structures of those stones. Such an investigation is
reported in this Appendix, and since in the present work stones were fed into
A8.2
-------
the fluidised combustors in the un-calcined state, particular emphasis has been
placed on following the development of pore structure at various stages of
calcination and h
-------
densities, to follow the development of pore structure on rapidly heating stones
and then heat soaking them for various times in chosen atmospheres,, Exploratory
experiments were made in which stone particles were dropped into a furnace at
1470 F and left in the furnace for specified times before removing them for
weighing and pore structure examination; the furnace-atmosphere was such that
it either initially contained air9 no attempt at flushing being mades or it
was flushed with nitrogen. The results of these experiments led to a second
series of experiments being carried out with the furnace„ at 1470°F or 1650°T9
flushed with a specified gas mixture - composition by volumeB 15% CO-a 3% 029
82% N2,with and without 2000 ppm of SO- being present,,- the aim being,, when
the SO- was present,, to simulate the behaviour of stone particles in the
combustor. The results have enabled a number of conclusions to be drawn
regarding changes of pore structure on calcination and sulphation and cause of
certain differences in sulphur oxide capacity found among the stones examined.
This has led to the specification of a proposed simple test by which stones of
unknown sulphur oxide capacities may be placed in order of capacity or 'screened'
before carrying out more extensive tests on promising stones.
3. Mercury porosimetry was carried out on calcined-only and sulphated
stone particles before and after breakage to obtain further information on the
'sulphate-shell'. Exposure of porosity on breakage occurred with Limestone 1359
sulphated in the laboratory, but not with the stone after sulphation in the
combustor; the reason for this difference is not certain. Breakage did not
3
expose further porosity in sulphated dolomites. Electron microprobe analysis
also revealed the presence of a 'shell' in laboratory sulphated Limestone 1359
while with sulphated ILK- Dolomite the sulphur was distributed more uniformly
throughouto
4. A limited investigation was performed to see whether repeated thermal
cycling of stones caused any reduction in their sulphur oxide retention
capability,, This experiment followed a suggestion that in the recycling of
stones in a combustor the alternate heating/cooling process might have such
adverse effect,, Only ILK. Dolomite and Limestone 1359 were investigated and
the results showed no systematic effect of repeated thermal cycling on
progressive sulphur oxide uptake.
A8,4
-------
5 = To provide input data for the mathematical model CAppendix 6)9
quantitative measurements of reaction rate were made using a flowing system
in which S0? - containing gas was passed through thin beds of stone particles
at the required temperature.
Each of the above items of work is described in detail in the following
sections of this Appendix.
A805
-------
2. POROSITY 'MEASUREMENTS; MERCURY POROSIMETRY AND DISPLACEMENT DENSITY
2.1 Introduction
When stones are injected into the fluidised-bed combustor they
are subjected to rapid heating. To obtain some1 information on the development
of pore structure under such conditions9 exploratory experiments were carried
out. in which stones were subjected to rapid heating and then heat soaking at
1470 F. The results suggested that pore volume? pore-entrance diameter and
the extent and time of calcination were related. Therefore,, further experiments
were done, to investigate, these effects, and those of sulphation3 using samples
prepared in more closely controlled conditions. These experiments involved
calcination only9 and calcination and sulphation together9 carried out under
oxidising conditions using controlled atmospheres (shown in Table 1). The
experimental method was arranged to allow rapid heating of the stone from room
temperature to 1470° or 1650°F.
2.2 Preparation of Samples
2.2.1 Exploratory samples
Samples of between 2 and 5g of the U.K. Dolomite and Limestone. 1359 were
rapidly heated by sprinkling them into a vertical furnace closed at the lower end
and maintained at 1470 F; the soaking times ranged from 15 min to 11.5 h0
In the first experiments., the atmosphere in the furnace tube was essentially .
stagnant air with C0_ escaping by diffusions causing the partial pressure of CO.
to increase with time. In later experiments the tube atmosphere was swept by
dry nitrogen gas.
The size grades,, BS mesh9 of the stones used were:
U.K. Dolomite -6 +• 82 -16 + 52S and -300,
Limestone 1359 -16 •*• 529 and -300,
The extents of calcination (E ) of the two stones were measured,
E is defined in this Appendix as:
E - MJZL % Cl)
e WT
where W.. is the mass Ioss9 due to CO™ losss undergone by the sample on the.
partial calcination and WT is the mass loss the sample would have undergone on
complete calcination. In these preliminary experiments,, W. was obtained by
weighing and WT from chemical analysis data for the uncaleined stone. The
A8.6
-------
calcination histories of individual stones and their designations are shown
in Tables 2 and 3. The prefix letter of a stone designation indicates its
size grade,, as shown in Table 4»
2.2.2 Samples treated in controlled atmospheres
The four stones used during the later part of the contract work9
Dolomite 1337S U.K. Dolomite and Limestones 18 and 13599 were prepared under
controlled conditions, enabling the development of the porous structure to be
assessed in an atmosphere that comprised C09/N»./0_ with and without S0_.
The apparatus consists of a vertical furnace tube in which the
sample is held on a removable perforated tray, in a layer c» 5 mm deep5 at the
centre of the tube. A feeder is provided which allows samples of material
(c. 5g were used) to be fed directly onto the tray thus facilitating rapid
heating of the sample to the furnace temperature. An atmosphere of known
composition is admitted to the furnace by equipment similar to that used in
the thermal cycling experiments (Section 5) and in the reactivity experiments
(Section 7)0
As noted aboves the experimental programme is shown in Table 15 and
consists of experiments using one range of particle sizeC~16 +52 BS mesh)0 one
gas composition with and without SO-, and two temperatures0
Details of the treatment of individual stones and their designations
are shown in Table 5«
Extents of calcination (see Equation 1P Section 2.2.1) for the samples
treated in:
(a) The. SOy-free atmosphere, were determined as described in
Section 2.2.1.
(b) The S02~bearing atmosphere,, were determined,, as correction
was necessary for mass gain due to sulphationy by calculating
W1 (Equation 1) from the chemical analyses of the samplesf
viz,, residual 'CO ' and 'S' present and taking into account the
composition of the original stone.
Sulphation (E ) of the samples was determined,, E being defined as:
S S
100 w..
E « ___i % (2)
S W
WT
A8-7
-------
where W.. is the mass of sulphur in the sulphated sample and W_ is the mass of
sulphur that, would have been present if all the CaCO had Been converted to CaSO,,
W^ was calc.ulat.sdy as with W.. mentioned under 0>) above 9 from the chemical analysis
data.
2.3 Experimental Techniques Used for Measuring the Porosity
Two basic techniques were used to obtain: (i) the total porosity
(excepting that in pores with entrances > 14,5 pm and < 0026 nm in diameter)„
(ii) the porosity with respect to certain pore-entrance diameter ranges.
These techniques were: (i) displacement density in two fluids„ helium and
mercury,, (ii) mercury injection porosimetry., They are described below.
2.3.1 Helium density measurement
The "helium density' of a solid is the mass of the solid divided by
the volume of helium it displaces when immersed in that gas,. Helium density,
in conjunction with the superficial and solid-matter densities givess
respectively,, the pore volume open and closed to helium? it often affords a
close approximation to the solid-matter density which is not always determinable.
The helium displacement volume (V ) was measured at 77 F using
apparatus in which a known quantity of helium could be. transferred to the sample
chamber9 enabling the volumes the gas occupied in the chamber9 empty and with
a known mass of the evacuated sample presents to be found using gas-law principles,
Vu is the difference between those two volumes„ The evacuation was at room
r
temperature at 1.0 torr. Experimental error was < 1% with the controlled-
atmosphere sampless but with the exploratory samples where the quantities
available were less, it could be up to 3 or 4%. The error is not considered
to have materially affected the general trends that emerged from the use of the
density values.
Helium is the nearest to the ideal displacement fluid because:
(i) It has the smallest molecule (kinetic diameter,, 0026 nm) and
penetrates all but the finest pores; slow penetration of helium
into samples,, seen as a slow decrease of V with lapsed time,,
would reveal the presence of pores or pore entrances with
diameters close to 0<,26 nnu
A8,8
-------
(ii) It is not significantly adsorbed at the measurement temperature
of 77 Fj, except by certain highly microporous materials such as
active carbons for which the measurement temperature must be
increased: adsorption of helium is expected to be insignificant
with the stones.
The justification for applying helium densities measured at 77°F,
when the stones are used at elevated temperatures, is discussed in Section 4.
2.3.2. Mercury density measurement
The 'mercury density' of a solid is the mass of the solid divided
by the volume of mercury it displaces when immersed in that liquid under a
specified pressure (P). Assuming that the mercury does not wet the solid,,
the fluid will not penetrate pores with entrances smaller than a certain
critical level9 depending on the value for P — see Section 2.3.4.
Mercury density was measured using a bulb of c. 5 cm volume. The
mass and hence volume needed to fill the bulb to a reference mark without
and with a known mass of previously evacuated stone present was found. The
mercury displacement volume is the difference between those two volumes. The
stone samples were evacuated at room temperature at 10 torr, and mercury was
admitted to the bulbs in- vacuo from a filling device: the bulbs were placed
in a thermostatic bath at 77 F for several hours before the mercury levels
were adjusted to the reference marks of the bulbs. The experimental error
in the mercury densities is up to c. 0.5%. For pressure P, an average value
of 760 torr (10013 bar) was taken for any particle. In the present work,
circular pore-entrances have been assumed (Section 2.3.4) and this pressure
has been taken as equivalent to a pore-entrance diameter of 14.5 urn.
2.3o3 Helium and mercury density
Mercury density and helium density together give the volume of pores
(V ) with entrances (assuming them to be circular) of diameter < Q and
J2C
> 0.26 nm, where D is the pore-entrance diameter value corresponding to pressure
P, and 0.26 nm is the kinetic diameter of the helium molecule,, noted above.
Vx = 103 (l/pRg - l/pRe) mm3/g (3)
3
where p.. and pu are the mercury and helium densities, g/cm s respectively.
rig he
A8.9
-------
With a lump material, it may be possible for pressure P to be made
sufficiently low so that no penetration of pores by mercury occurs, the
corresponding mercury density then being equal to the lump density s and V
A
in Equation 3 then being equal to the total volume CO of pores with entrances
> 0.26 nm in diameter , V_ may also then be expressed as a percentage of the
lump volume:
VT = 100 ciyPHg - iyPHq) PHg % (4)
Mercury density so measured is of valuable application to samples of irregular
shape whose lump densities cannot be readily determined by mensuration and
weighing.
With particulate materials, the pressure P must be sufficient to
ensure that spaces between the particles are filled by mercury, and this may
cause some penetration of the particles themselves, so that VT cannot be
calculated in the absence of independent knowledge on the volume of pores with
entrances > D in diameter. However, it is often valuable to express V as
X.
an approximation to the percentage of the particle superficial volume, for
example, for comparison among a set of samples, by putting the particle density
3
(mass per unit superficial volume ) pp g/cm equal to pfl in the following
equation:
vx - 100
to give Vx « 100Cl/PHg - l/pHe) PRg %
This approximate calculation of V as a percentage is used in the present work,
•A
2.3.4 Mercury injection porosimetry
Mercury injection porosimetry has been reviewed in detail by
Rappeneau and Scholten and discussed briefly by Innes ; recent papers have
* g
been reviewed b"y Spencer .
The method depends on the phenomenon of capillary depression, a
certain minimum pressure P being required to force mercury through an entrance
whose surface is not wetted by the mercury. In general terms if the entrance
has perimeter L and cross-sectional area A:
AP - L a cos (180 - 6) (5a)
ASolO
-------
where a is the surface tension of the mercury and 6 (> 90 ) is the angle of
contact *
In applying this relation to pore structure measurement, it is
necessary to make simplifying assumptions on pore-entrance shape: it is
normally assumed that the pore entrances are circular, when:
P = ^2 cos (180 - 9) (5b)
Occasionally, when a material is considered to have slot shape pores, then the
entrances have been taken to be.of rectangular cross-section, with long side nD
and small side D, with n>:-l, when;
P = ~ cos (180 - 9) (5c)
A pore-volume distribution, with respect to D, is obtained by
determining the cumulative volumes of mercury that enter the sample as the
pressure is increased in steps, the pressures being converted into D values;
the curve of cumulative pore volume vs D shows the pore volume lying behind
entrances with D values within any chosen limits in the range of D covered„
Additionally, the curve may be expressed in the first differential form, or
as a histogram^ It is important to note that D refers to pore entrances,
which may in some instances be narrower than the bodies of the pores themselves„
In almost all mercury porosimeters the previously evacuated sample
is immersed in mercury and the penetration into the sample is followed as the
loss of mercury from some form of reservoir, usually a uniform-bore tube,
connected to the sample chamber„ In the particular apparatus that was used
in the present work* such a tube is situated vertically above the sample chamber.
After evacuation, mercury is admitted to the sample chamber and the tube up to
a height (h) above the centre of the sample„ The pressure equivalent to h is
taken as the starting pressure„ The pressure is increased on the mercury
surrounding the sample by increasing application of gas pressure above the
meniscus in the tube: (1) by admitting air incrementally up to atmospheric
pressure; (2) after transfer of the sample chamber unit to a pressure vessel,
by admitting nitrogen
*The apparatus was developed at BCURA with permission from original drawings,
supplied by Morganite Carbon Ltd*, °f tne apparatus described in Refn9.
A8-11
-------
from a compressed gas cylinder to the vessel in steps until the pressure reaches
finally c. 8 bar; and C3) by compressing the gas in the vessel up to c. 1035 bar
by use of a hydraulic pumping system,, The penetration of the mercury is
measured as follows: a stretched wire lies along the principal axis of the tube,
part of this wire being immersed in the mercury. As the height of the mercury
decreases so the length of wire exposed, and hence its electrical resistance,
increases. This resistance forms one arm of a Wheatstone bridge. To
eliminate the effect, albeit small, of the compression of the mercury, the
opposite arm in the bridge is formed of a similar resistance-wire from a dummy
sample-chamber unit9 which during pperation contains a similar amount of mercury
to that in the sample units but no sample. The progressive change in output
from the bridge, measured with a digital voltmeter, is subsequently converted
through a previously determined calibration factor to the cumulative quantity
of mercury penetrating the sample.
Samples of stones for porosimetry measurements were sieved (+ 52 BS mesh)
to remove fines, (These same fines-free samples were used for specific surface
measurements - Section 6 - and for the density measurements.) After a
preliminary evacuation in a vacuum oven at 200 F, samples were transferred to
the sample chamber of the porosimeter and evacuated at room temperature before
admission of mercury. A metal gauze was used to prevent the stone particles
floating into the capillary measuring-tube.
In the present work, for the conversion of the pressures to D values,
it was assumed that the shape of the pore entrances of the stones is circular,
viz, Equation 5b above was used, values of 480 dyne/cm and 140 being taken for
cr and 9, respectively. The initial height h referred to above was c. 190 mm,
equivalent to a D value of c. 58 ym. Any pores with entrances having
diameters greater than this value would be filled before the measurements are
started and hence be undisclosed. The highest pressure attained,, c. 1035 bar,
is equivalent to a D value of 0.014 pm.
Calculations were carried out using an Elliot 4120 computer and the
distribution curves were plotted by an on-line digital plotter.
The cumulative distribution curves were begun arbitrarily at zero
pore-volume at the calculated D value of c. 58 ym corresponding to the initial
height h. Because the samples are granular, penetration of mercury into the
spaces between the granules will occur in addition to any penetration into the
material itself, but earlier work at BCURA on non-porous granular samples
shows that the intergranular penetration with the present samples should have
been virtually complete at a pressure corresponding to a D value of >^ 10 um.
A8ol2
-------
2*4 Results and Discussion
Mercury porosimetry measurements were carried out on samples from
the exploratory experiments; helium and mercury density measurements were made
on UoKo Dolomite samples only,
Mercury porosimetry, helium and mercury density measurements were made
on samples from the controlled atmosphere experiments<>
The locations of the results used in discussion are given in the
following Sections; the 'raw' mercury porosimetry data are collected at the
end of this Appendix <,
2o4ol Exploratory experiments
The cumulative pore volume distribution curves, obtained from the
mercury porosimetry, are displayed in Figs< 1 to 3, and the corresponding
first differential curves are given in FigSc 4 to 60 In Table 6 are listed:
the extents of calcination for the stated residence times in the furnace; the
total pore volumes reached by mercury, as measured, ioCo, the pore volume with
entrances between c» 58 ym and 0^014 urn (t»p»v0) - no attempt being made to
correct for any contribution due to intergranular volume; and the value for
the pore - entrance diameter (A) corresponding to the main peak in each of
the first differential curves»
Helium and mercury density results for UoKo Dolomite are referred
to in the next Section„
As might be expected, it is evident that apart from the early
decomposition of the MgCO. in UoKo Dolomite (see below), the partial pressure
of C0? in the furnace strongly influenced the rate of calcination, which
proceeded much more rapidly in the.nitrogen-flushed atmosphere (low partial
pressure of CO-)°
An important difference in behaviour between UoK<, Dolomite and Limestone
1359 is that the dolomite calcined much more rapidly over an initial 1/4 h
period: compare the dramatic development of pore structure in the dolomite after
1/4 h with the small development in the limestone after 1/2 ho This initial
calcination of the dolomite appears to be unaffected by the partial pressure of
C0» in the furnace atmosphere and corresponds to decomposition of MgCO-j, which
is known to occur at lower temperatures .than CaCO- decomposition,, A slow
weight loss with elapsed time ensued with both stones at high partial pressures
of C0_; although the corresponding results were not completely obtained at low
partial pressures, rate a£ weight loss was higher as expected»
A8»13
-------
The results for U.K. Dolomite,, Figs. 19 2? 4 and 5 and Table 6.,
show that:
(a) the total pore volume (t.p.v,) disclosed increases with
the measured extent of calcination, and for the samples
calcined to > 99% (samples C5;. C7 and C9? Tabla 6), the
t.p.v. appears to increase with the time of calcination.
(b) The peak pore-entrance diameter (A) for the samples that
have reached approximately the same extent of calcination,
vizs samples C2, C6, C8S and samples C5, C7, C9S Table 6,
»
increases with the-time of calcination.
In the series of Limestone 1359 sampless the t.p.v. increases with
increasing extent of calcination and with time of calcination (Table 6).
In summary,, the main differences between the two stones, as revealed
by these exploratory experiments, ares
(i) For the same calcination time more pore volume develops in the
dolomite than in the limestone;, and this difference is most.marked for short
calcination timesa vizs 1/4 or 1/2 h.
(ii) For the Iimestone9 A appears to reach a limiting value, whereas for
the dolomite no limit in A was seen.
(iii) This limit in A for the limestone (1.10 um) is larger than the
maximum value for A reached with the dolomite (0.46 ym).
i
(iv) With the dolomite, volume in pores with entrance diameters > A 0.26 nm in diameter;
and, from the mercury porosimetry, (5)(a) t.p.v. (as defined above in Section
2.4.1)s (b) the volume obtained by interpolation, in pores with entrances 14.5 pm diameters and (c) the volume, TT 9 obtained by interpolation, in
pores with entrances < 14.5 jun and > 0.014 pm diameter, the reason for
A8.14
-------
selecting the value of 14 »5 ym here being to coincide with the upper limit of
pore-entrance diameter to which VK refers. The location of other data is
indicated within the following text-,
In examining the data, attention has been given to seeking possible
correlations, and to this end a considerable number of curves have been plotted,
and are reproduced in this Appendix, The following Sections include details
of:
(i) linear correlations between reciprocal displacement density and
^
TTH (mm /g), which could be useful in estimating the porosity in
calcined stones, using simple.p^ measurement;
O
(ii) comparison of Vx with ^Ho>
(iii) porosity development as a function of (i) time, and (ii) extent
of calcination, and the reduction in porosity on sulphation -
in particular, development and modification of porosity
(including the effect of sintering) behind entrances with
diameters in specified ranges, without and with SQ~ being present
in the controlled atmosphere;
(iv) the way in which sulphation lags behind C09 loss when these
processes are carried out together.
Of immediate practical significance, the work shows that:
(a) the development of large(transport) pores is apparently necessary
if a stone is to be a good absorber (a condition not met by
Limestone 1359), but chat much or even most of the sulphur is
accomnodated in small pores;
(b) the change of reaction temperature of the dolomites from 1470
to 1650 F did not increase the rate of sulphation to the level
expected from chemical kinetics considerations, and a speculative
suggestion involving a surface species is put forward that might
account for this behaviour and also for the fall-off in sulphur
uptake > Co 1560°F in the combustor;
(c) the present: type of 'drop-tube' experiment could be used as a
simple screening test for placing unknown stones in order of
acceptor abilityo
A8,15
-------
2-4r2,l Lineai relation between 1/p.. and TTTT and between l/p.T and ^
&Hg tig —— He Mg
In the exploratory work it had been found for the U»K, Dolomite that
3
1/p,, and 1/PU are linearly related to IT., ram /g, and all were functions of
Hg tie Hg
weight loss from the stone. (The individual 1/p , 1/p results are included
in Table 14, together with the irTT values .)
Hg
The corresponding 1/p , 1/p v£ IT graphs for the stones from the
rig ilc -.^^™ ^o
controlled atmosphere experiments, calcined-only, are shown in Figs. 7 to 10,
which are likewise linear,
The intercept value of 1/PH at TTH =0 on the extrapolated line for
each stone equals, within experimental error, the value of 1/p for the raw
stone, this value being (ignoring.any pores closed to helium) the volume of
the solid matter. The l/pu values for the two raw dolomites are the same,
3 „
Co 355 mm /g, while those for the two raw limestones are higher, being
3 3
Co 370 mm /g for Limestone 1359 and c° 375 mm /g for Limestone 18. These
values are in line with expectations based on listed densities, equivalent to
3 3
specific volumes of 370 mm /g for CaCO-, 330 mm /g for MgCO- (hence c, 350
3 3
mm /g for dolomite) and 390 to 440 mm /g for silica, the main impurity of
Limestone 18.
The slopes of the 1/PH (or 1/PH ) lines for the dolomites are the
same and likewise for the Limestones.
Results for the calcined-sulphated samples from the controlled
atmosphere experiments are also given in Figs* 7 to 10. In general, the points
lie on or below the corresponding lines for calcination only. In Figs. 7 to 9,
for Limestone 18 and the two dolomites, broken lines have been drawn through the
1650 F points« The value of TT decreases with increasing sulphation (see
Tables 7 to 9)s and it is seen from the figures that with each stone, the lines
meet at iru = 0, and at a lower intercept value than the corresponding l/pu
Hg Hg ^
value for the samples that were calcined only, in accord with the lower specific
volume of CaSO, than that of CaCO.,. This difference of intercept value is
more marked with the Limestone 18 than with the two dolomites, in line with the
fact that the difference in specific volume between CaSO, and CaCO-
(co30 mm /g) is larger than that between CaSO,oMgCO- and CaCO_.MgCO_
(c»15 mm /g).
The corresponding points for the Dolomite 1337 and Limestone 18
samples calcined-sulphated at 1470°F (Figs, 7 and 9) tend to lie on the
appropriate calcination line or between the latter and the broken lines: it
A8.16
-------
is not clear if this is a real effect or due to experimental error »
An application of the above linear relations for the calcined-only
samples is discussed in Section 2,Ao2.4.
2.4o2.2. Evidence that the calcined and calcined-sulphated stones
have little or no open porosity behind entrances < 0.014 ym
in diameter, with possible exceptions
3
In Figs*, 11 to 14S V mm /g is plotted vs TT . For each stone,
X rig
the straight line through the points passed through the origin and is of
approximately unit slopes vizp for the samplesj osreral!9 V - TT . This
X rig
means that overall they must contain little or no porosity behind entrances
with diameters in the range 0.014 jxm to 0.26 nm9 but among possible exceptions
is the 4 hj 1650°Fs, calcined-sulphated Limestone 1359 Csample G41S Table 10) -
this point is noted in Sections 2.4,2.7 and 3.2.
2.4.2,3 Increase of pore volume with increase of extent of
calcinatioti
In Section 2.4.19 on the exploratory experimentss it was shown that
t.p.v. increases as the extent of calcination increases,, The way in which
3
"V % and TfH % (viz9 TL, mm /g converted to percentage of assumed particle volumes
rig a{£
1/p y as with V mm /g) change with extent of calcination is shown in Figs* 15
£*-{3 -™
and 16 for the samples calcined in the controlled atmosphere in the absence of
S0_; the corresponding data for UoK. Dolomite from the exploratory experiments
are included. (The variation of both V % and iru % is given for completeness.)
x rig
The straight lines were drawn through the points for the samples (excepting the
exploratory ones) and show that V. % or TT,, % is linearly related to the extent
of calcination;, although the points for Limestone 18 are scattered. In both
figures 9 the stone with the least porosity before calcinations Limestone 1359 ,
has the least porosity over the entire range. The order of increasing
initial porosity of the raw stone is maintained at all extents of calcination
with the exception of Limestone 18. In this cases howevers the porosity is
greater than for Limestone 1359 within wide errors at the highest calcination
extents. For a particular stone the straight line implies that the amount
of porosity formed is directly proportional to the amount of CO. lost,
A8ol7
-------
The rate of calcination of all the stones was rapid at ibW F: the
extent of calcination reached after 1/4 h was 85% or more (Tables 7 to 10),
and,as might be expected, further calcination occurred when heat-soaking
was prolonged up to 4 h. With calcination at 1470 F, however, the situation
was quite different,, The atmosphere used for the calcination contained 15% C0_
by volume; the equilibrium dissociation concentration of C0« over calcium
carbonate at 1470 F is only 26% by volume, hence the atmosphere during the
calcination can be expected to retard the rate of calcination„ The results,
Tables 7 to 10, indicate that this effect is more severe in Limestone 1359,
which has the lowest initial porosity: after 1 h at 1470 F, the extent of
calcination and porosity (V %) have reached, respectively, 4% and 5% compared
X
with 20% and 14% with Limestone 18„
With the dolomites (as was seen with U.K0 Dolomite in Section 2»4"1),
the calcination follows a two-stage process - calcination to the "halfway"
stage, CaCO-oMgO, expected to be unaffected by the CO- atmosphere of the
.3 ^
furnace, and calcination of the CaCO, entity, expected to be affected.,
Thus, at 1470 F, after 1/4 h in the (X>2 atmosphere, both dolomites develop
much more porosity than the limestones: with the dolomites the extents of
calcination and porosity (V %) are, respectively, 34% and 24% for Dolomite
•K
1337 and 57% and 34% for the UoK, Dolomite, which values are much higher than
the above mentioned 1 h values (say) for the limestones; for 1 h calcination
of the dolomites, the corresponding values are, in the same order: 62% and
38%; and 67% and 38%„
Curves showing the variation of porosity with time of calcination
will be seen in FigSo 27 to 35 - these are referred to in a later Section,,
It is noted that at 1470 F some difficulty was experienced in this
critical region with slight variations in furnace temperature which led to
the apparently anomalous situation where the sample of Dolomite 1337 calcined
for 1 h reached a greater extent of calcination than the sample calcined for
4 he
2o4o2c.4 Estimate of porosity development in stone, from mercury density
It should in principle be possible to estimate the porosity developed
in different stones on calcination in the standardised atmosphere (without SO-
present) used here, and hence place them in order of porosity development with
respect to calcination time, by carrying out simple mercury density (PH )
measurements on the calcined products. Thus, referring'to Figs, 7
A8 o 18
-------
to lOj as mentioned above : the slopes of the 1/p or the ly'p lines are
the same for the dolomites, and likewise for the limestones. This means that
if a stone is of known composition so that the intercept value of 1/PH
(viz, at IT = 0) can be placed, and hence the l/P^ and l./PH lines9 the
A1xS • o tic,
experimentally determined I7pp value for a particular calcined sample will
Hg o
then give TT Cor I7p to give 7 imm 7gp and hence IT % or V %B for that
rig tie X tig X
sample.
Such a procedure may be of value to obtain supporting information
in assessing the sulphation behaviour of stones discussed in later Sections,
2.4,2.5 Comparison of. the distribution of pore volume with respect
entrance diameter for the different stones
To obtain information on the extent to which pores with entrances
of a particular diameter are generated during calcination or are reduced in
volume during sulphation, the mercury porcsimetry data have been analysed in
two ways: the first consists of examining the volume in pores with entrances
of diameters between 14.5 urn and various smaller values down to 0,014 \m,
for irH | the second involves examining the pore volume for .chosen ranges of
pore-«entrance diameter within the overall range 14,5 pm to 0,014 pm.
The pore volumes, for the various calcined and calcined-sulphated
samples, behind entrances of diameters between 14.5 um and successively*3.15,
0.985S 0.2659 0.105, 0.0305 and 0,0143 )im are shown in Tables 11 and 12$ the
volumes are expressed as mm 7g and as percentages of particle volume (1/PH )•
Incremental pore volumes (%) for the ranges of pore-entrance diameter between
the successive values*l4.5, 3.159 0.985S 0.265, 0.105, 0.0303 and 0.0143 ym
are shown for the calcined-only stones in Table 13, The diameter values
< 14.5 -pm are for convenience those corresponding to the measured pressures
used in the mercury porosimetry measurements. For simplicity, these diameter
values are.written throughout as 39 19 0.3, 0.1, 0.03,, and 0.014 um.
The pore volumes CO for the calcined-only stones, for the ranges
14,5 um down to 0,014, 0,03, 0.1 and 0.3 pm, are plotted vs_ extent of
calcination in Figs. 16 to 19.
The incremental pore volumes % are displayed in histogram form in
Figs. 20 to 22o
* The third significant figure varies among the determinations.
A8ol9
-------
It is clear from Figs,, 16 to 19 that the .two dolomites have most
of their porosity in the pores with entrance diameters less than 0.1 pm.
Also,, although most of the relations show smooth curves, the porosity for
Limestone 1359 in 'Fig. 18 shows no simple,behaviour,, with porosity developing
in this range more sharply at the high temperature than the results at the
low temperature would suggest. In the range of pore-entrance diameters 14.5
to 0.3 ump the relations are all reasonably linear, as with the range 14.5 pm
to 0.014 pm,, but the order of development of porosity is changed, the dolomites
lying between the two limestones as far as volume in these large pores is
concerned. With Limestone 18 the formation of the latter occurs to a marked
extent, but Limestone 1359 remains relatively poor during calcination as regards
volume in such pores and this would be expected to militate against ease of.
access of S02 to the interior of the calcined stone, access being facilitated
by the presence of wide "transport pores".
The histograms for 1470OP9 in Fig. 20, clearly illustrate the lack
of pores with the wider entrances in Limestone 1359, discussed above. The
way in which the porosity within the overall range 14.5 to 0.03 pm develops
in Limestone 18 is seen. The two dolomites show little change in the range
14.5 to 0.1 pm over the 4 h period and the changes in porosity occur'in the
specific ranges 0.1 to 0,03 pm for Dolomite 1337 and 0.1 to 0.014 pm for
U»Ko Dolomite, The porosity in UUKU Dolomite in the region 0,03 to 0,014 pm,
which develops in the initial 1/4 h of calcination, disappears with time, but .
this disappearance is accompanied by increase in. the 0.1 to 0.03 pm region;
this phenomenon presumably involves a form of sintering (crystal growth), causing
a shift in entrance diameter from the smaller to the larger of these two ranges.
2.4.206 Effect of sintering on pore size
The histograms,, for 1650°F, in Fig. 21S show that the stones have more
porosity overall than after calcination at 1470°F (Figt 20), but for the range of
smallest entrances,, 0.03 to 0.014 pm, the dolomites have less porosity at
1650°F than at 1470°FS and the limestones have little at either temperature.
Sintering is evident in all the stones except Dolomite 1337; with Limestone 18
after 4 h calcination there is relatively little porosity with entrances
< 0.1 pm diameter, and with Limestone 1359 the progressive decrease .with time
of porosity with entrances between 0.1 and 0.03 pm diameter and the
progressive increase of porosity with entrances between 0,3 and 0.1 pm diameter
is most striking. The lesser development of wider pores (viz, having entrances
> 0.3 pm in diameter) in Limestone 1359 at 1650°Fis seen here.
A8020
-------
It is worth noting the extent of sintering in U.K. Dolomite during
the very long time of calcination in the exploratory experiments (Section 2.4.1) -
Fig. 22: Sintering is much more evident on calcining for 97 h than for the 4 h
used in the controlled-atmosphere experiments, and it is worth comparing also the
histograms in Fig, 22 for samples C7 and C5, both of which have reached
c. 99.5% calcinationa although admittedly the atmospheres used in these two
experiments were different,, It is seen that most of the pores developed in
the dolomite lie behind wider entrances in the exploratory experiments than in
the controlled-atmosphere ones.o The reason for this is not known.
Eventually, sintering could be expected to lead to enlargement of
some pore entrances to > 14„5 jam diameters which would then be penetrated by
mercury in the PH determination causing a decrease in 1/PH « A small
difference in this direction is apparent between samples C7 and C5 (Table 14),
but the observation is equivocal because the expected decrease in V is not
matched by a decrease in TT , With the calcined-only samples from the
*-TO
controlled atmosphere experiments9 the only clear evidence of a decrease in
1/PH and in "V and ir is seen with samples N13 and N15, Table 9 - for an
.8 x "8 • o
increase in time of calcination at 1650 F from 1 h to 4 h, the extent of
calcination remaining at 96,0%, However, there may also be ah analogous
effect with Limestone 1359: see samples G38 and G40, Table 10 (taking into
account the small difference in the extents of calcination, since 1/PH and
TT,, s expressed as volume per g of calcined samples, are being compared).
if
2o4.2o7The effect of sulphation on pore structure
In Figo 23, the level of sulphation reached by the various stones is
plotted vs their residence time in the furnace. It is immediately obvious
that Limestone 1359 is a relatively poor acceptor under the present conditions,
at either temperature^ since the stone has reached its limit of sulphation,
c,, 3% at 1470° and Co 8% at 1650°F8 after only 1 h. These values compare
well with the thermal cycling resultsP Table 22, for Limestone 1359 in the
same size grade (-16 * 52 BS mesh)9 where the sulphur uptakes correspond to
sulphations of < 6%» Limestone 18 shows a much better sulphur uptake
pattern than Limestone 1359 and shows a significant difference in level of
sulphation at the two temperatureso Each dolomite however shows little
difference in the level of sulphation at the two temperatures; for the
U.Ko Dolomite sulphated for 1/4 hc the sample at 1650°F is slightly less
sulphated than the sample prepared at 1470 F (10„7% compared with 11.8%
A8,21
-------
sulphation)„ If a normal reactioirrate temperature-dependence is expected,
then the rate of sulphation should be several times greater at 1650°F than at
1470 F, Since this is not the case with the dolomites it appears that
either the reaction has little or no activation energy,, probably a result of
catalytic mechanism, or that the reaction rate is controlled By other rate
determining factors such as a diffusion control mechanism. Since in the
pilot plantss the rate passed through a maximum, at c. 1560 F, a catalytic
mechanism may be at works and this point is elaborated,, speculatively, in
Section 2.402.8o It is noted that in Fig. 23, sulphation is the ratio of
the quantity of sulphur taken up by the sample to that taken up if all the
CaO were converted to CaSO,: this means, for example, that at 1650 F,
Limestone 18 would9 on a mass or bulk volume: of stone basis, be a better
acceptor than Dolomite 1337.
Now in the present sulphation experiments the sample was not
subjected to complete calcination before the sulphation was carried out, and
certainly at 1470**9 C02 was being evolved from parts of the decomposing
stone at the same time that sulphation was occurring in,other parts of the
structure. This is more akin to the initial situation in the combustor than
would be the case with complete precalcination. As noted previously, the
extents of calcination were measured after the particular.residence times in
the SO- bearing atmosphere. The way in which sulphation lags behind
calcination is seen from Fig. 24, where sulphation is plotted vs_ extent of
calcination for the same residence time (noting that with the dolomites,
initially,MgCO. decomposes to MgO, and that the sulphate is believed to be
unstable at the present reaction temperatures).
Given below are the differences (E_,% - E__%) between the extents
Oj. L/
of calcination reached by the stones for the same residence times (t) with
(E .%) and without (Ep-%) the SO present: the E % values were taken from
Tables 7 to 10,
A8.22
-------
Stone
Dolomite 1337
U-K. Dolomite
Limestone 18
Limestone 1359
t,
h
i
1
4 .
i
1
4
'i
1
4
i
1
4
Temperature and (E %- E .%)
Li 1 k Cz
1470°F
+28o2
+12.6
+35.0
+ 4.2
+ 4.8
+12 o 4
- 5 (mean)
+ 1.5
+36.1
+ 1.7
+ 3.7
- 9,0
1650°F
+5.5
+1.3
+9.0
-3.0
-1.0
-r.o
+0.2
-2.0
+4.0
+3.6
+9.0
+8.0
In most cases the extent of calcination, for a given time, appears to be
greater in the presence of SO. than in its absence. It would be tempting
to suggest that the presence of S0« accelerates the decomposition of the
stone, but as the results do not show any self-consistent pattern,, such a
mechanism is by no means certains and it has been noted previously (page is)
that at 1470°F, slight variations in furnace temperature led to apparently
anomalous calcination-only results for the 1 and 4 h Dolomite 1337 samples.
Further,, even if some such 'accelerating mechanism' did operate it might
be expected to be offset by the tendency of the evolving CO. initially to
impede the diffusion of SO. into the pores. If the decomposition of a
stone particle follows a moving front, vizs the front moving inward towards
the centre of the particles then pore formation will move inward and CO.
from inner portions of the particle will pass through pores already formed,
en route to the exterior of the particle; any effect of the inhibition of
entry of SO. by evolving CO. would be expected to be more pronounced in the
finer pores, in which there is more restriction to the movement of gas
molecules. With dolomites the early decomposition of the MgCO-j and hence
attendant early pore-formation, might possibly reduce any such hindrance to
SO. ingress: it is noted that after this initial decomposition the quantity
of C00 evolved per particle of stone would be less than that from limestone,
AS 23
-------
so that, overall, if egress of CO. hinders ingress of SO. that hindrance
should be more marked with limestone than with dolomite. These
speculations will be taken no further here.
In Section 2,4.2.1, it was noted that IT decreases with increasing
sulphation. In order to establish in detail the effect of sulphation on
the developing and developed pore structure, and in particular which.pores
accommodate the sulphur, it is necessary to make comparisons among calcined-
sulphated samples and also between the latter and calcined-only samples for
the same residence times, with the assumption that the calcined-only stone
is the correct datum. To some extent this assumption is open to question,
as indicated by the results in the table above on page 23, To investigate
this problem further, with respect to porosity, the apparent reduction in the
porosity V % caused by the sulphation has been calculated as:
K
(i) Vx2 - Vxl and (li) Vx3 - Vxl, where V^ is the measured YX% for the
calcined-sulphated stone, V „ is the measured V % for the corresponding
X£ 2£
calcined-only stone, and V is the value for V % estimated from the extent
Ji3 -A
of calcination of the calcined-sulphated stone using the appropriate line in
Fig. 15, on the assumption that this would be the value for the porosity
that would be present in the stone if the CaSO, formed were replaced by CaO,
no other change occurring. The results are given in the following tables.
A8 /2
-------
Qfrmo
tj U wLIC
Dolomite 1337
U.Ko Dolomite
Limestone 18
Limestone 1359
Dolomite 1337
UoK, Dolomite
Limestone 18
Limestone 1359
t,*
h
j
1
4
i
1
4
i
1
4
J
1
4
i
1
4
i
1
4
i
1
4
i
1
4
V % and differences in V %
x x
v
xl
v
Vx2
v
x3
(V -V )
x2 xl
(V -V )
x3 xl
Temperature: 1470 F
32
31
23
33
31
28
14
15
23
3
4
6
24
38
33
34
38
41
14 (mean)
14
17
5
5
14
39
46
52
36
42
46
10
16
37
5
6
7
-8
7
10
1
7
13
0
-1
-6
2
1
8
7
15
29
3
11
18
-4
1
14
2
2
1
Temperature: 1650°F
47
40
29
50
48
39
43
38
22
42
43
42
52
55
54
54
54
56
45
50
48
44
46
46
54
56
58
53
54
55
45
50
52
46
50
51
5
15
25
4
6
17
2
12
26
2
.3
4
7
16
29
3
6
16
2
12
30
4
7
9
* residence time
Excepting the 1470°F Dolomite 1337 samples, the values of V and
V _ for most of the samples agree within 10% relative, which is not
unreasonable considering the scatter in Figo 15 <, The large discrepancies
between V „ and V _ at 1470 F follow those between the extents of
x2 x3
calcination referred to above, but no further comment on these can be
made, except to note that they may.be related to the temperature
variation previously mentioned =>
A8.25
-------
I* Figs,, 25, 2.5a and 26, V^-V^, V^-V^. and i are
plotted ^s sulphatiori to illustrate, the general decrease in porosity on
sulphation, IT . and HH „ are TT % values, the subscripts 1 and 2 having
the same significance as for the V % values, It is noted that this
porosity reduction for a given value of sulphation (as defined herein) would
be expected to be greater with a limestone than with a dolomite because there
is more CaCO. present in the limestone than in the dolomite: this trend is
seen in Figs, 25, 25a and 26,
Before -proceeding with examination. of the porosity for various
ranges of pore-entrance diameter it is worth at this stage pointing to the
changes in superficial volume that occur on calcination-sulphation compared
with those for calcination-only, it being understood that a change in super-
ficial volume in the present context means either a change in the true
superficial volume or in the volume of pores with entrances with diameters
>14,5 Mm, cf,-, page 21, or in both, The changes (AV) are given in Tables
15 and 16 for 1470 F and 1650 F, respectively. They were calculated from:
AV = 100CW/pHgT - l/PHg0)/(l/PHg0)%
2
where p and p „ are, respectively, the mercury densities, g/cm , of
the original stone arid the treated stone (viz, after calcination-only or
calcination-sulphation) and W., g, is the mass of treated stone produced
from Ig of the original, As the values stand the following observations
may be made. Dolomite 1337 at 1470 F shows slight swelling on calcination-
only but shrinkage of up to 5% on sulphation, whilst at 1650 F calcination
alone produces a shrinkage that apparently decreases with time - sulphation
appears to enhance the shrinkage. The U,K, Dolomite, with calcination alone
at 1470 F, shows a slight shrinkage in the controlled atmosphere and a slight
swelling in the preliminary experiments, whilst at 1650 F a marked shrinkage
of 8% is observed; sulphation seems to retard the shrinkage at either
temperature, At. 1470 F, Limestone 18 on calcination alone appears to swell
slightly after. 1/4 h and then it shrinks, whereas at 1650 F, no swelling is
apparent and a shrinkage of up to 4% is seen; sulphation at both temperatures
interferes with the shrinkage. Limestone 1359 at 1470 F shows a slight
swelling on calcination alone and on sulphation, even though the extents of
both the calcination and sulphation are small, 19% and 3%, respectively,
after 4 h: at 1650 F, calcination alone produces up to 10% shrinkage whilst
A8o26
-------
sulphation .appears to enb.ar,;e ihe shrinkage still further, That there
is ample scope for shrinkage, due to sintering, is evident from the
3 3
specific volumes of CaCO-, 370 mm /g, and CaO, 300 mm /g. Thus Ig of
3
CaCO» of volume 370 mm calcines to Oo56 g CaO which in the close packed
J 3
fully sintered form would occupy c- 170 mm :a shrinkage of 54%*
The variation of porosity in calcined-only and calcined-
sulphated samples with residence time is shown in FigSo 27 to 35„
The situation in Figs, 27 to 29 for the results at 1470°F and
1/4 h calcination is clearly anomalous, probably due to a temperature
effect noted earlier since (Table 7) Dolomite 1337 sample J6 is calcined-
only to 33o6% in 1/4 h, while J9 is 61o8% calcined and partially sulphated
in 1/4 h., It is clear that at 1650 F most of the porosity filled, blocked
off, or otherwise eliminated on sulphation lies in pores with entrance
diameters in the range Ool to 0003 ym and that there is little change in
the porosity behind entrance diameters of 0»03 to 0,014 ym. This is to
be expected since the amount of porosity behind these finer entrances is
relatively small anyway (Figo 21 and see below also). Porosity in pores
with entrances having diameters larger than Ool ym is little affected by
sulphation, U,K» Dolomite in Fig, 30 follows the trend of Dolomite 1337
(time did not permit mercury porosimetry to be done on any of the
sulphated samples prepared at 1470 F)„
Of Figs, 31 to 34 for Limestone 18, the first two are practically
identical, consistent with the observation of no significant porosity
behind the smallest entrances, viz, in the range 0003 to 0«014 ym diameter
(Figs, 20 and 21) „ It is clear from Fig., 34 that pores with entrances
larger than 0,3 um diameter are active in sulphur uptake with Limestone 18„
The equivalent curves for Limestone 1359 (Figo 35) are unspectacular since
little sulphation took place after 1 ho The only point of interest is that
for sample G41, the sample sulphated at 1650 F for 4 h, •!:„ is appreciably
lower than V , This may be evidence for a sulphate 'shell' reducing or
-JC
blocking small pore entrances to mercury penetration (cfo Section 3)o
Time prevented mercury porosimetry being done on the other Limestone 1359
samples sulphated at 1650 F or on those sulphated at 1470 F»
A8,27
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The mercury porosimetry data for the sulphated samples are
presented in an alternative form in Figs. 36 to 38, which show the variation
of porosity for various, ranges of pore-entrance diameter for the two
dolomites and Limestone 18, It is clear that for the two dolomites, the
porosity behind the entrances with the largest diameters (i.e., > 0.3 ym)
shows little net change on sulphation. This can be interpreted to imply
continuing access of gases to the internal structure of the particles via
large (viz, 'transport') pores (cf. Section 2.4.205). This is true to some
extent of the Limestone 18, except that the porosity behind the largest
entrances does show some reduction on sulphation; the porosity behind
entrances < 0.3 ym diameter is much reduced after 4 h. The above points
are exemplified further in Fig. 39, which gives in histogram form the
differences in porosity, behind entrances with diameters in particular
.ranges, between calcined-only and calcined-sulphated stones for the same
residence time at 1650°F; the results are listed in Table 17. These
differences may be regarded as the changes in the porosities caused by
sulphation, the positive values corresponding to decreases. It is
helpful to examine Fig. 21 as well as Fig. 39. It is seen that the
sulphation is mainly in the smallest pores available (equating these with
the smallest entrances), with the exception of Limestone 18 where sulphation
occurs over the whole range of pore-entrance diameters. It is thought
that the negative porosity changes correspond to either experimental errors
or to early sulphation of pores that would in the absence of sulphur, sinter
and disappear on prolonged calcination, but which are prevented from
sintering by partial sulphation.
This apparet|t effect of sulphation restricting sintering and
particle shrinkage was seen earlier in this Section (Tables 15 and 16); it
seems to occur with all the stones at 1470 F, except Dolomite 1337 where
sulphation appears to enhance shrinkage,. At 1650 F, sulphation seems to
retard shrinkage in U.K. Dolomite and Limestone 18, but to enhance it in
Dolomite 1337 and Limestone 1359. Finally, it is noted that a marked
shrinkage of a stone with few transport pores may lead to a situation where
the outside of.the particle is compacted. Since the small pores tend to
block up on/sulphation, the initial sulphation may be enough to block
off much of the porosity in the outer region of the particle, thus slowing
the rate of sulphation. This situation has been described previously by
Satterf ield and Feakes^; such behaviour may have relevance to the poor
A8.28
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s-ulphation Behaviour of Limestone 1359 (at 1650°FS Table 16). Thus it does
appear that in the assessment of a stone its sintering/shrinkage behaviour
should be considereds and indeed Potter „ Chan et al and Glasson have
shown that increasing time of calcination leads to a decreasing surface area
and hence sulphation efficacy: although surface areas have not been
measured here9 it is clear that the same process is going on by the shift
of porosity into pores with entrance diameters increasing with time of
calcination,, referred to in Section 2.4.2.6 as sintering Ccf. ref. 16).
The role of impurities in the stones- MgO in the dolomites and SiO_ in
Limestone 18-is not entirely-clear except that the structures calcine
more rapidly and generate more porosity in a given time than the relatively
11 13
pure Limestone 1359. Chan et al and Glasson consider that silica is
liable to form a slag with the CaO and reduce the porosity by enhanced
sintering.
2.4.2.8 Sulphur fixation ;
The mechanism of sulphur fixation is not clear but some points,
leading to speculation, arise from the present work:
(a) Since sulphur is found in the smallest pores, the SO,, probably does
not react to sulphate at the point of first contact with the stone,
in which case the S0» must migrate in some form until a certain
favourable site or condition is obtained.
(b) In the elevated-temperature porosity work, it was found that:
CO CSection 4.5.3) removal of the last traces of water from
U.Ko Dolomite (presumably held as Mg(OH)2) was very difficult
in vacuum at 1470 Fs requiring the order of tens of hours of
pumping even though that hydroxide is thermochemically unstable
in relation to the oxide above 900 F;
(ii) (Section 4.5.2) xenon was strongly adsorbed in some samples of
U.K. Dolomite and Limestone 1359 and was even difficult to remove
at 1470 F in vacuum: this effect could be associated with the
above mentioned difficulty in removing water from the dolomite;
(iii)increasing the temperature from 1470°F to 1650°F does not cause
the increase in rate of sulphation with the dolomites that might
be expected from chemical kinetics considerations; moreover in
the pilot plant work the efficacy of removal of S0_ passes
reversibly
limestones.
reversibly through a maximum at c. 1560 F with the dolomites and
A8o29
-------
Bearing in mind these observations it can be argued very
speculatively (for the dolomites at least) that the sulphur migrates inside
the stone perhaps as the sulphite ion which is 'in itself stable up to
1900 ?, but thermochemically unstable with respect to the sulphate under
oxidising conditions. The sulphur may thus be able to enter the smallest
pores and be oxidised therein. The oxidising agent is not known but may
itself be a surface species such as the hydroxide or even a peroxide since
14
calcium peroxide is not much less stable than the hydroxide (Glasson ).
(The present conditions of controlled atmosphere could have been contaminated
with water through the method of injection of the S0_ into the gas stream}
This mechanism would imply that the important physical factor in uptake of
sulphur would be the access of the SO to the stone surface and from there to
the interior of the stone - hence the need to generate porosity in transport
pores and in small storage pores which have a higher surface/volume ratio -
and the chemical step to the sulphate would be dependent on the concentration
of hydroxide ions in the stone which, with increasing temperature and
instability of the hydroxide, would be expected to decrease at higher
temperatures. This mechanism, it is noted, would be in line with the
observations mentioned under b(iii) above. The exact role of the gas
phase oxygen is not clear. As noted in Section 1, Potter investigated
the relative merits as SO. acceptor of two stones (a limestone and a
dolomite) in their uncalcined, calcined and hydrated (after calcination)
forms; for each stone, the hydrated form proved the best acceptor over the
temperature range involved here. This may indicate either that the
presence of water is beneficial in increasing the uptake of S07, or that a
more active surface forms, with small pores, on calcination of the hydroxide
12
rather than of the raw stone, as indicated by Glasson
2.5 Conclusions
(i) The development of porosity on calcination is a time and
temperature dependent process. The amount of porosity (% v/v) formed is
for each stone a linear function of CO. loss.
(ii) On calcination, porosity is generated initially much more
rapidly in dolomite than in limestone. This difference is most marked in
a C0_ bearing atmosphere at 1470°F. The effect is evidently associated
with the decomposition of the MgCO_ in dolomite.
A8o30
-------
(iii) There is little, if any, porosity behind entrances with diameters
in the range 0.014 ym to 0»26 nm, with the calcined-only materials or, with
the likely exception of Limestone 1359, with the calcined-svilphated ones,
(iv) Sulphation varies with time, as shown in Fig. 23. It is
emphasised that the stones were not precalcined before being exposed to
S02; it was found that sulphation lagged behind C0_ evolution.
(v) Sulphation caused a reduction in porosity and it was found that
sulphur is accommodated in the smallest pores (as detected by the mercury
porosimetry) in the stone:, e,,g., with Dolomite 1337 at 1650°F most of the
porosity filled, blocked off, or otherwise eliminated on sulphation, lay
in pores with entrances having diameters between Od ym and 0.03 ym;
with Limestone 18, part of the sulphation took place in pores with entrance
diameters between 0.3 ym to 0,1 ym'o
(vi) As the results in Fig» 23 clearly show, Limestone 1359 is poor
compared with the other stones in its ability to absorb S0_. It is noted
that at 1650 F, on a mass or bulk volume of stone basis, Limestone 18 would
be a better acceptor than Dolomite 1337 (see (ix) below). The studies of
calcination-only showed that, of the stones, Limestone 1359 :is poorest in
the quantity of relatively large pores (say, with entrance diameters in
the range 14*5 ym to Go3 ym) whose presence would facilitate the more
rapid ingress of SO. to the interior of the particle and lead to more
rapid reaction. On the other hand, Limestone 18 shows a much more pronounced
development of pores in this range of pore-entrance diameter; for example,
after 4 h at 1650 F, the porosity in these pores in Limestone 18 is 29%
compared with only 4% in Limestone 1359= On sulphation, the volume of
pores with entrance diameters > 0,3 ym shows relatively little change with
the two dolomites, viz, the 'transport pores' tend to retain their identity,
but with Limestone 18 reduction in the volume of these pores occurs as the
level of sulphation at 1650 F increases.
The level of sulphation reached under the present conditions
clearly does not depend solely on the total amount of porosity developed
in the stone on calcination alone - a fairly high porosity is developed
in Limestone 1359 after 4 h at 1650°F (Vx = 46%). Indeed the porosity (Vx)
in the stone after 4 h at 1650 F in the S02 bearing atmosphere is as much
as 42%, and comparison of the latter with the mercury porosimetry data
suggests that the sulphation may have caused narrowing of some pore entrances
to < Oo014 ym diameter (see Section 3, and (iii) above).
A8.31
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Cvii] It appears that at least two criteria of pore structure have to be
•met if a stone is to Be a good SO- absorber:
(a) extensive volume in large, vizs transport, pores for ease of
access to the interior of the stone;
(bl extensive volume, for accommodation of the sulphur, in
relatively small pores - which have a higher surface,/volume
ratio than larger pores.
In the case where one factor is missing, as in Limestone 1359 with
little porosity in large pores,, or in Potter's work with Iceland Spar
containing low porosity, then the sulphur uptake is liable to be poor.
With stones not having a very well developed transport pore
system, the effect must also be considered of sintering, which could cause
contraction at the outer surface.'and impedance, after initial sulphation,
to further sulphation.
(viii) The mechanism of sulphur fixation is not clear,, but some points
arise from the present work:
(a) Since sulphur is found in the smallest pores the SO. probably
does not react to sulphate at the point of first contact with
the stone, in which case the SCL must migrate in some form
until a certain favourable site or condition is obtained.
(b) Increasing the temperature from 1470' "to 1650°F does not
<^use the increase in rate of sulphation with the dolomites
that might be expected from chemical kinetics considerations.
This effect may be related to the observation in the pilot
plant work that the efficacy of removal of SO™ passes
reversibly through a maximum at c, 1560 F.
Cc) With dolomites, at least,, a highly speculative suggestion,
based on the observation made during the course of the work
(see Section 4,5.3) that the last traces of water were difficult
to remove, is that an oxygen-containing species, perhaps
hydroxide, localised on the internal surface of the stone, is
necessary in the formation of the sulphate; increase of
temperature above a certain level could cause such a surface
species to become mobile resulting in reduced formation of
A8c32
-------
sulphate. In this case it is possible that subsequent
reduction in temperature could reduce the mobility of the
species causing an increase in sulphur uptake, in line with
the plant observations mentioned under (b) above.
The chemistry of the sulphur retention process, and the possible
influence of water on this, and on the formation of the pore structure
itself, would seem to Be worthy of further study, particularly as such
work may lead to an understanding of the mechanism, and hence perhaps
elimination, of the fall-off in sulphur retention above c. 1560°F,
(iz) A simple screening test for stones
The most simple and satisfactory laboratory-method of placing
unknown stones in order of acceptor ability would seem to be a sulphation
experiment wherein stone particles are dropped on to a mesh in a tube, at
reactor temperature, through which an appropriate SO^ bearing gas stream
flows, as described in the present work. Subsequent analysis for Ca,
CO. and SO,, content would enable curves such as those in Fig. 23 to be
constructed showing the variation of the level of sulphur uptake with
time. (It is noted that in Fig. 23, sulphation is the ratio of the
quantity of sulphur taken up by the sample to that taken up if all the
CaO were converted to CaSO,: this means, for example, that at 1650 F,
Limestone 18, on a mass or bulk volume of stone basis,would be a better
acceptor than Dolomite 1337.)
A8.33
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MERCURY POROSIMETRY ON PARTIALLY SULPHATED PARTICLES BEFORE AND
AFTER BREAKAGE
3.1 Method and Samples
It has been possible to demonstrate the presence of an
*impermeable' layer or *shellf within the particles of a sample of
Limestone 1359 sulphated in the laboratory using the method described in
Section 7, but not within a sample of that stone sulphated in a combustor.
It has also been possible to show that such a 'shell' does not exist
within sulphated samples of U.K. Dolomite and Dolomite 1337.
The method used was as' follows:
(i) Mercury porosimetry curves of the sulphated stones were measured.
(ii) Further samples of the sulphated stones were taken and the
particles broken individually using a razor blade; the product was then
sieved to remove particles smaller than 52 BS mesh and the porosimetry
curves of the +52 BS mesh particles were measured.
The mercury porosimetry method has been discussed in Section
2.3.4. The materials used were:
(i) Limestone 1359, -16 +52 BS mesh9 designated sample G7, sulphated
during laboratory reactivity tests (Section 7) until 5.8% of the SC^ stream
passing through the bed of limestone was retained. The sulphur content
of this stone was 3.6% w/Wj, a sulphation of c. 7%. The broken fraction
was designated G14o
(ii) To confirm that the'shell'was not an artefact of the calcination,
a sample of Limestone 1359 was fully calcined in an 02/N2 stream for 3 h
but not sulphated. This sample was designated G30. The sample was
subdivided and a broken fraction (G31) prepared as before.
(iii) Limestone 1359 sulphated in the 6 inch combustor (Task V, Test
Series .1.2). The sulphur content of this stone was 5.2% w/w, a sulphation
of c.ll %. The unbroken and broken samples were designated 01 and 02,
respectively. Ash was removed with a magnet, as in (v).
(iv) U.K. Dolomite, -6 +8 BS mesh, designated sample B5, sulphated
during laboratory reactivity tests until 8.7% of the S0_ stream was retained.
The sulphur content of this sample was 4.9% w/ws c. 17% sulphation. The
broken fraction was designated B6.
-------
(y) Dolomite 1337 removed from the bed of the pressure combustor after
Task II, Test Series 2; ash was removed from this sample with a magnet.
Subsequent analysis showed that the resultant sample contained 1.8% SiO.
and 0.6% 7eJ)^9 which compounds should form the major component of the ash,
indicating that most of the ash was removed. The sulphur content of this
stone was 9,3% w/w? c, 35% sulphation. The unbroken sample was
designated J2 and the broken .one J3.
(vi) U.K. Dolomite removed from the bed of the pressure combustor after
Task II, Test Series 1; ash was again removed with a magnet. The sulphur
content of this stone was.7.6% w/w, c, 28% sulphation. The unbroken sample
was designated M and the broken sample Ml.
3.2 Results
The measured porosimetry curves are shown in Figs. 40 to 45 and it
can be seen that the curves for the three samples of the two dolomites are
virtually unchanged by breakage (Figs, 43 to 45). The differences
between the two curves for ILK. Dolomite in Fig. 43 lie in the region of
interparticulate penetration and are not significant: the two curves are
virtually identical at pore-entrance diameters < 10 urn.
The curves for Limestone 1359 sulphated in the laboratory, Fig. 40,
show that there was considerable porosity within the whole sulphated particles
that has not been reached by mercury in the porosimeter but that some or all of
this porosity has been made accessible by simple cleavage of the particles.
The curves in Fig. 42 for the calcined, unsulphated limestone^ show that
this property is peculiar to the sulphated limestone.
To elaborate; if there were an impermeable shell round the exterior of each
unbroken sulphated limestone particle, then once the interparticulate
porosity had been filled by mercury little further penetration with the
unbroken particles should have been seen. However, this was not the case.
Bearing in mind that the pore-entrance diameter range of the porosimeter
used is c. 58 ym to 0.014 ym, one, very much simplified;, explanation of
the observations is that the unbroken particles have a pore structure that
consists of:
(a) that disclosed by the porosimetry, consisting of pore entrances
at the exteriors of the particles, leading to wider pores (having diameters
of < 58 pm), the original pore entrances having been narrowed by
sulphation; and
-------
0>) that not disclosed By the porosimetry, comprising pore entrances
of diameters < 0.014 um at the exteriors of the particles (and/or at the
surfaces of the pores described under (a)), leading to wider pores with
diameters in the range c. 58 pm to 0.014 pm, the original pore entrances
having been narrowed by sulphation, (It was noted (Section 2.4.2.2) that
most, if not all, of the pore volume of partly or fully calcined, unsulphated
stone lies behind entrances > 0,014 pm in diameter, but that Limestone 1359
sulphated for 4 h at 1650 7 in the controlled atmosphere appeared to have
some volume in pores with entrances < 0.014 pm diameter.) The breakage
would now result in mercury penetrating the pores described above under (a)
through entrances wider than the original ones: considering the porosimetry
curves below the line shown in Fig. 40, such penetration would account for
the shift to the left on breakage. Similarly9 the part of the porosimetry
curve above the line for the broken particles, could have resulted from
the breakage of pores described above under (b). Such narrowing of pore
entrances may be regarded as the forming of a 'shell', which would impede
successive sulphation,, and is in line with the more constricted structure
of the stone, compared with the more open structure of the dolomites which
do not show the breakage effect. The presence of a 'shell' in sulphated
- 3 .
limestone has been observed by optical microscopy and by electron
4 3 •**
microprobe analysis for sulphur (including Limestone 1359 - no
'shell* was observed with U.K. Dolomite)-
The absence of the breakage effect with the plant-sulphated
Limestone 1359 (Jig. 41) could mean that a 'shell* was destroyed, or was
prevented from forming, by attrition in the fluidised bed.
The calcined-only limestone was not a true precursor of the
sulphated material, and it would not be justified to attempt to compare
the corresponding porosimetry curves for the unbroken particles of these
two materials - the sensitivity of pore structure of stones to calcination
conditions has been discussed in Section 2.4. However, the breakage of
the calcined-only limestone resulting in a change in the porosimetry curve
(Fig. 42) in the opposite direction from that observed with, the laboratory
sulphated stone is in line with this sulphation having caused the
narrowing of some pore entrances down to diameters beyond the range of
the porosimeter, as discussed above.
A8.36
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The change in the porosimetry curve, on breakage of the particular
calcined-only limestone, could be accounted for-if the unbroken particles
contained pores of diameter greater than c. 58 ym but accessible only through
entrances indicated by the sharply rising portion of the porosimetry curve.
Now breakage would result in some of those pores becoming accessible through
entrances >c58 Pffl, and hence their volume would not now appear in the
porosimetry curve for the broken particles, which would lie below the
original curve.
In all the above discussions, any destruction of pore volume due
to the breakage has been ignored, as has any interparticulate penetration
corresponding to the pore-entrance diameter region c. 58 ym to c. 10 urn.
A8.37
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4. STUDIES 0? POROSITY AT ELEVATED TEMPERATURE ,
4.1 Ihtrod'action
When porous solids are used at elevated temperatures in processes
involving gasess the geometry and surface properties of the pores at the
temperature of operation often play an important or even dominant role.
As substantial changes of the accessible porosity of a solid may occur on
increasing its temperature -when standard pore structure tests made at
room temperature or below would not then accurately reflect the relevant
structure of the material - it was considered prudent to carry out some
tests of pore-accessibility change on calcined stones.
4.2 Principles
4.2.1 Types of pore involved
There are two types of pore that are affected by temperature in
different ways:
Type 1 pores with extremely fine entrances that exclude cold gas but
which are penetrated by hot gas either because of its greater kinetic energy
(Fig. 46), or because of an increase in the size of the pore entrances owing
to thermal expansion of the solid.
Type 2 pores that when cold are open but whose entrances become
sealed on increasing the temperature owing to anisotropic thermal expansion
of the solid (Fig. 47).
Type 1 pores are fairly common, e.g., they occur in synthetic
graphites ascoal chars f other carbons °, glasses . Their
penetration can result in a large increase of accessible surface; at a
given temperature the magnitude of the effect depends on the molecular
size of the gas. Type 2 pores are less common but are known to occur in
synthetic graphites .
4.2.2;, Experimental procedure for measurement
The two counteracting effects of Types 1 and 2 pores can be
measured separately using the apparatus described in the next Section. Two
procedures are required and are detailed in Figs. 48(a) and 48 (b).
The first procedure is named the 'pore penetration* experiment (Figs. 46 and
48(a)) and comprises the following stages: (i) evacuating the heated sample;
A8.38
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(ii) soaking it in a particular gas at elevated temperature T_ (1470°F) ;
(iii) cooling it to room temperature T- , the 'pressure of the ambient gas
remaining approximately constant. Now, gas that entered Type 1 pores can
no longer pass out through the mouths of those pores, i.e.9 it has become
trapped. In stage' (iv), the sample is evacuated at temperature T1 to
remove untrapped gass and, finally, in stage (v) the sample. is reheated
to temperature !„ or above, when the previously trapped gas can now pass
out of the pores into a mass spectrometer for measurement.
The second procedure is used to detect Type 2, pores. It is
named the 'pore closure' experiment CFigs. 47 and 48 (b)) and the thermal
cycle used is analogous to that of the first procedure, viz, following
• ' * ' ^
initial evacuation of the heated sample, it is cooled (to room temperature)
• * : ' ' .-' ' •;"' •
and soaked in a particular gasa after which the temperature is raised
o ' ' : * ' '
(to 1470 F) to effect any trapping; untrapped gas is then removed^ and
the sample again cooled to effect release. :
4.3. Experimental
4.3.1,. Description of apparatus
The apparatus is shown diagrammatical ly in Fig. 49. It is
basically a sample container connected to an AEI MS 10 mass spectrometer
and a Pyrex glass vacuum-system. The vacuum system comprises vacuum
pumps, Pirani gauge, 'probe" gas supply and an electric furnace. The
sample container is made of recrystallised alumina, impermeable to
helium at temperatures up to at least 3000 F. The necessary demountable
Vacuum-tight joint was made by cementing the alumina tube to Pyrex glass
•tubing with 'Araldite' resin AY 111. The Pyrex glass tubing is connected
to jine rest of the apparatus by a B19 ground glass joint sealed with
Apiezon T grease.
^'
For easier handling, the sample is packed in a recrystallised
alumina tube 75 mm in length. This tube is located in position in the
sample container by a length of 4 mm o.d. recrystallised alumina tubing.
A 2 mm bore capillary tube leads from the 4 mm bore stopcock T,
to the MSjjlO to form a slow leak path for the gas sample. This enables
••"'•/'•if' . -' ;
gas samples to be taken from the sample container while the;, gas in the
latter is at pressures up to a ^ayj^i^n of 1 torr; in these ''circumstances
'
-4 -
the MS 10 reaches its maximum operating pressure of 10 torr.
A8.39
-------
* The sample is degassed through 10 mm bore tubing, and 10 mm bore
stopcocks 1^ and T2 separated by a cold trap that is cooled by solid carbon
dioxide.
Four inert probes-gases were useds of increasing molecular size:
helium9 neon9 krypton and xenons the last being similar to S0_ in critical
molecular-diameter. They were supplied by the British Oxygen Co. Ltd. in
one-litre glass flasks and were of high puritys viz9 BOC Grade X. Gas is
fed from the flasks through stopcocks T~ and T. to the sample. The pressure
of the gas admitted to the sample is measured with a simple mercury manometer.'
An advantage of incorporating the spectrometer is that the sample
can be soaked in a mixture of the various gasess thus effecting saving in
experimental time, the quantity of each gas subsequently released being
readily measured. To ensure uniform mixing, the gases are admitted in turn
in increments of c. 15 torr until the total pressure of 200 torr is reached.
The composition of the mixture is calculated from the measured pressures.
The pressure of the ambient gas is not kept constant during the cooling or
heating of the trapping process of the pore-penetration and pore-closure
experiments, respectively, but it does not change by more than c. 10 torr,
which is an insignificant variation in the present work.
During the final stage of either type of experiment all the gas
released from the sample is pumped through the MS10 and the partial pressure
of the probe gas is monitored. The quantity of the gas released is
proportional to the area of chart drawn out by the MS10 chart recorder.
Only one vacuum system is described; there are two others so
that three experiments can be done at once. The time scale of the experiments
is such that the heated sample is degassed for 24 h. Soaking time was 24 h
in either type of experiment. Before the final gas release stage it was not
always practicable to reduce to zero the partial pressure of probe gas
diffusing from the samples,, because unreasonable lengths of evacuation time
would have been required, but sufficient time was allowed to reduce this
partial pressure to an acceptable level (10 torr in the MS10).
4.3.2s, Calibration of apparatus
The sample container (Fig» 49) is replaced by the Pyrex glass
dosing system (Fig. 50) frojgj which known amounts of gas are admitted to the
MS10 which is set to record the partial pressure of the particular gas
admitted. The calibration factor giving the quantity of gas perV,unit
A8o40
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chart-area is obtained and enables the area of chart drawn out in an experiment
to Be converted to the quantity of gas released from the sample.
To achieve the low pressure required for gas samples to be admitted
to the MS10, tyo sampling valves are used in series followed by a one litre
expansion bulb (Fig» 50). These valves were made from 2 mm bore three-way
stopcocks, one side arm of each stopcock being sealed-off , The valves were
connected by a short. length of glass tubing. The volume of each valve
including the sealed-off side arm, and of the connecting tubing, was measured
by filling with mercury and weighing. After evacuation of the valves, tubing
and one litre bulb, a sample of gas is taken into the first valve Tl. The gas
pressure is measured with a mercury manometer. On turning the key of valve Tl
anti-clockwise (Fig. 50), with valve T2 as shown, the gas is allowed to expand
»
into the connecting tube and valve T2. If the key of valve T2 is then turned
clockwise, only the gas in this valve (including that in the sealed-off side
arm) is admitted to the one litre bulb and the MS10.
The actual quantity (Q.) of a particular gas admitted to the MS 10
is obtained as follows:
Suppose the volumes of the valves Tl and T2, including their
respective sealed-off side arms, are 71 and V., respectively, and the volume
of the connecting tubing is V,. If P.. is the original pressure in valve Tl
and P? is the pressure of the gas in valve T2 before it is admitted to the
one litre bulbs, then, since Q. « P2V2!>
p v v
1 1 2
Q. '- - - « a constant X; P
1
Now ji^ should equal k
Ai
where A^ is the area drawn out by the recorder pen and k is a constant for the
particular gas and is the abovementioned calibration factor. Thus if the area
drawn out by the recorder pen in a pore -penetration or pore-closure experiment
is A., then the corresponding quantity of gas released is kA..
The calibrations for helium,, neon, krypton and xenon obtained in the
present work agreed with those from other work carried out earlier. The
latter showed k to be constant for each gas for the experimental range of
A. values .
A8o41
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4.4» Results
Of the four stones used generally in the present work, only U.K.
Dolomite and Limestone 1359 were examined. The results are given in Tables 18,
19 and 20 (cf, Tables 2 and 3} with the exception of certain pore closure
results - see Section 4.4.1 below. Those in Table 18 refer to exploratory
measurements, those in Table 19 to measurements made on previously uncilcined
material, and those in Table 20 to measurements made on the stones subjected to
the pretreatment in which they were dropped into a furnace at 1470°? and allowed
to heat-soak for various times - see Sections.2.2.1 and 2.4.1. The term
'stagnant' in Table 20 refers to the situation that the pretreatment furnace
atmosphere initially contained air, no attempt at flushing being made. The
quantities of trapped gas released are expressed in the Tables as the volumes
the gas would occupy at the admission pressure (c. 50 torr) at a temperature
of 1470 P (or 77 F!, in parentheses); each volume refers to unit weight of
material on completion of the experiment. It is important to note that
irrespective of the pre-treatment history of the stones these results are 'for
the fully calcined materials, since untreated or partially calcined stone would
become fully calcined during the initial evacuation of the heated sample.
t
4,4.1 Pore closure experiments
In addition to the pore closure experiments whose results are given
in Table 18, all the samples listed in Table 19 were subsequently examined by
this method as were samples B2, El and Gl in Table 20, but the results are not
included, because in each case the volume of the gas, helium, neon, krypton
3
and xenon, trapped and released was extremely small, i.e., < 0.1 mm /g, as with
those in Table 18. The Sprotborough 3/4 inch clipping (Table 18) was exposed
to helium and krypton only, but there is no reason to suppose that results with
neon and xenon would be any different from those obtained for the other stones.
4.4.2 . Pore penetration experiments
(i) Helium and neon; There was no measurable effect using helium as
probe gas in any of the experiments. The same is true for neon in most of the
experiments; the exceptions are seen in Table 18 - samples a and d and sample e
(the value for which is relatively insignificant) - but in view of the other
results, it is assumed that these high values are spurious, although no definite
explanation can be offered to account for this.
A8,42
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(ii) Xenon; Relatively large quantities of xeri:pii;W4re: released from some
of the UcKo Dolomite and Limestone 1359 samplesa Work described below indicated
that at least part of this xenon must have originally been adsorbed in open
pores at room temperature at the completion of the trapping stage of the
experiment and not removed by the evacuation before the heating in the release
stageo
Some indication of such residual adsorption was seen with either
stone and any of the size grades, in that at room temperature the residual
xenon atmosphere over the pumped sample decreased only slowly over 70 h
(observed by mass spectrometry), the effect being most marked with the
limestone,, On the other hand,, at the temperature of 1470 F, again with
either stone and any of the size grades, the total times taken for the xenon
to be released in vacuum were between c» 10 and 100 h; it seems unlikely
that all of this released xenon had been merely residually adsorbed, and part
of it might be expected to have originated from pores penetrated by the pore
penetration mechanism»
As a test of the magnitude of any such residual adsorption of xenon:
(a) U«Ko Dolomite sample Cll (Table 20) was exposed at room< temperature
to a pressure of xenon equal to the partial pressure of that gas in
the normal mixture of probe gases (GO 50 torr) and allowed to stand
overnight before evacuation at room temperature and subsequent heating
to release any residual gaso Although the volume of xenon released
(27.6 mm /g) was less than that released in the normal experiment
3
(43o5 mm /g), it is clear that a large proportion of the xenon
released from the samples could have been a result'of residual
adsorption at room temperatureo In addition, an equimolar mixture
of xenon, partial pressure c 50 torr, and SO_ was admitted to sample
Cll at room temperature (Table 20)„ The volume of xenon released on
subsequently heating the evacuated sample to 1470 F was less than 25%
of the volume of xenon released in the absence of S0_. This
evidently indicates that at room temperature S0_ is preferentially
adsorbed compared with xenon: S0» reached much the same surface
sites as xenon alone
(b) Limestone 1359 sample HI (Table 20) was given a much shorter pre-
release evacuation time at room temperature than H3 and most of the
very large quantity of xenon subsequently released must have been
residually adsorbed„
A8o43
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(iii) Krypton; The-majority of the experiments showed either no -measurable,
cr generally small, effects with krypton. The definite effects that were
observed are thought to be probably mainly due to residual adsorption analogous
to that mentioned above with xenon. Such residual adsorption of krypton is
apparent if the results for samples H3 and HI, Table 20, are compared (cf. above,
for xenon). Moreover„ krypton is less extensively adsorbed on surfaces in
general compared with xenon so that the residual-adsorption effect should be the
less with krypton, which is in line with the present results. It is noted that
where the xenon effect is not measurable (Tables 18 and 20) neither is that with
kryptons which also supports the conclusion that the positive krypton effects arise
(at least in part) from residual adsorption.
4.5 Discussion and Conclusions
4.5.1 Pore closure
The absence of any pore closure effects indicates that there is no
decrease of accessibility to gas molecules on increasing the temperature to
1470°F.
i
4.5,2 Pore penetration • .
4.5.2.1 Helium; The absence of any pore penetration effects with helium
indicates that there is no increase of accessibility to that gas on increasing
the temperature to 1470°F. This means that the pore volumes at 1470 F can be
estimated from helium displacement densities measured at room temperature, as in
the present work, in combination with the corresponding mercury displacement
densities; it must be assumed that this applies also to the measurements made
on the stones prepared at 1650 F, although this assumption is not entirely
justified. It is expected that change in pore volume owing "to thermal
expansion is relatively small-comparable to the present error in the helium
density results„
4.5.2.2 Xenon; The pore penetration results for xenon may be summarised
as follows:
(a) A large part of the xenon released from the calcined dolomite, and
probably from the calcined limestones is the result of desorption of gas
originally adsorbed at room temperature and not pumped away during the pre-
release evacuation, However,, there is evidence of some "genuine" pore
penetration; nonetheless,, as the total release-times were relatively long
A8,44
-------
and it is expected that any contribution of xenon due to pore penetration
would have.been-released mere slowly than that merely residually adsorbed,
it would seem that the penetration of any closed pores at 1470°F is a slow
process compared with the rate of sulphur uptake by the stone and is likely
to be of only secondary importance, if at all, in the combustor0 The
situation at 1650 F cannot be guessed at, however,
(b) A number of comparisons may be made between the quoted xenon
release values bearing in mind the limited number of samples examined, as
follows? (For convenience those samples subjected to pretreatment involving
the initial rapid heating in a gaseous atmosphere are termed 'Gas-type1,
and those calcined entirely _in vacuo in the pore-penetration/pore-closure
apparatus are designated 'Vac-type',)
(i) With the limestone, size grade -16 +52 BS mesh,
far more xenon was released from the Vac-type than from
the Gas-type samples-,
(ii) Dolomite, size grades -16 +52 BS mesh and -6 +8 BS mesh,
showed the reverse effect, i^e,, a much enhanced release from
.Gas-type than from the Vac-type samples„
(iii) However, for the -300 BS mesh material the release from the
•• • r
Gas-type limestone and the Vac-type dolomite was much greater
than from the corresponding -16 +52 BS mesh material,,
(iv) With the limestone in the -300 BS mesh size grade, the release
from the Gas-type material was of the same order as that from
the Vac-type material.
(v) With the Gas-type stones in the size grade:
(a) -16 +52 BS mesh, the release from the limestone was low
compared with that from the dolomite, which was high=
(b) -300 BS mesh, the release from the limestone was high and
of the same order as that from the dolomite,
(vi) With the Vac-type stones in the size grade:
(a) -16 +52 BS mesh, there was much more release from the
limestone than from the dolomite;
(b) -300 BS mesh, the release from the limestone was about
the same as that from the dolomite»
A8.45
-------
Pores in which, xenon is residually adsorbed would Be expected to be
extremely fine; they may even be micrcpores (having diameters of a fev ran
or less) in which, owing to the overlapping sorption-potential fields xenon
would be held more strongly than on an *open surface* or in wider pores;
spaces between adjoining crystallites could fcm such pores: their volume
could be quite small and thus not incompatible w^th the observations in
Section 2.4.2.2 concerning volume in pores with diameters < 0.014 ;pm. Further,
egress of xenon from the structure could be impeded if fine constrictions were
present in the pores„ Whatever is the true pore structure in question, it
does not seem unreasonable to equate its extent with the extent of xenon release.
If this structure is called "fine-pore structure' Cfps)0 then it seems that:
(I) With the -16 *52 BS mesh size grade Iimestone9 the Vac-type material
contained a greater extent of fps than the Gas-type material. It may be that
the difference in the initial heating rates between the two types contributes
to this effect9 and the atmosphere in which the calcination was carried out may
12
be critical. Glasson has postulated two sequential processes occurring in
the calcination of calcium carbonate: Q) recrystallisation of the cubic
oxide-lattice from oxide having a CaCO- (calcite^-like structures, and (2)
sintering of the recrystallised oxide. The first process causes increase in
surface area, the second a decrease. Glasson has shown that the presence of
C02 will Ca) inhibit nucleation-in the recrystallisation and (b) favour sintering:
calcination In vacuo gives a product having a higher surface area than one
calcined in an atmosphere containing added C02 or in air, the C02 forming in the
decomposing solid not being eliminated fast enough in the air. Thus a finer
pore structure9 associated with a smaller average crystallite size is developed
by calcination In vacuc 0 This finding would account for the abovementioned
difference in fps; a simple explanation could be that the Vac-type limestone
having the smaller average crystallite-size has the larger number of inter-
crystallite spaces in which xenon might be held.
(II) With the -16 --152 BS mesh dolbmiteg the Gas-type material seems to
possess a greater extent of fps than the Vac-type one. It is difficult to
explain this apparent observation, since the MgO formed should sinter more
readily in a gaseous atmosphere than in vacuo' as with CaO. However, it is
noted that some hydration took place after the pretreatment in the gaseous
atmosphere because the samples were allowed to cool in air (see Section 4.5.3):
now, it has been found by Girgis and Girgis that calcination of MgCO, in air
A8o46
-------
followed by hydration to MgCOttK by immersion in water, and then decomposition
in vacuo at 450 C9 gave a product having a higber surface area tban tbat of
the original calcined material, Hence it is possible that in the present work
the subsequent calcination. In vacuc, of MgCOttK foriaed resulted in the
enhancement of fps, but the corresponding role of CaCOE),, formed after the
pretreatment is not clear - the limestone samples were likewise cooled in air.
In conclusions some qualitative differences in xenon release have
been observed between the ~16 -1-52 BS mesh limestone and dolomite: no further
comment is made on these differences,, attention having been called to them
mainly because other differences have been observed between the stones, e.g.,
in their S02 sorption capabilities.
4,5.3 Incidental observations in the pore penetration experiments
Incidental to the pore penetration experiments two further observa-
tions were made as follows:
I. All the samples of TJ.K,, Dolomite were observed to release quantities
of water during the experiments after the initial heating ^n vacuo. As
noted earlier^ the normal experimental method was to evacuate the heated
sample of stone for 24 h in vacno,, add the mixture of probe gases, soak, and
then cool the sample to room temperature before evacuating. It was on
subsequently reheating the sample to release trapped probe gas that water
(and carbon dioxide) emission was observed. The quantities of water released
were greater with the samples pretreated in the gaseous atmospheres with
rapid initial heating than those calcined entirely in vacuo. The most likely
explanation of the origin of the larger amounts of water released from the
pretreated samples is that some hydroxide was formed on subsequently cooling
them in air. On reheating them in vacuo the last traces of water were
evidently difficult to remove. Since the effect was not observed in the
identically treated Limestone 1359S it is most likely to result from the
formation of Mg(OH)-.
The effect of hydration of calcined MgO followed by reheating in
vacuo in modifying the pore structure of the oxide has been noted above, and
Potter's work on the favourable effect of hydration of calcined Limestone
and dolomite on sulphur uptake by those stones has been noted in Sections 1
and 2.4.2.8. As suggested in Section 2.59 .the possible influence of water
on stone sulphation would seem to be worthy of study.
A8,47
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II. Finally, it was noted that during the gas release.stage of the
pore penetration experiments on the coarse U.K. Dolomite samples, f, g, and h,
Table 18, i.e,, on reheating to 1470°?, SO- was evolved CS02 was not
monitored during calcination),, The partial pressure of the SO- increased
rapidly on heating from 1470° to 1650°f. The quantity of S02 originally
present in this coarse material was estimated from this to be < 15 ppm.Cw/w).
Although this is a very small quantity the observation of the evolution may
have some significance, possibly in the problem of the reduction in SO- uptake
on increasing the temperature in the combustor above c. 1560 F, No attempt
was made to monitor SO- in the corresponding stage of the pore penetration
experiments with any of the other samples.
A8o48
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5, THE EFFECT 0? THERMAL CYCLING ON SO,. pPTAKE
5.1 Introduction
Elutriated stone fines are subjected9 if recycled,, to rapid
temperature changes and it has been suggested that such 'thermal cycling'
might have an effect on the capability of the recycled fines for absorbing
SO.. The experiments- described were designed to test this possibility.
5.2 Apparatus and Procedure
The apparatus comprises a long horizontal tube within which two
platinum boats may be manipulated individually, by use of iron attachments
and magnets. Part of the tube is heated by a furnace at 1470 7, and
thermal cycling is effected by moving one of the boats between the cool and
heated regions. This procedure enables two experiments to be done
simultaneously; one boat is taken through a thermal cycle experiment,
whilst the other is maintained in the hot region at constant temperature.
In this way it was intended that the effect of the thermal cycling only should
be apparent and possible differences that might have arisen -between separate
experiments9 due for example, to variations in S02 flow, .avoided. Suitable
gas mixtures may be streamed through the furnace tube, the flow rates being
measured using GAP flow meters. The small quantity of S02 required was
displaced from a Toepler pump by liquid paraffin. As the flow-rate of the
S0? was too small to actuate a standard flow-meter, the flow-rate of the
. paraffin, and therefore of the SO2, was measured using a further GAP flow-
meter. Initially both boats are inserted in the cool part of the tube and
the gas flow, excepting the S02 is begun. Both boats are then moved into the
1470°P zone and after a time interval (.t^) the S02 is turned on. The S02 is
allowed to flow for a period of time.(t2)9 after which it is turned off and the
thermal cycling boat removed to the cool zone. After a further period of
time (t,) that boat is replaced in the 1470°'F zone, and the cycle is repeated
a required number of times. Both boats are removed at the end of the last
cycle. .
further details of the experiments„ such as the gas composition,
the number of cycles and the actual values for t.9 t2 and t«, are shown in
Tables 21 and 22.
A8o49
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5.3 Results and Conclusions
The results for UoK, Dolomite are shown in Table 21; those for
Limestone 1359 are shown in Table 22„ There is considerable scatter among
the results. The difference between cycled and non-cycled stones is
expressed on a fractional basis in column 6: (b - a), the sulphur content
of cycled sample (b) less that of non-cycled sample (a), is divided by a»
The error of the sulphur determinations is less than ' O..l% absolute and it
appears therefore that there are real differences within most of the pairs of
samples, but as these differences do not show a consistent increase or
decrease on thermal cycling it is,impossible to conclude that thermal cycling
has a systematic effect on either stone.,
To enable some comparison to be made between the rows of results in
Tables 21 and 22, the percentage sulphur contents of the samples per unit
3
quantity of S0_, cm (stp), passed over them are shown in columns 3 and 5.
Despite the scatter among the results, the following observations can be made:
(i) Change of particle size of either stone from -16 +52 BS mesh to
-300 BS mesh results in an increase in S02 uptake for any of the gaseous
atmospheres used; overall the effect is larger with the limestone.
(ii) With both stones there is no clear-cut effect on SO- uptake of
increasing the C0_ concentration to 15% v/v, but a C02 concentration of
75% v/v causes a substantial decrease in S02 uptake with either particle
size: with the -16 +52 BS mesh materials, the decrease with the limestone
is much more marked than with the dolomite, but with the -300 BS mesh
materials the limestone shows only little more marked decrease than the
dolomite,
(iii) Overall, under the conditions of experiment , in the -16 +52 BS
mesh size-grade the dolomite is the better SO.-absorber, as expected, and
particularly so in the C0_ concentration of 75% v/v; changing the particle
size to -300 BS mesh appears largely to eliminate the difference in SO-
uptake between the two stones„
A8»50
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6. MISCELLANEOUS -
6.1 Optical Microscopical Examination
A brief optical microscopical examination showed that shells had
formed on individual particles of U.K. Dolomite removed from the bed of the
pressure combustor after completion of Task II, test Series 1. This material
was also used for the breakage studies, Section 3^ and as noted in that Section,
the major portion of ash was first removed with a magnet and the residue
sieved on a 52 BS mesh sieve. The +52 BS mesh particles were examined
(un-sectioned) under a stereo-optical microscope and are illustrated in the
(non-stereo) photomicrographs in Fig. 51. Generally the particles are
covered with a fused brown deposit; some of them are chipped or broken and
in others the shell seems to have become detached from the particle. The
shell is presumably a slag formed with ash in the combustor. No comment can
be made on the role of the shell in the sulphation process. No such shell
was observed on the samples prepared in the laboratory.
6.2 Surface Area
During the course of the work, a few measurements of, surface area
were made at liquid nitrogen temperature. The technique used is outlined as
follows. The apparatus is of the volumetric type,- an Orr surface-area,
pore-volume analyser (Model 2100, Micromeritics Instrument Corporation).
In principle, the increasing number of molecules (N) of krypton adsorbed by
the sample at 77 K is determined as the pressure (P) is increased in steps.
The value for N at which the surface just becomes completely covered with the
adsorbed molecules (N ) is deduced by use of the "B,E.T. "'equation. The
area of this surface is then N .A, where A is the cross-sectional area of each
adsorbed krypton molecule in the close-packed monolayer. The value taken
-20 2
for A was 20.2 x 10 m ; there is some uncertainty as to the value that
should be used: McCleiIan and Harnsberger list a number of values that have
been given in the literature and recommended the above value. That suggested
-20 2 .23
in the Orr instruction-manual is 21.0 x 10 m , (which value was used previously).
Nitrogen is widely used for high surface areas, but krypton is
preferred as an adsorbate at 77 K for samples, such as those considered here,
for which the total surface area present in the sample container is low.
This is because with krypton, which has a low saturation vapour pressure at
77°K, the quantity of gas in the dead volume of the sample container is low
compared with the quantity adsorbed, thus increasing the precision of measurement.
A8.51
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Some further notes on the experiment are as follows:
(i) Duplicate measurements were made using the:same portion
of sample.
(ii) Before each duplicate determination, the sample was
evacuated in the Orr apparatus at 360 F and <10 torr.
(iii) Dead volumes were determined using helium, also at the
low temperature.
(iv) The specific surface values, which are listed below,
refer to unit weight of evacuated sample, after heating as
in (ii).
Material
U.K. Dolomite, -6 +8 BS
mesh, sample B
U.K. Dolomite, -16 +52 BS
mesh, after 1 h heating
at 1470°F in a stagnant
atmosphere: 53% calcined,
sample Cl*.
Limestone 1359, -16 4-52
BS mesh, sample G
B.E.T. specific surface,
m2/g
(duplicates)
0.39, 0*39
i
2.59, 2.70
0.22, 0.23
* cf. Table 2. -
It was noted that a slow drift of krypton into the pores occurred on
the first addition of krypton to the partly calcined dolomite and the raw
limestone; no drift was noted with the raw dolomite. Such drifts normally
indicate the presence of micropores with entrance diameters close to that of
the particular probe gas molecule; in the present case the absence of drifts
A8.52
-------
in successive additions could merely mean that the micropores in question
became completely filled in the first additions The presence of fine pore
structure in fully calcined dolomite was indicated from the pore penetration
experiments in Section 4»
The three specific surfaces lie in the same order as the
o
corresponding porosity values (mm /g): V or t»p0v. or TT -* Tables 8, 10 and
14 (although the data for U°Ko Dolomite sample B is not reported, the specific
surface of sample C, sized -16 -K52 BS mesh, may be expected if anything to be
higher than that of sample B which is of larger particle size). With the
dolomite, therefore, increase of pore volume on partial calcination is
accompanied, as expected, by increase of. surface area»
Finally, the specific surface value for the partly calcined dolomite
2
is at first sight unexpectedly low compared with either the value of 43 m /g
18
obtained earlier in other work at BCURA for a fully calcined dolomite or
with the values obtained by Chan j^t al for various fully calcined dolomites.
Apart from a factor related solely to the difference in extent of calcination,
there are at least four factors that might be involved in this difference:
(1) the present sample was prepared with rapid initial heating, whereas all
the fully calcined materials were subjected to relatively slow initial heating;
(2) the ambient atmosphere with the present sample was 'stagnant', whereas the
fully calcined materials were heated in a nitrogen flushed atmosphere;
(3) the CaO in the present sample may have retained the crystal structure of
the original carbonate (see refs» 12 and 15), but not the CaO in the fully
calcined materials; (4) the surface area values may be subject to the
difficulties arising in interpreting sorption data 'for materials containing
micropores, e«go, such values may be (a) top high owing to 'micropore filling'
which can occur at the same time as normal monolayer formation in wider pores
19
or on open surface , or (b) too low owing to the 'activated diffusion
effect", whereby molecules require an activation energy to enable them to pass
through pore entrances very close in diameter to their own, the extent of
penetration being strongly temperature dependent and greatly restricted at
77°K o No attempt has been made in the present work to investigate the
possibility of such effects,,
A8«,53
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7C MEASUREMENTS OF SO^ REACTION RATE CONSTANTS
The purpose of this work was to provide quantitative values for the
reaction rate constants in a form suitable for use in the mathematical model.
7..1 Description of Apparatus and Experimental Procedure
The reaction tube (Fig° 52) consists basically of a Ij in diameter
quartz tube in which the test sample rests on a quartz sinter, the tube being
heated by a surrounding furnace, Gas of suitable composition is led in at
the bottom and after heating passes through the sinter and sample to the
offtake where the SO_ remaining is absorbed for subsequent titrimetric
determinationo
If the reaction rate were partly or wholly controlled by the
physical transfer of gases to or ^from the particle surface, the gas
velocity relative to the particles would be expected to influence the
22
reaction rate,, Argonne National Laboratory have found in previous work
that over the range of gas velocities likely to be used in fluidised combustion
systems the rate of reaction between SO- and limestone is substantially
independent of gas velocityo However, in the present work, velocities have
been kept as close as possible to those used in the plants, in order1to reduce
to a minimum any possible errors due to the dependency of reaction rate upon
mass transfer to the particle surface.,
Referring to Figo 52: air from a compressed air line was fed through
a centrifugal/silica gel drier to a "Flostat1 regulator to guard against
source pressure variations, and metered by a float type flowmeter regulated
and stabilised against back pressure fluctuations by a second 'Flostat'»
The arrangements for oxygen and nitrogen were similar, but no drier or entry
pressure regulator was used. Since the flowmeter calibrations are pressure-
dependent, care was taken to ensure that all gases were supplied at
constant pressure, the meters being periodically calibrated at working
pressure by use of a soap-film meter connected at the reaction tube outleto
Because of the low flow rate and corrosive nature of the S02, the
arrangements for this gas were quite different, the principle being to supply
a known mass of gas over a known time
A vessel C (Figo 52), of about twice the volume of SO- to be
delivered, had a fiducial mark half way down its surface. The volume of the
vessel between the mark and tap B was determined by filling with mercury and
weighing the mercury„ The vessel was half filled with liquid paraffin and
A8.54
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connected to (a) an SO- cylinder, (b) the apparatus, (c) waste and (d) a
water supply, as shown in Fig, 52, With the vessel full of paraffin and
water, it was connected to the SO- supply by tap B and water was allowed to
run to waste via tap A until the level of paraffin fell to the fiducial
mark. Tap A was turned off and, after a short-interval to ensure a slight
positive pressure of S0_ to build up in C, tap B was also turned off.
Venting tap B to atmosphere allowed the pressure in C to fall to atmospheric,
so that a known mass of SQ (approximately 0/17 g) was enclosed in C.
The S02 was displaced at constant rate into the gas manifold by
opening tap B to the apparatus and tap A to the water supply. The average
rate (and hence the concentration) was determined accurately by measuring
the time taken for the paraffin to rise from the mark to the top. The rate
and its constancy were adjusted and monitored by a water valve and flow meter,
The liquid paraffin occupied more than half the volume of C, and
the walls of the upper part were assumed to remain free of any water film-
The gases were then passed to the reaction tube. In order to
ensure thorough gas mixing and to effect heat transfer from furnace to gas it
was necessary to pack the tube below the sinter, The top of the tube was
also packed in order to constrain the thin layer of stone, This packing
material presented a large surface area to the gas and so it was essential
that the material should be inert, exert no catalytic effect and absorb no
appreciable amount of SO- at working temperature. It was found that these
requirements could be met by the use of recrystallised alumina, available in
convenient form as thermocouple sheathing, and itself kept in place with the
minimal quantity of quartz wool.
The tube and gas were heated by a muffle furnace having a long
constant temperatur? zone produced by four separately wound elements,
Temperature at the surface of the. stone was measured by a thp-morouple in a
quartz pocket.
The S0_ in the effluent gases was determined by removal in two
impact bubblers filled with ^00 ml each of 3 vol HjO-, adjusted to
neutrality, which generates sulphuric acid quantitatively according to the
reaction?.
-------
The sulphuric acid in the ffcrst oufchler was then titrated with
N/2 NaOH using bromo-cresyl green as indicator. The second Bubbler was
used as a guard trap but it was never found to contain more than 5% of the
total H-SO,. Hence error due to incomplete SO- absorption could be
neglected, , ;
The stones, Dolomite 1337, U.K. Dolomite and Limestones 18 and 1359,
were taken uncrushed as supplied and size fractions were derived from these
by sieving:
BS mesh approximate particle-^size
(a) -8 +16 -2000 +1000 Vm
(b) -16 +52 -1000 : +300 ym ,
Cc) -52 +150 -300 +105 pm
(d) -150 +300 -105 +53 ym : •
fe) -300 -53 pm
In the case of Limestones 18 and 1359, the original sample did not
contain enough large particles to permit the preparation of the largest sizes.
The great mass of runs, for stone type and size intercomparison,'
• ' I " .:
were made under standard conditions of temperature, an air/SO- atmosphere,.
fixed air rate, and SO- content corresponding to concentrations likely to
occur in combustion gases in the plants.
- The amount of sample taken was initially the subject of-some,.,,',. „,.. .
exploration, A portion of the selected sized stone was weighed out, placed
in a reaction tube, lightly tamped and shaken to give a level surface,: and
the top of the tuBe was then packed. CThe Bottom of the tube was normally
left packed in Between experiments;.} It was desired, if possible, to use a
. i ?
fairly thick bed to achieve uniform flow of gas across the bed, which might
not occur in thin Beds of coarse particles. Experiments were carried put
in beds of various thicknesses from 174 in to 1 in, with the intention of
extrapolating the results to zero thickness and possibly deriving a simple
°* .
expression for bed height. Experimental results showed no simple relation .
between bed height and SO- absorption. Accordingly these experiments were
abandoned, although the results are recorded in Table 23.
A8.56
-------
Insteadj thin beds were used for the remaining experiments. To
obtain uniform results9 a small fixed weight of material was used and to
avoid non-uniformities caused by packing problems etcui, this was mixed with
a fixed amount of recrystallised alumina of size 150 -pan to give a bed height
of 2 mm. The mixture was poured into place and the reaction tube was gently
tapped to give a layer of uniform thickness.
The reaction tube was retained in a vertical position, the quartz
wool plug and alumina packing replaced, the tube inserted in the muffle
furnace and the flow of carrier gas started. The start of the experiment
was delayed for 15 minutes after the apparatus had reached operating temperature
to allow calcination to proceed.
With freshly-filled absorption bottles in place the contents of
vessel C were passed into the carrier gas stream at constant rate as observed
by the water flow meter and controlled by the water valve. The exact time
required for passage of the measured amount was determined by the use of a
stop-watch. The SO- remaining in the system after this operation was chased
through with two further volumes of air from vessel C.
The whole process was repeated using fresh absorption bottles until
only a small proportion of SO^ was being removed by the stone.
The actual mass of S09 transferred from vessel C was monitored
from time to time by passing the gas straight from the reactor inlet-pipe to
the wash bottlesP a procedure itself checked initially by passing SO^ through
the hot, packed tube with no stone in the tube. All runs were duplicated,,
7.2 Mathematical Procedures
The input data are symbolised as follows:
C CaO in fully calcined stone %
L 100-loss on full calcination of initial stone 7,
V volume of N/2 NaOH to titrate blank mH
o
V volume of N72 NaOH to titrate H000 after
n *• J-
nth pass mil
t time taken for the nth pass s
n
S top size of original stone um
S bottom size of original stone ym
O
T temperature at start of run C
s o
Tf temperature at finish of run C
A carrier gas rate £/min
A8.57
-------
M mass of stone employed g
X
H height of bed mm
D diameter of bed mm G= 40 mm)
The experimental values of these quantities, with the exception of
D (given above) 5, are listed for each run undertaken in Table 23,.
The quantities evaluated and presented in Table 2 A were as follows:
T average temperature °K
S mean size jam
M mass S02 absorbed up to and including the
nth pass , • kg
R reactivity averaged over nth pass (kg S09/s) per kg CaO
n ^ *•
C concentration SO- vjv mg/m
w 3
k velocity constant (m /s) per, kg
U utilisation of stone after n passes Cequal to
sulphation E - see Section 2.2.2) -
S
U mean utilisation of stone during nth pass
these quantities were evaluated as follows:
T = (T_ + T. "* 546)/2
is
s - cs . s
m s
M = M . * 1.6 (V - V ) 10~5
n n-1 on
C
16 Vp x 60,000 ^ 293
w " A . t T
n
Rn = CMn * Mn~l)/Ctn ' C ' L
Vs
U = 87.5 M y(C . L , M. .
n n x
A8,58
-------
7.3 Results
As mentioned above, experiments with thick beds were discontinued.,
but the results are given,, together with the results of the thin bed method
finally adopted,, in Table 2.1 „
The data., recalculated in the form of results required., are
presented in Table 24.
.. J.eJL*-.e:!_ j_ and,_2 ; Ttve experimental results are displayed in Table 2-3 „
The results of Test Series 1 showed good repeatability and Test Series 2,, in
which variation in particle size was introduced, was begun „ It was found
that, a flow rate of 10 £7min of gas (corresponding to a hot. gas velocity of
Co 2 ft/s) could not be maintained with finer material (Runs 15-18) at the
highest gas pressure that it was possible to use,, and the rate had first to
be halved,, and reduced further still with the finest size (Run 26),
Test Series 3; The objective of this test series was to determine the
velocity constant of U<.Ko Dolomite as a function of particle size and
utilisation at constant temperature (1470 F) , The. results are recorded
in Tables 23 and 249 and plotted in Fig. 530 Velocity constant falls
linearly with increasing utilisation and more rapidly the greater the
particle size*
Test: Series 4., 5 and 6; The objective of the experiments was to repeat the
work of Test. Series 3 for Dolomite 1337 and Limestones 1359 and 18., • '
respectively,, The results are generally similar to those for U.K,. Dolomite.
(Figs, 54-56)
Test. Series 7; 7n this series,, temperature was varied from 129Cr to 1650 F
with the other parameters fixed.
Time allowed measurements to be made only on one stone<, and
Limestone 1.8 was chosen as the dolomites from presncus work were not
expected to be so sensitive to temperature variation (see ref, 18),.
The effect of CO, upon the reactivity of Limestone 18 was also
examined because i.t was learned that tests with that stone were planned using
the high pressure combustor (Task II) „
The results show (Figs. 57 and 58) that at zero utilisation the
reactivity increases with increasing temperature*- as expected ficm previous
laboratory work As the utilisation increases to values above 25% (iueJ;, to
* But see Addendum (Section 8)
A8.59
-------
conditions typical of the average bed limestone composition) the reactivity
at first rises with rising temperature and then falls as the temperature rises
further. This finding„ unforeseen from previous worka discussed in Appendix
6, on other stones is in agreement with certain observations on the pilot
plants,
18
The effect of CO- is in line with previous experience 9 in that the effect
of partial pressures of CO- above the equilibrium partial pressure for the
reaction:
CaCO- - CaO + CO-
in the case of limestone, is to reduce the reaction rate (Figs. 59-63), As
the temperature rises toward the equilibrium temperature for the partial
pressure of CO- employed 0607 F at 0.75 atm C0~) the effect is markedly
diminisheds but does not apparently quite disappear. With Limestone 18 the
Q
suppression of reaction at 1470 F is not so severe as with the limestone used
in previous work at BCURAS and this again is in accord with observations on
the pressurised rig in which Limestone 18 performed better than was expected -
but not so well as the dolomites. It may be noted here that the porosity
studies (.Section 2 - see,, for example^, Section 2,5) have disclosed an
extensive amount of transport pores in calcined Limestone 188 but. not in
calcined Limestone 1359,
7,4 Discussion
It is instructive t:o study the results obtained in measurement of
reaction rates of the different stones in conjunction with those in Fig. 23,
A difference in procedure must be emphasised between the rate constant
determination experiments and the drop-tube experiments (.Section 2) „ In
the former^ calcination was allowed to proceed for 15 minutes at temperature.
before SO.- was introduced,; whilst in the latter., no precalcination was carried
out.
One of the. most notable features in comparing the reactivities of
the stones is the poor performance of Limestone 1359 (Fig, 55), At low
utilisations the reactivity is about the same as that of Limestone 18,,
although less than that of the dolomites. As the utilisation increases
above about 5%, however.,, the reactivity of Limestone 1359 falls off very
rapidly until it is zero at between 10 and 25% utilisation., depending on
particle size. At. these utilisations, Limestone 18 is still almost as reactive
as the fresh calcined stone, (Fig, 56).
A8,60
-------
Looking at the results of the controlled atmosphere drop-tube
experiments (Section 2J on these two stoness we. see. Q?'igo 23} that -16 -*52
B3 -.mesh Limestone 1359 reaches a limiting sulphation -value of about 8%
rt ^
0650 'F) ox 3% (1470 F) after 1 hour,, whereas Limestone 18 continues to
absorb SO. for at least 4 bourse, by which time its utilisation is 46% (1650°F)
or 26% (1470 F)» Ft. is reasonable therefore to regard these drop-tube
e-xperiments as a reliable indicator of the reactivity of the stones,, although
further work, wight still .be required to make possible the derivation from
them of rate constants in a form suitable for input to a mathematical model0
The relation between the measured pore structure of these stones
and their reactivity has been mentioned briefly in Section 7,3 and discussed
in Section. 2, It is noted also that the material from one of>the rate
constant experiments on Limestone 1359 was used as the, subject, for porosity
measurements before and after particle breakage (Section 3S Fig0 40) 0
The dolomites both show initial reaction rate constants about 50%
higher than the limestones, and the. rate constants fall off steadily with
increasing utilisation.Of the two,., Dolomite 1337 is the better absorberv
Teaching 37% utilisation fox- large particles and over 50% for small.'ones0
The behaviour generally para I'I els the -results of the drop^-tube.
experiment* shown in Fig« 23, The geometric mean particle size in the
drop-tube experiments was 548 JJXD., so that the utilisation after 4 hours at
1.4!70~'P for Lime stone 18 in the. drop-^tube experiments., i.e.,, 26%,, corresponds
to quite a high reaction rate constant, (about 0,06 m /kg ss, from Fig0 56.)«
This is in keeping within the marked gradient of the sulphation curve after
4 hours in the drop—tube experiment,
Comparing the Dolomite. 1337 curves in the same way9 it is seen that
in the drop-tube e,xpertment the utilisation after1 4 hours at 1470 F was 53%9
which corresponds to s. fairly low rate constant. (Fig<, 54) „ This is in
agreement with the. small gradient of this curve, in Figu 23 at 4 hours.,
As; noted earlier,, there was time available to 'i>ary the temperature
ynd atDJOsphere with one st.one only., Limestone 18<, The results were interesting
in tbat for the first time in laboratory experiments they showed a decrease in
reaction rate with increasing temperature above 1470 F,, although this decrease
ot'Z.u'fs only with par t-j.j'l ly sulpha ted stone (Fig» 58) „ In atmospheres
con tain i.ng high partial pressures (0,75 atm) of CO,;,, the trends are dif t'exenti,
and at all uti.lis9t.ion?; up to 25% the reaction rate increases with temperature up
to 1650U'FU Ibxs Is. d.!.most certainly because at lower temperatures calcination
of l,he stone i? incomplete in, the presence of this partial pressure of CO^o
AS. 6 I
-------
8 - ADDENDUM.
A discuj5s:tcmof errors in interpretation of the rate constant
measurements of Section 7
Study of the results, which were evaluated by computer, showed
peculiar features, particularly the fact that for any given stone the
reaction rate constant at zero utilisation (fresh stone) was almost
independent of particle size and temperature, while for partly
sulphated stone there were appreciable differences in rate constant
for differences in particle size and temperature., Also, the rate
constants determined, when fed as input data to the mathematical
model (Appendix 6) failed to account adequately for the sulphation
undergone by the fine particles of size small enough to be
eJutriated from' the bed,
The purpose of this addendum is to show that the method
employed to determine reaction rate constants imposed an artificial
upper limit, owing to the fact that SO- was not supplied to the stone
as quickly as it could have been absorbed, in the case of fresh stone,
The error only applies to stone of less than about 10% utilisation
for the two dolomites, of less than about 5% utilisation for Lime-
stone 1359, and of less than about 25% utilisation for 1imestone 18
(at: 1A7Q F),. It is impossible to guess at the magnitude of the
error, but it may have been considerable for stones of zero
utilisation and small particle size,,
Calculation of art if icial ly imposed limit
In each pass, a fixed mass of SO,, 0,,1735 g, was passed
through the bed of stone during the specified period, The rate
constant was calculated as mass of SO absorbed per second, per
unit mass of CaO, per unit SO., concentration in the incoming gas
(kg/m3j,
Tables 23 and 2& supply all the necessary data for calculating
the rate constant limit imposed by the rate at which SO- was supplied
to the bed;
K .- Ms x 1 x J_ mVkgs
A8,62
-------
where 1C is constraining value of K (all SO- absorbed)
M is weight of S00 per pass (0.1735g)
S . 2.
t is duration of pass, s
M is mass of stone used, g
C is fraction of CaO in fully calcined stone
L is 1- (fractional weight loss on full calcination)
3
C is SO concentration in incoming gas, kg/m „
Table 25 lists values calculated for 1C for the first pass of
each run included in Table 24.
TABLE 25
Values of 1C
Run No.
27
28
29
30
31
32
49
50
51
52
53
56
57
59
61
62
64
65
• Stone
U.K. Dolomite
in
ii
it
ii
ii
Dolomite 1337
M
ii
ii
it
"
ii
ii
Limestone 1359
M
it
ii
1C m /kgs
0.107
0,109
0,109
0,109
0,109
0.110
0,130
0-130
0,131
0-130
0,131
0.132
0.133
0^135
0,074
0.074
0,072
0.074
Run No,
67
68
70
71
74
75
79
80
82
83
84
85
86
87
88
89
Stone
Limestone 18
, • .• " .-
ii ,
. • ii
it
ii
ii
ii
ii
ii
ii
M
ii
M
n
ii
1C m ,/kgs
0.079
0.080
0.079
0.078
0.077
0.077
0.067
0.073
0.071
0.069
0.068
0.076
0.077
0.088
0.085
0,079
A8.63
-------
Discussion
The values for K_ are seen to be in each case only slightly
higher than the value for the reaction rate constant determined in
the first pass,. It is considered that the evidence is overwhelming
that in most cases, were it not for the limit imposed by the
experimental procedure, considerably higher values would have been
found for low utilisations. The conclusions regarding the effect of
temperature upon reaction rate at low utilisations (Section 7,3) must
also be suspected-of being in error, since under these conditions the
reactivity was limited by the experimental procedure.
It is recommended that any further work on mathematical
modelling of sulphur retention by limestone addition to fluidised beds
should be accompanied by a re-determination of reaction rate constants,
special attention being paid to the elimination of this source of
inaccuracy.
In order to determine the rate constants without error it would
be necessary to carry out repeat experiments using much higher SO.
concentrations in the first (and possibly the second) pass, so that
there is a f airly'; large break-through of S0_ at the start of the
first pass- This would be easier to ensure if a continuous SO,,
analyser were available, as was not the case in the experiments
described in this Appendix.
A8.64
-------
9, GLOSSARY OF TERMS
Most of these terms are defined in the text: they are collected here
to facilitate reference«
Atmosphere, controlled The uncalcined stones were sprinkled on to a mesh
(at 14,70 or 1650 F) contained in a vertical tube, through which flowed a
gas mixture of controlled inlet composition., (Section 2o)
Atmosphere, flushed The uncalcined stones were sprinkled into a vertical
tube having a closed end (at 1470 F); a second tube through which a stream
of dry nitrogen flowed dipped into the first to reach the stone* (Section 2*)
A.tmosphere, stagnant The uncalcined stones were sprinkled into a vertical
tube having a closed end (at 1470 F)» (Section 2»)
c -^ c. o
jar Un.it of pressure equal to 10' N/m , 10 dyne/cm , Ot,987 standard atro,
14 o5 lbf/in2, 750 torr.
BJE,,T,. equation The equation of Brunauer, Eromett and Teller, used for
calculating the surface areas of solids from gas adsorption data (see ref. 24),
This is a standard method* (Section 6-2-.')
Co An abbreviation for circa (approximately),,
Calcination, extent of, EC The amount of C02 lost by a stone on calcination,
expressed as a percentage of the total amount of C0,_ that would be lost if all
the carbonate originally present were converted to oxide,,
Calcined-only stones Stones calcined in the absence of S0_,
Calei.ned-sulphated stones Stones calcined in the presence of SO,,,,
Dead volume The volume that is not occupied by the sample in the sample
container of the helium density or sorption apparatus«
Displacement density - helium, p,. The mass of a so.Ud divided by the
..ne ^ ^
volume of helium it displaces when immersed in that gas» Unit: g/cm „
(Technique, Section 2,3^,1 0
Displacement density - mercury, DU The mass of a sol.id divided by
the volume of mercury it displaces when immersed in that liquid under a
specified pressure; i.n the present work the average pressure on the
mercury in contact with each stone particle was taken as 760 torr
(Io013 bar)-, One use of this mercury displacement volume (although it
does not include the volume of pores with entrances of diameter >14n,5 urn,
A8.65
-------
assuming the entrances to be circular) is as an approximation to the
3
superficial volume of the particles* Unit: g/cm 0 (Technique, Section 2o3.2.)
Drop-tube experiment The calcination or calcination-sulphation experiments
in the controlled atmospheres,
Helium density See Displacement density - helium^
Helium specific volume, l/PHe Reciprocal of the helium density,.
Unit: mm^/g.
Intergranular volume; interparticulate volume The volume of the spaces
between stone particles constrained 'in the sample chamber of the mercury
porosimeter; virtually all this volume can be considered as being behind
entrances >10 um diameter and most behind entrances >58 ym;..
Mercury density See Displacement density - mercury„
Mercury specific volume, I/PH Reciprocal of the mercury density-
T
Unit: mmj/g^ ;. • >?
Mercury injection porosimetry A technique for measuring the volumes of
pores behind entrances with diameters between chosen limits within an
overall range: c, .58 om to 0,,014 ^m in the present work assuming the ;
entrances are circular« Mercury was forced into the stones under stepwise
increase of pressure up to c» 1035 bar, the cumulative amount,of mercury in
the stone being measured at each step-, (Technique, Section 2.-3o4°-)
Particle density, p The mass of particles in a sample divided by their
superficial volume,,
Peak pore-entrance diameter,A The pore-entrance diameter at the main
peak in each of the mercury porosimetry differential curves of FigSo 4, 5
and 60
Pore penetration experiment An experiment to determine the increase in
gas penetration on increase of temperature, (Technique, Section 4,)
Pore closure experiment An experiment to determine the decrease in gas
penetration on increase of temperature,, (Technique, Section 4n)
Pore-entrance diameter The diameter of an opening through which access
is obtained to a pore , This entrance may be narrower than the poreo When
a pore has more than one entrance, it is the larger one that is measured -
Where deduced from mercury porosimetry, the symbol is D or poe.d^; circular
entrances are assumed„
A8.66
-------
Porosity; pore volume The volume of pores behind entrances having a
specified range of diameters, expressed on a per gramme (mm /g) or
percentage of superficial volume of sample basis.
Porosity (helium - mercury density), Vx The pore volume accessible to
helium but not to mercury under 760 torr (1.013 bar) calculated from the
helium and mercury displacement densities. V is taken to be the volume
*• . X
behind entrances with diameters between 14.5 ym and 0.26 nm.
Porosity-mercury porosimetry
(i) Total pore volume, t.p.v. The pore volume behind entrances with
diameters between c. 58 ym and 0.014 ym, viz, the whole range covered by
the mercury porosimeter=
(ii) TTjj The pore volume behind entrances with diameters between 14.5 ym
and 0,014 um (the value of 14.5 ym being chosen to equal the upper entrance
diameter limit of V,.) »
J\.
Pore volumes with respect to other entrance diameter ranges have also been
evaluated.
No correction was-attempted for the contribution of intergranular volume,
which was small with respect to entrances <14.5 ym diameter.
Rapid heating Heating of uncalcined stones by sprinkling into the hot
zone at 1470 or 1650 F in the calcination-only or calcination-sulphation
experiments to simulate the rapid heating conditions in the combustor.
Reaction rate constant; velocity constant The mass of S0_ absorbed per
second, by unit mass of CaO in calcined stone, from a gas mixture containing
1 kgS02/m^ The reaction has been taken to be first order. Unit: m^/kg.s.
(Technique, Section 7.1.)
Reactivity A general term meaning the magnitude of the reaction rate
constant for a given stone under specified conditions, e.g., sulphation,
particle size.
'Shell' formation The formation of a sulphated layer that impedes
penetration of S0« to the internal pores of a particle, as found with
Limestone 1359 under laboratory conditions.
2
Specific surface Surface area per unit mass. Unit: m /go
A8.67
-------
Sulphation, E ; utilisation. U The amount of sulphur taken up by a
stone, expressed as a percentage of the total amount of sulphur that would
be taken up if all the CaCO. originally present were converted to CaSO,.
Sulphation,, limiting Level of sulphation.at which the reaction rate
constant falls to a negligibly low value.
Torr Unit of pressure equal to'1 mm of mercury at 0°C and standard
2
gravity 980*665 cm/s (750 torr =• 1 bar) „ The torr is often used in
vacuum technology to indicate residual gas pressures.,
Transport pores Relatively large pores necessary to facilitate access
of SO 2 to the interior of stone particles, In the present work these
pores have.been considered, for .reasons of comparison, as having entrances
between 14,5 ym and 0»3 ym,,
Utilisation See Sulphation
Veloci ty cons tant See Reaction rate constant
Volume, superficial, particle or 'lump' The volume of a stone including
that of all the pores it contains*
-------
10, REFERENCES
1. Potter, A.E. Amer.. Ceramic joe. Bull.^48(9), 855 (1969)o
2,. Falkenberry, HnLo and Slack, A.Vr, Chem. Engng. Prog.,
_65 (12), 61 (1969).
3. Bethell, F,V, Private Communication, 1970,
4,, Coutant, R,W,, McNulty, J.S,, Barrett, R,Eo, Carson, J,J.,
Fischer, R. and Lougher, E.H. 'Investigation of the
Reactivity of Limestone and Dolomite for Capturing S0_ from
Flue Gas': Battelle Memorial Institute Report to NAPCA,
August 30, 1968 c
5o Rappeneau, J- _in "Les Carbones', Vol. II, Ch. 14, Section C.II,
pp, 134-1,40, Masson, Paris, 1965,
6- Scholten, J..JUF, in "Porous Carbon Solids' (Ed* R.L, Bond),
Ch~ VI, pp, 225-249, Academic Press, 1967.
7, limes, W,B<- _in "Experimental Methods in Catalytic Research*
(Ed, R,Bn Anderson), pp. 80-81, Academic Press, 1968.
8» Spencer, D-H-To BCURA Monthly Bulletin, _33 (Non 10),
pp,, 228-239, October 1969,
9~ Carbon and Us Uses, Issue No-, 10, pp^ 1.6-22, Morganite Carbon
Ltd,, London, 1966,,
10, Satterfield, C N, and Feakes, F-. A^oCh,^,, Journal, ji, 115
(1959).
11, Chan, R,,K,, Murthi, K,S, and Harrison, Do CanadnJ,Chemo, 48,
2972 (1970)~
12o Glasson, D,R,, J ,Appl ,Chem., 8, 793 (1958),
13. Glasson, D,R, JnAppj Chem., 17, 91 (1967).
14, Glasson, D..R. J ,Appl .Chem., 13, 111 (1963),
15, - Glasson, D,R, J ,Appj -.Chem., J_l, 201 (1961).
16, Girgts, B-.S, and Girgis, L.G, J ,Appl.Chemo. jj, 292 (1969).
17, McClellan, A,L- and Harnsberger, H,F, J .Colloid Interface Sci., _23,
577 (1967),
18- Bethell, F,V, BCURA Doc.. No. FCP.5, 1969,
19, See, for example:
Lamond, T,G, and Marsh. H, Carbon, _!., 281, 293 (1964).
Gregg, S,J, and Sing, K,S.W~! "Adsorption, Surface Area and
Porosity', Ch,4, Academic Press, London and New York, 1967.
A8.69
-------
20 n See, for example:
Spencer, D. H, TV _Ln 'Porous Carbon Solids' (Ed. R.L, Bond),
p»133, et seg, Academic Press, London and New York, 1967.
21a, Napier, B,A. and Spencer, D.HoTo Nature (Lond-), 218,
948 (1968)n
21b, Napier, B-A-, and Spencer, D.H,T, To be published .
21c. Kipling, J,Jn, Sherwood, JoNo, Shooter, P,V,, Thompson, N,R.
and Young, RnN, Carbon, _4, 5 (1966),
21d, Norton, F.J., JoAppl oPhys,o, ^§, 34 (1957).
Stern, S,A, _in 'Argon, Heli.um and the Rare Gases'
Vol.1 (Ed, GnAo Cook), pp.217-218,
Interscience, New York and London, 1961.
21e- Graham, LoW^ Proc3 Second Conf -
Carbon Graphite, pn224 (contribution to discussion),
Society of Chemical Industry, London, 1966,
22. Jonke, A, A, Argonne National Laboratory: 'Reduction of
Atmospheric Pollution by the Application of Fluidized
Bed Combustion', Monthly Progress Report No. 3, p. 11,
Octo 1968,
23» NCB Second Three Monthly Progress Report to NAPCA,
November, 1970,
24. Gregg, S,J,, and Sing, K,S,W. 'Adsorption, Surf ace Area and
Porosity', Academic Press, London and New York, 1967.
A8o70
-------
11. ACKNOWLEDGEMENTS
The experimental work described in this, report was carried out at
BCURA Industrial. Laboratories Ltd., Leatherhead, Surrey, under the
overall direction of Mr. H,R. Hoy,,
The work described in:
(a) Sections 2 to 6, was mostly performed in the BCURA Pore
Structure Laboratory (Group Leader, D.H»T. Spencer) of the Materials
Characterisation Unit (Head, Mr. R.L. Bond), The authors of these
Sections - A,A. Herod, B0A<, Napier and DoHoT, Spencer - acknowledge
the contribution to the experimental work made by their colleagues,
Mr. D.J. Ando, Mr. M.A. Hooker, Mr. D.F. Libaert, Mr, N. Peters and
Mr, M.E.Turtle. Acknowledgement is also made to Mr. R, Dickinson,
of the Mathematics Department, for processing by computer the output
from the mercury porosimeter, and to Miss M. Kay, of the Analytical
Section of the Materials Characterisation Unit, who carried out
most of the sulphur determinations.
(b) Section 7, was carried out by two of the authors -
F.V. Bethell and G. McDonald - under the general supervision of
Mr. D.W. Gill.
Acknowledgement is made to Mr. Gill for preparing the
Addendum in Section 8.
A8.71
-------
Table A8,l, Scheme followed in the preparation of
calcined and calcined-sulphated stones,
with rapid heating and using controlled
atmospheres
Variables
Levels
Particle-size
grade of stone
-16 + 52 BS mesh
Composition of gas
passed into furnace
tube
(1) 15% C02, 3% 02, balance N2;
(2) 15% C02, 3% 02, 2000 ppm S02>
balance N2;
all quantities being 'by volume'
t Duration of particles
in furnace tube
i, 1 and 4 h
Furnace temperature
1470° and 1650°F
A8.72
-------
Table A8.2o Calcination details - U.K. dolomite; exploratory experiments and
pore-penetration, pore—closure experiments
Sample
designation
Bl, f
Bl (a),g
Bl (b),h
B2
C
C
Cl
C2
C3
C4
C5
C6
C7
C8
C9
CIO
Gil
E
El
Particle— size
grade ,
BS mesh
- 6 + 8
-6+8
-6+8
-6+8
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-300
-300
Calcination
history at 1470°F
in vacuum
in vacuum
in vacuum
rapidly heated; SA;** lh
in vacuum
slow in air and vacuum
rapidly heated; SA; lh
rapidly heated; SA; 23h
rapidly heated; SA; |h
rapidly heated; SA; |h
rapidly heated; SA; 97h
rapidly heated; N2; l§h
rapidly heated; N2; 16h
rapidly heated; N2; |h
rapidly heated; N2; 3h
rapidly heated; N2 ; . l|h
rapidly heated; SA; 3^h
in vacuum
rapidly heated; SA; 17h
Extent of calcination, %
After treatment
in atmosphere
_
-
-
50 .,5
.
-
52.8
69.0
48,5
49.4
99,5
67.1
99.6
69.8
99.1
83o4
52.9
-
60.7
*
After pp-pc
100 ,0
100.1
99,5
100.0
97,0
97.0
-
99.0
99.3
* Pore penetration — pore closure experiments (Section 4)
** SA = stagnant atmosphere
t Calcined in slower N2 flow
-------
Table A8.3. -Calcination details - limestone 1359: exploratory experiments and
pore-penetration, pore-closure experiments
Sample
designation
Ungraded
material
Gl
G2
G3
G4
G5
G6
G8
G9
G10
HI
H2
H3
H6
Particle-size
grade
BS mesh
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-300
-300
-300
-3*00
Calcination
history at 1470 F
in vacuum
rapidly heated; SA;**2h
rapidly heated; SA; $h
rapidly heated; SA; Jh
rapidly heated; SA; 17h
rapidly heated; SA; 115h
rapidly heated; N2; Iht
rapidly heated; N2J 2ht
rapidly heated; N«; Ih
in vacuum
rapidly heated; SA; Ih
rapidly heated; SA; 5h
rapidly heated; SA; 18h
in vacuum
Extent of calcination, %
After treatment
-
3.4
2.3
2.3
24.6
99.1
21.6
45.5
15.9
-
9.1
9.5
22.5
—
After pp-pc^l
99.6
99.0
99.3
96.5
* Pore penetration - pore closure experiments (Section 4)
** SA = stagnant atmosphere
t Calcined in slower N~
A8.74
-------
Table A8.4. Prefix assigned to sample of a particular
stone in a particular particle-size grade.
Stone
Dolomite 1337
"U.K. dolomite
Limestone 18
Limestone 1359
Particle-size grade, BS mesh,
and prefix
-6 + 8
_
B
-
-
-16 +52
J.
C
N
G
-300
—
E
-
H
A8.75
-------
Table A8.5 Designation of samples prepared in controlled atmospheres*
Atmosphere and temperature
Treatment time, h
Designation
Dolomite 1337
UoKc dolomite
Limestone 18
Limestone 1359
S02 absent, 1470°F
i
J6
C28
N3
G32
1
J4
C29
N2
G33
4
J5
C30
N4
G34
SO- present, 1470°F
1
' J9
C32
N6.
G36.
1
J8
C31
N7.
G35
4
J10
C33
N8
G37
S02 absent, 1650 °F
i
J14
C34
N14
G39
1
J15
C36 '
N13
G38
4
J16
C35
N15
G40
SO- present, 1650°F
i
J13
C39
Nil
G43
1
J12
C38
N12
G42
4
J17
C37
N16
G41
* 15% C02, 3% 02, 82% N2, with and without 2000 ppm S02, all v/v<
-------
irom exploratory experiments
Sample
C
Cl
C2
C4
U.K. C5
dolomite _,
Co
C7
C8
C9
CIO
G
G3
Limestone
1359 G4
G5
G6
G8
Calcination
Extent,
%
Nil
52.8
69.0
49,4
99.5
67.1**
99,6*
69.8*
99.1*
83.4*
Nil
2.3
24,6
99.1
21,6**
45.5**
Time,
h
'
1
23
1
97
U
16
i'
3
U
-
i
17
115
1
2
Total
pore volume
(top.v,),
mm3/g
41
190
280
180
510
260
470
280
440
340
18
33
100
360
70
140
Peak pore-
entrance
diameter (A)
ym
+
0.18
0.30
0.08
0,46
0,18
0.30
0.10
0.23
0.18
+
+
1.10
1.10
0.30
0.30
* Calcined in N_ flow
** Calcined in slower N_ flow
+ Indeterminate
i O -n
-------
Table A8.7. Results from controlled-atmosphere experiments: dolomite 1337
Sample
designation
J
J6
J4
J5
J9
J8
J10
J14
J15
J16
J13
'•• J12
J17
Calcination
Time,
h
Temp,,
F
Extent,
' %
Raw stone
I
1
4
J
1
4
. i
1
4
i
1
4
1470
1470
1470
1470
1470
1470
1650
1650
1650
1650
1650
1650
33o6
62o4
52oO
61,8
75,0
87oO
85,0
93oO
90 oO
90.5
94 o 3
99.0
Ciil r\V\a
tion
%
0
0
0
0
9,7
28.9
53,4
0
0
0
13*7
34.4
54.7
>He
g/cm
2,83
2.88
3o03
2,96
2,94
3,01
2,99
3,26
3 = 39
3,36
3.24
3,24
3»15
l/PHe
(x?e'
mm /g
354
347
330
338
340
332
335
307
295
298
309
309
318
PHg,3
g/cm
2,604
2,196
1,866
1,978
1.991
2,092
2.292
1,570
1,534
1 = 541
1,718
1,936
2.228
1/Pna
(x¥s'
mm /g
384
455
536
505
502
478
436
637
652
649
582
516
449
Porosity, Vx
(y r x)
mnr/g
30
108
206
167
162
146
101
330
357
351
273
207
131
%
7o8
23,7
38.4
33 oQ
32o3
30,5
23 ol
51 = 8
54,8
54,1
46,9
40,1
29.2
Mercury .
porosimetry porosity, mm /g
t <,p,Vo
46,3
117,6
212.4
186,4
187,3
165,4
125 o 7
351,2
375,2
394.9
296,3
221.9
152.8
Volume in pores
with entrances
>14»5ym dia.
9o3
13 = 3
12,2
19.8
20.2
12,8
18,7
20 ,0
30,3
26,3
22.2
16.8
19.0
TTHg
37=0
104 o :-
200,:
166»(
167 o]
152 d(
107, (
331,1
344 oS
368, 1
274 . 1
205 . ;
133J
-------
Table A8.8. Results from controlled-atmosphere experiments: U.K. dolomite
Sample
designation
C
C28
C29
C30
C32
C31
C33
C34
C36
C35
C39
C38
C37
Calcination
Time,
h
Temp, ,
F
Extent,
%
Raw stone
i
1
4
I
1
' 4
i
1
4
i
1
4
1470
1470
1470
1470
1470
1470
1650
1650
1650
1650
1650
1650
57,3
67.0
69,0
61.5
71.8
81.4
96.0
98.0
100.0
93,0
97.0
•
99.0
Sulpha-
tion,
%
0
0
0
0
11.8
22.9
37.4
0
0
0
10.7
22,7
41,5
PHe
g/cnr
2.83
2.98
3.03,
3.16 .
3.01
2.99
2.99
3,32
3.34
3.39
3.39
3 = 33
3.25
^H..
<*>
mnrVg
353
. 336
. 331
. 317
333
335
335
301
300
295
295
301
308
PHg,
g/cm
2.696
1,976
1,871
1.866
2e025
2o056
2.143
1.544
1.520
1.509
1,675
1,745
1,968
1/PHg,
(x)
mm-Vg
371
505
535
536
494
486
467
648
658
663
597
573
508
Porosity, Vx
(y - x)
3,
mm /g
18
169
204
219
161
151
132
347
358
368
302
273
200
%
4,8
33.4
38.1
40,8
32.6
31,1
28.2
53,5
54,4
55.5
50,5
47.6
39.4
Mercury -
porosimetry porosity mm /g
t.p.v.
40.8
199,1
225,5
231.3
395.0
402.7
414.1
328.8
287.9
220.7
Volume in pores
with entrances
>14.5vim dia.
16.5
26,1
27.0
22.7
36.6
33,0
38.5
29,0
29.3
21.6
T TT
Hg
24.3
173.0
198.5
208.6
358.4
369,7
375,6
299,8
258.6
199.1
oo
-------
Table A8.9. Results from controlled-atmosphere experiments: limestone 18
Sample
designation
N
Nl
N3
N2
N4
N6
N7
N8
N14
N13
N15
Nil
N12
N16
Calcination
Time,
h
Temp.,
Extent,
%
Raw stone
1
I
1
4
i
1
4
i
1
4
i
1
4
1470
1470
1470
1470
1470
1470
1470
1650
1650
1650
1650
1650
1650
14
16
19.5
30.5
~10
21.0
66.6
85.0
96.0
96.0
85.2
94.0
100.0
Sulpha-
tion
%
0
0
0
0
0
3.9
9.4
26.3
0
0
0
9.1
25.9
46.1
PHe
g/cm
2.67
2o66
2.66
2.66
2.68
2.75
2.77
2.89
3.12
3.24
3.14
3.13
3.16
3.03
"PH..
<*)
mm-Vg
375
.375
375
375
373
364
361
346
321
309
319
320
316
331
PHg,3
g/cm
2.471
2 .330
2.261
2.289
2.221
2.369
2.350
2.210
1.706
1.605
1.647
1.791
1.972
2.360
1/(>Hg>
<3J>
mm^/g
405
429
442
437
450
422
426
452
586
623
607
558
507
424
Porosity, Vx
(y 3 x)
mm 7g
30
54
67
62
77
58
65
106
265
314
288
238
191
93
%
7.4
12.6
15.1
14.2
17. l'
13.7
15.3
23.4
45.2
50.4
47.5
42.6
37.7
22.0
Mercury _
porosimetry porosity, mm /g
t .p.v.
50.1
71.5
92,8
85,4
96.5
67.0
77.4
115.4
292.7
323.8
298.9
246.2
209.8
100.7
Volume in pores
with entrances
> 14. 5pm dia.
18.3
11.8
19.3
14.1
15.3
15.9
17.2
13.9
26.5
28.0
26.8
18.7
21.0
18.0
"Hg
31.8
59.7
73.5
71.3
81.2
51.1
60.2
101.5
266.2
295.8
272.1
227.5
188.8
82.7
-------
Table AS.lOo Results from controlled-atmospaere experiments: limestone 1359
designation
r^
^3
332
333
334
336
.a 35
G37
3 39
1 3 38
3 40
G43
j
342
G41
Calcination
Time,
h
Temp.,
r
:
Extent
%
Paw stone
i
1
4
i
1
4
1
1
4
i
1
4
1470
1470
1470
1470
1470
1470
1650
1650
1650
1650
1650
1650
4.0
3.6
19.0 «
5.7
7,3
10.0
86,4
89.0
91.0
90.0
98.0
99.0
Sulpha-
tion,
%
0
0
0
0
1.5
3.1
3.3
0
0
..0
5.0
7.5
8.0
"He
gycm3
2,72
2.73
2,72
2,79
2.70
2.71
2.72
3,19
3-25
3.29
3. 20
3.28
3,26
^He,
Cx)
mm3yg
368
366
368
358
371
369
368
314
308
304
313
305
307
•pHg,
gycm3
2.669
2,604
2.583
2,407
2.606
2.594
2.566
1.789
1.769
1.775
1.848
1.857
1.900
iyPHg,
(y>
mm3yg
375
384
387
415
384
385
390
559
565
563
541
538
526
i
Porosity, Vx j Her cur
i
(y - x)
mm3yg
7
1
% <-,p -ot
1..9 1° 0
.
18 4.7 2 9
19
. .57...
13
16
4. ,9 3."- 3.
13,7 .6:'. 5
3.4
4,1
22 [ . 5,6
| - ...
245 I 43. 8 25... 7
i
y porosimetry porosity
mm3 /g
'iblume in pores
vith entrances
>14.5ym dia-
10,0
?0, 1
1,? ,1
10,4
. _•
lo.S
-
257 | 45,5 ','.8' 9 '?:• .4
259 1 46 ..0 .?- ,,Q
I
228 | 42.1
233 1 43 /•
219 j -1 :• 2:? ,1
•??. /
1^ 8
71
8,'
1 7 ,
21..
53.
236.'
265.
252.
19U
-------
Table A8.ll. Volume in pores (mm /g and percentage of particle volume
l/pn ) with entrances having diameters between 14.5ym
8 and values shown*
Dolomite 1337 (J samples) and U.K. dolomite (C samples)
Sample
design-
ation
J
J6
J4
J5
J9
J8
J10
J14
J15
J16
J13
J12
J17
C
C28
C29
C30
C34
C36
C35
C39
C38
C37
Cl
C5
CIO
C9
C7
3ym
mm /g
5.2
11.2
9.3
11.0
15.2
11.8
12.0
16.5
19.7
22.6
16.5
19.9
13.6
9.8
22.3
15.7
17.5
22.3
20.3
18.4 .
19.2
15.0
16.1
18.7
48.3
22.7
22.4
32.9
%
1.3
2.4
.1.7
2.2
3.1
2.5
2.7
2.6
3.0
3.5
,2.8
3.9
3.0
2.6
4.4
2.9
3.3
3.4
3.1
2.8
3.2
2.6
3.2
3.7
6.7
3.6
3.1
4.5
lym
3, •
mm /g
18.5
28.2
29.9
32.1
36.4
31.4
29.4
44.0
47.7
61.9
42.7
41.9
29.2
14.8
30.8
27.1
28.7
35.9
34.1
33.1
30.9
26.8
22.8
28.8
98.8
38.5
40.0
55.9
?'
4.8
6.2
5.6
6.4
7.2
6.6
6.7
6.9
7.3
9.5
7.3
8.1
6.5
4.0
6.1
5.i
5.3
5.5
5.2
5.0
5.2
4.7
4.5
5.7
13.8
6.1
5.5
7.7
0.3ym
mm /g
32.0
45.5
53.6
52.2
54.4
47.4
40.6
67.1
71.5
94:. 1
61.4
57.2
40.8.
19.4
42.6
39.5
43.4
53 .0
52.1
51.3.
45.0
35.1
29.0
50.4
406.8
87.4
115.0
249.0
%
8.3
10.0
10.0
10.3
10.8
9.9
9.3
10.5
11.0
14.5
10.5
11.1
9.1
5.2
8.4
7.4
8.1
8.2
7.9
7.7
7.5
6.2
5.7
10 .0
57.0
13.8
15.7
34.3
O.lum
3
mm /g
36.0
50.7
64.0
58.9
57.9
51.5
43.1
76.1
80.4
104.1
68.1
61.4
44.9
21.4
50.4
51.5
57.2
89.1
114.8
136.5
83.4
91.9
87.2
156.9
433.5
286.0
344.1
412.2
%
9.4
11.2
12.0
11.7
11.5
10.8
9.9
12.0
12.3
16.1
11.7
11.9
10.0
5.8
10.0
9.6
10.7
13.8
17.5
20.6
14.0
16.2
17.2
31.2
60.7
45.2
47.0
56.7
0.0 3ym
•j
mm /g
37.0
66.3
152.1
129.9
107.9
123.7
89.7
308.2
321.5
351.7
249.4
190.2
122.8
23.9
127.9
176.9
197iO
336.3
356.2
366.1
290.8
251.9
191.4
165.9
435.8
311.4
406.1
425.5
%
9.6
14.6
28.3
25.7
21.5
25.9
20.6
48.4
49.2
54.1
42.8
36.8
27.3
6.4
25.3
33.1
36.7
52.0
54.1
55.4
48.6
44.0
37.7
33.0
61.2
49.1
55.4
58.5
0.014ym
3,
mm /g
37.0
104.3
200.2
166.6
167.1
152.6
107.0
331.2
344.9
368.6
274.1
205.1
133.8
24.3
173.0
198.5
208.6
358.4
369.7
375.6
299.8
258.6
199.1
167.8
439.3
313.8
410.4
424 .5
%
9.6
23.0
37.4
33.0
33.3
31.9
24.5
52.0
52.9
56.8
47.1
39.8
29.8
6.5
34.3
37.2
38.9
55.4
56.1
56.8
50.1
45.1
39.3
33.3
61.5
49.4
56.1
58.4
Most of these are
approximations, for
A8.82
simplicity; see Section 2.4.2.5.
-------
Table A8.12. Volume in pores
and percentage of particle volume
• ' r Hr ~ r
I/PH } with entrances having diameters between 14.5"pm
and values shown*
Limestone 18 (N samples) and limestone 1359 CG samples)
Sample
L design-
Rat ion
N
Nl
N3
N2
N4
N6
N7
N8
N14
N13
N15
Nil
N12
N16
G
G32
G33
G34
G39
G38
G40
G41
3pm
mm3/g
5.3
8.6
10.0
8.6
9.0
8.3
7.5
6'. 6
13.9
6.5
13.0
10.2
15.9
6.1
2.4
2.6
3.8
3.6
7.0
8.9
5.5
6.4
%
1.3
2.0
2.3
2.0
2.0
2.0
1.8
1.5
2.4
1.0
2.1
1.8
3.1
1.4
0.6
0.7
1.0
0.9
1.2
1.6
1.0
1.2
1pm
mm3./g
14.9
24.5
30.3
27.0
28.0
21.2
20.2
25.1
69.2
76.2
71.4
52.3
58.5
24.2
4.1
5.3
6.2
6.2
11.8
15.5
8.2
18.1
%
3.7
5.7
6.8
6.2
6.2
5.0
4.8
5.5
11.8
12.2
11.8
9.4
11.5
5.7
1.1
1.4
1.6
1.5
2.1
2.7
1.4
3.4
0.3pm
mm3/g
22.6
40.6
50.5
48.1
54.3
35.2
35.7
55.2
132.9
153.7
174.3
109.3
107.8
50.5
5.9
7.5
8.4
10.7
19.7
30.7
24.4
32.6
%
5.6
9.5
11.4
11.0
12.1
8.4
8.4
12.2
22.7
24.6
28.7
19.6
21.2
11.9
1.6
1.9
2.2
2.6
3.5
5.4
4.3
6.2
O.lpm
mmf/g
25.9
52.4
63.2
60.9
75.1
43.8
48.9
90.8
189.3
269.1
265.5
157.7
173.9
70.5
6.5
10.4
12.9
35.0
35.3
134.2
223.5
169.2
%
6.4
12.2
14.3
13.9
16.7
10.4
11.5
20.1
32.3
43.2
43.7
28.2
34.2
16.6
1.7
2.7
3.3
8.4
6.3
23.8
39.7
32.2
0.03pm
mm3/g
30.6
57.9
71.6
70.0
80.4
49.6
58.1
99.1
264.5
292.6
269.6
224.9
186.8
78.3
7.6
16.0
18.8
48.7
228.5
263.4
247.2
188.5
%
7.5
13.5
16.2
16.0
17.8
11.7
13.7
21.9
45.1
47.0
44.4
40.4
36.8
18.5
2.0
4.2
4.9
11.8
41.0
46.5
43.9
35.8
0.014pm
mm3/g
31.8
59.7
73.5
71.3
81.2
51.1
60.2
101.5
266.2
295.8
272.1
227.5
188.8
82.7
8.0
17.8
21.2
53.1
236.9
265.5
252.2
191.3
%
7.9
13.9
16.6
16.3
18.1
12.1
14.1
22.5
45.5
47.4
44.8
40.7
37.1
19.5
2.1
4.6
5.5
12.8
42.4
47.0
44.8
36.4
* Most of these are approximations, for simplicity;
see Section, 2.4.2.5.
A8.83
-------
Table A8.13. Volume in pores (percentage of particle volume
1/p.. ) with entrances having diameters within
° ranges shown*
(a) Calcination alone at 1470°F
Stone
Dolomite
1337
U.K.
dolomite
UoKo
dolomite
(exploratory
experiments)
Limestone
18
Limestone
1359
Sample
design-
ation
J6
J4
J5
C28
C29
C30
Cl
C5
CIO
C9
C7
N3
N2
N4 .
G32
G33
G34
t- **
h
i
1
4
'i
1
4
1+
97+
1J++
3++
16++
J
1
4
k
1
4
14o5
to
3pm
2o5
1.7
2,2
4o4
2o9
3,3
3,7
6,8
3.6
3.1
4,5
2,3
2,0
2cO
0.7
loO
0.9
3
to
lym
3o7
3o9
4,2
1.7
2,2
2.1
2,0
7,0
2.5
2,4
3,2
4,5
4,2
4,2
0,7
0,6
0,6
1
to
0,3ym
3,8
4,4
3,9
2.3
2,3
2,7
4.3
43,2
7.7
10,2
26,6
4,6
4,8
5,9
0,5
0.6
1.1
0,3
to
0,lym
1,1
1.9
1,4
1,6
2,2
2,6
21,2
3,7
31,3
31,3
22.4
2,9
2,9
4,6
0,8
1.1
5,8
0,1
to
0,03iim
3o5
16.5
14,0
15,3
23,5
26,1
1.8
0,4
4.0
8,4
1,8
1,9
2,1
Io2
1,5
1.*
3,3
0.03
to
0.014ym
8.3
9.1
7.3
8.9
4.0
2.1
0.3
0.4
0.3
0,7
0,0
0.4
0.3
0.1.
0,4
0.6
1.1
* Most of these entrance diameter values are approximations,
for simplicity; See section 2,4.2,5,
** Time for calcination
+ In stagnant atmosphere
++ With nitrogen flush
A8.84
-------
Table A8.13 (contd). Volume in pores (percentage of particle volume
1/p. ) with entrances having diameters within
° ranges shown*
(b) Calcination alone at 1650 F
Stone
Dolomite
1337
U.K.
dolomite
Limestone
18
Limestone
1359
Sample
design-
ation
J14
J15
J16
C34
C36
C35
N14
N13
N15
G39
G38
G40
t,**
h
I
1
4-
k
I
4
J
1
4
k
1
' 4
I4o5
to
3pm
2,6
3oO
3 = 5
3o4
3.1
2.8
2,4
loO
2,1
1.2
1.6
1.0
3
to
lym
4.3
4.3
6=0
2,1
2.1
2,2
9 = 4
11.2
9.7
0.9
1 = 1
0 = 5
1
to
0 o 3ym
3.6
3o7
5oO
2o7
2.7
2.7
10.9
12.5
16,9
1.4
2,7
2.8
0 = 3
to
O.lym
1.5
1.3
1.5
5.6
9.6
12.9
9.6
18.5
15,0
2o8
18.3
35.4
0.1
to .
0,03ym
36.4
37.0
38.2
38.1
36.6
34.6
12.8
3.8
0.7
34.6
22.9
4.2
0,03
to
0.0l4ym
3.6
3.6
2.6
3.4
2.1
1.5
0.3
0.5
0.4
1.5
0.4
0.9
* Most of these entrance diameter values are approximations, for
simplicity; See section 2.4,2.5,
** Time of calcination
A8.85
-------
Table A8o14 Results from exploratory experiments on U.K. dolomite
Sample
design-
ation
C
Cl
C5
CIO
C9
C7
Calcination
Time,
h
0
1
97
U
3
16
Atmos-
phere
*
—
SA
SA
N2
N2
N2
Extent,
0
52.8
99.5
83.4
99.1
99.6
P
He'
g/on3
2.83
2.98
3.44
3.23
3.32
3.40
l/PHe 00
353
335
291
309
301
294
PHg'
gycm3
2.696
1.987
1.401
1.576
1.365
1.376
"sr
371
503
714
634
732
727
Porosity, Vx
Y - x,
18
168
423
325
431
433
*
4.9
33.3
59.2
51.2
59.0
59.6
Mercury porosimetry porosity
t.p.v.,
mm3/g
40.8
189.8
510.0
342.8
442.9
471.5
Volume in
pores with
entrances
>\'-. . 5'fjitt dia
mm3/g
16.5
22.0
70.7
29.0
32.5
47.0
' ^
mm3/g
24.3
167. 8
439-3
313.8
410.. 4
424.5
&
7,
6.5
33.3
61.5
49.4
56.1
58.4
oo
SA = stagnant
N2 = nitrogen flushed
-------
as percentage of 'superficial volume' of original stone*; treatment temperature 1470°F
Stone
Dolomite 1337
U.Ko dolomite
U.K. dolomite
(exploratory
experiments)
Limestone 18
Limestone 1359
t,**
h
i
1
4
1
1
4
1 X
97 x
l£ XX
3 xx
16 xx
1
1
4
J
1
4
Calcined-only
Sample
designation
J6
J4
J5
C28
C29
C30
Cl
C5
CIO
C9
C7
N3
N2
N4
G32
G33
G34
Difference,
%t
0.4
1.8
1.0
-0,9
-2.0
-3o4
1.4
loO
3.9
3o9
2.7
3.1
0.5
-0.9
0.6
1.6
1 = 6
Calcined-sulphated
Sample
designation
J9
J8
J10
C32
C31
C33
N6
N7
N8
G36
G35
G37
Difference, j
%t
-1.6
-4.2
-4.7
0.9
-0.9
-2.6
-
3.5
3.6
1.7
2.1
2.0
* 'Superficial volumes' used in the calculation do not include the volume
of any pores with entrances >14»5 ym diameter.
** Residence time in furnace.
t A negative sign corresponds to a decrease in 'superficial volume' on
treatment.
x In stagnant atmosphere.
xx With nitrogen flush.
-------
Table A8»16. Difference in 'superficial:, volume'between treated and original stone,
as percentage of-'superficial volume1 of original stone*; treatment temperature 1650 F
Stone
Dolomite 1337
U.K. dolomite
Limestone 18
Limestone 1359
t,**
h
i
1
4
i
1
4
i
1
4
i
1
4
Calcined-only
Sample
designation
J14
J15
J16
C34
C36
C35
N14
N13
N15
G39
G38
G40
Difference,
%t
-3.9
-5.0
-3.3
-6.1
-5.8
-8.3
-2.0
-2.7
-4.3
-7.9
-8.0
-9»9
Calcined-sulphated
Sample
designation
J13
J12
J17
C39
C38
C37
Nil
N12
N16
G43
G42
G41
Difference,
%t
-3.7
-5.3
-8.1
-2.8
-2.7
-3.0
3.2
3.3
-2.0
-7.2
-9.5
,-11.6
* 'Superficial volumes! used in the calculation do not include the volume.
of any pores with entrances >14.5 ym diameter.
** Residence time in furnace.
t A negative sign corresponds to a decrease in 'superficial volume' on
treatment.
A8.88
-------
Table A8.17. Difference in pore.volume between calcined-only and calcined-sulphated
stones for the same residence time in•: the furnace at 1650UF
Stone
Dolomite
1337
U.K.
dolomite
Limestone
18
Limestone
1359
. Sample designation
Calcined-
only
J14
J15
J16
C34
C36
C35
N14
N13
N15
G40
Calcined-
sulphated
J13
J12
J17
C39
C38
C37
Nil.
N12.
N16
G41
t,*
h
J
1
4
i
1
4
1
1
4
4
Differences in volume in pores (percentage of
. jpartiele volume 1/PHg) **with entrances having diameters:
Between 14.5.ym and. values shownt
3 ym
-0.2
-0.9
0.5
0.2
0.5
-0.4
0.6
-2.1
0.7
-0.2
1 ym
-0.4
-0.8
3.0
0.3
0,5
0.5
2.4
0.7
6.1
-2.0
0.3
ym
0
T-0.1
5,4
0.7
1.7
2.0
3.1
3.4
16.8
-1.9
0.1
ym
0.3
0.4
6.1
-0.2
1.3
3.4
4.1
9.0
27.1
7.5
0.03
ym
5.6
12.5
26.8
3.4
10.1
17.7
4.6
10.2
25.9
8.1
0.014
ym
4.9
13.1
27.0
5.3
11.1
17.5
4.8
10,3
25.3
8,4
Within ranges shownt
14,5
to
3 ym
-0,2
-0.9
0.5
0.2
0.5
-0.4
0.6
-2.1
0.7
-0.2
3 to
1 ym
-0.2
0.1
2.5
0.1
0
0.9
1.8
2,8
5.4
-1.8
1 to
0.3
ym
Oo4
0.7
2.4
0.4
1.2
1.5
0.7
2.7
10.7
0.1
0.3 to
0,1 ym
0.3
0.5
0.7
-0.9
-0.4
1.4
1.1
5.6
10.3
9.4
0.1 to
0.03
ym
5.3
12,1
20.7
3.6
8.7
14.3
0.5
1.2
-1.2
0.6
0.03 to
0.014
ym
-0,7
0.7
0,2
1.9
0.9
-0.2
0.2
0.1
-0.6
I
0.3 j
oo
•
00
* Residence time in furnace.
** A negative value corresponds to the pore volume in the calcined-sulphated stone being greater than that in the
calcined-only one.
t Most of these entrance.diameter values are approximations, for simplicity; see Section 2.4.2.5.
-------
Table A8.18. Results of preliminary pbre-penetfatibn arid pore-closure experiments
Stone
Lotherdale
Quarry
limestone
Spro thorough
I in clipping
(dolomite)
- U.K.
dolomite
Sample
design-
ation
a
b
d
. . . c
e
f
8
h
Particle-
size grade,
BS mesh
-16 + 25
-16 + 25
-16 + 52
-16+52
-16 + 52
-6 + 8
Calcination time
to
1470°F
23
92
1
144
144
1
29
29
at
1470°F
2
2
16
46
46
3
i
k
, h
at
1650°F
-
^»*
- •
— '
-
19
2
2
Type of
experiment*
p. pen.
p» closure
p. pen.
p. closure
p. pen.
p. pen.
p. pen.
p. pen.
p. closure
p. pen.
p. closure
p. pen.
p. closure '.
Probe gas and result, mm3/g**
Helium
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<(J.l
<0.1
<0.1
<0.1
<0.1
Neon
34.0
(9.4)
<0.1
_
27.6
(7.7)
<0.1
1.7
(0.5)
<0.1
<0.1
<0.1
0.1
<0.1
<0.1 .
Kryp ton
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
3.2
(0.9)
0.4
. (0.1)
' O.'L
<0,1
<0.1
<0.1
<0.1
Xenon
<0.1
<0.1
^"*
<0.1
<0.1
8.7
(2.4)
2.1
(0.6)
<0.1
5.2
(1-4)
- <0 . 1
3.2
(0.9)
<0.1
oo
VO
O
* p.pen. = pore penetration
p.closure = pore closure
** mm3 at admission pressure (~50 torr) and 1470 F
(or 77 F, in parentheses) per g of calcined sample
-------
Table A8.19. Results of pore penetration experiments; iin-p re treated stones
Stone
U.X,
dolomite
Limes tone
1359
Sample
designation
C
c**
E
G10
H6
Ungraded
material
Particle-size
grade ,
BS mesh
-16 + 52
-16 + 52
-300
-16 + 52
-300
-10
Probe gas and result, nmvVg*
Helium
<0.1
•
-------
Table A8.20. Results of pore penetration experiments on pretreated stones
VO
S3
Stone
U,K.
dolomite
Limestone
1359
Sample
design-
ation
B2
C3
C8
Cll
Gil
Cll
El
Gl .
G9
H3
HI
Particle-
size grade,
BS mesh
-6 + 8
-16 + 52
-16 + 52
-16 + 52
-16 + 52
-16 + 52
- 300
-16+52
-16 + 52
- 300
- 300
Pretreatment
Atmosphere
Stagnant
Stagnant
Nitrogen -
flushed
Stagnant
Stagnant
Stagnant
Stagnant
Stagnant
Nitrogen
f lushed
Stagnant
Stagnant
Time at
1470°F,
h
1
i
i
3i
3i
3J
17
2
1
18
1
3
Probe gas and result, mm /g*
Helium
<0.1
<0.1
<0.1
<0.1
Neon
<0.1
<0.1
<0el
<0.1
Krypton
<0.1
.v.3,0
(0.8)
6,6
(1.8)
10.8
(3.0)
Xe only, adsorbed at
77°F
Equimolar mixture of Xe
and SO™, adsorbed at 77°F
<0.1
<0ol
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0,1
<0.1
2o5
(0.7)
3,8
(1.1)
31.5
(8.8)
Xenon
26.5
(7.4)
26.7
(7.5)
28oO
(7o6)
43.5
(12.1)
27.6
(7.6)
6.1
(1 = 7)
59.3
(16.5)
<-o.i
5.1
(1.4)
31.5
(8.8)
220
(61)
Evacuation time at
77°F before final
release stage,
h
Not recorded
120
100
70
72
72
Not recorded
Not recorded
120
120
20
* mm at admission pressure.( -50 torr) and 1470°F (or 77°F, in parentheses) per g
of calcined sample
-------
Table A8.21. Results of thermal cycling experiments; ILK... dolomite
Particle-
size grade
of sample
BS mesh
-16 * 52
.
-30C
-16 + 52
-30C
-300
-16 +52
-300
-16 + 52
-16 + 52
-300
-16 + 52
-16 + 52
-16 + 52 :
-300 :
Sul
Not cycled
a ? w/w
3.8
7.4
6.6
11.0
10.9
5.2
5.9
5.9
6.1
7.9
6.5
5.8
5,3
12.5
a7q
x 100
i.o
2.1
1.3
2.2
2.2
1.7
2.0
1.0
1.0
2.4
0.5
0.5
0.4
1.0
phur content
Thermally cycled
b 9 w/w
4.7
8.5
6.9
12.2
12.7
4.2
6,9
7.2
5.2
9.4
5.8
6.6
6.0
12.8
b/q
x 100
1.3
2o4
1.4
2.5
2.5
1.4 .
2.3
1.2
0.9
2.5
0.5
0.6
0.5
1.1
1^*100,
24
. 15
4
11
20
-19
17
20
-15
19
- 9
14
13
2 :
Quantity
of S02
passed qs
c m 3Cstp}
360
360
500
500
500
300
300
600
600
375
1200
1200
1200
1200
Number
of
cycles
10
10
5
5
5
10
10
20
20
5"
10
10
20
10 :
Times , min
£;>
21
21
21
21
21
21
21
j
\
21
21
21
1
.21
t2
4
4
5
5
5
2
2
2
2
5
2
2
0*
2
t3
2
1
1
1
1
1
1
1
1
1
1
1
1
1.
Gas compos itions v/v
1
S02
ppm
1500
1500
4000
4000
4000
2500
2500
2500
2500
2500
10000
10000
10000
10000
N2
90
90
98
98
98
83
83
83
83
83
17
14
14 :
14
Co
z"
10
10
2
2
2
2
2
2
2
2
7
10
10
10
?2
0
0
0
0
0
15
15
15
15
15
75
75
75
75
VO
* In this experiment the thermal cycling was completed in a non-SO£ bearing
atmosphere and then the S02 bearing stream was passed for 20 min
-------
Table A8.22. Results of thermal cycling experiments; limestone 1359
Particle-
size grade,
of sample
BS mesh
-16 + 52
-300
-16 + 52
-16 + 52
-300
-16 + 52
-300
-16 + 52
-16 + 52
-16 + 52
-300
Sulphur content
Not cycled
a, w/w
%
2.8
7.1
2.0
1.9
8.2
1.4
6.0
1.0
1.3
1.2
10.0
a/q
x 100
0.8
2.0
1.1
1.1
2.2
0.5
2.0
0.1
0.1
0.1
0.8
Thermally cycled
b, w/w
%
3.1
8.4
2.1
0.7
6.2
0.7
7.1
1.0
1.1
Ic5
9.1
b/q-
x 100
0.9
2.3
1.2
0.4
1.7
0.2
2.4
Ool
0.1
0.1
0.8
^^ x 100
a
%
. 10
18
5
-63
-25
-50
18
0
-15
25
-8
Quantity
of S02
passed q,
cm3 Catp)
360
360
180
180
375
300
300
960
1200
1200
1200
Number
of
cycles
10
10
6
6
5
10
10
8
10
10
10
Times , min
tl
2|
2^
i
1
2£
21
2^
2£
21
J
2k
t2
4
4
2
2
5
2
2
2
2
0*
2
t3
1
l
4
i
i
1
i
1
i
i
1.
Gas composition, v/v
S02
ppm
1500
1500
2500
2500
2500
2500
2500
10000
10000
10000
10000
N2
%
90
90
83
83
83
83
83
14
14
14
17
02
%
10
10
2
2
2
2
2
10
10
10
7
C02
%
0
0
15
15
15
15
15
75
75
75
75
IO
JS
* In this experiment the thermal cycling-was completed in a non—S02 bearing atmosphere
and then the S02 bearing stream was passed for 20 min
-------
Table A8.23» Data record of reaction rate experiments
Series
1
;
1
Run
1
2
3
4
5
6
A
Jl/min
10
10
10
10
10
10
T
s
°c
800
800
800
800
800
810
Tf
°C
800
800
800
800
111
894
S
m
ym
1000
1000
1000
1000
1000
1000
s
s
ym
300
300
300
300
300
300
(g)
8
8
15
30
23
23
H
(mm)
6.35
6,35
12.70
25.40
19.05
19.05
n
1
2
3
1
2
3
1
2
3
• 4
5
I
2
3
4
5
6
7
1
2
3
4
5
1
2
3
4
5
6
t
n
(sees)
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
270
299
282
279
278
295
269
t
Vol
n
9.2
21.7
25.9
6.2
20.4
25.9
4.8
16.2
22.5
25.2
26.1
Oo2
0.9
9.1
16.3
20.5
23.8
25.6
0,6
9.7
20.2
24.1
26.1
1.9
10.2
17.7
23.3
25.2
26.2
Vol
o
(mi)
28.65
28.65
28.65
28,65
28.65
28.65
Stone
UoK,
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
% CaO
in stone
30.7
30.7
30 o 7
30.7
i
U.K.
Dolomite
30o7
•
UoK.
Dolomite
30.7
j
S
Cc
A:
A:
A:
A:
A:
A:
-------
Table A8.2-3 (cont'd) Data record of reaction rate experiments
Series
1
(contd]
2
Run
7
8
9
10
11
A
£/min
10
10
10
10
10
T
s
°C
820
.
812
800
800
800
tf
°C
882
870
835
850
860
S
m
Vim
1000
1000
1000
2800
2800
S
s
ym
300
300
300
2000
2000
\
Cg)
30
30
15
21
21
H
(mm)
25.40
25.40
12.70
19.05
19.05
n
1
2
3
4
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
n
(sees)
272
549
275
275
558
562
570
589
558
564
566
558
553
546
560
544
582
593
580
610
564
550
564
580
626
597
637
593
569
Vol
n
CmO
0.3
5.8
14.4
19.0
0.1
1.3
10.1
20.0
24.3
25.6
5.4
15.9
21.7
24.4
25.5
26.2
3.4
15.7
20.8
22.9
23.5
23.8
6.1
18.6
23.2
24.4
24.6
25.8
25.8
Vol
0
(mJt)
28.65
28.65
28.65
28.65
28.65
Stone
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
% CaO
in stone
30.7
30.7
30.7
30.7
30.7
Gas
Comp.
Air
Air
Air
Air
-
Air
-------
Table A8.23 (cont*d) Data record of reaction rate experiments
oo
i3
Series
2
(contd)
Run
12
13
14
15
16
A
i-/mir.
10
10
10
5
5
T
3
°c
790
800
800
790
800
~f
830
855
850
824
850
S
m
pm
2800
2000
2000
300
300
S
s
200
1000
1000
105
105
Cg)
21
23
23
23
18
H
(mm)
19.05
19.05
19.05
19.05
12.70
n
1
2
3
4
5
6
1
2
3
4
5
6
I
2
3
4
5
6
1
2
3
4
5
1
2
3
4
n
Csecs)
573
573
540
545
538
589
565
561
565
632
543
559
575
632
601
597
605
695
1310
1231
1230
1260
1290
1180
1200
1292
1298
Vol
n
Cm£)
5.3
17.6
22.0
24.2
25.2
26.1
1.8
13.3
20.2
22.5
24.1
24.2
2.2
14.1
21.4
23.9
24.9
24.7
0.4
1.0
6.9
14.1
17.1
1.8
10.2
14.5
14.4
Vol
0
28.65
28.65
28.65
28.65
28.65=
Stona
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
• '
% CaO
in Stone
30.7
30.7
30.7
30.7
i
r
|
U.K. | 30.7
Dolomite
GS.S
Camp .
Air
Air
Air
Air
Air
-------
Table A8.23 Ccont'd) Data record of reaction rate experiments
Series
2
(contd)
J
.
i
i
1
j
!
Run
17
18
19
20
21
22
A
Jt/min
5
5
10
10
10
10
T
3
°c
790
770
780
825
800
790
Tf
°C
865
810
835
840
830
810
w
300
300
1000
1000
1000
1000
s-
3
pm
105
105
300
300
c
300
300
(g)
17
17
19.5
19.5
19.5
19.5
H
Cram)
12,70
12.70
12.70
12.70
12.70
12.70
n
1
2
3
4
5
6
1
O
3
4
1
2
3
4
5
1
2
3
4
1
2
3
4
5
1
2
3
4
5
n
Csecs)
1230
1255
1252
1241
1310
1293
1309
1280
1317
1341
554
578
595
623
578
614
525
556
520
554
607
600
535
615
665
620
675
547
602
"Vol
n
Cm*)
7,2
14.9
17.6
19.7
20o7
21.2
19.2
22.2
23.0
2304
4.6
21.0
23.5
26.0
27.1
4.8
20.3
25.9
26.0
2.9
17.3
24.8
25.7
26.4
6.4
18,4
25.2
26.7
27.4
o
Cm*)
28.65
28,65
28.65
28.65
28.65
28.65
Stone'-
TJ.K.
% CaO
in stone
30.7
Dolomite
ILKo
Dolomit
1359.
1359
1359
1359
30.7
31
55.7
55.7
55.7
55.7
Gas
Comp.
Air
Air
Air
Air
Air
Air
-------
Table A8.2-3 (cont'd) Data record of reaction rate experiments
.Series
2
(contd]
3
Run
23
24
25
26
27
28
A
Jl/min
5
4
4
3.6
2.5
2.5
T
s
°C
. 790
824
810
800
790
810
>i
824
850
840
800
800
820
S
m
jiin
300
300
300
105
2800
2800
S
pm
105
105
105
53
2000
2000
"*
(g)
17
8
8
3
5
5
H
Gum)
12.70
3.56
3.56
0.75
0.20
0.20
n
1
2
3
4
1
2
3
4
5
1
2
3
4
5
1
2
3
1
2
3
4
5
1
2
3
4
5
n
Csecs)
1260
1400
1346
1338
1654
1176
1145
1177
1330
1152
1496
1066
1218
766
1351
1191
1036
286
450
431
431
366
465
498
560
524
339
Tol
n
On*)
5.4
19.0
23.4
24.0
2.4
17.4
18.2
19.0
21.2
2.9
13.5
16.4
17.8
20.8
3.7
16.8
21.9
2.6
5.2
7.0
8.6
9.2
1.4
4.6
7.0
7.4
9.4
Vol
o
GnO
28.65
28.65
28.65
28.65
10.70
10.70
Stone
TJ.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
% CaO
in stone
30.7
30.7
30.7
30.7
53.0
53.0
Gas
Comp..
Air
Air
Air
Air
Air
Air
('lOO-t,)
. %
45.0
45.0
>
oo
-------
Table A8.23 (cont'd) Data record of reaction rate experiments
Series
3
(contd)
}
i
I
I
j
1
i
4
!
'
1
Run
29
30
31
32
49
A
Jl/min
2 = 5
2.5
2.5
2.5
2,5
.
T
s
°C
810
800
790
790
810
Tf
°C
820
824
840
850
820
S
m
Vim
2000
2000
300
300
2800
S
s
Vim
1000
1000
105
105
2000
M*
(g)
5
5
5
5
5
H
(mm)
0020
0.20
0.20
0.20
0.20
n
1
2
3
4 -
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
1
2
3
4
5
6
1
2
3
4
5
6
7
8
t
n
(sees)
600
545
589
643
635
695
747
610
601
677
666
606
744
736
678
698
678
740
612
682
655
633
697
650
624
692
609
731
682
523
699
696
576
Vol
n
(m£)
1.4
4.8
7.2
8.0
8.4
9.4
1.6
402
6.6
7.4
8.2
9.0
0.5
1.8
4.4
5.4
7.1
7.6
8.6
1.2
3.2
4.8
5.8
7.2
7.6
0.2
2.2
4,3
5c9
7.1
7.1
7.5
8.1
Vol
o
(m£)
10.70
10,70
10.70
10.70
9.40
Stone
U.K.
Dolomite
UoK.
Dolomite
U.K.
Dolomite
U.K.
Dolomite
1337
% CaO
in stone
53.0
53.0
53.0
53.0
53.0
Gas
Comp
Air
Air
Air
Air
Air
(100-L)
%
45.0
'
45oO
45.0
45.0
47.4
•
>
00
-------
Data record oJf reaction rats ei
Series
Run
4 i 50
(contd)j
i
51
52
53
A
2.5
2,5
2.5
2,5
T
3
T.
°C
O 1 /""» O *"1 -1
olC' OiO
«
i
j
i
800
800
800
825
810
840
3
m
2800
2000
2000
1000
S
s
2000
1000
1000
300
Cg)
5
.5
5
5
H
(nun)
0,2
0.2
0.2
0.2
n
2
3
• 4
6
7
8
*
.1
2
^j
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
c
n
(.sees)
583
633
607
646
617
614
616
614
630
602
629
625
632
631
623
594
679
657
654
625
620
631
647
642
643
614
663
633
620
622
618
605
Vol
n
(mi)
Vo i
o
(mi }
|
0.5 9.40
2.8 1
4,7
5,7
6,6
7,2 [
7.7
8.0
0.25
1.2
3.1
5.1
6,3
7.0
7.5
8.2
0.15
0.8
2.6
4.8
6.3
7.1
7.7
8.2
0.05
0.35
1.3
3.3
5.7
6.5
6.8
7.0
9.35
9.35
9.30
Stone
1337
1337
1337
1337
% C30
in stoat.
Gas
Cornp
MOO-l.)
E /c
j
53.0
53.0
iAir
Air
.
I
53.0
53,0
Air
Air
t
I*!.*
\
I
I
47.4
47.4
47.4
-------
Table A8.23 (cont'd) Data record of reaction rate experiments
Series
4
(contd)
5
Run
56
57
59
61
A
Jl/tnin
2.5
2.5
2.5
2.5
T
820
•
810
820
800
Tf
°C
820
810
830
820
S
in
Km
1000
300
300
1000
S
s
vira
300
105
105
300
Cs)
5
5
5
5
H
(rom)
0.2
0.2
0.2
0.2
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
t
n
Csecs)
599
584
615
590
583
604
602
647
589
623
614
628
650
632
625
643
527
537
612
520
573
545
579
553
572
558
524
540
570
Vol
n
•Cm*)
0.1
0.1
0.5
1.8
4.0
5«4
6.8
7.3
0.2
0.8
2.5
3.7
3.9
4.5
5.0.
5.4
0.1
1.6
2.8
3.7
5.8
6.8
5.7
5.9
0.1
2,9
6.8
7.9
8.5
Vol
0
9.30
9.15
9.15
9.40
Stone
1337
1337
1337
1359
% CaO
in stone
53.0
53.0
53.0
93,0
Gas
Comp
Air
Air
Air
Air
(10'0-L)
47.4
47.4
47 = 4
43,6
-------
Table AS.23 (cont'd) Data record of reaction rate experiments-
) J
' Series 1 Ru;;
i ?
; j
; 5 j 62
| (coatdj
j I
i !
' ;
i j 64
i !
.' j
s
J
i
V 1
! i
I !
I i 65
t> i
f° 1
e i
Co !
| j
I
i
j
i
6 | 67
j
1
i
i
i
i
1
i
i
1'
i 1
" a - -
A • T"
i * ••»
5,/mi-nj \
i
i
2.5 | 820
|
i
!
\
j
1
2.5 790
t
i
i
t
|
i
1
;
1
2.5 1 830
;
f
I
'
!
}
2.5 : 825
i
'
j
i
i
j
1
j
t
i
:
T ,
"<-=
u " -1
"" ^
c'20
•
815
.
'
i
•
;
'•: 8^0
1
1
i
i
.
": 830
'
'
;
I
s_
'.t-
1000
300
300
2000
i
~^ i
s
WE
300
VAC
1.05
1000
M.
k..
Cg)
5
5
5
5
H
T.
.nun,
0..2 i
2
3
i 4
5
0.2 I
2
3
'•t
5
6
7
C.2 1
2
3
4
5
i 6'
7
8
0.2 1
2
3
4
5
1 6
"?
8
|
!
"
I7"
"* ^
ft
{.sees';
64.3
600
605
.586
598
6.33
617
621
645
622
658
656
640
640
670
649
690
665
678
661
553
595
634
623
&6C
615
619
580
I
'
T "
V O ..
1~:U
-.-. . -L-. _
0.2
2.5
6.6
-> c
S..I
0.1
1.0
2.2
3,7
5.4
7.0
7,8
0,05
0.&
2,2
3,8
5.1
6.1
6.7
7.4
0.02
Oo05
0.1
0,3
lc 2
2»&
5,4
_
°
1* . •
,,*
9 „ 40
9.55
9,55
9.30
;
Svj;::.s
p
1359
1359
1359
18
]
% GaO | GAS
in 3tcri-;i C~r:yp
i
I
j
9?.0 i Air
i
'
i
i
i
i
1
93,0 ! Air
;
!
i
i
•
•
:
|
93,0 i Ai:>-
1
.
1
!
j
t
i
1
i
73.9 | Air
i
j
t
i
i
I
!
1
I
i
1
:
;
J_ L
ClOO-L)
%
43 , 6
-43.6
4.3.6
36,6
-------
Table A8.2-3 (cQiit'd) Data record of reaction rate experiments- -
Series
6
(contd)
00
M
O
Run
68
70
71
74
A
2/min
2 = 5
2o5
2 = 5
2,5
T
s
°C
840
820
820
810
of
840
880
820
820
S
m
yin
2000
1000
1000
300
S
s
Vim
1000
300
300
105
(g)
5
5
5
5
H
(mm)
0,2
Oo2
0.2
0.2
n
1
2
3
4
5
6
7
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
t
n
(sees)
597
540
610
617
597
577
580
673
661
697
731
720
790
750
715
739
762
730
680
606
802
608
624
640
611
610
700
629
610
Vol
n
(m£)
0.05
0.1
0.2
0.4
1.5
3.2
4 = 9
0.05
0.05
0.1
0.4
1.1
2.4
0.05
0.05
0.1
0.4
1.1
2.0
3.0
4.1
0.02
0.05
0.3
1.4
2.5
2.7
3,9
5.0
Vol
o
(m*,)
9.30
9.60
9.40
9.40
Stone
18
18
18
18
% CaO
in stone
73.9
73.9
73.9
73.9
Gas
Comp
Air
Air
Air
Air
(100-L)
36.6
36.6
36.6
36.6
-------
Table A8.23 -Ccont'd) Data record of reaction rate experiments
Series
6
(contd)
T.
03
1— '
O
Run
75
79
80
82
A
Jl/min
2.5
2.5
2.5
2.5
T
s
°C
810
710
700
690
Tf
°C
820-
..-
710
740
710
S
m
pm
300
2000
2000
2000
S
s
pro
105
1000
1000
1000
<*)
5
5
5
5
H
(mm)
0.2
0.2
0.2
0.2
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
t
n
(.sees)
608
602
615
645
613
596
654
689
609
629
697
663
695
685
567
598
592
611
613
563
547
600
560
565
558
570
626
560
580
Vol
n
0.05
0.1
0.5
1.0
2.1
3.0
4.1
4.8
0.1
0.3
1.0
2.8
4.2
6.0
0.1
0.2
0.7
2.0
3.2
4.2
5.8
0.07
0.4
1.9
3.4
4.7
5.9
6.7
7.0
Vol
o
9.50
9.80
9.20
9.20
Stone
18
18
18
18
% Cao
in stone
73.9
73.9
73.9
73.9
Gas
Cpmp
Air
Air
Air
Air
(100-L)
36.6
36.6
36.6
36.6
-------
Table A8.2-3. (cont'd) Data record of reaction rate experiments
Series
7
(contd)
CO
1— >
o
Run
83
84
85
86
87
A
205
2.5
2.5
2.5
2o5
T
s
°C
690
680
800
800
940
Tf
°C
695
690
820
810
940
S
m
ym
2000
2000
2000
2000
2000
S
s
1000
1000
1000
1000
1000
(g)
5
5
5
5
5
H
(jnm)
0,2
0.2
0.2
0,2
0.2
n
1
2
3
4
5
6
7
8
1
2
3
4
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
n
Csecs)
585
615
582
631
599
578
607
616
560
607
562
547
585
630
570
569
593
579
578
565
546
512
540
585
594
624
658
561
575
608
Vol
n
On*)
Ool
0.3
0,9
2ci
3.4
4,9
5.9
6.4
2.7
5.7
7.1
8.0
0.5
1.8
2,7
5o5
7.2
8.2
0.6
2.0
2.6
6^5
8.0
0.05
0.2
1.0
2,0
3.3
4.5
Vol
o
Cm*)
9.45
9.40
9.50
9.40
9.25
Stone
18
18
18
18
18
% CaO
in stone
73 = 9
73.9
73,9
73.9
73.9
Gas
Comp c
Air
(100-L)
36,6
CO,-75%
0, -10%
N^ -15%
CO.-75%
_/
0, -10%
H, -15%
z.
CO -75%
0- -10%
N, -15%
2
Air
36.6
36.6
36.6
-------
xable A8.23 (ccmt'd) Data record of reaction rate experiments
Series
7
(contd)
j
i
Run
88
89
i
i 1
A
2.5
2.5
T
s
°C
890
900
Tf
°C
910
905
S
m
pm
2000
2000
S
s
pm
1000
1000
Cg)
5
5
H
Onm)
0.2
0.2
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
n
Csecs)
627
608
632
640
623
595
607
613
527
548
558
510 .
545
547
555
n
Cm*)
0.02
0.1
0.7
2.4
4.5
6.3
6.8
7.5
0.8
1.4
1.8
2.8
5.0
6.8
7.4
Vol
o
9.25
9.90
Stone
18
18
% CaO
in stone
73.9
73.9
i
Gas
Comp,
Air
CO -75%
0-10%
N^ -15%
2
(100-L)
.36.6
>
00
-------
Table A8.24 Reduced experimental results
Test
Series
3
i
Run
27
28
29
30
31
A
x/min
2 = 5
2.5
2,5
2,5
2,5
T
deg. K
1068
1088
1088
1085
1088
S
pm
2366
2366
1414
1414
177
n
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
M
n
(g)
0.13
0.22
0.28
0,31
0.33
0.15
0.25
0.31
0.36
0.38
o.fs
0.24
0.30
0.34
0.38
0.40
0.15
0.25
0.32
0.37
0.41
0.44
0.16
0.31
0.41
0.49
0.55
0.60
0.63
C
w
Cmgym3)
3870
2460
2570
2570
3020
2340
2180
1940
2070
3210
1810
1990
1840
1690
1710
1560
1460
1790
1810
1610
1640
1800
1460
1480
1600
1560
1600
1470
1780
R .105
n
31.10
13.40
9.42
5.35
4.50
22.00
13.40
7.25
6.91
4.21
17.00
11.90
6.52
4.61
3.98
2.05
13.40
11.70
7.49
5.35
4.12
3.08
15.10
13.30
10.20
8. -34
5.83
4.60
3.77
K .102
w
8.04
5.46
3.67
2.08
1.49
9.40
6.16
3.74
3.33
1.31
9.40
5.96
3.54
2.73
2.32
1.31
9.17
6.55
4.13
3.33
2.52
1.71
10.30
9.00
6.37
5.35
3.64
3.13
2.. 12
U
n
7.8
13.1
16,6
18,6
2C = 1
8.9
14.8
18 3
21.5
22.8
8.9
14.6
18.0
20.6
22.8
24.0
8.7
15.0
18.9,
22.1
24.5
26.1
9.8
18.3
24.4
29.5
32.9
35.9
37.9
U
n
3.9
10.4
14.8
17.6
19.4
4.5
11.9
16.6
19.9
22.1
4.5
11.8
16.3
19.3
21.7
23.4
4.4
11.9
17.0
20.5
23.3
25.3
4.9
14.1
21.4
26.9
31.2
34.4
36.9
Stone
U.K.
Dolomite
U.K
Dolomite
U.K.
Dolomite
U.K.
Dolomite
U.K,
Dolomite
Gas
Coinp.
Air
Air
Air
Air
Air
00
o
00
-------
Table A8.24 (cont'.d) Reduced experimental results
Test
Series
3
4
Run
32
49
50
51
A
Hjmin
2.5
2.5
2.5
2.5
T
deg. K
1093
1088
1088
1085
S
pm
177
2366
2366
1414
n
1
2.
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Mn
Cg)
0.15
0.27
0.37
0.45
0.50
0.55
0.15
0.26
0.34
0.40
0.44
0.47
0.50
0.52
0.14
0.25
0.32
0.38
0.43
0.46
0.49
0.51
0.15
0.28
0.38
0.44
0.49
0.53
0.56
0.58
C^7 o
.(mg/m )
1590
1650
1710
1550
1660
1730
1380
1570
1310
1400
1830
1370
1370
1660
1640
1510
1570
1480
1550
1550
1550
1550
1510
1580
1510
1520
1510
1510
1530
1600
R ,105
n
15.30
12.60
10.20
7.72
5.91
5.45
15.30
13.60
8.01
5.89
5.05
3.78
3.13
2.59
17.50
12.00
8.89
6.57
5.21
4.11
3.17
2.62
16.60
15.50
11.40
7.81
5.54
4.27
3.41
2.22
K ao2
w
9.64
7.61
5.99
4.97
3.55
3.15
11.10
8.66
6.13
4.21
2.77
2.77
2.28
1.56
10.70
7.94
5.65
4.45
3.37
2.65
2.04
1.68
11.00
9.83
7.54
5.13
3.68
2.83
2.23
1.39
U
n
9.1
16.3
22.0
26.7
30.1
33.0
9o2
16.5
21.6
25.1
27.4
29.7
31.6
32.9
8.9
15.6
20.3
24.0
26.8
29.0
30.7
32.1
9.1
17.3
23.6
27.9
30.9
33.3
35.2
36.3
U
n
4.6
12.7
19.2
24.3
28.4
31.6
4.6
12.9
19.0
23.4
26.3
28.6
30.7
32.3
4.5
12.3
17.9
22.1
25.4
27.9
29.9
31.4
4.6
13.2
20.5
25.7
29.4
32.1
34.2
35.7
Stone
U.K.
Dolomite
1337
1337
1337
Gas
Comp.
Air
Air
Air
Air
o
VO
-------
Table A8.24 (cont'd) Reduced experimental results
Test
Series
4
Run
52
53
56
57
A
2/min
2,5
2,5
2,5
2,5
1
deg. K
1078
1093
1093
1083
S
pm
1414
548
548
177
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Mn
(g)
0.15
0.28
0.39
0.46
0.51
0.55
0.58
0.59
0.15
0.29
0.42
0.52
0.57
0.62
0.66
0.69
0.15
0.29
0.44
0.56
0.64
0.70
0.74
0.77
0.14
0.28
0.38
0.47
0.55
0.63
0.70
0.76
Gngym )
1410
1460
1460
1530
1550
1520
1480
1490
1480
1530
1420
1490
1520
1510
1520
1550
1570
1610
1530
1590
1610
1560
1560
1450
1580
1500
1520
1490
1440
1480
1490
1450
R ,105
n
15o60
14.90
11.80
8.36
5.65
4.09
2.93
2.06
16.70
16.70
13.90
10.90
6.66
5.17
4.64
4.36
17.60
18.10
16.40
14.60
10.40
7.41
4.77
3.55
17.40
15.40
12.40
9.96
9.27
8.45
7.62
6.69
K .102-
w
11.00
10.20
8.09
5.45
3.65
2.70
1.98
1.38
11.30
10.90
9.77
7.33
4.40
3.42
3.05
2.81
11.20
11.20
10.70
9.16
6.47
4.76
3.05
2.44
11.00
10.30
8.18
6.70
6.46
5.72
5.10
4.61
U
n
9.2
17.8
24.6
29.2
32.2
34.5
36.2
37.3
9.3
18.3
26.3
32.3
36.0
38.8
41.3
43.6
9.2
18.5
27.3
34.9
40.2
44.1
46.6
48.6
9.0
17.4
24.1
29.5
34.8
39.5
43.6
47.4
U
n
4.6
13.5
21.2
26.9
30.7
33.4
35.3
36.7
4.6
13.8
22.3
29.3
34.1
37.4
40.0
42.4
4,6
13.9
22.9
31.1
37.5
42.1
45.3
47.6
4.5
13.2
20.7
26.8
32.2
37.1
41.6
45.5
Stone
1337
1337
1337
1337
Gas
Coup.
Air
Air
i
t
Air I
1
i
Air
-------
Table A8.24 (cont'd} Reduced experimental results
Test
Series
4
5
j
t
Run
59
61
62
64
65
i
A
Jl/min
2.5
2,5
2.5
2.5
2.5
T
deg. K
1098
1083
1093
1075
1108
S
jim
177
548
548
177
177
j
n
1
2
3
4
5
6
7
8
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
«n
(8)
0.14
0.27
0.37
0.45
0.51
0.55
0.60
0.65
0.15
0.25
0.29
0.32
0.33
0.15
0.26
0.30
0.33
0.35
0.15
0.29
0.41
0.50
0.57
0.61
0.63
0.15
0.29
0.41
0.50
0.58
0.63
0.68
0.71
*>y _
(inRy m ^
1750
1710
1500
1770
1610
1690 '
1590
1670
1680
1720
1830
1780
1680
1480
1580
1570
1620
1590
1550
1590
1580
1520
1580
1490
1500
1490
1490
1420
1470
1380
1430
1400
1440
R ,105
n
19.70
16.10
11.90
12.00
6.71
4;95
6.84
6.75
9.92
7.11
3.03
1.69
0.96
8.73
6.91
2.82
1.87
1.33
9.11
8.45
7.22
5.53
4.07
2.36
1.63
9.06
8.53
6.69
5.41
3.93
3.17
2.56
1.98
K .102
w
11.30
9.41
7.92
6.79
4.18
2.93
4.30
4.05
5.92
4.14
1.65
0.95
0.57
5.91
4.37
1.80
1.16
0.84
5.88
5.32
4.57
3.64
2.58
1.59
1.09
6.08
5.73
4.71
3.68
2.85
2.21
1.83
1.38
U
n
9.1
16.7
23.1
28.5
31.9
34.2
37.7
41.0
5.0
8,4
9.8
10.6
11.1
4.9
8.5
10.0
11.0
11.7
5.0
9.6
13.5
16.7
18.9
20.2
21.2
I
5.1
9.8
13.8
16.8
19.2
21.1
22.6 |
23.7
;
U
n
4.5
12.9
19.9
25.8
30.2
33.1
36.0
39.3
2.5
6.7
9.1
10.2
10.9
2.5
6.7
9.3
10.5
11.3
2.5
7.3
11.6
15.1
17.8
19.6
20.7
2.5
7.5
11.8
15.3
18.0
20.1
21.8
23.2
Stone
1337
1359
1359
1359
1359
Gas
Ccifp.
Air
Air
Air
Air
!
Air
-------
Table A8.24 (cont'dl Reduced experimental results
Test
Series
6
j
Run
67
68
70
71
^
i/min
2,5
T
deg, K
1100
I
2,5
2.5
2.5
1113
1123
1093
S
pm
1414
1414
548
548
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
1
2
3
4
5
6
1
2
3
4
5
6
7
8
<&
0.15
0.30
0.44
0.59
0.72
0.82
0.89
0.94
0.15
0.29
0.44
0.58
0.71
0.81
0.88
0.15
0.31
0.46
0.60
0.74
0.86
0.15
0.30
0.45
0.59
0.72
0.84
0.95
1.03
Gw 3
Gng/m )
1690
1570
1470
1500
1410
1520
1510
1610
1550
1710
1510
1500
1550
1600
1590
1400
1430
1360
1290
1310
1200
1270
1330
1290
1250
1300
1400
1570
1180
R ,105
n
11.50
10.60
9,91
9.87
8.38
7.44
K .102
w
6.79
6.77
6,73
6.58
5.92
4.90
4.30 2.85
3.89
10.60
2.41
6.84
Ilc60 6.80
10,20
9.85
8.92
7.22
5.18
6.73
6.58
5.77
4.51
3.25
9.69 | 6.90
9.87 | 6.90
9.31
8.60
8.06
6.22
8.51
8.93
8.60
8.07
7.77
6.87
6.65
6.14
5.20
6.72
6.72
6.68
6.47
5.97
7.43 j 5.32
7.21
4.51
4.60
3.81
U
n
5o6
11 -.1
16c6
22.0
26.8
30.8
33.1
35.1
5.5
11.0
16.5
21.8
26.4
30.1
32.7
5.7
11.4
17.1
22.6
27.7
32.0
5.6
11.2
16.7
22.1
27.1
31.5
35.3
38.5
U
n
2,8
8.3
13 „ 8
19.3
24.4
28.8
32.0
34.1
2.8
8.3
13.7
19.1
24.1
28.3
31.4
2.8
8.6
14.3
19.8
25.1
29.8
2.8
8.4
14.0
19.4
24.6
29.3
33.4
36.9
Stone
18
18
18
18
Gas
Comp0
Air
i
i
Air
1
Air
•
•
•
Air
;
:
•
:
,
:
:
i
:
00
-------
'--K1 - A8.24 (cont'd)
Table A
Reduced experJaueuLal results
00
I-1
U)
Test
Series
6
7
I
Run
74
75
79
80
A
£/min
2.5
2.5
2.5
2.5
T
deg. K
1088
1088
983
993
S
pm
177
177
1414
1414
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
1
2
3
4
5
6
7
<&
0.15
0.30
0.44
0.57
0.68
0.79
0.88
0.95
0.15
0.30
0.45
0.58
0.70
0.80
0.89
0.97
0.16
0.31
0.45
0.56
0.65
0.71
0.15
0.29
0.43
0.54
0.64
0.72
0.77
w ^
(togyni )
1570
1530
1490
1560
1560
1360
1520
1560
1590
1600
1570
1500
1570
1620
1480
1400
1810
1750
1580
1660
1580
1600
1800
1710
1730
1670
1670
1810
1870
R .105
n
10.50
10.20
9.71
8.94
7.73
6.54
5.97
4.93
10.60
10,70
10.00
9.00
8.24
7.45
5.64
4.66
10.90
10.30
8.62
7.21
5.50
3.79
11.00
10.30
9.81
8.05
6.69
6.07
4.25
K ao2
w
6.71
6.69
6.51
5.72
4.94
4.79
3.94
3,15
6.69
6.66
6.37
6.02
5.24
4.60
3.82
3.33
6.03
5.90
5.47
4.35
3.48
2.36
6.08
6.02
5.68
4.81
4.01
3.34
2.27
U
n
5.6
11.2
16.6
21.4
25,5
29.5
32.8
35,5
5.6
11.3
16.6
21.7
26.1
30.0
33.3
36.1
5.8
11.5
16.7
20.9
24.3
26.5
5.4
10.8
15.9
20.2
23.8
26.8
28.8
U
n
2.8
8.4
13,9
19.0
23.5
27.5
31.2
34.1
2,8
8.5
14.0
19.2
23.9
28.1
31.6
34.7
2.9
8.6
14.1
18.8
22.6
25.4
2.7
8.1
13.4
18.0
22.0
25.3
-2.7.8
Stone
18
18
18
18
Gas
Comp .
Air
Air
Air
Air
-------
Table A8.24 Cpont'd) Reduced experimental results
Test
Series
7
Run
82
83
84
85
86
A
Hjmin.
2,5
2.5
2.5
2.5
2.5
T
deg. K
973
965
958
1083
1078
S
urn
1414
1414
1414
1414
1414
n
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
1
2
3
4
5
6
1
2
3
4
5
6
<&
0.15
0.29
0.40
0.50
0.57
0.62
0.66
0.70
0.15
0.30
0.43
0.55
0.65
0.72
0.78
0.83
0.11
0.17
0.20
0.23
0.14
0.27
0.38
0.44
0.48
0.50
0.14
0.26
0,37
0.44
0.49
0.51
C
1740
1860
1840
1870
1830
1670
1860
1800
1840
1750
1850
1710
1800
1870
1780
1750
1930
1280
1920
1980
1660
1540
1700
1700
1630
1670
1670
1700
1760
1880
1780
1650
R ,105
n
10.40
10.70
8.82
7.10
5.39
3.60
3.05
2.59
10.90
10.20
10.00
7.96
6.90
5.38
3.99
3.38
8.17
4.16
2.80
1.75
10.50
8.35
8.15
4.80
2.65
1.53
10.40
8.95
8.51
6.14
3.67
1.63
K ,102
w
6.00
5.77
4.78
3.80
2.95
2.16
1.64
1.44
5.92
5.79
5.41
4.65
3.83
2.88
2.25
1.93
4.23
2.34
1.45
0.88
6.34
5.43
4.79
2.82
1.62
0.92
6.24
5.25
4.82
3.26
2.06
0.99
U
n
5.5
10.7
15.1
18.6
21.2
23.2
24.7
26.0
5.6
11.1
16.2
20.6
24.2
26.9
29.0
30.8
4.0
6.2
7.6
8.4
5.4
10.0
14.0
16.4
17.8
18.6
5.3
9.7
13.7
16.5
18.2
19.1
U
n
2.7
8.1
12.9
16.8
19.9
22.2
24.0
25.4
2.8
8.3
13.6
18.4
22.4
25.5
28.0
29.9
2.0
5.1
6.9
8.0
2.7
7.7
12.0
15.2
17.1
18.2
2.6
7.5
11.7
15.1
17.4
18.6
Stone
18
18
18
18
18
Gas
Air
Air
CO -75%
0, -10%
N^ -15%
CO -75%
0-10%
N2 -15%
C02-75%
02 -10%
N -15%
>
00
-------
Table A8.24 (cont'd) Reduced experimental results
Test
Series
7
Run
87
88
89
A
2.5
2,5
2.5
T
deg. K
1213
1173
1175
S
pm
1414
1414
1414
n
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
(g)
0,15
0.29
0.42
0.54
0.64
0.71
0.15
0.29
0.43
0.54
0.62
0.66
0.70
0.73
0.15
0.28
0.41
0.52
0.60
0.65
0.69
W *5
(mg/m )
1420
1350
1280
1500
1470
1390
1390
1430
1380
1360
1400
1470
1440
1420
1770
1700
1670
1830
1710
1700
1680
R .105
n
10.60
9.91
8.56
8.83
7.07
5.34
10.10
10.30
9.24
7.31
5.21
3.39
2.76
1.95
11.80
10.60
9.91
9.51
f>.14
3.87
3.08
K ,102
w
7.44
7.32
6.68
5.87
4.81
3.84
7.23
7.16
6.69
5.36
3.72
2.31
1.92
1.37
6.67
6.23
5.94
5.20
3.59
2.27
1.83
U
n
5.5
10.9
15.8
20.2
23.7
26.6
5.5
11.0
16.1
20,2
23.0
24.8
26.3
27.3
5.4
10.5
15.4
19.6
22.5
24.4
25.9
U
n
2.8
8.2
13.4
18.0
21.9
25.1
2.8
8.2
13.5
18.1
21.6
23.9
25.5
26.8
2.7
8.0
12.9
17.5
21.1
23.5
25.1
Stone
18
18
18
Gas
Comp,
Air
Air
CO -75%
0-10%
N^ -15%
-------
600 i' 11 i i i—i—i 1 M i i i i—H
oo
•
t=!
o>
500+
400+
en
erf**
^300
£
D
o
>
£ 200
£
10O4
KEY :
Sample No,
C
C 1
C 2
C 4
C 5 -
Calcination
Atmosphere
—
Stagnant
Time at 147O°F,h
0
1
23
1/4
97
0 I M I I I I h
I I M
1OOO
100 10 1
Pore-entrance diameter : micron
U.K. Dolomite Sample C (-16 + 52 B S)
Fig. A8.1. Assessment of pore structure
O-O1
-------
60O
>
CO
500 ••
-------
*»«w
40O
01 32O
E
* •
^
po 3
b o
00 >
C9
C_
O
a- 16O
8O
0
10
TT-
1 1 1 1 1 1 1 1 t 1 1 1 t 1 1 1 1 1 t 1 t 1 t 1 —
KEY:
Sample No
G
G3
G4
G5
G6
G8
Calcination
Atmosphere
-
Stagnant
Nitrogen Flush
Time at 1470°Fh
0
17
115
1
2
/
.fc^afeattSffwS^S
1 1 1 1 i i i i i iiiitit — t <
G5
/ G8
/ S^~~~~~**
•4- i jjttfffW wvv*vy VY
/ Y—Y-Y^Y—Y-™"Y^ '""~ ^» c
/ X * .iilHHl '
r JT X _^ * * **
X / ***^ G 3
OO 100 1O 1 0.1 O.C
Pore-entrance diameter : micron
Limestone 1359 Sample G (-16*52 BS)
Fig. A8.3. Assessment of pore structure
-------
oo
675--
(D
-M
-------
990
>
oo
to
o
-825 +
L.
-------
- 00
80O-
c
4)
J> 32O
o
a
en
o
160-
0
n 11 i i i—i
KEY:
SampleN?
G
G 3
G4
G 5
G6
G8
Calcination
Atmosphere
—
Stagnant
Nitrogen flush
Time at1470°Fh
0
1/2
17
115
1
2
1000
111 I I I
100
Pore-entrance diameter: micron
Limestone 1359 Sample G (-16 + 52 BS)
0-01
Fig. A8-6. Assessment of pore structure
-------
700
in
E
E
* «
in
0)
E
2 600
8
Q.
in
00
50O
to
0>
E
TJ
C
O
E
'•5 400
I
3001
T i i i
• O Calcination only
A A Calcination and sulphation
(•> ^ Refer to 1650°F
Open points are mercury specific volumes
Filled points are helium specific volumes
4=*=i
0 20 40 so 80100 2OO TC Hg: mm3/g 30° " ' 400
J.7. Specific volumes in helium and mercury vsTCHfl. Dolomite 1337
-------
680
O)
IE
E
$600
E
o
u
u
0)
Q.
500-
fl)
co
T3
C
o
400-
o
I
30O-
• O Calcination only
A A Calcination and sulphatfon
(•) ^ Refer to 165O°F
Open points are mercury specific volumes
Filled points are helium specific volumes
0 20 4O 60 8O 100
4OO
Fig.A8.8. Specific volumes in helium and mercury vs TIHQ. U.K. Dolomite
-------
7OO
Q»
rT"
E
E
•^600
3
U
1_
0)
TJ
C
a
400
3OO
T
• O Calcination only
4 A Calcination and sjlphation
(•) 4 Refer to 165O°F
Open points are mercury specific \/oiumes
Filled points arehelijrn specific volumes
20
40
6O
80
1OO
TIHg:nnm3/g
200
. A8. 9. Specific volumes in helium and mercury vs TiHg. Limestone 18
-------
600
en
"*
E
_D
o
u
3
»
500
400
en
C
O
300
d>
I
• O Calcination only
A A Calcination and sulphation
<•> ^ Refer to 1650° F
Open points are mercury specific volumes
Filled points are helium specific volumes
20
4O
60
80
100
: mm3/g
200
3OC
Fig. A8.1O. Specific volumes in helium and mercury vs
Limestone 1359
-------
4OO
300
E
E
2OO
>x
00
Ol
100
80
60
40
20
O Cdlcined only
A Calcined and sulphated
CJ> ^ Refer to 1650°F
2O 40 60 8O 100
200
Fig. A8.11. Porosity \kvs nHg
300
: mm3/g
Dolomite 1337
400
-------
40O
O Calcined only
Calcined and sulphated
A Stagnant and flushed atmosphere
experiments (calcined only)
Refer to 1650°F
2O 40 GO SO HOO
Fig.
200
VK vs TCHg
300 KHg 'mrrrVg
UK. Dolomite
4OO
5OO
-------
400
300
g ^200
100
80
60
40
20
O Calcined only
A Calcined and sulphated
Refer to 165O°F
I
0 20 40 60 80 1OO 200 3OO 4OO
TCHQ: mm3/g
Fig. A8-13. Porosity Vx vs TiHg . Limestone 18
-------
400
300
O
A
(•>
Calcined only
Calcined and sulphated
Refer to 165O°F
01
en
E
200
X
100
80
6O
40
20
0
20
4O
60
SO
100
Fig. A8. 14. Porosity Vx vs Ti
: mm3/g
Limestone 1359
200
3C
-------
65
60
55
50
45
40
35
>x
30
in
I-
a.
20
15-
1O-
V Dolomite 1337
A U.K.Dolomite (filled triangles are from stagnant and
flushed atmosphere experiments)
Q Limestone 18
0 Limestone 1359
10 20 30
40 50 60 70 80 90 100
Calcination:%
Fig. A8.15. Porosity (helium-mercury densities) vs extent
of calcination
A8.130
-------
65
60
55
50
45
40
35
V Dolomite 1337
A U.K.Dolomite (filled triangles are from stagnant
and flushed atmosphere experiments)
Q Limestone 18
O Limestone 1359
1
A
10
20 30
40 50 60 70
Calcination: %
80
90 100
Fig. A8.16. Porosimetry porosity as percentage of'lump'
volume vs extent of calcination
(i) volume in the range of pore-entrance diameters 14'5 to 0-014 u,m
A8.131
-------
65
60
55
50
45
40
V Dolomite 1337
A U.K. Dolomite
Q Limestone 18
O Limestone 1359
I
10
20 30
40 50 60
Calc(nation:%
70
80 90
100
Fig. A 8. 17. Porosimetry porosity as percentage of'lump'
volume vs extent of calcination
(ii) volume in the range of pore-entrance diameters 14-5 to 0-03
A8.132
-------
V Dolomite 1337
A U.K. Dolomite
0 Li me stone 18
O Limestone 1359
40 50 60
Calcination: %
Fig. A8.18. Porosimetry porosity as percentage of clump3
volume vs extent of calcination
(iii) volume in the range of pore-entrance diameters 14-5 to 0-1 pm
A8.133
-------
50
45
40
35
30
7 Dolomite 1337
A U.K.Dolomite
Q Limestone 18
0 Li mestone 1359
30 40 50 60 70 80 90 100
Calcination: %
Fig. A8.19. Porosimetry porosity as percentage of lump
volume vs extent of calcinatfon
(iv) volume in the range of pore-entrance diameters 14-5 toO-3jim
A.8.134
-------
15
10
0
20
15
10
.. 5
S 0
&
25
20
15
10
Dolomite
1337
UK
Dolomite
Limestone
16
ru—'
Limestone
1359
(raw stone porosities
are superimposed on
1/4h histograms-shaded
portions)
1h
4h
.•53 1 -3 -MJ3W 14-53 1 -3 -1-03-OH K-5 3 1 -3 -1-03-dU U-S 3 i '3 -i-fa-UK
Pore-entrance diameter: micron
Fig. A 8.20. Porosity of stones calcined at 1470°F- pore volumes as
percentages of'lump'volumes in various ranges of pore-entrance
A8.135
-------
Dolomite
U.K.
Limestone
40
3J5
30
25
20
15
10
5
40
35
30
25
? 20
±? 15
5 10
O
°- 5
^^
40
35
30
25
20
15
10
5
n
~
—
"
^B
-
-
I-
-
-
-
-
-
M ^^^^
p"*""1""!—
-
-
-
-
-
_
- i—«— j
(i
i—^™
•B
••••1
L/l/IV"
-I fcd
_| mfafom—
\ V^~^~^
\ r^Ti
//
BB
•••••
( C1 /U
1'4H
(raw stone poro;
superimposed o
histograms - she
portions)
r-r-L-T
D ^m**mm
(—
J
__i
^ J h_
\
4/>
r
^3 fi i i ^=q
Limestone
1359
_n
x
U-53 1 -3 -1 -03-OUU-53 1 -3 -1-03-OU U-5 3 1 -3 -1-03-OU K-5 3 1 -3 -1 -03-OU
Pore-entrance diameter;micron
Fig. A8.21. Porosity of stones calcined at 1650°F-pore volumes
as percentages of'lump'volumes in various ranges of pore -
entrance diameter
A8.136
-------
25
20
15
10
£40
'Jo 35
8
O
Q.
30
25
20
15
10
1h
stagnant
atmosphere
C1
1-5h
flushed
atmosphere
C10
3h
flushed
atmosphere
C9
16h
Hashed
atmosphere
C7
97h
stagnant
atmosphere
C5
U-5 3 1 0-3 0-1 0-030-OUU-5 3 1 0-3 0-1 0-03 O-OUU-5 3
Pore-entrance diameter:micron
1 0-3 0-1 0-03 O-OU
Fig. A8.22. Porosity of UK.Dolomite calcined at 1470°F in
stagnant and flushed atmospheres. (Porosity is pore volume
as percentage of*lump' volume in various ranges of pore-entrance
diameter) A8n is?
-------
55h
50
45
40
35
V Dolomite 1337
A U.K. Dolomite
0 Limestone 18
O Limestone 1359
V 1650°F
1470'F
Time: h
Fig. A8.23. Variation of level of sulphation with time and
temperature
A8.138
-------
55
50
45
40
35
c30
O
O
£25
20
15
10
V Dolomite 1337
A UK. Dolomite
D Limestone 18
O Limestone 1359
1470 F
V
A
V
A
I
1650 F
I
10 20 30
40 50 60 70 80
Calcination:%
90 100
Fig.A8.24. Variation of sulphation level with extent of
calcination
A8.139
-------
>
00
(A
0)
C
<> a>25
* *
20
15
'o —
«£x en
en T3
O c
fe °
2!
£
5
I I I
V Dolomite 1337
A U.K. Dolomite
Q Limestone 18
O Limestone 1359
O V
0-A
. A
A
10 15-20 25 3O 35 4O
Sulphation:°/o
45 5O 55 6O
Ffg.AS. 25. Change of porosity (helium-mercury densities) on sulphatron
with level of sulphation
-------
00
I—"
£t
3O
25
2O-
>X15
>X10
147O°F 165O°F
7
0
O
(•)
o .
Dolomite 1337
U. K. Dolomite
Limestone 18
Limestone 1359
a
) 5 1O 15 20 25 3O 35 40 45 5O 55 6O
Sulphation : %
Fig. A8. 25a. Sulphated samples: differences between
estimated porosity VX3 and measured
porosity Vxi
-------
00
•
t—•
^
to
«n30
4O 45 5O 55 60
Fig. A8. 26. Change of porosity (ponosimetry TtHg) on sulphation with
level of sulphation
-------
10
Dolomite 1337
0 Calcined only
A Calcined and sulphated
Time : h
0'ig.A8.27 Variation of porosity (14-5to0-014jam) with
\ ' .
time of calcination and sulphation
A8.143
-------
f 1650*F
O Calcined only
A Calcined and sulphgted
Dolomite 1337
V '4 • f • i_ ^
Time: h
Fig. A 8. 28. Variation of porosity (14-5 to 0-03jam) with
time of calcination and sulphation
A8.144
-------
50
45
40
35
30
£25
*Jn
O
£20
O Calcined only
A Calcined and sulphated
Dolomite 1337
j i
1
Time: h
Fig A 8.29. Variation of porosity (14-5 to0-1/urn) with
time of calcination and sulphation
A8.145
-------
U.K. Dolomite
I
A
O Calcined only
A Calcined and sulphated
Q Porosimetry results at
1650°Ffor partially
sulphated samples TTHg-
1
Time : h
Fig. A8-30. Variation of porosity (helium-mercury density)
with time of calcination and sulphation
A8.146
-------
15-
10
Limestone 18
O Calcined only
A Calcined and
sulphated
0 \
Time :h
Fig. A 8.31. Variation of porosity (14-5 to 0-014/am) with
time of calcination and sulphation
A8.147
-------
Limestone 18
i . I
O Calcined only
A Calcined and sulphated
I
1,
1
Time: h
Fig. A 8.32. Variation of porosity (14-5 to 0-03fim) withj
time of calcination and sulphation i
A8.148
-------
Limestone 18
I
O Calcined only
A Calcined and
sulpha ted
I
Time : h
Fig. A 8.33. Variation of porosity (14-5 to 0-1 (j.m) with
time of calcination and sulphation
A8.149
-------
O Calcined only
A Calcined and sulphated
Limestone 18
Time : h
Fig. A 8.34. Variation of porosity (14-5 toO-3|Lim) with
time of calcination and sulphation
A8.150
-------
55
50
45
40
35
^30
25
o
Q.
20
(•> Calcined only
A Calcined and sulphated
Porosimetry results
> if'
Limestone 1359
Time : h
Fig. A 8.35. Variation of porosity (helium-mercury density)
with time of calcination and sulphation
A8.151
-------
>
09
to
i i r
Dolomite 1337
Filled points 1650 F
Open points 147O°F
0-3 urn
1-0 um
3'0jum
I
I
10 15 2O 25 30 35
Sulphation: %
4O
45
4h
5O
55
6O
Fig.A 8.36.Variation of porosity (between 14-5fim and pone-entrance dia.shown) with level c
sulphation
-------
50-
I I I I I
UK.Dotomite at 1650'F
10 15 20 25 30
Sulphation:%>
35
40 45
Fig. A8.37 Variation of porosity (between 14'5 |im and pore
entrance d I a. shown) with level of sulphation
A8.153
-------
1
i
1
Limestone 18 at /650V
10 15 20 25 30
Sul phot ion :°/o
35 40 45
Fig A 8.38. Variation of porosity ( between 14-5jam and pore
entrance dia. shown) with level of sulphation
A8.154
-------
Dolomite
1337
U.K.
Dolomite
Limestone
16
Limestone
1359
15
10
#5
• •
>*
— o
I*
CL
15
10
''4h
1h
H—I—h
+
11-53 1 -3 -1-03-014 tt-5 31-3-1 -03-OH 11-53 1 -3 -1 -03-OU U'53 1 -3 -1-03-OU
Pore-entrance diameter:micron
Fig A 8.39. Changes in porosity (% of 'lump* volume) of calcined
stones (1650°F),in the ranges of pore-entrance diameter
14-5-3pmf 3-1/am, 1-0-3jam, O-3-O-ljjim, 0-1-0-03fim
and 0-O3-0-014 pm, on sulphation at 1650 ° F
A8.155
-------
48O
po
I—•
en
o>
4OO
E
E
* *
o>
E24O
a! 160
80
1000
Broken particles
Unbroken particles
100
10 1
Pore -entrance diameter: micron
O-O1
Fig. A8.4O. Effect of breaking Limestone 1359particles (3-6%w/wS)
-------
>
00
•
K—'
CJ1
2OO
O)
E15O
* •
flj
I
0100
-------
>
00
en
00
30O
250
4)
2150
o
0)
100
50
10OO
— Broken particles
Unbroken particles
1OO
10 1
Pore-entrance diameter: micron
O-1
O-C
Fig. A8.42. Effect of breaking Limestone 1359particles (10O% calcined)
-------
480
4OO
320
O)
en
£
oo
Ul
CO
JM60
-£•
80
10OO
Broken particles
Unbroken particles
100
10 1
Pore-entrance diameter: micron
0-O1
Fig.A8.43. Effect of breaking U.K. dolomite particles (4-9%w/wS)
-------
240
200
cn160
"E
E
• •
£120
> D
.* o
H- >
CsJ ^^
°
-------
240
200
o
CO >
-------
COLD
nT
HOT
HOT
>
CO
O»
to
Gas molecules
cannot penetrate
pore entrance
Gas mojecules
penetrate entrance
because of increased
kinetic energy
Gas molecules
cannot escape
through entrance
Gas escapes
and is detected
O Cold molecules
Q Hot molecules
Fig. A8.46- How an increase in accessible porosity may occur
on heating, and how it is detected
-------
COLD
HOT
cool
COLD
OS
CO
Gas molecules
penetrate pore
entrance
Entrance closed Gas still
to gas by anisotropic in pore
expansion
Gas escapes
and is detected
O Cold molecules
0 Hot molecules
Fig. A8.47. How a decrease in accessible porosity may occur
on heating, and how it is detected
-------
UJ
Time
Fig.AS. 48(a). Pore penetration: outline of experiment
a>
a
E
a>
Time
Fig.AS. 48(b). Pore closure: outline of experiment
A8.164
-------
>
00
CJ1
Thermocouple Sample in
/alumina tube
To
MS10
Pi rani gauge
Alumina tube 'Araldite joint 'Pyrex* glass
ITo gas
supply
•z
5
-Cold trap
To vacuum
pumps
Fig. A8. 49. Pore-penetration, pore-closure apparatus
-------
>
CO
O)
05
Sampling valves
(two-way stopcocks with
one side-arm sealed off]
To gas supply
(at-10cm Hg)
Pressure KTMorr
Fig.A 8.5O. Calibration system
-------
Fig.AS. 51. Shells formed during Task I, Test Series 2.
U.K.Dolomite particles x10 magnification
A8.167
-------
Cone & socket
with 'let Ion'sea I
atmosphere
Recryst. AI2O3
packing
bubblers
3vol. H2O2
Quartz
wool
Stone
Sinter
4 element
muffle furnace
Position of
T/C pocket
Quartz wool
Flostats
Fiducial mark
from
cylinders
Waste
Water flowmeter
Flow meters
Flostat'
Pressu re
/.gauge
Air
line
Mains
water
Fig.AS. 52. Limestone reactivity apparatus
y A8.168
-------
0-1
0-09
0'08
0-07
en
0-06
c
o
•fj
c
o
u
0-05
0-04
u
O
0-03
0-02
0-01
Stone- U.K.Dolomite
Temperature-1470 F
.177pm
2366pm
10
20
Utilisation: %
30
40
Fig.A8.53. Velocity constant as a function of size and
utilisation
-------
0-1
0-09
0-08
0-07-
0-06
0-05
0-O4- •*-•
0-03
0-O2
0-01
O)
» 9
c
O
c
O
u
u
O
Stone -1337
Temperature- 1470°F
548p.m
10
20
Utilisation: °/o
30
40
Fig.A8.54.Velocity constant as a function of size and
utilisation
A8.170
-------
0-1
0-09
0-08
0-07
EU«
0-06
c
0
0-05
c
o
u
0-O4
u
O
-------
0-09
0-08
0-07
O)
.*
nIO-06
c
$0-05
c
o
u
'0-04
u
O
0-03
0-02
0-O1
Limestone 18
Temperature - 1470°F
10
20
Utilisation: %
30
40
Fig.A8.56. Velocity constant as a function of size and
utilisation
A8.172
-------
0-1
0-09
0-08
in
en
0-07
O-O6
c
$0-05
c
o
u
0-04
C>
(D
> 0-03
0-02
0-01
1290 F
10
Limestone 18 (1414 >im)
Atmosphere - air
20
Utilisation: %
30
40
Fig.A8.57 Velocity constant as a function of temperature
and utilisation
A8.173
-------
>
CO
0-06
0-O7-
OO6
0-O5-
c
o
-M
(O
c
o
-------
0-1
0-09
0-08
-------
0-1
0-09
0-08
0-07
O)
0-06
c
o
0-05
c
O
0-03
0-02
0-01
Limestone 18
Temperature - 1470°F
10
20
Utilisation: %
30
40
Fig.A8.6O.Velocity constant as a function of
atmosphere and utilisation
A8.176
-------
0-09
0-08
0-07
to
en
0-06
g 0-05
c
o
(J
O
>0-03
0-02
0-01
10
Limestone 18 (1414jim)
Temperature - 1650°F
20
Utilisation: °/0
30
40
Fig.A8-61.Velocity constant as a function of atmosphere
and utilisation
A8.177
-------
CO
1—"
-a
00
0-08
O-O7
0-O6
U)
O-O5
5 0-04
tn
c
o
u
>>0-03
0-02
0-01
Limestone 18(1414 jam)
Atmosphere- CO2-75°/o
O2 -10%
N2 ~15°/o
973
1O73
Temperature: °K
Utilisation 5%
25%
7
I ~
I
1173
Fig.A8.62.Velocity constant as a function of utilisation and temperature
-------
0-1
0-09
0-08
0-07
Dl
O-06
§ 0-05
c
o
-------
MERCURY POROSIMETRY DATA
A8.180
-------
Sample B 5
Sample B 6
PORE»ENTRANCE
DIAMETER,
MICRONS
58.5831
38.2530
29.0364
22. 1939
18.9238
16-2040
14.0393
1 1 .8998
10.7217
9.7506
8-9411
8.2557
7 .6688
7. 1600
6-7144
6.3213
5.9708
5-6577
5.0013
4. 48 1 6
3.7093
3.1641
2.7585
2.4451
2.1955
1 .9922
1 .8233
1 .2805
0.9867
0.6764
0.5145
0.4152
0.3480
0.2629
0.21 12
0.M17
0. 1066
0.0854
0.07 1 3
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.01 43
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
3.43
6.23
9.24
12.04
14.33
16.82
19.73
22.32
22.84
23.46
24.09
25-33
26.68
27.93
29.48
30. 1 1
31 .35
33.53
36. 13
38.20
40.49
41.84
43. 50'
44. 54
45-89
46.51
48.59
51 .08
53-47
54.92
55.65
56-27
57.62
58.45
63-95
99.77
125-83
140.36
149. 19
163. 10
185.83
209.81
231 .62
247 . 19
261 .72
271 .07
278.33
284.56
288.72
292.87
290.79
295.98
297.02
299.10
297.02
300 . 1 3
299. 10
302.21
303.25
302.21
304.29
304.29
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.7573
28. 339«
22.8555
8.9777
6 . P3HS
/i.p.i3s
1.9184
tf.74PP
'-> . 7 6 9 7
8.9576
8. "706
, 7 . A81 f,
7 . 17^7
6-7239
6 .329*
5.978K
S . 6 6 4 S
5.037 1
/i . /i 9, 6 f,
3.7 1P8
3 . 1 A67
0 . 7607
2 • /I 4 A 9
?. 197"!
1 .9935
1 .824/1
1 .281 1
•"; . 9 R 7 1
1.6766
0 . SI 46
3 . /i 1 S 3
n . 3 /i 8 '.'1
n.2609
1.P1 1 3
"! . | /i 1 7
: 1 . IT 6 6
•1 . :T^5/i
n . n 7 i 3
'I . !1 M 1
'i.ns3s
n .n/i76
n .:ni/iP9
0 . 1T9-1
n.OTS7
ii . o 3 ,T r\
3.0306
n.n2H6
0 . "\ v f. ct
0.3252
n .0238
0 .09P6
0.32 1 S
3 .3204
0 . 0 1 9 S
3.3187
0.01 79
3.0172
0.0165
0.0159
0.0153
0.01 48
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
'i.i.vi
9 . 3 I
16.53
21.76
26.67
33.65
34. 1 0
37 .24
/i 1 .63
42.99
43.83
/i /i . 9 S
/i 6 . ] 3
47. 18
/i R . 5/i
SO. 11
51.15
51 .99
ss.no
SR. ! 6
A-n . /i 6
62. 76
6 S . 3 *.
6 7 . S 8
6 8. '13
73. /in
71 . A A
75. 1 1
7 « . n /i
82. 43
8 4 . 8 4
R 7 • 3 3
«R . SO
40 . 6K
96.55
1 3 . ? S
/i 3 .30
73.33
87.04
9 8 . /i /i
013.78
226.79
2/iS.PQ
061.51
273. S/i
P82. 33
293.2 |
099 .59
30S.97
310.99
31 3-82
316. S/.
3 18. /i?
.119.89
320.7P
321 .77
322.40
322.92
323.65
324.59
324.38
324.59
324.70
-------
Sample C
Sample C 1
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.2228
28.9940
23. 1801
18.9048
1 6.2476
14. 1796
11.7974
10. 6370
9 . 68 1 3
6.8825
8.2050
7. 6244
7. 1203
6. 6792
6.2885
5.9419
5. 6308
4.9797
4. 4637
3. 6968
3. 1549
2. 751 4
2. 4394
2. 1909
1 .9884
1 .82101
1 .2769
C..9858
(:!. 6759
0. 51 43
i;. 41 50
0. 3479
0.2628
0.2112
£ . 1416
0. 1065
0. Ob54
0.0712
0.061 1
U.0535
U.0476
0 . 0 428
0.0390
0.0357
0.0330
0.0306
0.02«6
0.0268
0.0252
0.0238
0.0226
0.021 5
0. 0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.01 53
0 . 0 1 48
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0. tit)
7. 46
0 . 7 6
3.05
4. 46
5. 61
6.75
7. 69
9.04
19. 57
19.91
20.05
26.58
20.99
21 . 66
21. 66
22.33
22. 40
23.27
24.35
25.22
26.30
27.04
27.58
28. 18
28. 59
29. 13
30.67
31 .28
33. 43
34.37
34. 64
•35.25
3 5 . b 5
36- 79
3 7 . 60
37.87
3b. 34
38. 1)1
39. 1 5
3b. 54
39. 49
39. OK
39.69
40 . 1 6
40. 2v
40. 43
40. 56
40. 09
40. 29
40. 56
40. 1 6
40. 63
40. 63
40 . 5 6
40. 76
40. 70
40 . 43
40. 76
40. 56
40. 43
40.83
40.83
PORE-ENTRANCE
DIAMETER ;
MICRONS
58 .5831
38.9514
28 . 1975
22.6667
19.1153
1 6-2707
1 4. 1620
1 1 .8039
10.6460
9.6895
8.8908
8.2135
7. .6308
7.1263
6.6844
6.2937
5.9465
5.6352
4.9335
4.4667
3-6990
3. 1 565
2 .7527
2.4404
2.1918
1 .9891
1 .8208
1 .2793
0.9860
3.6761
0.51 44
0.4151
0 . 3479
0.2629
0.21 12
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0 .'1429
0.0390
0 .0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.01 87
0.0179
0.0172
0.0165
0.01 59
0.0153
0.01 48
0.01 43
CUMULATIVE
PORE-VOLUME i
CU MM/G
0.00
7.70
13.04
1 6-03
18.75
20.83
22.74
25.36
28.26
29.26
30.25
31.16
31 .34
32 . 1 6
32.97
33-51
34.33
34.78
36.32
37 .59
39.31
40.67
41.94
43.03
43.75
44. 57
45.47
48. 10
50.82
55.98
60.60
63.95
A5. 58
72.37
91.67
1 6 1 .05
178.90
184.06
184.96
186.05
186.78
187.23
187.41
187. 68
187. 1 4
188.23
187.95
188-23
188.41
188 . 41
188.41
188-68
188.77
188.59
188.41
189. 1 3
189.40
189.40
189.40
189.67
189.86
189.67
A8.
-------
POKE-ENTRANCE
DIAMETER}
MICRONS
58.5831
38.3718
28.2027
22.2902
18.5815
15.7544
13.9060
12.0792
10.8694
9.8759
9 .0490
8.3470
7.7477
7.2280
6.7756
6-3740
6.0175
5.6996
5.0336
4.5076
3. 7274
3. 1773
2.7686
2.4531
2.2020
1 .9977
1 .8279
1 .2829
0.9883
0.6773
0.5152
0.4157
0.3484
0.2632
0.21 15
0. 1418
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0 . 0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.01 53
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
13.30
21.90
28.45
32.75
36.84
39.6
1
41 .65
44.93
46-67
48.5
1
48.82
50.1
5
50.97
53.32
53.53
53.73
54.96
56.49
59.26
62.12
64.48
66-32
68.37
69.70 .
71 .74
72.66
78.39
85-56
101 .93
122.40
141 .34
160.78
227.92
252.48
272.95
277.04
278.07
278.07
279.09
280. 1
1
279.09
279.09
279.09
280. 1
280.
280.
280.
280.
280.
280.
281 •
281 .
281 •
281 .
281 •
281 •
281 •
281 .
281 •
281 .
282.
282.
1
1
1
1
1
1
1
A
4
4
A
4
A
A
A
A
A
6
6
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
37.8068
28.0371
22.0751
8.2213
5.6453
3.79.01
1 .8344
0.6699
9.7088
8.9057
8.2258
7.6424
7. 1366
6.6933
6.3017
5.9532
5.641 1
4.9879
4.4709
3.7020
3. 1587
2.7543
2.4417
2. 1929
1 .9900
1 .8214
1 .2796
0.9862
0.6762
0.5144
0.4151
0.3479
0.2629
0;.21 12
0. 1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.01 48
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
6.12
10. 15
12.83
15.68
18- 1 1
19.71
21 .63
24.07
24.82
25.24
25.91
26.58
27.42
28.09
28.68
29.01
29.35
30.52
32.70
34.38
35.97
36.98
37.65
38.91
39.49
39.75
42.76
45.20
49.22
52.24
54.67
55.76
58.78
60.96
71.53
87.54
1 16.39
151 .35
165.52
170. 14
173.07
173.91
174.75
174.75
174.33
175. 17
174.75
175.59
175.59
176.42
176.01
176. 42
176.42
176.42
176.84
176.84
177.68
177.68
177.26
176.84
177.68
178.94
A8.182
-------
POM-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.7797
3268
3733
5831
5379
5274
9487
0.7761
9.8004
8.9831
8.2919
7.7018
29
23
9
6
4
1
7.1888
6.7394
6.3434
5.9914
5.6757
5.0164
4.4947
3.7191
3.1719
2.7649
2.4504
2000
9962
8269
2827
9884
2.
1 .
1 .
1 .
0.
0.6778
0.5159
0.4164
0.3489
0.2635
0.21 16
0.1418
.1067
.0855
.0713
.0612
.0535
.0476
.0429
.0390
0.
0.
0,
0.
0.
0.
0.
0.
0.
0.
0.
0.
0'
0.
0.
0.
0.
0357
0330
0306
0286
0268
0252
0238
0226
0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
POHE-VOUJME,
CU MM/Q
0.00
18.81
39.01
49.34
57.12
64.66
70.70
77.78
86. 02
88.69
89.51
90.43
93.10
94.61
95.78
97.40
99. 14
99.95
104.02
109. 13
1 13.77
1 18.99
123.52
127.47
130.37
134.09
138.50
152.08
169.49
234. 85
325.40
398.54
429.88
477.48
492.57
503.02
504. 18
505.34
505.34
505.34
505.34
505.34
506-51
506.51
505.34
506.51
506.51
506.51
506.51
507.67
508.83
508.83
508.83
508.83
508.83
509.99
509.99
509.99
509.99
508.83
511.15
509.99
509.99
PORE-ENTHAHUB
DIAMETER,
MICRONS
58.5831
37.3325
27.4709
22.5606
18.6588
15.9988
14.1003
1 1 .9537
10.7783
9.7966
8.9791
8.2880
7.6954
7.1821
6.7333
6.3387
5.9861
5.6708
5.01 14
4.4895
3.7149
3.1685
2.7618
2.4477
2.1977
1 .9940
1 .8248
1.2813
0.9873
0.6767
0.5148
0.4153
0.3481
0.2630
0.21 13
0.1418
0. 1066
0.0854
0.0713
ek06i i
0'.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
-------
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.9614
28.8373
23. 1898
19. 1713
16.3215
14.2503
11.9666
10.7782
9.7984
8.9828
8.2925
7.7001
7. 1880
6.7378
6.3419
5.9901
5.6755
5.0149
4. 4929
3.7174
3.1701
2.7634
2. 4490
2. 1988
1.9949
1.8256
1.2818
0.9876
0.6769
B.5149
0. 4155
0.3483
0.2633
0.21 15
0. 1418
0. 1067
0.0855
0.0713
0.0612
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/6
0.00
17.90
28. 18
34.88
40.07
44.35
47.35
51.39
55.09
56. 13
57. 63
59.13
60. 17
62.25
62.59
64. 10
65.83
67.91
69.75
73. 57
76.80
79.92
83. 50
85. 69
87.54
b9.04
90.20
95.85
102.90
1 17.22
129.81
1 48 . 52
176.93
295.99
367.02
436.89
459. 18
468. 53
470.38
47 .30
47 .88
47 . 76
47 .76
47 .88
472.23
472.00
472. 46
473. 15
472.57
473.03
473.38
473. 61
473. 61
474.07
474.31
473.96
473.50
47 1 . 1 9
471.07
471.42
471. 19
471.53
471.30
PORE-ENTRANCE
DIAMETER,
MICRONS
CUMULATIVE
FOBE-VOLUME,
CU MM/Q
58.5831
37.5664
27.9517
22.5424
18.5979
15.8854
13.9635
1 1.8433
10. 6758
9.7132
8.9094
8.2286
7. 6445
7. 1376
6.6943
6.3027
5.9541
5. 6423
4.9890
4. 471 4
3.7023
3. 1589
2.7545
2. 4420
2. 1930
1.9901
1 .8216
1.2797
0.9863
0.6762
0. 5144
0.4151
0.3479
0.2629
0.21 12
0. 1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
0.00
10. 64
16-51
21.06
24.27
27.26
28.59
31.14
33.91
34. 69
35.24
35.91
36.57
37.02
38.01
38.90
39. 45
40.23
42.23
44.33
46. 44
48.21
49.76
51. 76
52. 64
53. 53
54.31
58.30
61.84
67.05
71.15
74.92
76.25
82. 12
89.55
135. 10
187.85
246.37
260. 1 1
266.98
271.30
273.08
273. 63
273.96
274.30
274.30
274.30
274.74
275.29
275. 63
275. 18
275.41
275. 41
275.96
275.96
275.96
275. 63
275.85
275.74
275.52
275. 63
276.29
276.29
A8.184
-------
DIAMETER,
MICRONS
PORE-VOLUME,
CU MM/Q
DIAMETER,
MICRONS
PORE-VOLUME,
CD MM/Q
58.5831
38.3754
28.4637
22.8485
18.8125
16.3108
14.0245
11.9108
10.7332
9.7601
8.9491
8.2623
7. 6731
7. 1633
6.7168
6.3226
5.9723
5.6585
5.0017
4.4817
3.7094
3. 1642
2.7586
2.4451
2. 1956
1.9923
1.8234
1.2806
0.9868
0.6765
0.5146
0.4153
0.3481
0.2630
0.2114
0. 1418
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
0.00
14.69
23. 19
28.35
30.80
32.34
32. 60
32. 47
36-72
37.37
38. 14
38.79
39. 17
40. 46
41. 49
42. 52
43. 68
44. 46
46.78
49.35
52. 19
54.89
57.08
58.37
60.05
61.47
62.75
67.91
72.55
81.83
91.23
99.99
106.44
147. 54
21 1.33
318.54
376. 65
412.09
422. 66
428.97
432.32
435.03
436.32
437.22
437.73
437.99
438. 64
439.02
439.02
439. 54
439.80
441.08
440.96
441.21
441.21
440. 57
441.86
441.34
441.73
442.37
442. 12
442.89
443. 15
58.5831
38.5329
28.7251
22.5522
18.9323
15.963.1
13.8840
1 1 .8618
10.7050
9.7376
8.9310
8.2469
7.6600
7 . 1 50'6
6.7046
6.31 1 1
5.9616
5.6488
4.9933
4.4749
3.7046
3. 1606
2.7559
S.4430
2. 1939
1 .9909
1 .8222
1.2800
0.9865
0.6763
0.5145
0.4152,
0.3480
0.2629
0.2113
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
0.00
1 1 .32
17.87
21.86
25.08
28-41
30.85
32.74
40.51
41 .40
42.51
43.06
43.51
43.62
43.62
43.73
44.28
44*84
45.39
47.61
49.39
51 .72
53.61
55.16
56.05
57.71
58.60
63.04
67.48
75.58
83.13
90.34
94.34
1 16.42
164.37
268.03
314.98
334.51
337.73
338.95
339.17
340.06
340.28
340.17
340.50
340.72
340.39
341 .50
341.17
341 .28
341 .28
341 .94
341 .83
342.17
342-17
343.05
342.83
342.50
342.83
?42.50
342.61
342.72
342.39
A8. 185
-------
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
37.0153
28.0101
22.6505
19.1038
16.2827
14.3801
11.8278
10.6811
9.7158
8.9150
8.2338
7.6509
7.1426
6.6983
6.3067
5.9580
5.6463
4.9919
4.4740
3.7040
3.1603
2.7554
2.4426
2.1935
1.9905
1.8219
1.2799
0.9864
0.6762
0.5145
0.4151
0.3480
0.2629
0.2112
0.1416
0.1066
0.0854
&.0712
0.0611
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
9.41
15.02
19.45
21.79
24.43
26.14
29.26
35.64
35.64
37.27
37.89
39.29
39.29
39.76
40.69
4 1 . 32
4S.33
43.42
45.28
46.68
48.40
48.86
49.95
50.57
51 .12
51 .59
54.54
56.88
60.92
63.26
65.05
66.37
68.70
70.34
73.68
76.56
82.94
88.39
94.54
101.62
1 10.80
120.37
132.58
139.59
146.43
153.98
159.89
166.58
172.58
179.50
183.86
187.59
190.78
192.81
194.91
196.00
197.63
198.02
198.80
199.11
198.25
199.11
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.8697
29.3038
23.3808
19.1089
16.5272
14.2451
11 .8932
10.7170
9.7463
8.9389
8.2546
7.6684
7.1592
6.7132
6.3195
5.9695
5.6560
4.9991
4.4802
3.7082
3.1629
2.7576
2.4444
2.1951
1 .9919
1 .8230
1.2804
0.9867
0.6764
0.5146
0.4152
0.3480
0.2629
0.2112
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0'.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
10.33
16.16
20.28
23.46
25.09
27.19
29.21
31.31
31.54
32.55
33.33
34.49
35.27
35.89
36.51
37.21
37.76
38.38
40.79
42.03
42.73
43.97
45.37
46.38
47.47
48.01
50.73
54.07
58.50
61 .37
63.39
64.09
66.50
68.99
72.79
78.54
92.92
103.40
1 13.58
129.04
143.65
162.99
177.13
185.83
197.17
203.86
208.75
21 1 .86
215.74
218.46
220.40
221 .34
222.58
223.28
224.13
224.13
224.68
224.99
225.45
225.30
225.92
225.53
-------
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.3912
28.7251
22.7233
18.7728
16.0522
14.1232
1 1.8284
10.6631
9.7037
8.9012
8.2233
7.6402
7.1351
6.6923
6.3014
5.9535
5.6420
4.9886
4.4710
3.7021
3.1587
2.7544
2.4418
2.1930
1 .9901
1 .8216
1 .2797
0.9863
0.6762
0.5144
0.4151
0.3480
0.2629
0.21 12
0.1416
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
8.18
13.04
16.20
18.79
21.38
22.84
25.1 1
26.97
27.86
28.18
29.40
30.05
31 .10
31.99
32.96
33.77
34.66
35.88
37.26
38.96
40. 17
41 .55
42.68
43.73
44.54
45.44
48.43
51 .43
56.69
59.77
61 .80
62.85
66.09
68.44
72.57
79.94
100.43
113.71
125.70
145.54
170.73
184.90
199.48
209.76
215.92
219.73
223.05
225.23
226.69
227.99
228.47
229.04
229.61
229.93
230.58
230.66
231.23
231.31
231.63
231 .39
S31.79
231.31
A8.
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.2412
29.3391
23.1850
19.2002
•16.3607
14.2986
1 1 .8527
10.6838
9.7183
8.9156
8.2337
7.6494
7 . 1 42 7
6. 6989
6.3069
5. 9 581
5.6459
4.9919
4.4738
3.7040
3. 160?
2.7555
2.44P7
2.1936
1 .9906
1.8220
1.2799
0.9864
0.6762
0.5145
0.4151
0.3480
0.2629
0.21 IP,
0.1417
0. 106*:6
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
187 0'0M3
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
14.65
22.02
26.51
31.11
34.10
36.78
39.88
42.66
42.76
44.26
44.79
45.76
46.82
47.89
48'. 86
49.60
591.46
5?. 38
54.63
56.87
58.91 .
60.29
61 .68
6P . 7 5
64.04
64.89
68.85
72.48
77.61
81 .89
84.88
85.85
89.59
9P.9M
101 .45
125.72
166. 13
181 .53
197.88
220.01
252.83
288.43
324.78
350.12
363.80
372.89
378.55
383. 15
385.72
387.64
389.35
390.96
391.28
392.35
393.09
393.63
393.63
393.73
394.38
394. 16
394.38
395.02
-------
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.5219
28*7463
22.9133
19.0551
16.3293
14.2146
11.8504
10.6731
9.7123
8.9093
8.2295
7.6459
7.1392
6.6955
6.3037
5.9553
5.6434
4.9897
4.4718
3.7025
3 . 1 59 1
2.7546
2.4420
2. 1930
1.9902
1 .8216
1 .2797
0.9863
0.6762
0.5144
0.4151
0<. 3480
0.2629
0.21 12
0ol417
0el066
0.0854
0.0713
r.0.061 1
i^.0535
%\0476
0\0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0»0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0e0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
.0.00
16.73
24.66
29.56
33.36
36.48
38.60
40.94
40.72
42.06
42.95
44.18
45.29
46.08
46.97
47.75
48.64
49. 45
51 . 10
52.88
55.00
56.90
58.24
59.80
60.80
62.03
63.14
67.38
71.6-2
77.65
82.1 1
87.02
89.25
89.81
93.49
129.52
175.04
204.27
224.24
246.55
276.23
316.39
350.64
378.64
393.93
401 .07
404.64
407.54
408.54
409.55
410.44
410.77
411.00
411.22
410.89
412.00
412.00
412.23
413.23
413.45
413>56
4i:3l 56
414.12
A8.
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.521 1
28.7797
22.8057
18.8641.,
16.1989
14. 1430
11 .8361
10.6678
9.7058
8.9045
8-2254
7.6422
7.1365
6.6932
5.9535
5.6413
4.9878
4.4704
3.7013
3.1583
2.7541
2.4415
2.1927
1 .9898
1 .8213
1 .2796
0.9862
0.6762
0.5144
0.4151
0.3479
0.2629
0.21 12
0. 1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
188
CUMULATIVE
PORE-VOLUME*
nu MM/G
0.00
12.76
20.36
24.65
28.39
31.14
33.12
36.31
38.29
38.73
39.94
41.15
42. 15
43.36
44.24
45.89
46.22
47.43
49.52
50.51
53.26
54.69
56.01
56-89
57.66
58.65
63.05
67.12
72.96
76.26
79.45
80.55
85.06
88.91
105.64
147.78
180.14
197.85
316.89
243.41
283.02
322.42
354.88
374.47
384.04
389.21
392.95
394.05
395.26
395.48
396.36
397.68
398.34
398.89
399.23
400.1 1
400.33
400.55
401 .10
401.98
402.20
402.75
-------
C 37
Sample C 38
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.0547
28-5054
22.8896
18.9843
16.2368
14.1003
1 1 .8437
10.6805
9.7153
8.91 1 1
8.2309
7.6473
7.1406
6.6970
6.3051
5.9566
5.6446
4.9905
4.4722
3.7028
3. ,1592
2.7547
2.4420
2. 1930
1 .9901
1 .8215
.1 .2796
0.9862
0.6761
0.5144
0.4151
0.3479
0.2628
0.21 12
0.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CM MM/G
0.00
5.76
12.53
15.32
17.86
19.80
21.75
23.87
27.17
27.17
27.59
28.44
29.37
30. 13
30.89
31 .57
32.25
32.92
34. 1 1
35. 12
36.56
37.75
38.68
39.61
40.29
40.79
41 .22
4 3.33
44.43
46.21
47 .06
47 .82
48. 16
50.61
53.32
86.24
108.84
125.17
134.23
143.79
1 58.35
177.56
196.09
205.9.1
209.89
211.4]
213.02
214.29
215.05
215.64
216.24
216.83
217.51
218.44
218.78
218.86
219.03
219.1 1
219.20
219.28
220.05
220.47
22CU72A8
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
37.6096
28.2897
22.6405
9. 1276
6.0516
4.1 108
1 .8485
0.6778
9.7FI84
8.9047
8.2248
7.6409
7.1349
6.6917
6.3002
5-9522
5.6403
4.9869
4.4695
3.7014
3. 1579
2.7539
2-441 7
2. 1928
1 .9899
1 .8214
1 .2796
0.9862
0.6761
0.51 44
0.4151
0.3479
0.2628
0.21 12
0. 1417
0. 1066
0.0854
0.07 1 3
0.0611
0.0535
0.0476
0 .0429
0.0390
0.0357
0.0-330
0.0306
0.0286
0.0268
0.0252
0.0238
3.0226
0.0215
3.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
IRQ 0-0143
CUMULATIVE
PORE-VOLUME*
CM MM/G
0.00
1 1.76
17.64
21 .44
24.00
26.56
29.41
34.34
36.05
34.34
34.53
35. 19
35.57
36.33
37.00
37.57
38.33
38-70
39.56
4 1 .08
43.92
44.30
46. 10
48.95
49.71
50.47
51 .04
53.88
56.07
58.82
59.67
60.43
60.71
64.41
66.03
92.1 1
121 .24
146. 19
159.94
174. 17
195.52
229.38
254.81
268.37
275.68
279.38
281.18
282.41
283.84
284.78
285.16
285.26
286.21
286.02
286.30
286.30
286.59
286.49
286.40
286.30
287.16
287.25
287.92
-------
Sample Q
Sample C 39
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.2301
28.6145
22.6905
18.7928
16. 1043
14.0595
1 1 .8065
10.6472
9.6895
8.8894
8.2107
7.6287
7.1243
6-6824
6.2920
5.9445
5.6334
4.9816
4.4649
3-6976
3.1554
2.7517
2-4396
2.191 1
1 .9886
1 .8203
1 .2790
0.9858
0.6760
0.5143
0.4150
0.3479
0.2628
0-21 12
0.1416
0.1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
10-47
17.32
21 .48
24.84
27.12
29.00
31 .69
35-58
36.52
37. 19
37.32
37-86
38.94
39-87
40.81
41 .35
41 .89
43.37
44.57
46-32
48-20
49. 14
50.35
51 .42
52-50
53-44
57.06
59.88
63-77
67-13
69 - 1 4
70.22
73.98
75-99
=?2«84
1 12.37
145.94
160.57
176.28
201 .66
240.73
277.92
299-53
312- 15
317.12
319.80
321 .82
323-30
324.37
325.58
325.98
326.79
326.79
326.65
327.05
327-32
327.32
327.73
328-13
328.26
328.80
328.80
A8.190
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.3305
27.7585
21 .8222
18.2449
15.6364
13.6866
1 1 .9048
10.7182
9.7467
8.938P)
8.2525
7.6640
7. 1548
6.7086
6.31 44
5-9642
5.6507
4.9946
4. 4749
3.7040
3. 1597
2.7550
2 . 4/iP2
2. 1931
1 .9901
1 .8215
1 .2795
0.9861
0.6761
0.5143
0.4151
0.3479
0.2628
0.21 12
0.1416
0. 1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0 .0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
POREiVOLUME,
CO MM/3
0.00
4.63
7.71
8.89
9.65
10.02
10.13
10.94
10.99
1 .05
1 .42
1 .59
1 .53
1 .86
1 .96
1 .91
1 .96
12.02
12.18
12.23
12.29
12.39
12.77
13-04
13.20
13.31
13.31
13.74
14.12
14.87
15.25
15-52
15.57
15.90
15-95
16.06
16.49
16-76
16.49
16-54
16-76
16.71
16-81
17.19
17.14
17.57
17.57
17.41
17.46
17.51
17.30
17.68
17.41
7.46
7.68
7.62
7»89
7.73
7.84
7.62
18.00
18.05
17.73
-------
oampxe
POBE-ENTRANCE
DIAMETER,
MICRONS
58.5831
37.8620
28.5630
22.8653
19.0067
16. 1205
1/1.0302
1 1 .9363
10.7462
9.7704
8.9564
8.2680
7.6.780
7. 1670
6.7194
6.3245
5.9731
5-6591
5.0013
4. 4808
3-7084
3. 1631
2.7575
2.4441
2. 1946
1 .991 4
1 .8226
1 .2801
0.9864
,. 0.6762
0.51 44
0.4151
0.3479
0.2629
0.21 12
0.1416
0. 1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/Q
0.0M
4.92
6.96
8.32
9.40
9.85
10.13
10.3R
10.81
10.98
10.93
1 1 .09
1 1 .26
1 1 .60
11.77
12.00
12.30
12.23
12.51
13.19
3-70
4.21
4.49
4.66
4.77
4. 89
4.89
5.23
15-68
16.87
17.15
17.49
17.77
18.62
18.96
19.98
21.17
24.06
24.79
25.58
26.89
27.51
28.58
28.98
29.43
29.83
30.45
30.68
31.19
31 .24
31 .47
31 .98
32.09
32.43
32.49
32.60
32.77
33.00
32.94
33.00
33.05
33-22
33.34
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
39.9391
28.9229
23.2376
19.0616
1 6.3794
14*1763
1 1 .9733
10.7788
9.7978
8.9814
8.2898
7.6976
7.1841
6.7345
6.3379
5.9852
5.6701
5.0104
4.4885
3.7141
3. 1676
2.7613
2. 4473
2. 1976
1 .9939
1 .8249
1 .2816
0.9880
0.6773
0.5151
0.4156
0.3483
0.2630
0.21 13
0.1417
0. 1066
0.0854
0 .07 1 3
0.0611
0.0535
0 -0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/Q
0.00
6.61
1 1 .23
3.71
5.23
6.74
7.91
9.01
20. 19
20.53
21.15
21 .49
22.05
22.46
22-67
22.94
23.08
23.49
24.39
25-56
27.08
28.59
29.90
31 .28
33.55
34.03
35.41
42.65
59.87
82-05
86-53
89.56
89.91
89.98
90-60
91 .22
92 . 32
94.18
95.35
96-45
98-59
99-83
100.24
101 .00
101 .27
101.14
101 .69
101 .89
102.03
102.03
102.24
102.45
102.86
102.86
1 02 - 65
103.07
103.07
103.13
103.34
103.62
103-62
103.55
103.48
A8.191
-------
Sample G 5
Sample G 6
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.6341
28. 1233
32.5308
8-4046
5.8575
A .0/426
1 .9149
0.7286
9. 7550
8.9439
8.2575
7.6691
7,1587
6.7122
6.3181
5.9679
5.6543
4. 9978
4. />779
3.7064
3.1618
2-7566
2.4435
2. 1942
1 .991 1
1 .8225
1 .2828
0.9907
0.6794
0.5165
0.^165
0.3489
0.2634
0.2116
0.1418
0. 1066
0 .0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.01 65
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
8.04
1 .64
3.86
5.76
6-40
7-77
18.83
19.67
19.67
19.89
20.20
20.63
20 .84
21 .26
21 .58
22. 11
22.53
23.48
24.3 3
25.39
26.97
27.93
28. RS
29.30
30.04
32.69
98.69
203.62
300. 30
335. 10
347. 1 6
350.65
354.56
356.05
356. 15
356.26
357. 10
357.53
357.42
357.31
357.31
357.31
357.31
357.42
357.42
357.63
357.63
357.84
357.84
358.27
357 .84
358.06
358.06
357.84
357.84
358.48
358.06
358.58
359.64
360.06
358.69
358.90
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
37.8967
28.5224
22.5668
18.9062
16.0855
13.9951
11.8533
10.6762
9.7127
8.9087
8.2271
7.6424
7.1355
6.6914
6.2997
5.9512
5.6392
4.9857
4.4681
3.6995
3.1566
2.7526
2.4403
2.1916
1.9889
1.8205
1.2791
0.9858
0.6760
0.5143
0.4151
0.3479
0.2629
0.2112
0.1417
0.1066
0.0854
0.0712
0.0611
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0.00
3.88
5.51
6.64
7.20
7.82
8.20
8.64
8.64
8.89
9.14
9.20
9.26
9.39
9.45
9.64
9.83
9.95
10.27
10.70
11.02
11.39
11.83
12.14
12.33
12.64
12.77
13.52
14.15
15.96
19.53
25.10
29.23
42.75
49.51
56.21
59.40
62.35
63.85
64.54
65.41
66.67
67.23
67.35
67.86
68.48
68.79
69.17
69.48
69.73
69.92
70.36
70.11
70.48
70.55
70.55
70.61
70.36
70.92
71.11
71.05
71.74
71.80
A8.192
-------
Sample G 7
Sample G 8
PORE- ENTRANCE
DIAMETER,
MICRONS
58.5831
38.2506
29.0030
22.9283
18.9655
16.3646
14.0866
1 1 .7692
10.6165
9.6641
8.8676
8.1920
7.6123
7. 1095
6.6686
6.2791
5.9326
5.6225
4.9724
4.4573
3-6923
3.1513
2.7486
2.4371
2. 1891
1 .9869
1 .8188
1 .2782
0.9854
0.6757
0.5142
0.4150
0-3478
0.2628
0.2112
6.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0 . 0;47 6
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0 .0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0.00
7.60
11.17
13.23
14.59
15.66
16.34
16.95
19.08
19.61
19.84
19.92
20.07
20-37
20.45
20.45
2P1.52
20.68
20.75
21.13
21.97
22.42
22.88
23-34
23.87
24.25
24. 48
25.46
26.98
30. 18
32.84
35.35
36.87
42. 34
67.27
163.73
187.37
198.77
203.33
210.17
217.01
223-86
226. 14
227 .66
228.42
228-42
228.42
229 . 18
229.18
229.94
229.94
229.94
229.94
229.94
229.94
230.70
230.70
231 .46
230.70
2.30.70
230.70
230.70
231.46
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
39.1600
28.8380
22.8893
18.8986
16.1890
14.1289
11.8712
10.6969
9.7299
8.9227
8.2391
7.6S27
7.1449
6.6998
6.3071
5.9577
5.6448
4.9899
4.4712
3.7018
3.1583
2.7539
2.4413
2.1924
1.9896
1.8211
1.2794
0.9861
0.6762
0.5145
0.4153
0.3482
0.2631
0.2114
0.1417
0.1066
0.0854
0.0713
0.0611
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
5.24
7.85
9.16
9.85
10.47
10.85
11.47
12.72
12.97
13.09
13.15
13.21
13.53
13.65
13.84
13.90
13.90
14.03
14.15
14.84
15.27
15.65
16.14
16.39
16.77
17.02
18.08
19.07
26.18
39.64
58.78
73.74
107.59
122.24
130.22
132.46
134.14
134.95
136.01
136.57
137.63
138.19
138.63
139.13
139.00
139.44
139.38
139.63
139.82
139.88
140.44
140.87
140.69
140.63
140.81
140.94
140.94
141.50
141.44
141.37
141.56
141.69
A8.193
-------
Sample G
Sample G 30
PORE-ENTRANCE
DIAMETER/
MICRONS
58.5831
39.21 1 1
28.9416
22.7038
18-3601
15.7828
13.8289
1 1 .9207
10.7409
9.7702
8.9593
8.2729
7.6834
7. 1730
6.7257
6.3304
5.9796
5-6651
5-0073
A. 4871
3.71 33
3. 1673
2.7612
2 . /i 47 5
2. 1975
1 .99/10
1 .8249
1 .281 5
0.9R75
0.6769
fl. 51 49
0.4154
0.3482
0.2630
0.21 14
0.1417
0- 1066
0.085/1
0.07 1 3
0.061 1
0.0535
0 .0476
0.PI429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0 .0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
12.05
20. .04
25-27
30.60
33.80
34.76
38.60
42.01
44.03
45.53
47.13'
48. 19
49.79
50.97
51.71
53-10
53.7/1
56. 3
-------
Sample Q 31
Sample G "52
PORE- EN TRANCE
DIAMETER,
MICRONS
58.5831
37.7561
28.5005
22.9409
19.0512
16.0680
14. 1305
11.7001
10.5597
9.61 65
8.8268
8. 1571
7.5819
7.0824
6.6445
6.2584
5.9144
5.6057
4.9594
4. 4470
3.6858
3. 1472
2.7455
2. 4347
2. 1871
1.9854
1.8176
1.2776
0.9850
0. 6756
0.5141
0.4149
0.3478
0.2628
0.21 12
0.1416
0. 1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
6.53
9.50
1. 19
2. 13
2.80
3.57
4.92
7. 13
7.55
7.55
7. 55
7.64
7. 64
7. 55
18.06
18.32
18.06
18. 40
19.08
21.28
23.83
24. 51
24. 67
25. 18
27.39
27. 13
28. 15
29.25
32. 56
34.34
34. 60
35.36
38.07
41.04
49. 60
56.56
63. 59
68. 43
73.26
79. 45
85.98
91.07
101. 67
10.57
22. 10
32.70
44.32
55.76
64. 33
73. 57
179.93
187.99
193.75
199. 18
204.69
208.42
209.52
208.85
210.80
214.10
215.46
215.63
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.3669
29.7319
23. 6875
19.0992
16.5888
14. 4427
12. 1462
10.91 44
9.9090
9.0731
8.3670
7.7643
7.2417
6.7841
6-3820
6.0249
5.7050
5.0374
4.5094
3.7278
3. 1769
2. 7680
2. 4525
2.2014
1.9970
1.8273
1.2824
0.9878
0. 6769
0.5148
0. 4154
0 . 3 48 1
0.2630
0.2113
0. 1417
0.1066
0.0854
0.0712
0.061 1
0.0535
0. 0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME,
CU MM/G
0.00
4.98
6.97
8.28
9. 12
9.70
10.07
10. 54
10.75
10.85
10.96
10.96
1 . 43
1 .59
1 .38
1 . 64
1 .95
1 .85
12.32
12.53
12.90
12.74
13.00
13.58
13* 68
13.95
13.95
14. 57
15.36
16. 15
16.57
16.88
16.93
17. 62
17.93
19. 61
20.55
21.50
22.02
22.49
23.07
23.64
24.33
24.80
25.32
25.48
26. 1 1
26. 16
26.69
26.58
26.95
26.95
27.21
27.26
27.52
27.58
27. 42
27.68
27.58
27.84
27.73
28.15
27.89
A8.195
-------
Sample G 33
Sample G
PORE-ENTRANCE
DIAMETER*
MICRONS
58. b«31
38.2546
29.7297
23. 6693
19.2990
1 6 . 5 48 4
14.3645
12. 1394
10.9099
9.9066
9.0718
8.3664
7.7626
7.2401
6.7833
6.3810
6.0237
5.7043
5.0365
4.5089
3. 7276
3. 1770
2.7680
2. 4524
2.2014
1 .9970
1.8273
1 .2824
0.9878
0.6769
0.5148
0. 4154
0.3481
0.2630
0.2113
0.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0. 0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.01 65
0.0159
0.0153
0 . 0 1 48
0.0143
CUMULATIVE
PORE- VOLUME*
CU MM/G
0.00
5.42
8.00
9. 66
10.84
1 1.59
12.02
12. 61
12.99
13.37
13. 63
13.79
13.90
14.01
» 4.01
14. 17
14.28
1 4. 44
14. 65
15.08
15.57
15.89
16. 10
1 6.37
1 6.64
16.91
17. 18
17.82
18.30
19.00
19.32
19. 70
19.86
20. 50
21. 58
23. 46
24.96
26. 68
28. 72
29.04
29.47
29. 68
29. 79
30.22
30. 59
30. 65
30.92
31.29
31.40
31. 56
31.56
31. 72
31.88
32.21
32.21
32.58
32. 63
32.63
32. 69
32.85
33. 12
33. 17
33.33
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.6588
28.3197
22.4950
19. 1 101
16. 1262
14.0453
12.0164
10.8092
9.8235
9.0019
8.3069
7-71 10
7. 1952
6.7440
6.3463
5.9927
5.6766
5.0148
4.4915
3. 7156
3 . 1 68 2
2.7614
2. 4471
2. 1972
1.9935
1 .8244
1 . 28 1 0
0.9870
0. 6765
0.5146
0. 4152
0 . 3 48 0
0.2629
0.21 12
0. 1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268 ,-
0.0252
0.0238
0.0226
0.0215
0. 0204
0.0195
0.0187
0..0I79
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME/
CU MM/G
0. 00
4.57
7.35
8. 69
9.36
10. 14
10.58
1 1.08
1 1.25
1 1. 64
11.86
12.03
12.03
12. 14
12.20
12. 42
12.53
12.70
12.92
13-31
13.70
14.03
14.26
14.37
14.81
15.09
15.20
1 6.04
16. 60
17.32
17.99
18. 49
19.05
21.11
23.89
34.36
45. 45
53.52
54.86
55.69
56.25
56.81
57. 42
57.87
58.25
58.70
59.09
59. 59
60.20
60. 48
60. 71
61. 10
61.21
61.37
61. 71
62. 10
62. 15
62.49
62.77
62.99
63.27
63-32
63.49
A8.196
-------
Sample G 38
Sample G 39
PORE-ENTRANCE
DIAMETER,
MICRONS
58.58
39.23
30.24
23.9^
20.13
17.45
15.29
11.76
10.61
9.65
8.86
8.19
7.61
7.11
6.66
6.28
5.93
5.62
4.97
4.46
3.
3-
2.
2.
2.
1.
1.
0.
0.
.69
.15
.75
.44
.19
.99
.82
1.28
0.985
0.676
0.514
0.430
.358
.269
0.215
0.143
0.108
0.086
0.072
0.0614
0.0537
0.0478
0.0430
0.0391
0.0358
C.0331
0.0307
0.0287
0.0269
0.0253
0.0239
0.0226
0.0215
0.0204
0.0195
0.0186
0.0179
0.0172
0.0165
0.0159
0.0154
0.0148
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0.0
8.25
12.62
15.98
18.33
19.45
20.57
22.60
23.62
24.44
24.84
25-45
25.66
25.96
26.47
26.57
26.98
27.90
28.30
28.71
29.53
30.34
31.36
31.56
32.07
32.89
33.40
35.23
36.86
41.74
42.15
43.88
44.80
52.13
57.53
90.92
155.58
250.98
271.85
27^.37
280.20
281.73
282.65
282.95
284.17
284.38
284.78
285.09
285.70
285.09
285.39
285.50
285.50
286.01
285.80
286.41
286.31
286.31
287.33
286.82
286.82
286.92
286.72
PORE-ENTRANCE
DIAMETER,
MICRONS
58.58
38.74
29.21
22.90
18.78
16.08
14.14
11.79
10.63
9.67
8.88
8.20
7.62
7.12
6.67
6.28
5.94
5.63
4.98
4.46
3-69
3.15
2.75
2.63
2.19
1.99
1.82
1.28
0.985
0.676
0.514
0.430
0.358
0.269
0.215
0.143-
0.108
0.086
0.072
0.0614
0.0537
0.0478
0.0430
0.0391
0.0358
0.0331
0.0307
0.0287
0.0269
0.0253
0.0239
0.0226
0.0215
0.0204
0.0195
0.0186
0.0179
0.0172
0.0165
0.0159
0.0154
0.0.148
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0.0
8.17
11.71
14.02
15.67
16.58
16.91
17.82
19.; 06
19.22
19.55
19.96
20.38
20.79
20.95
21.20
21.53
21.70
22.19
22.77
23.26
23.84
24.25
24.83
25.24
25-57
25-99
27.22
28.63
30.36
32.09
33.33
33.82
36.46
38.36
43.39
52.14
78.04
112.28
156.25
188.42
212.68
227.53
234.87
238.91
242.62
245.26
246.50
248.07
249.06
249.47
250.13
250.62
250.87
250.87
251.04
251.53
252.19
252.27
252.60
253-02
253.26
253-68
A8.19 7
-------
Sample G 40
PORE-ENTRANCE
DIAMETER,
MICRONS
58.58
38.53
29.05
2J.19
19.21
16.42
14.44
11.80
10.63
9.68
8.88
8.21
7.62
7.12
6.68
6.29
5.94
5.63
4.98
4.46
3-69
3.15
2.75
2.44
2.19
1.99
1.82
1.28
0.985
0.676
0.514
0.430
0.358
0.269
0.215
0.143
0.108
0.086
0.072
0.0614
0.0537
0.0478
0.0430
0.0391
0.0358
0.0331
0.0307
0.0287
0.0269
0.0253
0.0*39
0.0226
0.0215
0.0204
0.0195
0.0186
0.0179
0.0172
0.0165
0.0159
0.0154
0.0148
0.0143
CUMULATIVE
PORfi-VOLUME,
CU MM/G
0.0
16.43
21.03
21.66
22.60
22.81
22.71
23.13
25.32
26.16
26.37
26.58
26.68
26.89
26.89
27.21
27.73
27.83
27.94
28.04
28.15
28.25
28.36
28.67
28.67
28.78
28.99
30.24
30.97
33-90
37.57
42.27
42.69
47.09
70.84
173.38
246.22
266.32
268.30
267.68
268.83
269.56
270.40
270.82
270.19
269.87
269.87
270.82
271.34
271.76
272.07
272.07
272.07
272.07
272.18
272.28
271.86
272.38
272.91
273.54
274.90
274.90
274.58
Sample G 41
PORE-ENTRANCE
DIAMETERj
MICRONS
58.58
36.94
28.55
22.58
18.78
16.02
14.13
11.81
10.64
9.68
8.88
8.21
7.63
7.12
6.68
6.29
5.94
5.63
4.98
4.46
3.70
3-
2.
2.
2.
1.
1.
1.
A8.198
.15
.75
.44
.19
.99
.82
.28
0.99
0.68
0.51
0.430
0.358
0.269
0.215
0.143
0.108
0.086
0.072
0.0614
0.0537
0.0478
0.0430
0.0391
0.0358
0.0331
0.0307
0.0287
0.0269
0.0253
0.0239
0.0226
0.0215
0.0204
0.0195
0.0186
0.0179
0.0172
0.0165
0.0159
0.0154
0.0148
°.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
0.0
7.49
10.06
12.20
13.44
14.47
14.91
15.94
17.12
17.12
17.41
18.00
18.07
18.22
18.44
18.59
18.81
19.25
19.54
20.20
20.57
21.16
21.75
22.04
22.11
22.19
22.33
24.46
32.91
33-06
33.50
38.50
41.58
47.38
79.49
150.75
183.96
196.30
200.41
200.85
201.59
202.62
202.62
202.98
203.50
202.76
203.28
203.94
204.45
204.31
204.67
204.38
205.19
205.11
205.85
205.63
205.33
205.41
205.48
206.14
206.07
205.48
206.00
-------
Sample J
Sample J 2
PORE-ENTRANCE
DIAMETER>
MICRONS
58.5831
37.4924
28.9469
22.9448
18.9670
16.0292
14.1870
11.6975
10.5606
9.6165
8.8268
8.1571
7.5818
7.0823
6.6445
6.2577
5.9148
5.6065
4.9605
4.4478
3.6855
3.1463
2.7449
2.4344
2.1869
1.9850
1.8174
1 .2779
0.9853
0.6759
0.5142
0.4150
0.3479
0.2628
0.2112
0.1416
0.1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/6
0.00
3.51
4.21
4.91
6.37
8.60
9.42
9.88
11.99
12.
12.
12.
12.
12.
12.
12.
12.92
13.04
13.63
14.04
14.21
14.50
15.03
16.02
16.38
16.55
17.55
22.81
27.78
36.38
38.31
40.30
40.47
41.29
41 .64
43*04
45.33
46.14
46.79
47 .43
48.37
48.42
48.25
48.07
48.54
48.42
48.48
48.42
48.48
48.37
48.25
47.90
47.55
46.85
46.26
46.20
45.73
45.62
45.56
45.62
45.85
46.20
46.32
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.3933
28.7686
22.6361
18.7882
16.0091
13.9187
1 1.7469
10.6015
9.6506
8.8564
8.1829
7.6042
7.1023
6.6629
6.2743
5.9287
5.6193
4.9707
4.4575
3.6931
3.1529
2.7503
2.4389
2.1907
1 .9884
1 .8204
1 .2793
0.9862
0.676P
0.5145
0.4152
0.3480
0.2629
0.21 13
0.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/6
0.00
1.23
2.03
2.68
3.26
3.70
4.06
4.57
7.32
7.54
7.83
8.05
8.12
8.34
8.77
8.99
9.28
9.64
10.59
13-05
15.15
18.34
20.45
22.55
24. 14
25.96
28.42
35.02
41.62
49.45
55.54
60.32
64.17
76.71
90.78
107.09
1 14.41
1 17.89
1 18.55
120.21
120.50
120.65
121.16
121 .52
121.81
121.81
121.88
121.95
122.32
122.75
122.61
122.61
122.68
122.75
122.39
122.75
122.75
123.62
123.84
123.62
124.06
123.77
124.13
A8.199
-------
Sample J 3
Sample J
PORE-ENTRANCE
DIAMETER*
MICRONS
58.583!
38.7933
28.0818
22.4419
18.6905
15.9070
13.8540
11 .8123
10.6501
9.6906
8.8901
8.21 16
7.6294
7. 1242
6.6820
6.2914
5.9442
5.6331
4.9817
4.4664
3.6993
3. 1573
2.7538
2.4418
2.1930
1 .9903
1 .8220
1 .2802
0.9868
0.6765
0.5146
0.4153
0.3481
0.2630
0.2113
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
3.07
4.83
5.48
6.26
7.05
7.83
8.68
10.18
10.31
10.57
10.76
10.96
11.16
1 1.48
1 1 .74
12.13
12.40
13.44
15.79
17-74
20.16
22.70
25.31
26.62
28.38
30.66
37.51
43.38
50.43
55.84
60.28
63.80
76.20
87.29
04.51
11.17
15.99
17.49
18.28
18.54
18.73
18.80
19.26
19.26
19.45
19.84
120.04
120.43
120.43
121 .02
121.02
121.08
121.60
121 .67
121.86
122.13
122.45
122.45
122.39
122.52
122.58
122.97
POKE- EM TRANCE
DIAMETER
MICKONS
58.5831
38.71 19
28.5648
22. 7777
18.7050
15.8967
I A. 1201
1 1 • 6736
10.5374
9.5975
8-81 17
8. 1 449
7.5720
7.0743
6. 6378
6.2522
5.9081
5. 6007
4.9558
. A. 4443
3. 6837
3. 1453
2. 7442
2. 4339
2. 1867
1 .9850
1.8175
1 .2778
0.9853
0. 6758
0.5142
0. 4150
0. 3*79
0.2628
0.2112
0.1416
0 . 1 0 6 b
0.BS54
0.6,712
0.0611
0.0535
0. 0476
0.0428
0.0390
B.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
POKE- VOLUME
CU MM/G
0.00
6.08
7.01
8.03
9.97
1 1.22
2.31
3. 48
5.35
5.58
5.90
6.21
6. 60
6.91
1 / . 0 6
17.38
17.06
17.38
1 7.92
18.93
20. 42
21.51
22.83
24.23
25.87
27. 43
29.38
34.91
42. 08
bl.74
56. 57
60 . 08
61.40
65. 76
68. 73
73. 17
76.21
80. 10
83-22
86. 49
92.72
105.27
1 19.22
134.26
1 46. 49
155.53
1 64.26
172.75
1 8 1 . 48
188.80
193. 71
197. 68
200.80
202.90
205. 63
206.88
208.36
209. 53
210.54
210.85
21 1. 63
212.25
212. 41
A8.200
-------
Saaple J 5
Sample J 6
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39. 1604
28.8749
22.9602
19. 1 1 44
16.2701
14.2354
1 1.7045
10.5556
9.6141
8.8257
8. 1568
7.5825
7.0839
6.6470
6.2606
5.9168
5.6084
4.9621
4. 4497
3.6873
3. 1480
2.7463
2.4356
2. 1880
1 .9860
1.8183
1 .2783
0.9856
0. 6760
0.5143
0.4151
0.3479
0.2628
0.2112
0. 141 6
0. 1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME*
CU MM/G
0.00
7. 60
1 1.97
14. 76
1 6.79
18.52
19.95
21. 76
21.83
22.51
22.81
23. 1 1
23.57
24.09
24.77
25.22
25.82
26.05
26.95
28.31
29.51
30.79
32. 15
33. 66
34.94
36.21
37. 49
44.80
51.88
60.84
65.50
67.91
69. 19
72.05
73. 71
76.72
78.75
81.92
84. 70
89.22
95.32
04.81
14. 14
21.97
33.34
41.85
49. 68
56.91
63.31
69.93
73.70
76.33'
78.97
180.92
182.35
183.26
18.4.24
184.61
185.22
185.44
185.52
186. 12
186.42
PORE- EN TRANCE
DIAMETER*
MICRONS
58.5831
39.2900
28.7222
23. 1678
19. 1461
,6.3148
14.2490
1 1.9727
10.7825
9.8009
8.9829
8.2913
7.6979
7. 1845
6.7352
6.3391
5.9869
5.6713
5.01 10
4.4890
3.7142
3. 1675
2.7610
2. 4470
2. 1972
1.9936
1.8246
1 . 28 1 4
0.9874
0. 6768
0. 51 48
0.4154
0.3481
0.2630
0.2113
0. 1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0J48
iKt.'0&J43
CUMULATIVE
PORE- VOLUME*
CU MM/G
0.00
4.59
7.82
9. 69
10.98
12.35
13.49
14.86
17.01
17.37
17.66
18.09
18.23
18. 73
19. 16
19.81
20.38
20. 60
21. 10
22. 47
23.54
24.55
25.34
26.56
27.92
28. 78
29.93
35. 17
41 . 49
48.95
53. 19
55.05
56.56
58.79
60. 15
62.23
64.03
65.96
67.04
68. 40
69.84
71.56
73.36
75.29
76.66
78.02
79.60
80.89
82.83
85.27
87.93
90.80
94.31
96.40
99. 12
103. 14
105.30
108.02
110.46
112. 12
114.63
IT6.28
1 1»7'£93
A8. 201
-------
Sample J 8
Sample J 9
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.4980
29.8187
23. 1898
19.2175
16.2836
14.3469
11 .8983
10.7249
9.7523
8.9422
8.2557
7.6676
7. 1581
6.7116
6.3174
5.9675
5.6543
4-9979
4.4781
3.7070
3.1626
2.7576
2.4445
2.1953
1 .9921
1 .8234
1 .2808
0.9871
0.6767
0.5147
0.4153
0.3481
0.2629
0.21 13
0.1417
0.1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
3.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CM MM/G
0.00
4.12
6.71
8.83
10.36
11.95
12.82
14.61
17.20
17.27
17.60
17.66
17.93
18.39
18.59
18.73
19.26
19.72
20.39
21 .12
22.64
24.57
26. 16
27.69
29.75
30.95
32.07
38.38
44.23
51 -53
54.98
57.57
57.71
60.16
61.36
63.48
64.35
67.27
69.79
72.91
79.82
95.09
104.26
1 15.08
123.65
130.95
136.53
142.18
147.69
151.41
154.39
157.05
157.78
1 59 . 64
160.97
161 .37
1 62 . 69
163.23
164.42
164.95
165.28
165.55
165.42
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.7453
28.2152
23.2702
19.0468
16.31 16
14.2588
12.0218
10.8197
9.834(3
9.0111
8.3153
7.7206
7.2043
6-7527
6.3550
6.0008
5.6837
5.021 1
4.4972
3. 7204
3. 1725
2.7649
2.4503
2.2003
1 .9962
1 .8268
1 .28P6
0.9881
0.6771
0.51 50
0.4155
0.3482
PI. 2630
0.2113
0.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.04?9
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME
CU MM/G
0.00
7.19
1 1 .80
14.25
16.76
18.79
20.25
21 .93
23.47
24.44
24.86
25.28
26.26
26.75
27.24
28. 14
28.49
28.63
29.54
31.01
33.10
35.41
36.39
38.27
41 .83
43. 16
44.56
51 .75
56.57
63.90
68.30
71 .65
72.70
74.59
75.49
78.01
78.08
81.15
82.55
85.06
87.93
92.33
97.91
105.94
1 14.60
122.91
128.08
1 32 . 62
138.77
145. 12
152.25
159.23
164.47
169.01
174.32
178.09
180.60
182.49
183.53
184.37
185.98
186-68
187.31
A8.202
-------
Sample J 10
Sample J 12
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.2666
27.7254
22.9938
19.1468
16.2377
14.3287
1 1.8017
10.6454
9.6862
8.8876
8.2106
7.6288
7.1241
6.6827
6.2921
5.9449
5.6342
4.9824
4.4661
3.6989
3.1566
2.7529
2.4409
2.1921
1 .9896
1 .8213
1 .2798
PI. 9865
0.6763
0.5145
0.4152
0.3480
•0.2629
0.2112
0. 1416
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
9.02
12.29
14.88
17.15
18.03
18.66
19.42
21 .69
21.69
22.26
22.82
23.14
23.52
24.21
24.53
24.97
25.60
26.42
27.68
29.32
30.70
32.09
33.67
34.23
36. 19
37.89
43.69
48. 10
54.28
56.30
57.31
58.07
59.33
59.64
60.84
61 .79
63.55
65.82
70.55
78.49
84.48
90.22
95.71
101.32
105.35
08.38
1 1 .28
14.05
15.94
18.09
19.28
120. 17
120.67
121 .43
122.25
123.00
123.89
124.27
124.64
124.77
125.46
125.72
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.8718
28.6947
22.8446
18.7905
16.2334
14.1649
1 1 .8265
10.6644
9.7037
8.9023
8.2226
7.6393
7.1333
6.6904
6.2988
5.9507
5.6391
4.9861
4.4688
3.7004
3.1575
2.7534
2.441 1
2. 1924
1 .9897
1 .8213
1 .2797
0.9863
0.6762
0.5144
0.4151
0.3479
0.2629
0.21 12
0.1416
0.1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0 .0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.01 43
CUMULATIVE
PORE-VOLUME
CU MM/G
0.00
6.00
9.80
12.13
14.09
15.68
16.91
18.74
22.66
23.52
24.62
25.36
26.09
26.83
27.81
28.30
28.91
29.65
30.99
32.83
34.79
36.75
38.47
40.67
42.27
44.23
45.82
52.92
58.68
65.54
68.60
70.44
71.42
73.01
74.36
76.69
78.16
82.20
85.39
88.33
94.58
1 12.71
144. 56
174.21
192.58
201 .89
207.04
210.35
212.92
215.25
216.47
217.57
218.31
218.43
220.39
220.15
219.90
220.51
220.64
221 .74
221 .86
221 .98
221 .49
A8. 203
-------
Sample J 15
Sample J
PORE-ENTRANCE
DIAMETER*
MICRONb
58.5831
38.2707
28.7161
22.9731
' 19.0556
16.2991
14.2005
11.8725
10.6967
9.7316
8.9261
8.2429
7.6573
7.1493
6.7047
6.3119
5.9627
5.6498
4.9948
4.4761
3.7055
3.1612
2.7564
2.4436
2.1944
1 .9915
1.8228
1 .2806
0.9870
0.6766
0.5147
0.4153
0.3480
0.2629
0.21 13
0.1417
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.01 53
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
9.29
13.90
16.64
19.03
20.80
22.39
24.08
25.49
26.47
27.44
27.97
28.77
29.48
30.36
30.98
31 .78
32.22
33.64
35.41
37. 18
38.68
40.36
42.40
43.99
46.20
47.71
57.27
64.88
73.82
77.27
79.93
81.17
83.65
84.62
87.63
90.29
94.45
97.28
100.55
105.69
117.11
143.13
182.08
227.93
257.05
271 .65
278.73
283.51
287.05
289.00
290.59
291 .48
292.54
293.34
293.43
293.96
294.22
294.05
294.75
294.93
295.73
296.26
A8.
PORE-ENTRANCE
DIAMETER*
MICRONS
58-5831
39.2188
29.0327
22.8080
19.1062
16.2742
14. 1729
1 1 .8667
9.7313
8.9248
8.2416
7.6555
7. 1474
6.7027
6.3100
5.9606
5.6480
4.9933
4.4750
3.7046
3.1606
2.7560
2.4432
2.1941
1 .9912
1 .8226
1 .2805
0.9869
0.6766
0.5147
0.4153
0.3481
0.2629
0.21 13
0. 1417
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
204
CUMULATIVE
PORE- VOLUME*
CU MM/G
0.00
7.44
1 1 .57
14.51
16.62
18.46
20.20
22.04
25.81
26.36
26.82
27.27
27.83
28.47
29.02
29.48
30.03
31 .41
33.34
34.71
36.55
38.39
40.22
41 .78
44.26
46.28
55.56
6/1.01
74.66
80. 17
82.93
84.21
87.15
89.54
93.49
96.06
100.83
105.70
112.13
125.17
153.27
199.56
247.95
289.64
313.61
328.21
335.84
340.34
343.64
345.76
346.95
348.05
348.42
349.34
348.79
350.44
349.89
350.90
350.25
350.99
351 .27
351 .17
-------
Sample J 15
Sample J 16
"ORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.5256
28.2288
23.3329
19.0908
16.3205
14.2695
1 1.7790
10.6245
9.6696
8.8736
8.1986
7.6196
7. 1 164
6.6757
6.2862
5.9397
5.6296
4.9791
4.4636
3.6968
3.1551
2.7517
2.4399
2.1915
1 .9890
1 .8208
1 .2796
0.9864
0.6763
0.5145
0.4152
0.3480
PI. 2629
0.21 12
0.1417
0.1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0 .0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
12.54
19.56
23.02
26.58
29.48
30.51
32.75
35.37
35.66
36.50
37.34
38.46
39.21
40.15
40.80
41 .55
42.58
44.27
46.23
47.73
49.97
51 .85
54.19
55.78
57.93
60.08
69.35
77.96
88.81
94.61
97.23
98.45
101 .82
104. 16
107.53
110.71
116.14
121 .19
126.43
137.29
163.40
214.03
267.84
31 1 .26
338.31
351 .78
359.55
364.70
367.88
369.56
371 .06
371.34
372.28
372.75
373.87
373.59
374.06
374.15
374.80
374.71
375.27
375.08
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.3228
28.3000
22.7004
19.0883
16.2418
14.0585
11 .7515
10.6006
9.6499
8.8576
8.1863
7.6079
7.1062
6.6664
6.2774
5.9317
5.6223
4.9734
4.4589
3.6939
3. 1530
2.7502
2.4388
2.1907
1 .9884
1 .8203
1 .2795
0.9864
0.6763
0.5145
0.4152
0.3480
0.2629
0.21 12
0.1417
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.02T5
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
C!J MM/G
0.00
10.81
14.99
17.88
21 .09
23.98
26. ,55
29.76
32.22
32.54
33.83
35.54
36.18
37.04
37.79
38.00
38.75
39.72
41 .54
43.68
46.35
48.92
51 .28
54.71
57.49
60. 16
63.06
76. 12
88.21
101 .06
108.98
1 14.33
1 18.40
120.44
122.90
128.47
130.39
137.03
144.20
153.20
170.75
. 204.69
263.25
310.46
349.00
369.23
378.01
383.47
386.90
388-29
389.89
390.43
391 .50
391 .93
392.89
393.53
393.64
394.39
394.39
394.60
394.82
394.71
394.93
A8.205
-------
Sample J 1?
Sample M
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.7412
29.3360
23.1009
19.1635
16.3882
14.2581
1 1 .7583
10.6083
9.6578
8.8642
8.1907
7.6109
7.1088
6.6689
6.2798
5.9336
5.6238
4.9743
4.4592
3.6940
3.1529
2.7501
2.4385
2.1902
1 .9880
1 .8198
1 .2790
0.9859
0.6760
0.5143
0.4151
0.3479
0.2628
0.21 12
0.1416
0.1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE -VOLUME,
CU MM/G
0.00
7.61
1 1.49
14.25
16.49
17.76
19.03
20.82
23.05
23.73
24.62
25-29
25.37
25.96
26.56
26-86
27.23
27.68
28-73
29.70
31 . 19
32.61
34.02
35.29
36.26
37.83
38.80
44. 17
48.20
53.50
56. 1 1
57.53
58.20
59.76
60.64
62.60
63.94
66.1 1
68.34
7! .33
77.22
90.65
107.74.
122.51
132.73
138.03
141 .76
144.75
146. 16
147.51
148.77
149.15
1 50.04
150.27
1 50.04
150.34
150.49
151 .39
150.71
150.71
151 .76
152.36
152.80
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.4184
28. 1686
21 .8623
17.7289
15.3649
13.4817
1 1 .6332
10.5015
9.5697
8.7893
8.1270
7.5583
7.0644
6.6304
6.2468
5.9049
5.5982
4.9561
4.4482
3.6886
3.1503
2.7494
2.4389
2.1910
1 .9888
1 .8207
1 .2799
0.9868
0.6767
0.5148
0.4154
0.3481
0.2630
0.21 13
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
A8.206
CUMULATIVE
PORE-VOLUME
CU MM/G
0.00
4.79
8.16
10.76
3.20
5.22
7.41
8.25
9.43
20.35
21.11
22.03
23.38
24.98
26.07
27.33
28.34
29. 10
32.55
39.27
45.83
51 .38
58.36
64.50
68.20
71 .57
74.60
89. 14
104.70
126.65
137.92
1,43.98
146.33
150.79
153.65
158.27
160.29
162.14
163.82
164.83
165.76
166.60
167.27
167.69
168.7'0
169.46
169.71
170.81
171 .06
170.89
171.48
171 .65
172.40
172.15
172.91
172.74
173.33
173.24,
173.33
174.08
174.08
174.6,7
174.3*
-------
Sample H 1
Sample N
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
37.5396
28.0118
28.5396
18.4469
15.6140
13.7182
11.6712
10.5419
9.6048
8.8187
8.1518
7.5783
7.0808
6.6454
6.2598
5.9176
5.6105
4.9645
4.4532
3.6915
3.1523
2.7503
2.4393
2.1913
1 .9892
1.8210
1 .2798
0.9867
0.6766
0.5147
0.4153
0.3481
0.2630
0.21 13
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
8.63
13.03
15.31
18.57
20.69
21.66
23.21
26.88
28.26
28.91
29.65
30.22
31.11
32.58
33.55
35.43
37.06
38.93
42.68
47.97
53.02
57.25
62. 14
65.40
69.63
71 .83
82.58
95.37
1 12.96
122.41
126.81
129.49
133.89
137.39
141.71
143.83
146.43
147.57
148.96
150.26
150.67
151 .65
152.46
153.19
153.44
153.60
153.52
154.82
155.31
155.56
155.31
155.47
156.53
156.53
156*78
158.08
157.76
158.33
158.81
158.73
159.22
159.79
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.2586
29.2035
23.2693
19.2335
16.2472
14.1749
1 1 .7369
10.5841
9.6362
8*8443
8.1726
7.5956
7.0948
6*6561
6*2686
5.9235
5.6145
4.9666
4.4529
3*6894
3.1492
2.7472
2*4361
2.1884
1.9864
1 .8185
1 .2783
0.9855
0.6758
0.5142
0.4150
0.3478
0.2628
0.2112
0.1416
0.1065
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0*0286
0.0268
0.0252
0.0238
0*0226
0.0215
0.0204
0.0195
0*0187
0*0179
0.0172
0.0165
0*0159
0*0153
0.0148
0*0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0*00
8*85
13*05
15.18
16*24
17*70
18*2%
19.10
19.55
19*72
19*94
20.11
20.28
20.44
20.72
21.00
21.17
21 .40
21.84
22.46
23.13
23.64
24.59
25.15
26.16
26.83
27.50
30.58
33.16
36*18
37.75
38.98
39.43
40.89
41.78
43.35
44.19
45.54
46.15
46.82
46.99
47.33
47*61
48*00
48.45
48.50
48*95
48*95
49.51
49.23
49.57
49.79
49.68
49.57
49.57
49.74
49.62
50*02
49*79
49.85
49.51
49.74
50.13
A8. 207
-------
Sample N 2
Sample N 5
PORE -EN TRANCE
DIAMETER*
MICRONS
58.5831
38. 1070
28.9915
22.7824
18.9891
16. 1377
14.0099
1 1.6402
10.4972
9.5651
8.7846
8. 1217
7.5522
7.0573
6.6227
6.2388
5.8974
5.5910
4.9486
4.4387
3.6801
3. 1431
2.7427
2.4329
2. 1859
1 .9844
1.8170
1.2776
0.9851
0. 6757.
0. 5142
0. 41 50
0.3478
0.2628
0.21 12
0. 141 6
0. 1065
0.0854
0.0712
0.061 1
0.0535
0 .0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME,
CU
MM/G
0. 00
6. 69
9. 69
0. 72
2.42
3.51
4.26
4.95
3. 65
4. 13
4.47
4. 74
5. 15
5. 56
5.70
5.97
6.52
6. 79
7. 68
18. 77
20. 48
22. 66
24.30
26. 48
28.05
29.55
31.33
36. 58
41.09
46.82
50.92
54. 60
56.51
62. 18
66.34
72. 55
75.97
78. 70
80. 40
81.36
82.04
82.52
82.93
83. 34
83.34
83. 41
84.09
83.88
84.22
84.29
84.57
84.09
84.22
84.70
84.50
84.70
85.04
85.52
84.91
85. 1 1
85.32
85.79
85. 45
PORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
38.4729
29.5644
23-7544
19.2729
16.6194
14.5280
1 1 .7429
10.5889
9.6420
8.8501
8.1775
7.6000
7.0989
6.6599
6.2720
5.9268
5.6174
4.9692
4.4556
3-6913
3.1511
2.7487
2.4376
2.1898
1 .9876
1 .8197
1 .2790
0.9860
0.6761
0.5144
0.4151
0.3479
0.2629
0.21 12
0.1417
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
9.24
13.33
15.74
17.48
18.49
19.36
20.50
21 .03
21.70
22.24
22.44
22.71
23.04
23.44
23.85
24.25
24.45
25.32
26.73
27.66
29.34
30.81
32.82
34.63
36.37
38.31
44.28
49.57
56.00
59.82
63.10
64.57
69.80
73.08
79.18
82.52
85.61
86.74
87.82
88.75
89.42
89.83
90.09
90.50
90.56
90.90
91 .10
91.30
91.43
91.50
91.57
91.70
91.90
91.90
92.24
92.10
92.10
92.17
92.10
92.37
92.71
92.77
A8. 208
-------
Sample N
Sample N 6
PORE- EN TRANCE
DIAMETER*
MICRONS
58.5831
39.3419
28.7727
23.0485
19. 1675
16.3764
14. 1444
1 1.7526
10.5968
9.6462
8.8534
8. 181 6
7.6036
7. 1015
6. 6618
6.2732
5.9277
5.6182
4.9695
4. 4557
3. 6918
3. 1515
2 . 7 49 1
2. 4379
2. 1900
1.9878
1.8199
1.2791
0.9860
0.6761
0.5144
0.4151
0.3480
0.2629
0.21 12
0. 1417
0. 1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE- VOLUME*
CU MM/G
0.00
7.21
10.82
12.39
13. 64
14. 56
15.48
16.20
16.72
16.79
17.25
17.90
18. 17
18.23
18.43
18. 56
18.82
19.02
19. 54
20.79
22. 49
24.33
25.90
27.74
29. 64
31.28
33. 12
38. 5e
43.28
49.32
54.04
58.37
61. 19
69. 58
75.62
86-31
90. 44
91. 68
92. 41
93. 19
93. 65
94.37
94. 57
94.83
95.09
95. 49
95.75
96. 14
96. 60
96. 41
96. 67
96.86
96.93
96.86
96.80
96. 60
96.01
96.08
96. 14
96.21
96.27
96.47
96.47
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
37.9648
28.6848
22.7135
18.8406
16.0184
13.9651
1 1 .8663
10.6917
9.7256
8.9194
8.2375
7.6523
7.1442
6.6999
6.3070
5.9576
5.6450
4.9909
4.4722
3.7029
3.1595
2.7551
2.4426
2.1936
1 .9907
1.8221
1 .2801
0.9866
0.6764
0.5145
0.4152
0.3480
0.2629
0.2112
0. 1417
0.1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0*0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME
CU MM/G
0.00
7.01
10.98
13.02
14.51
15.50
16.19
16.93
17.92
18.17
18.36
18.85
19.29
19.47
19.91
20.03
20.09
20.22
21.15
21 .52
22.82
24.25
25.55
27.10
28.15
29.08
30.08
33.55
37.15
41 .80
43.53
45.70
47. 13
51.16
53.39
58.17
59.72
61 .70
62.88
63.44
64.06
64.31
64.68
64.68
65.30
65.24
65.55
65.55
65.86
65.80
66.23
66.60
66.17
66.04
66.42
66.17
66.60
66.91
66.54
66.79
67.04
66.66
67.04
A8.209
-------
Sample N 7
Sample N 8
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.0204
88.6174
22.5037
18.7391
15.9464
14-1193
1 1 .8652
10.6895
9.7230
8.9176
8.2353
7.6499
7 . 1 42 5
6.6979
6.3053
5.9567
5.6442
4.9898
4.4717
3.7024
3.1589
2.7546
2.4420
2.1932
1 .9904
1 .8219
1 .2799
0.9865
0.6763
0.5145
0.4152
0.3480
0.2629
0.21 12
0.1417
0.1066
0.0854
0.0712
0.061 1
0.0535
0.0476
0.0428
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE PORE-ENTRANCE CUMULATIVE
PORE-VOLUME* DIAMETER* PORE-VOLUME*
CU MM/G
0 .00
8.50
12.12
14.26
15.46
16.67
17.27
18.08
18.88
18.95
19.28
19.55
19.82
20.22
20.42
20.55
21.09
21 .22
21 .69
22.56
23.70
24.70
25.84
26.98
28.32
29.39
30.53
34.21
37.36
41 .71
45.26
47.33
48.80
52.95
56.57
62.26
66. 14
69.89
71 .23
72.17
72.44
73.24
73.57
74.24
74.44
74.64
75.31
75.38
75.52
75.72
75.78
75.92
76.32
76.25
76.32
76.25
76.45
76.72
76.85
76.72
76.85
76.79
77.39
MICRONS CU MM/G
58.5831 0.00
38.7532 5.53
29.3854 8-86
22.9039 10.94
19.0248 12.63
16.1849 13.39
14.3730 13.95
1 1 .8252
10.6536
9.6948
8.8941
8.2154
7.6328
7. 1271
6-6843
6.2934
5.9460
5.6346
4.9824
4.4658
3.6983
4.71
4.77
5.21
5.59
S.90
6. 15
6.28
6.47
6.72
7. 16
7 .28
7.85
8.73
9.61
3.1559 20.55
2.7524 21.93
2.4405 23.82
2.1920 25.01
1.9895 26.58
1.8212 28.22
1.2798 34.13
0.9865 38.97
0.6764 46.95
0.5146 51.41
0.4152 56.12
0.3480 58.20
0.2629 69.07
0.2113 77.05
0.1417 97 . 10
0.1066 104.70
0.0854 108.04
0.0713 109.29
0.0611 109.42
0.0535 1 10.49 .
0.0476 10.99
0.0429 11.37
0.0390 1 1 .93
0.0357 12.25
0.0330 12.50
0.0306 113.00
0.0286 113.19
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
3.25
3.69
3.88
3.88
3.88
4.01
4.19
4.26
4.63
4.95
4.76
5.45
5.51
5.39
5.39
A8. 210
-------
Sample N 11
Sample N 12
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.0434
29.4354
23.2170
19.1685
16.3648
14.2703
1 1 .8367
10.6633
9.7041
8.9009
8.2200
7.6365
7.1310
6.6875
6.2961
5.9480
5.6366
4.9844
4.4685
3.7004
3.1576
2.7539
2.4417
2.1930
1 .9905
1 .8221
1 .2807
0.9873
0.6770
0.5150
0.4155
0.3482
0.2631
0.21 14
0.1417
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0-0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
8.30
12.57
15.67
16.22
18.62
18.85
19.16
19.32
20.25
20.33
20.25
20.41
20.95
21 .03
21 .26
21 .41
21 .80
23.04
25.68
27.31
28.86
31.19
33.60
35.38
38.87
41 .51
56.72
70.99
95.28
104.20
1 15.07
1 18.71
128.02
136.79
1 55.88
176.36
207.94
221 .36
231 .06
236.03
239.83
241.54
242.24
242.78
243.40
243.56
243-79
244. 10
244.33
244.56
244.72
244.95
245.26
245.57
245.88
245.96
246.04
246.27
246.50
246.27
246.35
246.19
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.7627
29.1564
23.2173
19.0867
16.3576
14.3102
1 1 .8703
10.7009
9.7327
8.9264
8.2437
7.6577
7. 1496
6-7045
6.3119
5.9624
5.6495
4.9946
4.4757
3.7057
3.1621
2.7574
2.4446
2. 1954
1 .9925
1 .8241
1 .2818
0.9879
0.6772
0.5151
PI. 4156
0.3483
0.2631
0.21 14
0.1417
0. 1066
0.0854
0.07 1 3
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME;
CU MM/G
0.00
10.03
13.95
16.79
18.71
19.99
21.13
22.56
25.05
25. 19
25.76
26.40
26.90
27.47
27.89
28.53
28.96
29 . 32
30.45
31.66
33.87
36.86
39.28
42. 19
44.33
47.82
52.23
67.67
79.48
95.85
1 37 .09
1 14.20
1 17.05
128.79
142.10
177. 18
194.89
203.50
205.21
206. 14
206.06
206.42
206.85
207.27
207 .63
207.70
207.77
207.99
208.27
208.48
208.84
208.77
209.05
208.98
209.27
209.27
209.05
208.91
209.34
209.34
209.41
209.55
209.76
-------
Sample N 13
Sample N
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
39.7882
29.3041
23.1789
19.3302
16.4201
14.3310
1 1 .8246
10.6456
9.6792
8.8799
8.2027
7.6215
7.1 171
6.6753
6.2851
5.9386
5.6283
4.9783
4.4631
3.6966
3.1551
2.7524
2.4406
2.1925
1 .9900
1.8219
1 .2809
0.9876
0.6771
0.5150
0.4156
0.3483
0.2631
0.21 14
0.1418
0.1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
0V0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252
0.0238
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
13.71
21.13
21.32
28-17
27.99
28.17
28.17
26.01
23.39
23.48
23.67
23.85
23.95
24. 04
24. 14
24.79
25.45
27.33
29.77
31 .46
34.47
39.26
42.17
47.05
51 .00
55.88
81 .71
104-25
131 .29
143.69
156.93
162.47
181 .73
204.08
262.12
297.15
314.43
317.34
318.56
318.94
319. 13
319.60
320.16
320.16
320.54
320.63
321 .00
321 .47
321.76
322.32
322.88
322.88
322.79
322.70
322.98
323.45
323.45
324.39
323.82
324.10
323.63
323.82
PORE-ENTRANCE
DIAMETER*
MICRONS
58.5831
38.6934
29.3017
23.0317
18.8789
16.2718
14.2473
1 1 .8642
10.6891
9.7239
8.9182
8.2361
7.6515
7. 1442
6.6997
6.3074
5.9584
5.6458
4.9915
4.4734
3.7041
3. 1605
2.7562
2.4438
2. 1951
1 .9922
1 .8238
1 .2818
0.9880
0.6773
0.5152
0.41 56
0.3483
0.2631
0.21 14
0.1417
0. 1066
0.0854
0.0713
0.061 1
0.0535
0.0476
0.0429
fl.fl.19Pl
0.0357
0.033PI
0.0306
0.0286
0.0268
0.0252
0.023R
0.0226
0.0215
0.0204
0.0195
0.0187
0.0179
0.0172
0.0165
0.0159
0.0153
0.0148
0.01 43
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
12.51
17.73
20.74
22.96
25.02
26.68
27.87
28.90
29.37
29.69
30.16
30.88
31.51
31 .99
32.54
33.01
33.25
34.36
35.86
38.32
40.38
43.31
47.03
51 .22
55.02
59.62
79.73
95.72
1 17.89
132.53
141 .96
146. 15
159.45
170.22
194.76
215.82
246.86
263.33
273.78
281 .06
285.65
288. 42
289.85
290.56
290.80
291 .04
291 .67
291 .91
291 .59
291 .99
291 .59
291 .12
290.96
291 .91
291 .99
291 .99
291 .99
291 .83
292.38
292.38
292.70
292.70
212
-------
Sample N15
fwno— £i».L iviuiv/n
DIAMETER,
MICRONS
58.58
39.38
29.05
22.92
19.06
16.21
14.09
• * • V X
11.86
10.69
9.72
8.92
8.23
« • *-. _y
7.65
f • ^.x
7.14
f • A i
6.70
6.30
5.96
^/ • x"
5.64
4.99
••XX
4.47
3.70
3.16
_X • ^v^
2.76
2.44
2.19
1.99
1.82
1.28
0.99
0.68
0.52
0.430
0.358
0.269
0.215
0.143
0.108
0.086
0.072
0.0614
0.0537
0.0478
0.0430
0.0391
0.0358
0.0331
0.0307
0.0287
0.0269
0.0253
0.0239
0.0226
0.0215
0.0204
0.0195
0.0186
0.0179
0.0172
0.0165
0.0159
0.0154
0.0148
0.0143
^unuiitti\LV&
PORE-VOLUME,
CO MM/G
0
12.55
19.38
21.56
23.74
25.47
26.84
28.02
29.84
30.39
30.93
31.20
31.48
31.66
32.02
32.57
33.12
S *s • •^«—
33.57
34.66
.35.84
37.30
39.76
43.31
46.94
50.86
55-13
59.41
81.24
98.17
123.28
138.01
152.75
161.67
201.15
241.73
286.49
292.31
294.13
294.26
294.77
294.77
295.04
295.32
295.68
295.77
296.04
296.41
296.23
296.77
297.41
297.41
297.68
297.96
297.86
297.68
297.59
297.50
297.86
29V.68
298.41
298.68
298.87
299.32
°ORE-ENTRANCE
DIAMETER,
MICRONS
58.5831
39.0653
28.8529
22.9621
19.0113
16.3489
14.1715
1 1 .8235
10.6'522
9.6913
8.8905
8-21 16
7.6300
7.1246
6.6823
6-2919
5.9442
5.6330
4.9813
4.4649
3.6976
3.1557
2.7522
2.4402
2. 1918
1 .9893
1 .8210
1 .2797
0.9865
0.6763
0.51 46
0.4152
PI. 3 480
0.2629
0.21 13
0.1417
0. 1066
0.0854
0.07 1 3
0.061 1
0.0535
0.0476
0.0429
0.0390
0.0357
0.0330
0.0306
0.0286
0.0268
0.0252 -
0.0238
0.0226
0.0215
0.0204
0.0195
0*0187
0.0179
0*0172
0.0165
0.0159
0.0153
0.0148
0.0143
CUMULATIVE
PORE-VOLUME*
CU MM/G
0.00
8.72
12.97
14.82
16.25
17.09
18.04
18.76
18.82
18.70
18.88
18.94
19.36
19.48
19.72
20.08
20.26
20.43
21 .03
21 .87
22.59
24. 14
25.39
26.65
28.14
29.64
30.65
36.51
42.18
49.00
53.78
57.96
60.41
68.47
75.64
85.44
88.55
91 .00
9 1 .66
92*38
92.61
93.27
93.69
94.23
94.82
95.78
96.26
96.74
97.45
98.05
98. 1 1
98.77
98*83
99.37
99.60
99.72
99.55
100.14
100.92
100.92
100.62
100*86
100.74
A8. 213
-------
Sample 01
Sample 02
PORE-ENTRANCE
DIAMETER,
MICRONS
58.58
38.39
23.04
19.06
16.41
14.30
13.06
11.80
10.64
9.69
8.89
8.21
7.63
7.13
6.69
6.30
5.95
5.64
4.990
4.473
3.703
3.
2.
2.
2.
1.
1.
.160
.756
.443
.194
.991
.822
1.280
0.987
0.677
0.515
0.4JO
0.358
0.269
0.215
0.143
0.108
0.086
0.072
0.0537
0.0430
0.0358
0.0307
0.0269
0.0239
0.0215
0.0195
0.0179
0.0165
0.0154
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/G
8.98
19.24
22.55
25.98
28.55
30.28
32.80
35-49
35.64
36.59
38.24
39.59
41.24
42.73
43.92
45.02
46.21
49.44
51.89
54.41
57.80
60.55
63.09
65.13
67.03
68.76
75.70
82.24
95.97
109.21
123.16
131.84
148.8?
159.68
174.18
180.11
184.12
185.86
187.91
189.57
190.75
192.01
192.72
193.19
193.67
194.45
195.16
195.48
195.79
196.35
PORE-ENTRANCE
DIAMETER,
MICRONS
58.58
38.87
28.89
22.85
18.99
16.37
14.26
12.87
11.79
10.64
9.68
8.88
8.21
7.63
7.12
6.68
6.29
5.95
5.64
4.98
4.4?
70
16
2.75
2.
2.
1.
1.
1.
.44
.19
• 99
.82
.28
0.987
0.677
0.515
0.430
0.358
0.269
0.215
0.143
0.108
0.086
0.072
0.0537
0.0430
0.0358
0.0307
0.0269
0.0239
0.0215
0.0195
0.0179
0.0165
0.0154
0.0143
CUMULATIVE
PORE-VOLUME,
CU MM/Q
10.11
16.09
20.14
22.81
24.75
27.04
28.79
29.84
32.35
33.16
34.13
35.18
35.91
36.88
37.93
39.39
39.95
40.60
43.84
47.4?
50.79
53.14
55.80
57.66
58.79
61.22
63.49
72.38
78.45
93.24
107.72
120.51
129.88
142.02
154.32
165.79
171.22
175.82
177.31
178.35
181.63
183.87
184.46
185.65
185.95
186.10
186.10
186.50
186.70
187.74
187.59
A8. 214
-------
NATIONAL COAL BOARD
FINAL REPORT
JUNE 1970 - JUNE 1971
REDUCTION OF ATMOSPHERIC POLLUTION
APPENDIX 9. METHODS FOR DETERMINATION OF NITROGEN OXIDES
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
411 WEST CHAPEL HILL STREET
DURHAM, NORTH CAROLINA 27701
FLUIDISED COMBUSTION
REFERENCE NO. DHB 060971 CONTROL GROUP
NATIONAL COAL BOARD
SEPTEMBER 1971 LONDON, ENGLAND
-------
Research on reducing emission of sulphur oxides,
nitrogen oxides and particulates by using
fluidised bed combustion of coal
Appendix 9. Methods for determination of nitrogen oxides
Report prepared by: J.T. Shaw
Report approved by: A.D. Dainton and H.R. Hoy
A9. iii
-------
Page No.
1. Introduction A9. 1
2. Sampling Trains A9. 1
2.1 Probe used in 48 in x 24 in pressurised combustor A9. 1
2.2 Probes used in atmospheric pressure combustors A9. 2
2.3 Rate of flow of gas through the probes A9. 2
2.4 Material of connecting tubes A9. 2
2.5 Conditioning the probes and associated tubing A9. 3
2.6 Rate of off-take of gas from the probes to the
analytical train A9. 3
2.7 Removal of SCL, HC1 and other soluble gases from the
gas led to the analytical train A9. 3
3. Methods of Analysis A9. 4
3.1 Determination of NO remaining in the gas A9. 4
x o
3.1.1 Use of BS 2069 grab-sample bottles
containing Saltzman's reagent A9. 4
3.1.2 Use of BS 2069 grab-sample bottles not
containing any reagent A9. 6
3.1.3 Use of BCURA NO Box A9. 7
X
3.2 Determination of NO removed from the gas by water A9.10
X
3.2.1 Analysis of the quenching water A9.ll
3.2.2 Analysis of the water from the Drechsel bottles A9.ll
3.3 A typical calculation A9.12
3.4 Relevance of the 'Saltzman Factor' A9.13
4. References A9.14
Figures A9.1 - A9.4
(Note that when referring to Tables and Figures in the text the
prefix A9 is omitted).
A9.v
-------
1. INTRODUCTION
Measurements of the NO content of the flue gases were made in
X
Tasks I, II and III. The difficulties encountered in obtaining an
accurate measurement of the concentration of oxides of nitrogen in
flue gases are well-known and much more development work is necessary
before a definitive method can be proposed. Accordingly, the pro-
cedures used in the present programme are described in detail in this
Appendix.
Because of delays in delivery of equipment it was not possible
to measure the NO concentrations by infra-red absorption, as had
X.
been intended.
2. SAMPLING TRAINS
The determination of reactive constituents of flue gas such as
NO and NO- is complicated by their tendency to 'disappear' as they
pass through the sampling system. Therefore, in addition to the
importance of choosing a sampling position that permits a truly
representative sample to be obtained is that of ensuring that as far
as possible the sample so obtained is preserved without change in
NO content until it enters the analytical system.
• Halstead, Nation and Turner in work confirmed and extended
7
by Shaw and Gray , showed that hot stainless steel is amongst those
materials capable of causing losses of NO in certain conditions,
X
whereas silica appears to be inactive. These findings led to the
following designs of sample probe.
2.1 Probe used in 48 in x 24 in pressurised combustor
The flue gases from this combustor were at 1450 F and 5 atm
pressure. These conditions; coupled with the general design of the
combustor made it difficult to fit a silica probe. A stainless
steel probe having water injection at the gas inlet was therefore
set .up. The flow of water was sufficient to cool the gas very
quickly to below 200 F, thus it is believed quenching the reactions
that might otherwise have led to undue loss of NO or of NO^. An
incidental advantage of using water is that it removed S0_, HC1 and
other soluble compounds that if allowed to remain would have
interfered with the chemical determinations of NO in the gas. The
X
A9.1
-------
amount of NO removed from the gas phase by the water was determined
X
by methods described in section 3.2.
Water injection was not always used. Tests were carried out to
see what difference was made by turning the water on and off. No
difference was found, indicating that the water was unnecessary in
the conditions in which the combustor operated. The conditions in
which the water might have been expected to be really necessary (low
0_, high CO in the gas) were never encountered during the present
tests.
2.2 Probes used in atmospheric pressure combustors
A silica tube supported externally by a steel tube was used
for sampling from the atmospheric combustors where the gas temperature
was typically 600 F.
2.3 Rate of flow of gas through the probes
In order to minimise surface/volume effects the rate of flow
of gas was kept as high as possible.
There was no difficulty in getting a high rate of flow from
the pressurised combustor, about 45 litres/min, but from the 1 atmos.
combustors the capacity of the pump used ( a Dymax II) was a limita-
tion and enabled only some hundreds of ml/min to be withdrawn.
2.4 Material of connecting tubes
At the pressurised combustor the main length of tube connecting
the probe to the analytical train (about 20 metres) was made of
stainless steel. The great preponderance of NO over N0_ in the
NO content of the flue gas made it practical to use flexible PVC
X
tubing as opposed to PTFE to connect the glass apparatus in the
analytical train, but the lengths were kept short, i.e. about
1 metre in all. The rate of flow through the PVC was 100 ml/min.
At the atmospheric pressure combustors, NO again preponderated greatly
over N0? in the flue gas making it again practical to use flexible
PVC. The main length of tube connecting the silica probe to the glass
apparatus was of this material, with some PTFE. Total length was about
5 metres.
A9.2
-------
3. METHODS OF ANALYSIS
This section describes the analysis of the gas and of the water
used for injection and in the Drechsel bottles, and ends with a
comment on the 'Saltzman Factor1.
3.1 Determination of NO remaining in the gas
Of the three methods that were used to determine the NO content
X
remaining in the gas, two were chemical and one used an instrument,
the BCURA NO Box. The three methods are described in detail below.
X
3
3.1.1. Use of BS 2069 grab-sample bottles containing Saltzman's reagent
This method has the advantage that absorption of NO in the reagent
X
can begin as soon as the sample has been obtained. Grab-sample bottles
made up in accordance with BS 2069 and having a volume of about 400 ml
were used. They were cleaned initially, and later whenever necessary,
with trichlorethylene which was then washed out with acetone. Before
each test the bottles were cleaned by rinsing with nitrite-free hot
water followed by acetone which.was then evaporated off in a current
of air. The taps were greased with the minimum of Apiezon N.
To carry out a test, Saltzman's reagent was made up in
4
accordance with instructions. The grab-sample bottles were partially
evacuated to enable the required quantity of reagent to be sucked in;
a convenient volume was found to be 40 ml of reagent in each bottle.
Air was then removed from the bottles as far as possible by means of
a filter pump. The taps were closed and checked for leakage, after
which the bottles were ready for use. Before taking a sample into
the first of a series of bottles, the flue gas was led at 100 ml/min
through the Drechsel bottles described in section 2.7 for about 10
minutes to flush out all air as described in sections 2.5 and 2.7.
The gas was then drawn slowly into the gas sample bottle by suction,
keeping the flow through the Drechsel bottles at about 100 ml/min.
The gas sample bottle was held upright with the gas inlet at the
bottom so that the gas bubbled through the reagent. When no more
gas would enter, the tap was closed. After disconnecting the bottle,
the tap was carefully opened a little in order to bring the pressure
back to that of the atmosphere (the flow control valves were always
adjusted in such a way as to ensure that the pressure in that part
of the line between the pump and the grab sample bottle slightly
A9.4
-------
2.5 Conditioning the probes and associated tubing
In order to reduce any effect of the probes and tubing on the
samples, gas was drawn through at the normal rate for about an hour
before analyses were begun. This occasionally produced condensation
in the tube leading from the dry probes (i.e. those without water
injection) but this was ignored on the grounds that the condensate
would be in equilibrium with the NO in the gas and that, because
the N02 concentration was low, losses of this gas could safely be
ignored. The purging for 1 hour did not extend to the Drechsel
bottles (section 2.7) where these were used; they were purged for
10 minutes only to prevent undue contamination of the water.
2.6 Rate of off-take of gas from the probes to the analytical train
From the probes the main gas flow was divided into a major
portion, which went to waste, and a minor portion, 100 ml/min, which
was led to the analytical train through short tubes.
2.7" Removal of S0?, HC1 and other soluble gases from the gas led to
the analytical train
The gas flowing at 100-ml/min to the analytical train from the
silica probe still contained' S0_, HC1 and other soluble gases, as
this probe had no water injection. These constituents were removed
by leading the gas through two 250 ml glass Drechsel bottles in
series, each containing about 200 ml of (initially) distilled water,
which was changed regularly, usually after about 5 litres of gas had
bubbled through. Chemical analysis showed that, although the water
removed SO very efficiently, it did not dissolve much of the NO in
2, X
the gas passing through, the amount dissolved usually being under 5%
of the amount of NO remaining in the gas. Purging the Drechsel
X
bottles with flue gas was carried on for 10 minutes at 100 ml/min
before1 the'first grab-sample bottle of a series was attached. (See
also section 2.5).
As mentioned in section 2.1 some of the tests at the pressurised
combustor were carried out without water injection, and for these the
system of Drechsel bottles was used to ensure the removal of S0_. The
visual indication of flow afforded by the Drechsel bottles was found
to be useful and they were retained thereafter whether the injection
water was on or not.
A9.3
-------
exceeded that of the atmosphere to preclude any possibility of
inleakage of air). Because the NO content of the gas was
X
preponderantly NO, any error involved through excess absorption
in the reagent during the very brief period of slight excess
pressure can be ignored.
The barometric pressure and the temperature of the sample
bottle were measured and the next bottle was then applied to the
gas flow.
A description of the technique of working up the solutions
follows.
3.1.1.1 Working up the solution
(a) The gas bottle containing reagent was left for about
30 minutes. Then it was held vertically over a flask
and the bottom tap was opened to let the coloured
reagent run out, if the pressure in the bottle would
permit this. If the reagent ran out freely (as when
the laboratory was warmer than the sampling site)
care had to be taken not to lose some gas also.
If the reagent did not run out freely the top tap
was opened to let in air, thus allowing the reagent
to run out.
(b) When all the reagent had run out the taps were closed
and the central portion of the bottle was cooled in
solid CO.. (A special box was made from expanded
polystyrene for this purpose; the ends of the bottle
carrying the taps protruded through holes at each end
of the box).
(c) A vessel containing a fresh quantity of Saltzman's
reagent was connected to the gas sample bottle. The
tap of the bottle was opened to admit the reagent,
which was drawn in by suction. As much reagent as
possible was drawn in at this stage.
A9.5
-------
(d) The gas sample bottle was removed from the solid CO-
and was allowed to warm up. After about 30 minutes,
the bottle was again held vertically and the lower
tap was opened to allow the (by now coloured)
reagent to flow into a graduated flask. Although
the pressure within the bottle was often more than
sufficient to expel all the reagent, in which case
particular care was taken to avoid loss of gas, it was
often the case that not all the reagent would flow out.
The upper tap was then opened to admit air and allow
the rest of the reagent to flow into the flask. The
solution was diluted at this stage with fresh reagent
if the colour was very strong.
(e) The gas bottle was cooled again, and more reagent was
sucked in, together with some air to encourage oxida-
tion of the NO remaining in the bottle, if not enough
air had been drawn in previously.
(f) The procedures (d) and (e) were repeated until the
colour developed by the solution after 30 minutes was
no longer appreciable with respect to that of the first
extraction. The solutions were then pooled and made
up to a known volume with fresh reagent. After dilution
of an aliquot with fresh reagent, if necessary, the
intensity of the colour was measured. This precluded
error due to loss of colour intensity overnight in
this solution.
(g) Procedure (e) was repeated and the bottle was left
overnight.containing the reagent. The coloured solution
was withdrawn the following morning, was made up to a
known volume, and the intensity of colour was measured
at 550 nm using a Unicam SP600 spectrophotometer.
3.1.2 Use of BS 2069 grab-sample bottles not containing any reagent
Provided that reagent was introduced within a few minutes of
obtaining the sample, so as to minimise losses due to conversion of
N0_ to nitrate or other causes, this method was found to give results
A9.6
-------
in good agreement with that described in section 3.1»1, but had the
advantage that the volume of gas sample trapped in the bottle could
be 'more accurately known.
The bottles were not evacuated after washing and drying,
but were attached one at a time to the .flow of gas., emerging from
•' Che ;Drechs;;el bottles referred to in sections 2.5, 2.7 and 3.1.1
and gas was allowed to flow through at 100 ml/min (checked by a
rotameter at the outlet end) for 20 minutes. The taps were closed,
and after removing the bottle from the gas-line and bringing the
contents down to atmospheric pressure by momentarily opening one
tap, the bottle was cooled in dry ice as described in section 3.1.1 (b)
for introduction of reagent. Subsequent procedure was as described in
3.1.1 (c) onwards.
3.1.3 Use of BCURA NOjE Box
The heart of the NO Box is an oxidant-sensing device, the basic
X 56
principle of which was described by Hersch ' ' It was described again
by Shaw who gave a modified construction for it. Further improvements
have since been made and the latest construction is shown in Fig. 1.
The device is not specific but will determine N0_ if this is the only
species reaching the device that is oxidisable or reducible at the
electrodes.
To determine NO or NO by means of this meter it is necessary
X
to incorporate an oxidiser that will convert NO to N0?. The one used
in the BCURA NO Box, consisting of glass wool impregnated with
chromium trioxide and sulphuric acid, was described by Bethell, Shaw
8 7
and Thomas and again by Shaw .
Other necessary qonstituents of the NO Box are a gas flow-
X
meter and a microammeter. Optional adjuncts are a gas flow control
valve and a constant-flow device, gas-washing bottle, a drying tube,
a soda-lime tube, a gas pump, a range-change facility and a plug to
connect the electrical output of the meter to a chart recorder.
(The recorder does not form part of the meter), Except for the range-
change facility and plug for electrical connection to a recorder,
which are mounted in or on the casing of the NO Box, these optional
adjuncts can be mounted inside the box or they can be kept separate
if that is more convenient.
The flow chart for the NO Box is given in Fig. 3.
X
A9.7
-------
3.1.3.1 Galvanic principle of the NCU sensor
The NO sensor is believed to work as follows:
At the moist platinum gauze electrode:
N02 + H20 + 2e = NO + 20H~
Hydroxyl ions travel through the electrolyte to the active
carbon electrode, at which:
20H~ + ' ' 'C(s) - H20 + ' * °CO + 2e
The hydroxyl ions are discharged, and the electrons flow
through the external circuit where they actuate a galvanometer, and
return to the platinum gauze. The oxygen combines with the active
carbon to form a (presumably) solid product written as " ' 'CO.
Not all the N0? reaching the sensor reacts thus. Some is
dissolved non-galvanically.
H20 + 3N02 = 2HN03 + NO
and the NO thus produced is swept out of the sensor with the rest of
the gas, which normally also contains some N0_ that has not reacted
in any way. The rate of the non-galvanic reaction is temperature-
dependent, as also is the efficiency with which NO- diffuses to the
gauze. Accordingly, the efficiency with which NO- is trapped to
react galvanically is also a function of temperature. For the best
results therefore, the instrument should be kept at constant tempera-
ture.
3.1*3.2 Eleptrolyte
This consists of 3 moles KC1 and 0.1 mole each of KH2PO, and
K2HPO, per litre of water.
3.1.3.3. Electrical Circuits
For most purposes hitherto encountered by BCURA, a 100 ya fsd
microammeter is sensitive enough to give useful indications of the
output from the sensor, as at low concentrations of N0» the response
is about 1 ya per p.p.m. v/v, when the flow rate of gas is 100 ml/min.
A9.8
-------
The response falls off at higher concentrations so that a current
of 100 ya represents more than 100 p.p.m.
/
For concentrations that would-otherwise overload the micro-
ammeter a shtint is fitted. (If this is not sufficient the gas
must be diluted). For use with concentrations, that would give
too small a deflection on the microammeter there is a potential
divider the potential difference across which can be recorded on
a chart recorder if one is available. This is usually arranged to
give sensitivities equal to x 10 and x 100 that of the micro-
ammeter.
The circuit diagram for a typical example of the meter is
given in Fig. 4 and is discussed below.
The full sensitivity of the sensor/microammeter set-up is
obtained by having no resistance in series with .them. To obtain
good sensitivity on a recorder, together with a range-change facility,
and at the same time make the recorder indicate a number (e.g. 6.7
millivolts) corresponding to the number (e.g. 67, 6.7 or 0.67 micro-
amperes) indicated by the pointer of the microammeter, a fairly high-
resistance potential divider is connected in parallel with the sensor
and microammeter. In the range-change facility the resistances
across which the recorder can be connected are 100, 1000 or 10,000
ohms. The total resistance of the potential divider shown on Fig. 4
is 11,500 ohms, which is 10 times that of the microammeter that was
fitted to the NO Box for which the circuit was prepared. For a
X
microammeter having a different resistance obviously a different
make-up resistance would be needed in order to obtain a potential
divider having 10 times the resistance of the microammeter.
Resistances of the exact values needed are not normally obtainable
but can easily be made up by connecting resistances in series and/or
in parallel.
The resistance of the potential divider as a whole is high enough
to have little desensitising effect on the meter, i.e. it shunts off
only 9.1% of the total sensor current output. This slight loss can
easily be further reduced e.g» if the resistance of the potential
divider were made 10 times as great, the current shunted off would
become only 0.99% of the total sensor output.
A9.9
-------
A further shunt is shown on Fig. 4. This, a resistance of
760 ohms, is the amount found necessary by trial and error to
divide the meter and recorder readings by 2, on the instrument for
which the circuit was prepared.
An account of the way in which the NO Box responds to changes
• X
in the NO concentration, flow-rate of carrier gas, and temperature
7
is given in Shaw .
3.1.3.4 Setting up the NO Box
*™ ""*""™"™^™X —^^™»
The electrolyte level was checked. The Drechsel bottles (see
sections 2.5, 2.7 and 3.1»1) were filled with fresh distilled water.
About a dozen small lumps of blue silica gel were placed in the PVC
tube leading from the Drechsel bottles to the dxidiser of the NO Box.
This was enough to dry the gas sufficiently well to prevent undue
6 •
moistening of the oxidiser, but. not enough to cause undue delay in
reaching equilibrium conditions as regards passage of NO over the
drying agent, which absorbs MO to some extent.
3.1.3.5 Calibrating the NO Box
This was done by passing known concentrations of NO in N»
through the Drechsel bottles, drying agent and NO Box at the
A
standard flow rate of 100 ml/min and waiting till a steady electrical
output was attained in each case. The known concentrations were
obtained from cylinders,supplied by British Oxygen Ltd., London.
A graph was plotted in order to relate the meter, reading of
the NO Box to the known NO concentration passing in. .
3.1.3«6 Determination of the NO content of a flue gas
The gas was passed at 100 ml/min through the Drechsel bottles,
drying agent and NO Box until a steady electrical output was obtained.
The NO concentration was read from the calibration graph referred to
in section 3.1.3.5.
3o2 Determination of NO removed from the gas by water
^^"™*"^™^—*"^™*^^""'^*"^"^^^"^^^**^^"'"^^^™™X ^"^
This section covers analysis of the quenching water used with
the stainless steel probe, and of the water from the Drechsel bottles
used with both probes.
A9.10
-------
3.2.1 Analysis of the quenching water
The rates of flow of water and gas were measured. The analysis
was carried out by means of Saltzman's reagent. Probably because of
the presence of dissolved sulphur dioxide, the colours obtained were
not very stable. It was found, also, that if Saltzman's reagent was
added to aliquots of a sample at different times after obtaining the
sample, the strongest colour was obtained from the aliquot treated
first. The experiments were therefore carried out without loss of
time after each sample had been obtained.
In calculating the results, it was assumed that for each mole
of NO dissolved from the gas, half a mole of nitrite ion appeared
in the water.
The method was quick and was easy to use, and from that point
of view had great advantages over the phenol disulphonic acid method.
The validity of the method was tested by an experiment in which flue
gas was drawn through a probe not fitted with water injection during
combustion conditions such that loss of NO in a dry probe would not
2C
be expected. Good agreement was obtained between the NO values so
obtained and those obtained through the "wet" probe after adding the
concetration of NO removed by the water and determined as above.
X
3.2.2 Analysis of the water from the Drechsel bottles
This was carried out by two methods, namely the Saltzman method
and the phenol disulphonic acid method.
3.2.2.1 Saltzman method
As with the quenching water, Saltzman's reagent was added to
aliquots of the 'Drechsel water1 and the colour intensity was
measured. It was assumed that each mole of NO dissolved from the gas
gave rise to half a mole of nitrite ion in the water.
3.2.2.2 Phenol sulphonic acid method
This was carried out in accordance with the provisions of NCB
0
Report No, 26/95 but phenol disulphonic acid was used instead of
phenol para sulphonic acid. The method is closely similar to that of
ASTM D 1608-60 «,10
A9.ll
-------
3.2.2.3 Results of analyses of the 'Drechsel water'
The two methods referred to above each indicated that the amount
of NO dissolved from the gas sample by the water in the Drechsel
X
bottles was small, although they varied in their indications of
quite how small. On the whole the Saltzman method used with the
assumptions mentioned gave the highest results, usually showing that
the water had retained NO amounting to up to 5% of the quantity
X
determined as remaining in the gas.
3.3 A typical calculation
Barometric pressure 765 mm Hg.
Temperature of gas bottle 23 C.
Volume of gas bottle 407 ml.
Coloured solutions were pooled and made up to 250 ml.
An aliquot of 10 ml was diluted to 50 ml.
Optical density of the diluted aliquot : 0.343 units.
Optical density of a solution containing 2.00 ml of Na N0?
(0.0203 g/1) made up to 50 ml with Saltzman's reagent was
0.539 units.- (1.00 ml of the nitrite ElO,0 y 1 of N0_ at
25°C, 760 mm Hg.
Vapour pressure of water at 23 C : 21.13 mm Hg.
The Drechsel bottles were purged with gas for 45 minutes
altogether, at 100 ml/min.
The equivalent of 20.4 yg of NOj was found in the first
Drechsel bottle, by the phenol disulphbnic acid method.
The equivalent of 6.9 yg of N0? was found by the same
method in the second Drechsel bottle.
P.p.m. v/v (dry basis) of NO in the gas sample in the
X
bottle:
250 50 0.343 1000 760 296 ( 760 ) 7Q_.,
••«•• "V "^™^ Y ••^••^il^*" "V ^^™^«^»" V ™^*™^ V »^B«^"™ V »"»™™M*««».^B™» T / U J fl
20 x 50 x 10 x 0.539 407 765 298 (760-21)
Volume of NO , per 407 ml of sample, dissolved by the Drechsel
X
water:
407 ml- A
46 A «•«"•* - 45 x 100
(Assuming constant rate of solution)
A9 = 12
-------
On a p.p.m. v/v basis the correction becomes A x -rr=-
407
(20:4 + 6.9) . ___. 104 „ _
_ x 0.0224 x-rr— = 3.0
46 45
Therefore,
Total NO in the original gas sample
X
(dry basis) = 796.4 p.p.m., say 800.
3.4 Relevance of the 'Saltzman Factor'
NO measurements quoted in the Main Report and the Appendices
have been calculated on the basis that the 'Saltzman Factor' is 0,72.
There is reason to believe that when grab sample bottles are used
(as in the work reported here) as opposed to sintered bubblers a
Saltzman Factor of 1.0 may be more appropriateo If this proves to
be true it means that the NO concentrations quoted up to now are too
X
high and should be multiplied by 0.72.
The NO Box was calibrated with NO/N,, mixtures the concentration
X £»
of which, certified by British Oxygen Company Ltd. London, is believed
to have been measured on the basis of a 0.72 factor when possibly it
should have been 1.0, as grab sample analysis was used by British
Oxygen Company Ltd. London. If this is so, it means that the NO Box
X
values are also too high and should be multiplied by 0.72. The good
agreement between NO Box and Saltzman determinations at the fluidised
X
bed combustors would remain unaffected if this were so0
A9ol3
-------
4. REFERENCES
1. Halstead, C.J., Nation, G.H. and Turner, L. 1970, Private
communication.
2. Shaw,:J.T. and Gray, B.A. 1970, Private communication.
3. BS 2069 Design of grab-sample bottles. British Standards
Intitute, London, 1954.
4. Saltzman, B.E. Analyt.Chem., 1954 _26, 1949-1955.
5. Hersch, P. & Deuringer, R., Paper to Anachem. Conf., Detroit,
October 1963.
6. Hersch, P. Galvanic analysis, Advances in Analytical
Chemistry and Instrumentation, Ed. Reilly, C.N., Vol. 3,
Interscience, New York, 1964. 230,233-234.
7. Shaw, J.T., 1968, Brit. J. Anaesth. 40, 299-303.
8. Bethell, F.V., Shaw, J.T. and Thomas, A., Chem. Ind. 1968 (3)
91.
9. NCB, East Midlands Division Scientific Dept. Rpt. No. 29/65,
1965.
10. D 1608-60. American Society for Testing Materials, 1960.
5. ACKNOWLEDGEMENT
Members of staff of BCURA who took part in the experimental work
included B.A. Gray and M.P. Mendoza.
A9.14
-------
PVC
tubing
Gas outlet
Pt gauze
containing
glass fibre
paper wick
PTFE tubing
Gas inlet
Wick dips into
electrolyte
Tightened clip
Pt wire
, Electrolyte
reservoir
Active carbon
electrode
Pt wire
n
Electrolyte
level
J
Tightened
clip
PVC tubing
Fig. A9.1. The sensor : 1970 design
A9.15
-------
CO
I—I
Oi
Gas inlet
fitted to
PTFE tubing
Ground glass joint
very lightly greased
xxxxxyxxxxxxxxxxxxxxxxxxxxx
XXXXXXXXXXXXXXXx X X X X X X X X X XX
XXXXXXXXXXXXXXXXX X XXXXXX XX X
Gas outlet
Fig. A9. 2. NO oxidiser unit, oxidising NO to NO2- Also retains some SO2
-------
Filter
Dymax n
diaphragm pump
Drechsel bottles
containing
distilled water
From flue
Row
control
valve
Fast flow
to waste
Small
drying
tube
(silica gel)
Gas to
waste
Oxidiser
Flowmeter
Sensing unit
(see Fig.2)
t
Microammeter
Fig. A9.3. Flow chart for use when determining NQ< in flue gas
when sampling from a duct at atmospheric pressure. (The
NOX is presumed to be mainly NO) j
A9.17
-------
Sensor
(Fig.1)
CO
H-"
CO
Micro-
ammeter
L
Recorder
-760 ft
150O 9OO 1OO 9OOO
Q Q Q n
Fig. A9. 4. Circuit diagram with typical resistance values for BCURA NOx meter
------- |