United States
Environmental Protection
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S9-85/020  Sept. 1985
Project  Summary
Proceedings:  First  Joint
Symposium  on  Dry 862 and
Simultaneous  SO2/NOX
Control  Technologies
P. Jeff Chappell, Compiler
  The First Joint Symposium on Dry
SOz and Simultaneous SO2/NOX Con-
trol Technologies was held November
13 through 16, 1984, in San Diego,
California. Forty-six papers were pre-
sented, beginning with a keynote ad-
dress on acid rain strategies and control
technology implications, followed by
overviews of EPRI, EPA, and Canadian
programs and the utility perspective for
dry control technologies. Other papers
focused on the latest advances in fun-
damental research and process design,
power plant integration and economics,
field applications, and full-scale testing.
  Participants from West Germany,
France, The  Netherlands, Austria,
Canada, and Japan  provided a world-
wide update on technological develop-
ments and an international perspective
on SO2 and SO2/NOX control issues.

  This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in two separate volumes of the
same title (see Project Report ordering
information at back).

  The First Joint Symposium on Dry SOz
and  Simultaneous  SOz/NO, Control
Technologies was held November 13
through 16, 1984, in San Diego,  Cali-
fornia, and jointly sponsored by EPRI and
EPA,  was  the  first meeting of its kind
devoted solely to the discussion of emis-
sions control processes based on dry
injection of calcium or sodium sorbents to
meet S0a and NO, regulations for coat-
fired power plants. Processes that were
discussed included: direct furnace injec-
tion of calcium-based sorbents, sorbent
injection combined with low-NOx burners
for simultaneous SOa/NO* control, and
post-furnace injection of calcium  and
sodium sorbents.  The symposium  pro-
vided a timely forum for the exchange of
data for information on the current status
and plans for these emerging technol-
  Forty-six papers were  presented, be-
ginning with a keynote address on acid
rain strategies and control technology
implications, and followed by overviews
of the EPRI, EPA, and Canadian programs,
and the utility perspective for dry control
technologies. Other papers focused on
the latest advance in fundamental  re-
search and process design, power plant
integration and economics, field applica-
tions, and full-scale testing. A panel of
representatives from architect-engineer-
ing firms, boiler manufacturers, and utility
companies discussed  the impact of dry
S02  control processes on new  and
existing power plants.
  Speakers included EPRI and EPA staff
members as well  as representatives of
utility companies, manufacturers of utility
boilers and process equipment, sorbent
suppliers, and research and development
groups conducting investigations spon-
sored by EPRI, EPA, and  others. Partici-
pants from West Germany, France, The
Netherlands, Austria, Canada, and Japan
provided a worldwide update on techno-
logical developments and an international

perspective on S02 and S02/NOX control
  Symposium Cochairmen were Michael
W.  McElroy, Subprogram Manager of
EPRI's Air Quality Control Program in the
Coal Combustion Systems Division, and
Richard D.  Stern, Chief of EPA's LIMB
Applications Branch of the Air and Energy
Engineering Research  Laboratory.  The
welcoming  address  was given by John
Hamrick, Vice  President of Customer
Service for San Diego Gas & Electric, and
the keynote address was given by Donald
J. Ehreth, Deputy Assistant Administrator,
Office of Research and  Development,

  The  symposium  proceedings  have
been published in two volumes:

 • Volume 1: Fundamental Research and
   Process Development
   —Session I: Introduction
   —Session II:  Fundamental Research
   —Session III: Pilot-Scale Development
     of Furnace Injection
   —Session IV: Burners for Simultane-
     ous SO2/NOX Control
   —Session V: Post-Furnace SOz Re-

 • Volume  2: Power Plant  Integration,
   Economics, and Full-Scale Experience
   —Session VI: Process Integration and
   —SessionVII: Sorbent Availability and
   —Session VIII: Field Applications and
     Full-Scale Testing

  1.  "Acid  Deposition Strategies and'
     Implications for Control Technology
     Requirements," Donald J. Ehreth,
     EPA/Office of Research and  De-
  This paper  represents the keynote
address for the First Joint Symposium on
Dry S02 and Simultaneous S02/N0,
Control Technologies. The paper presents
the factors that have guided EPA's inter-
est in the Limestone Injection Multistage
Burner (LIMB) technology. The approach
and funding for the demonstration of this
technology are also discussed.

  2.  "The  EPRI Program—Background
      and Motivation," John S.  Maul-
      betsch,  EPRI/Coal Combustion
      Systems Division
  This paper presents the Electric Power
Research Institute's (EPRI's) perspective
on  dry  SC*2 control and simultaneous
SOz/NO, control. The paper includes an
 historical overview  of the scope of the
EPRI research effort and present plans for
future programs.

Session I—Introduction
Richard Stern, EPA/AEERL, and
Michael McElroy, EPRI, Session Chairmen
  3.  "EPA's LIMB R&D Program—Evolu-
     tion, Status, and Plans," G.  Blair
     Martin*  and James H. Abbott,
  The LIMB R&D program has provided a
detailed understanding of  the key pro-
cesses governing sulfur capture  with
sorbents. While it appears that limestone
alone will  not  achieve  program goals,
several other promising sorbents  have
been identified. Based on the R&D results
and  cost  estimates of using  these sor-
bents, LIMB shows substantial promise as
a SOX and NOX control technology for
retrofit applications.  The ongoing  R&D
program  should resolve the  remaining
technical questions and  provide a basis
for widespread private sector commercial-
  This paper provides a brief history of
sorbent injection technology,  synopsizes
the status of  LIMB R&D, and discusses
future program plans.

  4.  "Overview of Canadian Research,
     Development and Demonstration
     Program for Low A/Ox/S02 Control
     Technologies,"  William  A. Warfe
     and  G.  K.  Lee, Energy, Mines &
     Resources Canada
  One of the major concerns, associated
with the expanded use of coal for heat and
electricity, is the emission to atmosphere
of the acid rain precursors, NOX and S02.
  This paper  outlines the  technologies,
the status of research, development and
demonstration activities, and future plans
for low NO«/SO2 control technologies in
Canada. It includes federal government
activities as well as those of the Canadian
Electrical Association.

  5.  "The Utility Perspective on Dry SOz
     Control  Technologies,"  George P.
     Green, Public Service Co. of Colo-
  This paper summarizes current under-
standing  and provides  comparative de-
scriptions of two promising techniques for
dry SOz control in utility applications: flue
gas  sodium sorbent injection, and in-
furnace calcium sorbent injection. In both
cases, dry sorbents are injected in pow-
dered form and react chemically with S02
to form a dry paniculate  waste which
'Speakers are listed first.
potentially can be collected  in either i
baghouse or electrostatic precipitatoi
(ESP). Two electric utilities. Public Service
Co. of Colorado and the Colorado Spring:
Dept. of Public Utilities, have  announcec
firm  plans to employ flue gas sodium
sorbent technology. In-furnace calcium
sorbent injection is still  under active
development, and no  long-term utility
commitment to  this technology has yet
been made in  the U.S.  Both control
techniques show potential as reliable,
efficient,  and economic  S02  control
options, giving utilities greater flexibility
in meeting their  environmental control
  6.  "EPA Experimental Studies of the
     Mechanisms of Sulfur Capture by
     Limestone," Robert H. Borgwardt,
     EPA/AEERL, and K. R. Bruce and J.
     Blake, Northrop Services, Inc.
  Reaction kinetics of limestone particles
were measured under  conditions that
eliminate pore-diffusion and interparticle-
diffusion effects. Included in these labora-
tory studies were: the reaction of HzS and
sulfur  with CaC03, the calcination  of
CaC03 to CaO, the reaction of CaO with
H2S  and COS, and the reaction of CaO
with S02. The results show that nascent
lime formed  immediately after  CaCOs
decomposition has a specific surface area
of about  80 mVg.  In  all  cases,  the
reactivity of the CaO increased with the
square  of the B.E.T. surface area. The
reactivity  is  markedly  affected by  the
presence of foreign metal oxides or salts
on the CaO  surface;  carbonates and
sulfates of the alkali metals are effective
additives for  promoting CaO  reactivity
under laboratory conditions.

  7.  "Flow Reactor Study of Calcination
     and Sulfation,"  Lawrence Muzio
     and V. P. Roman, KVB, Inc., Michael
     W. McElroy, EPRI, Kerry W. Bowers
     and David T.  Gallaspy, Southern
     Company Services
  The renewed  interest in direct furnace
injection of dry  sorbents for SO2 control
from coal-fired boilers has prompted
bench-scale studies of the calcination and
sulfation  of  calcium  compounds. The
bench-scale study was  conducted in  a
one-dimensional flow reactor. The objec-
tive  of the study was to determine the
inter-relationships of the calcination and
suffation processes and  how these pro-
cesses are influenced  by the type of
sorbent material, temperature,  and resi-
dence time. Four materials were studied:
two limestones, a calcium/hydroxide, and

a pressure-hydrated dolomitic lime. Cal-
cination and sulfation of these sorbents
were  investigated over  the temperature
range of 760-1,093°C and residence
times of 0.20-0.75 seconds. The reaction
environment consisted of combustion
products from a natural-gas or hydrogen-
fired burner doped with  SO2 and C02-

 Session II—(Part 1) Fundamental
 Kerry  Bowers,  Southern  Company
 Services, Session Chairman

  8.  "Calcium-Based Sorbents for Dry
      Injection," Jeffrey L.  Thompson,
      Dravo Lime Company
   Dry injection technologies for S02 cap-
 ture required that the mass mean diameter
 of the sorbent particle be relatively small,
 less than 20 //m, to obtain removal  rates
 high enough to make the process econom-
 ically competitive with wet scrubbers. The
 least expensive method of producing fine
 sorbent particles  is by hydrating  lime.
 Typical commercial hydrates have a mass
 mean diameter  less than  5 /urn.  New
 studies  of hydrate particles used in S02
 capture show that the reactant layer is
 less than 1000 A thick, the subject of this
 paper. These studies define  the limiting
 mechanism for sorbent utilization; i.e., the
 conversion ratio of CaO CaSCu. Moreover,
 this understanding of the S02 adsorption
 process points to how hydration produc-
 tion methods  might be modified to en-
 hance S02 capture.

  9.  "Laboratory-Scale Production and
      Characterization  of High Surface
      Area Sorbents,"  David A. Kirch-
      gessner, EPA/AEERL
   The objectives of the research described
 are to produce high surface area sorbents
 in an apparatus amenable  to scale-up,
 and to determine those characteristics in
 the raw carbonates which correlate to the
 development of high surface areas in the
 calcined product. Thus far,  limestones
 crushed to  minus  600 /urn  have  been
 calcined to produce maximum surface
 areas of 40-58 mVg in a laboratory-scale
 fluidized-bed reactor with a pulsed air
 flow.  A dolomite similarly  treated  has
 produced a surface area of 74 mVg.
   Particle size and elemental analyses of
 the raw stones have been performed, and
 a significant negative correlation between
 maximum surface area  development and
 iron content has been noted. No correla-
 tion between surface area development
 and petrographic properties has yet been
 10.   "Reactivity of Calcium-Based Sor-
      bents  for  S02  Control."  Randy
      Seeker, J. A. Cole, J. C. Kramlich, G.
      S. Samuelsen, and  G.  D.  Silcox,
      Energy and Environmental Research
  Laboratory-scale controlled-tempera-
ture experiments were used to  study
aspects of SO2 capture  by  limestone
sorbents in a flame-gas  environment.
Experimental parameters  were  sorbent
type,  temperature, residence  time, and
the effects of mineral additives, or pro-
moters, on sorbent reactivity. The data
revealed that isothermal capture is great-
est at 1,000°C, and that above 1,000°C
sintering of the limestone can occur which
reduces the sorbent utilization. High sur-
face area precalcined sorbents achieved
moderately higher  ultimate  utilization
than their parent carbonates, but their
real advantage was more rapid sulfation
at lower temperatures where raw stones
were limited by calcination. At 900 and
1,000°C the time for calcination  of car-
bonate sorbents was significant. Pressure
hydrated (type S) dolomite  limes consis-
tently achieved the highest utilizations.
The results suggest that—at ideal sulfation
conditions(1,000°C, isothermal residence
times greater than 1 second, nodeactiva-
tion of the sorbent by coal ash minerals)—
the best calcium utilizations achievable
would be  about 25-30% with the raw
limestone tested (Vicron 45-3), about 30-
35% with the raw dolomite tested, and
about  40% with precalcined dolomite
(precalcined to a surface area of 60 mVg)
and with pressure-slaked dolomitic lime.
The addition of Cr203> alkali metal salts,
and  certain other  promoters  increased
the utilization of limestone. Cr2O3 effected
a factor of 3.5 increase in utilization after
calcination at 1,600-1,700°C.

Session II—(Part 2) Fundamental
Dennis Drehmel, EPA/AEERL, Session

 11.   "Bench-Scale Evaluation ofSulfur-
     Sorbent Reactions," David  W.
     Pershing,  D.  M. Slaughter,  G. D.
     Silcox, P. M. Lemieux, and Gerry H.
      Newton, University of Utah
  High temperature, isothermal data on
calcination and S02 capture were obtained
as a function of temperature,  residence
time,  and  Ca/S  molar  ratio for a wide
variety of sorbents including limestones,
dolomite, and slaked limes. The calcination
results include the extent of both calcina-
tion and surface area and definition of the
 relationship between the thermal envi-
 ronment and sorbent characteristics. The
 experimental sulfation data indicate that
 sulfur capture is strongly dependent  on
 the  general class  of sorbent. Reaction
 zone temperature  was also found  to
 critically influence the overall effective-
 ness of sulfur capture by sorbent injection;
 as the local temperature increases, the
 rate of heterogeneous chemical and dif-
 fusion increase but they are ultimately
 compensated for by a decrease in initial
 sorbent surface area due to desurfacing
 during flash calcination. The results from
 the  experimental studies are compared
 with theoretical predictions  using a com-
 bined diffusion/heterogeneous chemical
 reaction model which  was developed
 based on a grain formulation.

 12.   "Evaluation  of S02  Removal  by
      Furnace Limestone Injection with
      Tangentially FiredLow-NO*Burner."
      K. Tokuda, M. Sakai,  T. Sengoku,
      and Nobuaki Murakami, Mitsubishi
      Heavy Industries, Ltd., Michael W.
      McElroy, Electric Power Research
      Institute, and  K.Mouri,  Electric
      Power Development Co.
  Mitsubishi Heavy Industries (MHI) con-
 tracted with the Electric Power Research
 Institute (EPRI) and Electric Power Devel-
 opment Company (EPDC, Japan) to eval-
 uate the S02-removal effectiveness  of
 furnace limestone injection when applied
 in combination with a Iow-N0« burner.
  The evaluation  included  a series  of
 furnace  limestone  injection tests con-
 ducted at MHI's 4 ton/hour pulverized
 coal-fired test furnace equipped with the
 Low-NO, PM burner developed by MHI.
 The  results showed 30-40% reduction of
 S02 at a Ca/S molar ratio  of 2:1  while
 maintaining Iow-N0« combustion condi-
 tions compatible with full-scale  utility
 boilers and operating practices.
  Basic (bench-scale) tests were carried
 out prior to the combustion tests, using
 an electrically heated flow  reactor. The
 results from the basic tests were applied
 in interpreting the results  from the
 combustion tests.

 13.   "Performance of Sorbents With and
      Without Additives, Injected into a
     Small Innovative Furnace," Sam L.
     Rakes,  EPA/AEERL,  and G.  T.
     Joseph and J.  M. Lorrain, Northrop
     Services, Inc.
  The Environmental Protection Agency
(EPA) Innovative Furnace was used  to
develop information on the performance
of sulfur sorbents  with and without
additives. The sorbents were injected  at

two points in the furnace using the low-
NOx-type burner fired at a 14-kW thermal
input rate on coal or liquefied petroleum
gas  (LPG), propane.  The sorbents,  a
calcitic limestone (Vicron), a pressure-
hydrated dolomite,  and  pure  calcium
hydroxide [Ca(OH)2], were tested at Ca/S
ratios of 1  and 2. The additives NaHCO3
and  Na2C03,  mixed with the sorbent,
were tested at 5 weight % of the sorbent.
Sodium carbonate (Na2C03) appears to be
an effective additive, giving increases in
sulfur reduction of 6 to 12 percentage
points, depending on  the  amount of
additive, the sorbent, and injection loca-

 14.   "Pilot-Scale Characterization  of a
     Dry  Calcium-Based Sorbent  SOi
      Control Technique Combined with
     a Low-NO * Tangentially Fired Sys-
     tem," John Kelly, Shigeto Ohmine,
      and Richard Martin, Acurex Corpo-
      ration, and Dennis  C.  Drehmel,
  A  380-kWt (1.3 million Btu/hr) two-
burner-level tangentially fired pilot-scale
facility was used to characterize a dry
calcium-based sorbent  S02  capture
technique combined with an offset auxil-
iary air low-NOx burner with and without
overfire air. Baseline tests using a con-
ventional burner design, with and without
overfire air, showed  that the  facility
properly simulates full-scale uncontrolled
and controlled NO emissions and furnace
temperature histories. SO2 test results
with dry sorbent injection and the con-
ventional burner were consistent in level
and  trend  with  limited field data. Effici-
ency, as determined by carbon monoxide,
unburned  hydrocarbon and  carbon in
flyash levels, was good for all test condi-
tions and consistent with field practice.
  Dry sorbent  SO2 test results showed
that SO2  capture is increased  by: (1)
utilizing conventional rapid fuel/air mix-
ing burners; (2) injecting sorbent away
from the flame (i.e., not mixing sorbent
with the fuel); (3) avoiding contact be-
tween ash and sorbent; and (4)  holding
sorbent in the sulfation temperature zone
(i.e., 1,505 to 1,255K) as long as possible.
In addition, fuel and sorbent type had a
significant impact on SO2 capture.

 15.   "Boiler Simulator Studies on Sor-
     bent Utilization forS02 Control," D.
     W. Pershing, B. J. Overmoe, S. L
     Chen, L. Ho, W. R. Seeker, and M. P.
      Heap, Energy  and Environmental
     Systems Corporation
  A 300-kW  Boiler Simulator Furnace
was used to investigate the influence of
combustion and sorbent parameters on
the effectiveness of dry sorbent injection
forSOzControl under conditions typical of
current utility practice. Extensive char-
acterization studies were conducted to
investigate the role of  boiler thermal
history on capture effectiveness for lime-
stone, dolomites, and slaked limes. Data
were also obtained for high surface area
sorbents  (produced by pressure slaking)
and for promoted sorbents (produced by
the addition of appropriate metallic addi-
tives) as  a function of thermal environ-
ment, sorbent injection location, calcium-
to-sulfur  molar ratio, and  S02 partial
pressure. In general, the results show
that captures in excess of 50% at a Ca/S
ratio of 2.0 can be achieved by several
alternative  methods. The experimental
studies were supported by  theoretical
calculations using grain and pore models
which combined  consideration of the
heterogeneous chemical reaction  and
diffusion  processes.

Session III—Pilot-Scale
Development of Furnace
Michael McElroy, EPRI, Session Chairman
16.  "Studies of Sorbent Calcination and
     SOz-Sorbent Reactions in a Pilot-
     Scale  Furnace," Roderick  Beittel,
     Southern Research Institute, Law-
     rence  J.  Muzio,  Fossil Energy
     Research Corporation, and John P.
     Gooch and Edward B.  Dismukes,
     Southern Research Institute
  Furnace  injection  of  calcium-based
sorbents for SO2 reduction was examined
using a 1 x 106 Btu/hr pulverized-coal-
fired combustor. The effects of sorbent
type and  rate, residence time, injection
site, staged combustion,  and CO2-
enriched  transport air  on overall  SO2
removal are reported. Properties of cal-
cine  were determined for  gas firing at
selected conditions.
  Variations in calcine surface area of 2-
30 mVg  were found, corresponding to a
range of  calcium utilization of 12-38%.
Sorbent type and temperature at the point
of injection  were primarily determinants
of calcium utilization.

17.  "Recent IFRF Fundamental  and
     Pilot-Scale Studies on the Direct
     Sorbent Injection Process," S. Bortz
     and P. Flament, International Flame
     Research Foundation
   Pilot-scale experiments (2-4 MWt)
using a  staged combustion air burner
have shown that under optimised condi-
tions, substantial reduction of SOz emis-
sions by direct injection of Calcium-based
sorbents is possible. Various fuels includ-
ing coals, ranging from subbituminousto
low volatile bituminous, petroleum resi-
dues, and SO2-doped  gas flames, have
been tested with this technique and SOs
capture levels, with a Ca/S molar ratio of
2 and  a calcium hydroxide sorbent, of
between 70 to 80% have been achieved
in cases when the peak flame tempera-
tures were reduced to about 1,250°C or
lower.  Both the temperature field in the
furnace and the sorbent type used have
been shown to strongly influence the SOs
capture efficiency, with other parameters
(such as the S02 and  O2 concentration]
playing a somewhat lesser role.
  Some more fundamental work has also
been conducted in plug flow reactors,
both isothermal and non-isothermal, to
better define calcination and sulphation
rates at  temperature levels  of  700-
1,300°C. The work which is only partially
complete, will also examine the effect of
sorbent characteristics, gas environment,
and initial particle size distribution on the
calcination and sulphation process. The
results obtained thus far  have showr
that, at temperatures above  1,000°C
calcination is more than 80% complete ir
less than 200  ms with CaCO3 and less
than 40 ms with Ca(OH)2. Sulphation alsc
appears to be reasonably fast,  reaching
an asymptotic value in less than 600 ms
for CaCOg when the gas temperature is
between 1,000 and 1,100°C. The mear
particle size, in the range 3-50 yum, has i
large influence  on calcium utilization foi
short particle residence times.

 18.  "Demonstration of Boiler Limestone
     Injection in an Industrial Boiler," R
     M. Statnick, C. E. Fink, N. S. Harding,
     B. J. Koch, and D. C. McCoy, Conocc
     Coal Research Division,  and T. J
     Hassell, E. I. DuPont de Nemours
     and Company
  Consolidation Coal Company (Consol)
through its Research & Development arm
Conoco Coal Research Division, made £
commitment to expedite the developmen
of Boiler Limestone Injection (BLI) tech
nology  via  demonstration  in a  DuPon
boiler (110,000 Ib/hr of steam) during the
summer and fall of 1984. The goal of the
program was to demonstrate the technics
and economic viability of both  LIMB ant
LI (injection above the burner zone) a:
low-cost retrof it S02 control technologies
while burning  a Consol  Northern Wes
Virginia high-sulfur coal. Technical ob
jectives included S02 removal capability
with 50%  as a minimum target, boile

operability issues, and ESP impacts.
Commercial low-NOx burners purchased
from Foster Wheeler Energy Corporation
were used in the LIMB testing. Research-
Cottrell supplied an ESP and humidifica-
tion system. The demonstration program,
test equipment, preliminary results, and
BLI economics are described.

 19.  "Pilot-Scale Studies of In-Furnace
     Hydrated Lime  Injection for Flue
     Gas SOz Emission Control." G. F.
     Weber,  M. H. Bobman, and  G. L
     Schelkoph,  University of  North
     Dakota Energy Research Center

  Simultaneous control of SOX/NOX
emissions, derived from the combustion
of low-rank coal, is under investigation at
the University of North Dakota's Energy
Research Center (UNDERC). Process de-
velopment work has been performed on
both bench-and pilot-scale systems.
Direct furnace injection of calcium-based
SC>2 sorbent materials is the SOZ control
technique under evaluation.
  Furnace injection tests have focused
on the  direct injection  of  pressure-
hydrated lime at flue  gas temperatures
ranging from 815 to 1,650°C, followed by
collection in  a baghouse operated  at
temperatures up to 540°C. Sorbent util-
ization values up to 55% at a Ca/S  mole
ratio of  1.0 have been  observed. SOz
reduction of 80% has been observed at
Ca/S mole ratios of <2.0. Sorbent utiliza-
tion in the baghouse has never exceeded
10% for baghouse temperatures ranging
from 425 to 540°C. Residence time and
the temperature regime of the sorbent
i njection location appear to be the critical
parameters controlling SOz reduction
and sorbent utilization.

 20.  "Bench-Scale Process Evaluation
     of In-Furnace /VOX and SO* Reduc-
     tion by Reburning and Sorbent
     Injection." W.  R.  Seeker,  S.  B.
     Greene, S. L. Chen, D. W. Pershing,
     and M.  P. Heap, Energy and  Envi-
     ronmental Research Corporation

  Reburning  involves the injection of a
secondary fuel above the main firing zone
of a combustor to produce a reducing
zone which acts to reduce NO* to molec-
ular nitrogen. Overfire air is added above
the reburn reducing zone to complete the
combustion. The reburning process has
been  combined  with the injection  of
calcium-based sorbents (e.g., limestone)
to investigate the potential for combined
NOK  and  SOX reduction.  Bench-scale
evaluations of the process carried out in a
plug flow furnace at 23 kW, have indicated
that NO* reductions  of up to 70% and
sulfur captures of up to 50% (at Ca/S = 2)
can be achieved depending on a number
of process variables. The dominant vari-
ables include the initial NOX level that is to
be  reduced, the reburning fuel type
(pulverized coal or natural gas), and the
residence time and temperature  in the
reducing zone. For sulfur control, the
dominant parameters are the amount of
sorbent added, the sorbent type, and the
injection temperature.

 21.  "Evaluation of  Low-NOi Burners
      forSOzControl."R. Payne and A. R.
      Abele, Energy and Environmental
      Research Corporation
  Limestone injection  with  multistage
burners, termed "LIMB," was conceived
as a process in which sulfur capture by
sorbent material injected through burner
passages may be combined with  condi-
tions which produce Iow-N0x emissions
in  staged  pulverized-coal flames.  The
potential for simultaneous NOX/SOX con-
trol by Iow-N0xdistributed mixing burners
was  evaluated in pilot-scale  research
furnaces. Experimental and commercial
burner designs, ranging in capacity from
10 x 106 to 100 x  106  Btu/hr,  were
considered.  Sulfur capture by injected
sorbents was relatively  insensitive to
burner design. Sulfur capture with lime-
stone was generally in the range of 35-
40% at Ca/S = 2, and up to 40-55% for
hydrated lime. The key factors in S02
removal were reactivity of the sorbent
and the temperature history to which the
sorbent particles were exposed.

Session IV—Burners for
Simultaneous SO2/NOX Control
G.  Blair Martin, EPA/AEERL,  Session

22.   "Limestone Injection with an In-
      ternally Staged Low-NO* Burner,"
      Joel Vatsky and Edmund S. Schind-
      ler, Foster Wheeler Energy Corpo-
  Foster Wheeler's internally staged,
Controlled  Flow/Split-Flame Iow-N0x
burner has been in utility field service
since 1979. The ease of retrofit to existing
steam generators would make the burner
a cost-effective means of implementing
the LIMB concept if satisfactory  sulfur
capture can be achieved. Two methods of
limestone injection internal to the burner
are available: premixed with the coal and
separate from the coal. The former tech-
nique was evaluated in a joint program
with USEPA, while the latter was evalu-
ated independently by Foster Wheeler
Energy Corporation using a novel injection
method. Over 60% greater sulfur capture
was obtained using the FWEC technique
on a 50 x 106 Btu/hr single-burner test

23.  "Development of Internally Staged
     Burners for LIMB," G. C. England,
     R. Payne, and J. Clough, Energy and
     Environmental Research Corpora-
  This paper discusses an experimental
investigation directed toward the develop-
ment of  retrofit technology to achieve
simultaneous in-furnace control of NOX
and SO* emissions from coal-fired boilers.
Results obtained in a 2.9 MW, (10 x 106
Btu/hr) test  furnace show that  NOX
reductions of 50% can be obtained from
high-velocity pre-NSPS burners by modi-
fication of both the coal nozzle and the air
distribution without the use of external
air ports. The effectiveness of calcium-
based sorbent injection for S02 control is
limited by sorbent  reactivity and time/
temperature characteristics of the boilers.
Experimental results suggest that sorbent
injection  can be optimized using  coaxial
air/sorbent jets to achieve maximum
sorbent  reactivity  and dispersion, and
thereby optimize SOz removal.
 24.  "Characterization  of Alternate
     Sodium Sorbents for Fabric Filter
     SOz Capture," R. Hooper, Electric
     Power Resea rch I nstitute, Arapahoe
     Test Facility
  Injection of dry-sodium powders into
the inlet plenum of fabric filters (bag-
houses) has been demonstrated to be an
effective flue gas desulfurization (FGD)
technique. On a full-scale utility boiler,
injected  sodium products  have been
shown to meet New Source Performance
Standards (NSPS) of 70% removal for
low-sulfur coal applications. Higher levels
of SOz removal have also been demon-
strated  with  the injection of greater
quantities of sodium reagent. The amount
of reagent required  is shown to  be
sensitive to the reagent particle diameter.
Results are given for commercially avail-
able sodium bicarbonate, trona, and light
soda ash (sodium carbonate). Supply of
sodium reagents is becoming increasingly
more  abundant as several chemical
commodity suppliers  expend both  re-
search and venture capital dollars to enter
the potential  utility market. To date,
sodium bicarbonate reagents have been
shown to provide better sodium utilization
than sodium carbonate and trona.

25.  "Dry Injection Scrubbing of Flue
     Gases  with the SHU Processes,"
     Manfred Schutz,  Saarberg-Holter
     Umweittechnik GmbH
  The SHU dry sorbent injection process
has been installed at the Ruhr recycling
center refuse incinerator to remove stack
gas SOx, HCI, and HF. The incinerator
produces 60,000-142,000 mVhr of flue
gas with typical or design concentrations
of 70-275 ppm SO,, 300-1,080 ppm HCI,
and20ppmHF. Prior to gaseous pollutant
cleanup,  particulates are removed in an
ESP, and the combustion gases are cooled
to 200-220°C by heat exchangers. Dry
scrubbing occurs in a contact section fed
by calcium hydroxide and steam at a feed
ratio of 0.5  kg steam/kg Ca(OH)2. The
feedrate is metered based on the pollutant
level in the  treated gas. The flue gas,
Ca(OH)2,  and steam are swirled to en-
hance contact and absorption. Following
absorption, spent sorbent is removed by a
fabric filter. The unit entered service in
1982. Test results show SO2  removal
efficiencies of 55-85%, depending on inlet
concentration, and HCI removal efficiency
usually over 90%. Selected  solids anal-
yses showed about 37% calcium hydrox-
ide consumption corresponding  to  a
utilization ratio of 1:2.7.
Session V—Post-Furnace SO2
Dan Giovanni, Electric Power
Technologies, Session Chairman

26.  "Flue Gas Desulfurization  by
     Combined Furnace  Limestone
     Injection and Dry Scrubbing," L. E.
     Sawyers and P. V. Smith, Babcock
     & Wilcox Company, Research &
     Development Division, and  T. B.
     Hurst, Babcock  & Wilcox,  Fossil
     Power Division
  Furnace limestone injection with dry
scrubbing offers a viable economic alter-
native  to wet scrubber systems for flue
gas desulfurization. The combined tech-
nology is most promising from a technical
and economic standpoint in application to
eastern high-sulfur coals,  where SO2
reduction  requirements are most strin-
gent.  Combining the  two systems can
offer required SO2 reduction in excess of
the sole  use of either  system.  Also,
combined use of the  two systems can
represent significant savings in reagent
costs over more expensive lime reagent.
This is because low-cost limestone is
injected into a furnace for calcination to
lime, and collected lime and ash materials
are recycled and employed at the principal
reagent in the dry scrubber system.
  In  pilot plant tests sponsored by the
Department of Energy, which investigated
the  combined  process  as applied to
eastern high-sulfur coals, variousfurnace
injection methods, calcium-to-sulfurstoi-
chiometric ratios (Ca/S), furnace load,
and  rear-furnace  temperatures were
studied. Results indicated potentially high
S02 removal and a cost-effective process
with a combined optimized system. These
test  results, in addition to Babcock &
Wilcox research and development exper-
ience with the two technologies (sepa-
rately and in combination), are reviewed
in this paper.

27.  "Pilot Evaluation of Combined S02
     and Paniculate Removal on a Fabric
     Filter," Franz G. Pohl,  Southern
     Research  Institute, and Michael
     McElroy and Richard Rhudy, Electric
     Power Research Institute

  The  injection of calcium compounds
into the flue gas upstream of a fabric filter
is under evaluation as a means of simul-
taneous S02 and  particulate emission
control. Pilot tests are being conducted on
a 200 acfm slipstream from a pulverized-
coal-fired boiler burning 3% sulfur coal.
Water injection, steam injection, and heat
extraction are used to condition the flue
gas to desired temperatures and  humid-
ities. S02 removal occurs in the flue gas
ductwork, in the expansion plenum up-
stream of the fabric filter, and across the
fabric  dustcake. Tests with pressure-
hydrated dolomitic lime indicated higher
SO2  removal as the flue gas temperature
approached the saturation temperature.
SO2  removal of 50% was observed at an
approach temperature of -4°C when the
sorbent was injected at a calcium-to-
sulfur  ratio  of 1:1  and up to  80% SO2
removal at a calcium-to-sulfur  ratio of

28.  "Fireside Consequences of Furnace
     Limestone  Injection  for S02
     Capture," G. J. Goetz and M. D.
     Mirolli, Combustion Engineering,
     Inc., and D. Eskinazi, Electric Power
     Research Institute
  The influence of limestone injection on
the furnace performance characteristics
of two coals was investigated experimen-
tally in Combustion Engineering's pilot-
scale Fireside Performance Test Facility
(FPTF), under an EPRI-sponsored study.
The  slagging, fouling, and emission char-
acteristics  of a high-sulfur,  high-iron
Illinois No. 6 bituminous coal and a low-
sulfur, high-sodium Montana subbitumi-
nous coal were investigated under low
NOX conditions. Calcium-to-sulfur ratio:
of 2-4 were investigated in detail.
  Results indicate that limestone can be
injected without adversely affecting the
slagging and fouling performance of unit:
firing these fuels. For high-sodium coal:
it has significant potential for reducing
fouling by weakening the deposit-to-tube
bond, thereby enhancing sootblowei
cleaning  effectiveness. With each coal
upper limits for limestone dosage were
established based  either on deposi
accumulation and/or heat transfer rates.

29.  "Effects of Furnace Sorbent Injec
     tion on Fly Ash Characteristics anc
     Electrostatic Precipitator Perform
     ance," Roberts. Dahlin and John P
     Gooch, Southern Research Insti
     tute, and James D. Kilgroe, EPA/
  The effects of furnace sorbent injectior
on the electrical resistivity and the size
distribution of particles suspended in flue
gas have been studied at temperature;
near 149°C. In-situ resistivity and im
pactor data  have been obtained using
various sorbents and sorbent injectior
modes while firing coal in a 1.06GJ/hr(1
x 106 Btu/hr) combustion system. Labor
atory resistivity measurements have als(
been made with fly ash/sorbent mixture;
using various simulated flue gas condi
  When using a 2.3% sulfur Indiana coal
the fly ash resistivity was in the range of i
x 10s to  1 x 109 ohm cm at a flue gas
temperature of  147-153°C and in th<
presence of  26-31 ppm of SO3 producec
from the coal. With burner injection  o
Vicron 45-3 limestone at a calcium-to
sulfur  ratio  of  1.8,  the resistivity was
increased to 1  to 2 x 10'2 ohm cm witt
virtually no  measurable S03 left in thf
gas phase  at  150-158°C. Experiment!
with flue gas conditioning showed tha
the resistivity  of ash/sorbent mixture;
produced from limestone injection couli
be reduced to less than 5 x 1010 ohm err
with the injection of 30-40 ppm of S03, i
residence time for  uptake of SO3 wai
adequate. Preliminary data suggest tha
the effectiveness of  SO3  conditionini
may be influenced by sorbent injectioi
temperature when hydrated lime is in
jected downstream from the burner.
  The  implications  of  these and othe
results on ESP performance are discus
sed, together  with  potential  correctivi
measures for  improving the collectioi
efficiency of ash/sorbent mixtures.

Session VI—Process Integration
and Economics
David Lachapelle, EPA/AEERL, Session

30.  "Evaluation of Temperature Histor-
     ies in the Radiant and Connective
     Zones  of a Pulverized-Coal-Fired
     Steam Generator." D. G. Lachapelle,
     EPA/AEERL, and B. M. Cetegen, J.
     L. Reese, K. Kurucz, and W. Richter,
     Energy and Environ mental Research
  The effectiveness of in-situ desulfur-
ization by direct  injection  of  calcium-
based dry sorbents is sensitive to the
thermal  environment  in  boilers.  More
specifically, the temperature histories of
gas and sorbent particles in the radiant
zone and the high-temperature convec-
tive pass sections play an important role
in the sulfur capture process. Estimation
of temperature histories  requires  a de-
tailed description of the furnace heat
transfer  and flow field. This paper dis-
cusses the detailed field measurements
of temperature and velocities in a wall-
fired  utility boiler. The temperature
measurements at full boiler load indicate
that an assumed sulfation temperature
window (800 
36.  "An Update on the Application of
     Lime Products for S02 Removal,"
     David C. Hoffman, Chemical Lime,
     Inc., and  Donald H.  Stowe,  Jr.,
     Dravo Lime Company (in conjunc-
     tion with the National Lime Associ-

  In the early years of utility SOz removal
in the U.S. scrubbing equipment manu-
facturers offered several "wet" processes
utilizing different reagents.  As in most
industries where technology is continu-
ously evolving, these processes have
become more and more efficient, along
with the commercialization  of a  major
new process—dry scrubbing. Because of
the need for further S0a reductions from
existing sources, new technologies are
starting to be visualized and are receiving
more laboratory and developmental at-
tention.  One of the more promising
technologies involves the direct injection
of lime-based absorbents into the hot flue
gas stream.
  The major objective of this discussion is
to highlight current economics on today's
most popular wet scrubbing systems with
major  emphasis  on reagent aspects.
Additionally, state-of-the-art  technical
and  economic considerations  on  direct
lime injection will be reviewed, with the
commercial reagent emphasis  centering
on today's existing lime industry (location,
tonnage, manufacturing processes, etc.).
The question of lime manufacturing flexi-
bility to meet current and projected lime
demand will be discussed with respect to
assumed commercialization of direct lime
injection technology.
  With these variables in better perspec-
tive,  it can  be  seen that today's lime
industry  is attuned to 862  removal re-
agent needs, and will readily respond to
the  anticipated  needs for  lime-based
alternative absorbents.

37.  "Dry Injection FGD Sodium-Based
     S or bents: A vailability and Economic
     Evaluation."  R. M.  Wright,  FMC
     Corporation, Alkali  Chemicals
  Dry  injection using sodium-based
sorbents offers a simpler and less costly
method  of SOz  removal  than can  be
realized  with either wet scrubbing or
spray drying for boilers firing low-sulfur
coal. Sorbents for dry injection FGD
include the minerals trona and nahcolite
along with compounds derived from them.
Huge deposits of these minerals are found
in Wyoming, California, and  Colorado.
  The general properties and availability
of the  various candidate  materials are
discussed. In addition, the effects of inert
content, molecular weight, and reactivity
on the ultimate cost of using each of the
materials are addressed. Finally, ad-
vanced products which are being devel-
oped are touched upon.

Session VII—Sorbent
Availability and Costs
Richard Hooper, EPRI, Session Chairman

38.  "Sodium Bicarbonate for Sulfur
     Dioxide Emission  Control," Ray
     Shaffery, Church & Dwight Co., Inc.
  It is anticipated that more and more
stringent controls on SOz emissions from
public  utility and industrial coal-fired
boilers  will be imposed. It  is  further
recognized that  wet  scrubbers, spray
dryers, and variant systems require heavy
capital investment and are troublesome
to operate. The dry sodium-based sorbent
injection technique using a bag house for
collection of  fly ash  and reactants  is
attractively simple in operation and effec-
tive. Important considerations in the
selection of this technique over alterna-
tive systems are the reliable availability of
sorbents and the impact of freight  to
allow dry injection to be competitive with
alternative systems.
  The focus of the paper will be on a
concept to economically provide sodium
bicarbonate as a sorbent to control SOz
emissions using the dry injection tech-
39.  "Reduction ofSOz-Emission in Brown
     Coal Combustion, Results from Re-
     search and Large-Scale Demonstra-
     tion," K. R. G. Hein and G. Kirchen,
     Rheinisch-Westfalisches  Elektrizi-
  For more than 10 years the Rheinisch-
Westfalisches Elektrizitatswerk (RWE),
Germany's largest utility company, was
involved in the development of the Dry
Additive Process (DAP) for SOz removal
by utilizing dry calcium-based materials.
Based upon  results  from trials at a
combustion rig and a 60-MW utility boiler,
a full-scale demonstration plant was
installed at a 300-MWe brown coal boiler.
  During this program that lasted over a
year at this installation, the reduction of
S02emissions and the maximum possible
amount of additives with regard to opera-
tional behavior of various power station
components and different injection modes
have been  investigated. The large-scale
operation was accompanied by rig tests
concerned with the application of CaO-
rich ashes from  different  preparation
  The paper deals, apart from the major
results for SOz reduction of the three
different test scales, with various opera-
tional problems associated with the addi-
tive injection and discusses the experi-
ence with practical solutions.

40.  "Reduction of SO2 Emissions from
     a Coal-Fired Power Station by Direct
     Inject/on of Calcium Sorbents in
     Charbonnages  de France, CER-
     CHAR, H. Brice, Charbonnages de
     France, Houilleres de Lorraine, R.
     Manhaval, Charbonnages  de
     France,  Houilleres  de  Provence,
     and M. Vandycke, Stein Industrie
  Houilleres de Provence, a company of
the Nationalized  Group "Charbonnages
de France," has conducted a  trial series
in a 50-MWe power station in Gardanne
(south of France) in order to evaluate the
feasibility of applying direct SOz capture
in flames by dry calcium sorbents injec-
tion to a newly built 600-MWe unit.
  This  campaign  of  measurements  on
the 50-MWe boiler followed a preliminary
study—subcontracted to the International
Flame Research Foundation (Ijmuiden) in
1982—where effects of sorbent  quality,
sorbent injection location, flame temper-
ature, and flue gas  recirculation upon
efficiency of SOz capture had been de-
  The experiments have indicated similar
trends on the 50-MWe boiler as  on pilot
scale except for flue gas recycling which
was effective in improving SOz capture in
the pilot-scale experiments but  had no
effect on the boiler.
  On the boiler, it was found that natural
retention of sulphur in  the calcium-rich
ash followed similar trends as retention
by injected calcium carbonate; more than
50% SOz removal could be obtained with
Ca/S = 3.  Ca(OH)z  was a much more
efficient sorbent, and 60% SOz removal
could be obtained with some Ca(OH)2
injection and a high  ash coal at a total
Ca/S = 3 (2.4 for the  ash and  0.6  for
  Injection of sorbents  above the upper
burners elevation gave the best  results.
The results of the 50-MWe tangentially
fired boiler have been used to design the
modifications required for applying the
technique to the 600-MWe boiler which
has just started operating.

Session VIII—Field Applications
and Full-Scale Testing
Richard  Stern,  EPA/AEERL,  Session

 41.   "Direct Desulfurization at the 700-
      MW Weiher III  Unit," M. Yaqub
      Chugtai, L&C Steinmuller GmbH
      Abstract not available.

42.   "Laboratory Tests, Field Trials, and
     Application of Furnace Limestone
     Injection in A ustria, "G.Staudinger,
     Technical University Graz, H.
     Schrofelbauer,  Osterreichische
      Draukraftwerke AG
  In Austria six boilers ranging from 20 to
330  MWe, having tangential firing or
wall-firing, are  equipped with furnace
injection. In  all cases, the limestone
powder is introduced with the secondary
air. Addition of the additive through the
coal mills was less effective. Ca/S molar
ratios  of 3  to  4 gave average sulfur
removal rates of 50-60%, depending on
the type and size of the furnace and on
fuel. Fouling is  a serious problem with
hard coal at full load, not at all at reduced
load,  and only  under  certain circum-
stances with lignite.
  Furnace conditions were simulated in
laboratory experiments by putting single
limestone particles with diameters from 3
to 100 //m for 3  to 20 seconds into a hot
flue gas stream.  The question on reaction
rates as  a function of particle size, SO:
concentration, temperature (900-
1,150°C) and residence time could be
  Experiments in a pilot bag filter with
1 m2 filter area and jet cleaning showed
that the poor utilization of dry limestone
in furnace injection of only 10% can be
improved to up to  26%  if the ash is
separated from  the flue gas. Sulfur re-
moval of up to 80%  and SOz outlet
concentrations as low as 100 ppm were

43.   "Experience with Furnace Injection
      of Pressure-Hydrated Lime at the
      50-MW Hoot Lake Station," H. Ness
      and T. P. Dorchak, USDOE, James
      R. Reese, Energy and Environmen-
      tal Research Corporation, and Verlin
      Menz, Otter Tail Power Company
  Tests were recently completed at a 50-
MW power plant to evaluate direct fur-
nace injection of pressure-hydrated lime
to reduce  S02  emissions. Both  high
calcium and dolomitic limes were evalu-
ated over a range of injection rates. The
sorbents were injected at selected points
above the burners in the radiant sections
of the boiler. Temperatures in these
sections ranged from about 1,090 to over
1,370°C. The low-sulfur lignite fired was
from the Beulah mine in North Dakota.
The boiler. Hoot Lake Station, Unit 2, was
a tangentially fired, balanced  draft unit
equipped with an ESP for paniculate
emission control. The burners were oper-
ated within normal ranges except in one
test with a low-NO* configuration. Some
30  short-term tests were conducted,
typically 2 to 4 hours long. The tests also
included injecting hydrated lime  for a
continuous 30-hour period to evaluate
longer-term effects on boiler perform-
  This paper gives preliminary results of
sulfur reduction and calcium utilization.
Sulfur reduction values are based on SOz
measurements in the gas stream. The
simple pneumatic system, used to inject
the dry sorbents,  is also described. The
results are compared to those from earlier
tests at the station evaluating  limestone
as the sorbent. Impacts on the perform-
ance of the boiler and ESP are briefly
44.  "EPA Wall-Fired LIMB Demonstra-
     tion,"  Robert V.  Hendriks, EPA/
  The USEPA is engaged in  a research
program to develop improved  control
technologies for emissions of sulfur and
nitrogen oxides (SOX and NO*) from the
combustion of  fossil fuels.  Previously
developed Iow-N0x systems for coal
combustion are  being demonstrated, and
methods for removal of SO, in the com-
bustion process  in conjunction with these
systems are under development.
  A low-cost method for SOX control is
the use of Limestone  Injection with a
Multistage Burner (i.e., Iow-N0x burner).
This technology, abbreviated LIMB, prom-
ises to be retrofittable to large and small
coal-fired  boilers at  lower capital  and
operating costs  than currently available
pollution control alternatives such as flue
gas desulfurization.
  EPA has recently awarded a contract to
Babcock & Wilcox for a full-scale utility
size demonstration of LIMB.  This paper
describes the recently initiated EPA LIMB
Demonstration Project with emphasis on
outlining the project objectives and scope
and describing  the demonstration host

45.  "The Homer City Experience in
     Developing a LIMB Process for Use
     with Coal Preparation," D.I. Cessna,
     J.  H.  Tice,  and  D.  W.  Carey,
     Pennsylvania  Electric  Company,
     and the New York State Electric and
     Gas Corporation
  Pennsylvania Electric and the New York
State Electric and Gas Corporation have
been experimenting with and  further
developing a system of Limestone Injec-
tion  Multistage Burner (LIMB) that can
supplement  an existing  coal cleaning
application to bring their Homer City No. 3
unit  into compliance with EPA's  1971
New Source Performance Standard. Two
series of limestone  injection tests have
been carried out during short runs on the
full-scale unit with encouraging  results.
Small-scale combustion tests are now
being performed by contractors to lead to
the design of a flexible boiler LIMB retrofit.
This flexible system will be operated while
varying the parameters of injection loca-
tion,  furnace  load, firing  mode,  and
limestone type during a 4-month test
series planned for late-1985. The objec-
tives for the Homer City retrofit are 25%
SOz removal from flue gas containing 1.6
Ib S02/106 Btu using a calcium/sulfur
ratio  of 1.0 or less. This paper  gives
results of the owner's tests to date and
their plans for further LIMB development
specific to Unit No. 3.

 46.   "/V0x/S0z  Control Experience at
      Saskatchewan Corporation's Bound-
      ary Dam G.S.—Unit  #6," R. D.
      Winship, Combustion Engineering-
      Superheater Ltd., and J. A. Haynes,
      Saskatchewan Power Corporation
  This paper describes the S02 emission
reductions achieved with Combustion
Engineering's Modified Combustion Tech-
niques,  with and  without limestone in-
jection on a lignite-fired utility boiler at
Saskatchewan Power. The  paper dis-
cusses  the  operational considerations
and effects of the modified operation on
boiler fouling and efficiency.
  An outline of the system design and the
modifications to the No. 6 unit are de-
scribed. The results of the SOz and NO*
testing under different operating condi-
tions are summarized. The paper provides
a preliminary indication of the economics
of the C-E Modified Combustion Tech-
nique and outlines future research and
development plans.

47.   "Suction Pyrometry Tests  and In-
      novative Furnace,"  Samuel L.
      Rakes, EPA/AEERL
  Suction pyrometry  tests were  con-
ducted on the EPA's innovative furnace at
Research Triangle Park, NC, to establish
the actual gas temperatures at  several
points in the furnace at specified opera-
ting conditions. Gas residence times were
calculated using the temperatures estab-
lished by the suction pyrometry tests and

     gas compositions measured by the moni-
     tors. At the selected firing rate of 47,300
     Btu/hr (14 kW) thermal input, gas resi-
     dence times of about 1.5 sec between the
     temperatures of 2,250 and  1,600°F
     (1,232 and 871 °C) were calculated.

     48.  "Surface . Characterization  and
          Microanalysis of Sorbents  and
          Ash/Sorbent  Mixtures," R. S.
          Dahlin, Southern Research Insti-
          tute, and David A. Kirchgessner,
       This paper presents a survey of tech-
     niques for the surface characterization
     and microanalysis of particulate samples
     related to  EPA's  Limestone Injection
     Multistage Burner (LIMB) program. The
     following  techniques are  discussed:
     scanning electron  microscopy (SEM),
     carbon replica  transmission  electron
     microscopy (TEM),  thin section TEM,
     energy dispersive X-ray (EDX) analysis,
     electron microprobe analysis (EMS), elec-
     tron spectroscopy for chemical analysis
     (ESCA), and Auger electron spectroscopy
     (AES).  Example applications of these
     techniques to various LIMB samples are
     presented,  and the limitations of the
     techniques are discussed.
The EPA compiler, P. J. Chappellfalso the EPA Project Officer, see below), is with
  Air and Energy Engineering Research Laboratory, Research Triangle Park, NC
The complete report, entitled "Proceedings: First Joint Symposium on Dry SOz
  and Simultaneous SOz/NO* Control Technologies," consists of two volumes:
    "Volume I. Fundamental Research and Process Development/'fOrder No.
     PB 85-232 353/AS; Cost: $32.50. subject to change).
    "Volume II. Power Plant Integration, Economics, and Full-Scale Experience,"
     (Order No. PB 85-232 361/AS; Cost: $29.50. subject to change).
The above reports will be available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Air and Energy Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Research  Triangle Park, NC27711
U. S. GOVERNMENT PRINTING OFFICEt 1985/559-111/20672

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