DEVELOPMENT OF A METHOD FOR
THE DETERMINATION OF CARBON AND HYDROGEN
IN SOLID WASTE
A Division of Research and Development
Open-File Report (RS-03-68-17)
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
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DEVELOPMENT OF A METHOD FOR
THE DETERMINATION OF CARBON AND HYDROGEN
IN SOLID WASTE
A Division of Research and Development
Open-File Report (RS-03-68-17)
written by
Donald L. Wilson, Research Chemist
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Environmental Health Service
Bureau of Solid Waste Management
1970
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ABSTRACT
Characterization of solid wastes materials is necessary in the plan-
ing, designing, operation, and evaluation of refuse processing and disposal
systems and facilities. A literature survey of existing methods revealed
that a generally new macroanalytica) technique would have to be developed
for the determination of carbon in solid wastes materials. With this
method the chemist must be able to analyze a one to two gram sample of dry,
generally uniform, solid waste substance for its total carbon content, which
may exist in various forms and may range in concentration from approximately
10 to 60 percent.
An investigation into the basic types of carbon methods revealed that
the dry combustion-purification—gravimetric approach, which also yields the
hydrogen content of samples, is the most promising. This report is an ac-
count of the development of such a carbon-hydrogen method.
The newly developed method permits the analyst to determine precisely
and accurately the carbon and hydrogen contents of all types of solid waste
materials. With this new method solid wastes samples can have a carbon con-
tent of 0.5% to 83.0% and a hydrogen content of 0.01% to 7.80%; however, all
substances must be thoroughly dried and generally uniform before being
analyzed. Normally between one to two grams (not less than one gram) samples
were used in each determination, although as much as ten grams can be
employed. Since this method is specifically designed for application to the
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determination of macro amounts of carbon and hydrogen in solid wastes samples,
sample portions of solid wastes material less than one gram should not be
used for analysis.
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TABLE OF CONTENTS
Page
Abstract lii
I. Introduction . 1
II . Approach 2
III. Results 4
IV. Conclusions 15
V. References 16
VI. Appendix 18
A. Figures and Tables
B. Cost
C. Sample Preparation Procedures
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I. IntroductiQn
The carbon and hydrogen contents of various solid wastes materials
are important to some volume reduction processes used to dispose of wastes.
In the case of incineration, the efficiency of operation of an incinerator
can be measured by material balance techniques, in which carbon and hydrogen
analyses are essential. In view of the fact that incinerator residue or
compost may be used for land filling, and the stability of these solid wastes
products is a function of their carbon and hydrogen contents, the carbon
and hydrogen analyses must be performed.
Conventional carbon-hydrogen methods either required an extremely
homogeneous sample because of the small amount of material (usually 50 mg)
analyzed or a low carbon content sample (less than 6%) which contains no
impurities which affect the carbon-hydrogen analyses. Solid wastes samples
are two heterogeneous and contain too many interferences for these conven-
tional methods.
The newly developed carbon-hydrogen method described herein overcomes
the problems of analyzing solid wastes materials with conventional methods.
However, the precision and accuracy of the new carbon-hydrogen method, as
with most solid wastes methods, is greatly affected by sample preparation
techniques. Therefore, the sample preparation procedures used during the
development of the carbon-hydrogen method are discussed in this report
(Appendix).
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II. Approach
The six basic means of analyzing samples for their carbon contents
are: (1) Gravimetric, 1,2,3,4,5,6 in which the sample is combusted and
the carbon dioxide evolved is absorbed and weighed; (2) Volumetric 7,8
in which the carbon diQxide evolved during sample combustion is collected
in a solution which is then titrated to an end point with a standard acid
solution; (3) percent Ash Relationship where the sample is muffled at
600 C and carbon content is calculated using a previously established re-
lationship between the ash and carbon content; (4) Alkalimetric 10 where
a combination of acids, catalysts, and heating techniques convert all the
carbon in the sample to carbon dioxide and the carbon content is calculated
from the loss in sample weight; (5) Manometric 11 in which carbon dioxide,
released from an acid-sample reaction, is measured by the volume it displaces
in a calibrated manometer; (6) Oxygen-Flask 12 in which the sample is ignited
electrically in a specially designed flask which contains a carbon dioxide
absorbent.
The gravimetric system which also reveals hydrogen content of samples,
apoeared to be the most promising means of analyzing solid waste samples.
The volumetric methods involve absorption solutions which may not be capable
of absorbing large amounts of carbon dioxide emitted from solid wastes
materials. The percent ash relationship technique, although sometimes used
for compost samples, has not shown a consistant relationship between the
percent ash, and the carbon content of samples. The alkalimetric system
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relies upon an acid—catalyst-heat combination which cannot handle such
heterogeneous solid wastes samples. The manometric method relies upon (1)
acids which cannot react with all the carbon in solid wastes materials and
(2) an absorbing column which is not selective for carbon dioxide only.
The oxygen-flask procedure cannot completely combust all solid wastes sub-
stances and is hazardous to the analyst.
Having selected the gravimetric approach, the next step was to
determine what chemicals and equipment were necessary. According to the
literature of conventional methods, the gaseous impurities which affect
the results in the gravimetric method are fluoro-compounds, oxides of
sulfur, oxides of nitrogen, and halogens. Since solid wastes materials
usually contain all these interfering impurities, the carbon—hydrogen
train (Figures 1. and 2.) was constructed to remove these substances.
After several modifications (already incorporated in Figures 1. and
2.), the carbon and hydrogen contents of pure sucrose could be analyzed
accurately and precisely. The applicability of this modified method in
analyzing each type of solid wastes materials was established by (1)
varing the sample weights to insure complete combustion; (2) adding excess
interfering impurities to insure their removal ; (3) adding various forms
of carbon to insure the complete recovery of all types of carbon.
After the method was proven satisfactory for analyzing each type of
solid wastes materials the precision of the method was established for
each type of material.
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III. Results
The literature survey involved a review of the last ten years of
chemical abstracts, various books, and personal communications.
Since a furnace which fulfilled the requirements of the gravimetric
method was unavailable, a construction and purchase contract was awarded
to the Lindberg Company whose technical staff then altered the design and
function of their Hevi-Duty, Organic Carbon, Multiple Unit, Tube Type,
Electric Furnace Model 123_T* to meet our specifications.
The gravimetric method requirements placed upon the furnace were:
(1) the furnace must have a 2” bore which could handle a ceramic tube,
1 1/2 inch 0. D. and 30 inches long; (2) the furnace must have three
sections, 8, 12, 4 inches, respectively. The temperatures of the three
sections must be 900, 800, and 200 degrees centigrade, respectively and
be individually controlled.
When the carbon-hydrogen train was put into operation, the 30-inch
ceramic tube proved to be too short and caused the rubber stopper to burn
slightly. A 38-inch Vycor tube was found superior, especially since the
action taking place in the tube could be observed and the tube could be
easily cleaned. If a Vycor tube is not available, a ceramic tube, longer
than 30 inches, could be used. After a 25 day-investigation of 12 variables
(Table 1) the modified gravimetric method was successfully employed to ana-
lyze NBS grade sucrose.
*product (or manufacturer) identification shown in this report does not
imply endorsement by the United States Public Health Service.
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The effect of each of the 12 variables was evaluated independently.
The first investigation involved a comparison of the applicability of a
glass baffle versus a ceramic baffle. The glass baffle is shorter and
produces a better baffling effect; however, it is more costly and needs
modification. Although the ceramic baffle breaks more easily, its cost is
so much less than the glass baffle that the breakage cost is not signifi-
cant, The less efficient baffling aspect of the ceramic baffle proved to
have no effect upon the sample analyses. The decision was therefore made
to use the ceramic baffle rather than the glass type.
The change in baffle types did affect the sample insertion procedure
(the next variable listed in Table 1). The original sample insertion pro-
cedure was to insert the sample into a cold combustion zone, heat to 900 C,
then cool to remove the samDle. This insertion procedure required much time
and strained the heating elements of the furnace. A sample inserter was
devised which allowed the analyst to insert the sample slowly into an al-
ready hot combustion zone. If this insertion is too fast the exothermic
combustion reaction produces too much pressure and causes the stopper,
baffle, and sample inserter to be shot out of the combustion tube. In-
serting the sample container one inch per five minutes prevents a too
violent reaction. Although the ceramic baffle causes the sample’s ini-
tial position to be closer to the combustion zone,the insertion procedure
works satisfactory with either the ceramic or glass baffle.
Keeping the combustion zone at a constant temperature affords longer
life to the heating elements and allows greater control over the tempera-
5
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ture. This greater temperature control permitted the combustion tempera-
ture to be raised to 950±50 C, closer to the maximum furnace temperature
of 1010 C. Since the decomposition temperature of calcium carbonate is
898 C, the temperature increase to 950 C assured the conversion of all
the calcium carbonate present in a sample to carbon dioxide.
The gaseous mixture from the sample combustion first goes through a
special packinq mixture of platinized asbestos, asbestos, and aluminum
oxide (Figure 3). The platinum assures the conversion of any methyl
groups to carbon dioxide. The aluminum oxide removes any fluoro-compounds
which would be collected in the carbon dioxide adsorbing material and hence
affect the carbon result. Mixing these ingredients prevents the aluminum
oxide from caking and inhibiting the gas flow.
Next, the mixture of gases diffuses through lead chromate, 12-20 mesh
or powder which has been fused at 820 C for one hour to prevent caking.
The lead chromate removes oxides of sulfur by oxidizing any sulfur dioxide
to sulfur trioxide and, finally, to the non-volatile lead sulfate. Since
the lead chromate functions best at about 600 C, the lead chromate is lo-
cated so that it is heated by the cooler end zones of the 12-inch furnace
which is maintained in the center at 800 C. A one-inch air gap between the
8-inch and 12—inch furnaces allows for a temperature gradient and does not
allow the moisture from the combustion to condense in this area which has
an outside tube temperature of 160 C midway between the furnaces. Between
the lead chromate is copper oxide which converts any carbon monoxide to
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carbon dioxide and functions best at about 800 C. Several endeavors
were perfornied before the right combination of positions and quantities
of the lead chromate and copper oxide was accomplished.
After leaving the second lead chromate section, the gaseous mixture
passes through silver wool (wool was found easier to pack than wire).
The silver wool’s purpose is to remove the halogens.
Lead dioxide follows the silver wool and removes oxides of nitrogen.
The lead dioxide made some modifications in the procedure necessary.
Firstly, the hygroscopic-lead dioxide is affected by the moisture in the
system and if a blank is analyzed with this ingredient in the tube, the
following sample analyses will be incorrect. Thus, the blank analyses
must be performed using an unpacked combustion tube. Secondly, the prob-
lem with the lead dioxide is the low temperature (usually 190 C) at which
it performs. When the lead dioxide is maintained at 190 C with the 4
inch-furnace, water vapors from the combustion of the sample condense in
this area of the tube. Employing a temperature of 200 C, wrapping the
reduced end of the combustion tube with aluminum foil, and using an
oxygen flow of 250cc. per minute prevent the formation of liquid water in
this area of the combustion tube. Again an air gap is made between furnaces
to allow a temperature gradient; but, the gap does not allow moisture to
condense in the tube since the outside tube temperature is 175 C midway
between the furnaces. This air gap is one-half inch and is between the
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12-inch and 4-inch furnaces.
The oxygen gas flow rates tried were in the range of: 50 to 100 cc./min.
to 200 to 300 cc./min.. and 350 to 400 cc./min. A gas flow rate of 250
cc/mm. is the minimum rate that can be used. A slower flow rate does not
enable the system to be flushed sufficiently in the one hour-analysis-time
and allows a back flow of gases when the sample ignition occurs.
The minimum sample combustion period, starting with the placement of
a sample container in the combustion tube and ending with the removal of
the absorption bulbs, is 60 minutes when an oxygen flow rate of 250 cc./min.
is employed. Other combustion periods of 30, 45, 75, and 90 minutes were
evaluated and found undesirable.
The carrier gas used in this method is oxygen, 99.5 percent pure and
prepared from liquid air. Before the oxygen goes into the combustion tube
it is purified by passing it through: (1) concentrated sulfuric acid, which
removes water and sulfur dioxide; (2) magnesium perchlorate, which removes
any remaining water; (3) Ascarite, which removes carbon dioxide; (4) acti-
vated alumina, which removes water created by the reaction between Ascarite
and carbon dioxide. A valve, located before the concentrated sulfuric
acid, prevents the back flow of acid when the oxygen is turned off. A
flowmeter is located after the purification system for regulating the oxygen
flow at 250 cc./min. A glass stopcock, T-bore, follows the flowmeter and
allows the oxygen to be diverted if too much pressure builds up during sample
ignition. If this glass stopcock is closed while the train is not being used
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for one-half hour or more, the need for continuous reconditioning of the
combustion tube is eliminated.
A freshly packed combustion tube contains too much moisture and must
be dried by flowing the dry—purified-oxygen through the tube at 250 cc./min.
for at least two hours. After which, the train is checked by analyzing
pure sucrose until accurate results are obtained. Once the train has been
utilized, the combustion tube needs reconditioning only if it has been idle
for more than one day. The reconditioning of a used tube involves analyz-
ing a standard until the results are accurate; usually only one or two
analyses are needed. Because the lead dioxide is affected by the moisture
in the system, a standard, similar in nature to the material being analyzed,
must precede the analyses of each type of solid wastes material.
The density of a sample is the only factor that determines the type
of boat or container utilized to hold the sample. The types of containers
tried included ceramic and low carbon nickel boats of various sizes, usual-
ly 3 to 6 inches long. These boats were made mainly for carbon analysis;
however, all boats and their lids are ignited at 950 C for one hour in a
muffle furnace and stored in a desiccator until needed. Tests showed that
making fluffy samples into pellets in order to fit the 1—2 gram samples
into small boats yields low results.
The types of absorption bulbs used to collect the carbon dioxide and
the water were: Nesbitt, Miller, and Stetser-Norton, The efficiency of
these bulbs did not differ. However, t 1 he Mesbitt type is preferred be-
cause it is easier to clean after the absorption of the carbon dioxide and
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when the glass stopper is turned both the inlet and exit openings are
closed to the atmosphere. The cheaper Stetser-Norton bulbs performed
satisfactorily for the water collection. Glass fittings of these bulbs
and all other fittings were lubricated with a nonreactive Kel-F #90 grease.
All absorption bulbs must be loosely packed to enable the free flow of
gases.
Since magnesium perchiorate is more efficient at absorbing water than
many materials, such as, Drierite or silica gel, it was the only substance
tried for the water absorption and presented no problems. Only two absorp-
tion bulbs were ever needed for the collection of all the water vapors.
Although Ascarite (8-20 mesh) can be used to collect the carbon di-
oxide gas, Indicarb (6-10 mesh) is preferred because it has 50 percent
greater capacity for collecting carbon dioxide than Ascarite and has less
tendency to cake which stops the flow of gases. Activated alumina should
be placed on top of the Indicarb to collect the water which results from
the reaction of the carbon dioxide and sodium hydroxide. Several absorp-
tion bulbs, never less than two, were needed for collecting all the carbon
dioxide.
For absolute insurance of complete combustion, an accelerator must be
employed with each sample. The two types of combustion aids tried were
Combax, iron chips, and Combustion-Accelerator, granular tin metal. Either
accelerator may be used, but the cheaper iron chips are preferred. The
position of the accelerator does produce a difference in the final results.
The best technique is to sparsly sprinkle a small amount of accelerator
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over the weighed sample and, using a spatula, through ly mix the accelerator
throughout the sample.
To determine if the gases are flowing through the train satisfactorily
and if any carbon dioxide is escaping in the exit gas, a gas washer con-
taining 150 ml of carbon dioxide detecting solution is employed at the
exit end of the train. The presence of high carbon content and/or inter-
ferences in a sample can reduce the flow of the exit gas almost to zero.
As a safety precaution, if the exit gas flow stops completely for one or
two minutes the glass stopock must be turned to divert the oxygen flow
from entering the combustion tube to the room air. The analyst must ob-
serve this exit gas flow rate periodically to assure the system is operating
correctly. At times, the carbon dioxide absorbent cakes and stops the gas
flow; however, an explosion will not occur if the inhibition of gas flow
is noticed in time and the absorption bulb is removed. If the sample is
highly combustible, two absorption bulbs may not collect all of the carbon
dioxide. If carbon dioxide does escape the last absorption bulb it will
be detected in the exit gas washer solution. Rosolic acid solution, which
turns red with addition of bicarbonates plus carbon dioxide or faintly
yellow with carbon dioxide only, was tried as a carbon dioxide detecting
solution. A more satisfactory solution is 150 nil of barium hydroxide-
thymolphthalein solution. A good preparational procedure for this detecting
solution is 150 ml of barium hydroxide solution (12.0 cirams to one liter) pluc
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0.5 nil of thymo]phtha]ein solution (1.0 gram to 100 ml of ethanol). This
detection solution turns from blue to blue-white or white upon the absorp-
tion of carbon dioxide.
With one goal being a carbon-hydrogen method that would analyze com-
pounds containing various forms of carbon within one actual percent of the
true value, the accuracy of this newly developed method was established as
satisfactory (Table 2). For these tests, naphthol and urea were selected
to represent hydrocarbons. Graphite was employed as elemental form of car-
bon and calcium carbonate as an inorganic form.
The applicability of this new carbon-hydrogen method in analyzing solid
wastes material was investigated (Table 3). Because the possibility existed
that sand particles may retain part of the carbon during combustion, ordin-
ary sand and sodium silicate along with various forms of carbon were added
to each type of solid wastes material. These additives produced no affects
upon the method’s capability of analyzing solid wastes materials (Table 3).
Experiments proved the combustion tube packing removes even large ex-
cesses of interferring substances from every type of solid wastes sample
(Table 3).
As a precaution against the samples collecting moisture before
being weighed for analyses and after the initial drying in sample prepara-
tion procedures 13 (Appendix), all samples must be redried no more than
a few days before the analyses are performed. The procedures found for
this redrying are that those samples which were originally dried at 70 C
must be redried at 70 C for four hours and those samples originally dried
at 105 C must be redried at 105 C for one hour. Studies showed that after
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initial drying, the age of the sample, the type of storage, or the redrying
procedures have no effect upon the carbon and hydrogen results. After the
redrying procedures had been performed all samples were kept in tightly
closed containers and in a desiccator until the analyses. Weighed samples
with containers and lids were kept in a desiccator until each was inserted
into the combustion tube.
The precision of the new method was determined by analyzing, in trip-
licate, a number of solid waste samples of various types. The pooled
standard deviation of the observations for each type of solid wastes was cal-
culated using Olivetti Underwood Programma 101. The calculations revealed
that, in the analysis of each type of wastes, the duplicate and triplicate
determinations were equally precise (Table 4). A calculation of the residual
error between the 2-replicate and 3-replicate analysis was performed by a
statistician 14 using the observed contents of 20 compost samples, and con-
firmed our calculations.
With this macro method the analyst normally uses a one to two-gram
sample, but he is not restricted to this amount. Compost samples up to ten
grams have been analyzed with no difficulty; however, the extra sample weights
add little to the precision of this method.
The great effect upon the precision is the preparation procedures of the
heterogeneous solid waste material. This was demonstrated when a sample,
prepared in the unual manner (Appendix), was analyzed before and after ad-
ditional preparation. The sample used for this study was the “fines 0 frac-
tion of an incinerator residue. This sample fraction, after the usual prep-
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arations, was visibly nonuniform which caused poor precision in the
carbon and hydrogen analyses (Table 5). This sample was further separated
into three portions, each of which was analyzed for carbon and hydrogen.
The carbon and hydrogen average values of these three portions add up to
less than the average values of the original sample, which indicates that,
not only is the precision of the analyses of the original sample bad; it is
impossible to obtain a uniformly mixed sample and hence an accurate average
carbon or hydrogen value with three observations (Table 5).
One of the three portions of the above residue (fines) sample could
not be ground with the Wiley Mill, or pulverized with the Tier Pulverizer.
This portion was studied so that we could understand the reason why it could
not be ground or pulverized. A biologist 15 performed a microscopic exam-
ination of the sample and found the following: wood charcoal and sawdust-
65% or more; magnetic iron; hematite; copper; quartz; calcite; asphalt;
wood resins; coal ash; soft metal of some type—chrome or aluminum identi-
fied. A research chemist 16 performed an emission spectrographic analysis
on a nitric-hydrochloric acid solution of the sample portion, which un-
fortunately only partly dissolved in this acid medium. His analysis of the
solution revealed that the major constituents were zinc, iron, aluminum,
copper, and lead. Also present, in smaller concentrations, were boron,
manganese, nickel, and barium. Cadmium, arsenic, molybdenum, beryllium,
silver, cobalt, chromium, vanadium, and strontium were all either absent
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Or below the detection limits.
Exactly why this sample portion could not be ground or pulverized is
still not clear. Perhaps just this particular combination of ingredients
caused the problem. This sample protion was the only material our laboratory
has received that could not successfully be prepared for analyses using the
Wiley Mill or her Pulverizer. Although the problem is unresolved, the
likelihood of this situation reoccurring is rare.
IV. Conclusions
A macro-carbon—hydrogen method is now available which can analyze 1 to
2 gram samples of solid waste materials. These materials can contain almost
any impurity of any concentration and these carbon-hydrogen analyses are
not affected. This method can accurately analyze samples whose carbon con-
tents are between 0.46 and 83.31 percents or whose hydrogen contents are
between 0.01 and 7.80 percents.
Before the carbon-hydrogen analyses can be performed the samples must
be throughly dry. To ensure good precision the particle size of the sample
must be less than 2 mm or pass through a #60 sieve, then thoroughly mixed
before analyzing.
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V. References
1. American Public Works Association. Test for Hydrogen and
Carbon. In Municipal refuse disposal. 2d ed. Chicago,
Public Administration Service, 1966. p. 398-399.
2. American Society for Testing Materials, Committee 0-5 Coal
and Coke. Sampling of Coal and Coke, D-271-58. In 1958
Book of ASTM standards, part 8. Philadelphia. American
Society for Testing Materials, 1958. p. 101 6-1020.
3. Furman, N. H. ed. Carbon. In Scott’s standard methods
of chemical analysis. 5th ed. V. I. Princeton, D. Van
Nostrand Co., 1925. p. 218-228.
4. Horwitz, N. ed. Carbon and Hydrogen, 38. 005-38.008.
In Official methods of analysis of the association of
official agricultural chemists. 10th ed. Washinciton,
U. C., Association of Official Agricultural Chemists,
1965. p. 741-743.
5. Roga, B. and L. Wnekowska. Carbon and Hydrogen. In
Analysis of Solid Fuels, chapter 3. Katowice, Poland.
Panstwowe Wydawnictwa Techniczne, 1952. p. 209-219.
Available from the U. S. Department of Commerce, Clear-
inghouse for Federal Scientific and Technical Information,
Springfield, Virginia. TT61-3l316.
6. Steyermark, A. Microdetermination of Carbon and Hydrogen.
In:Quantitative organic microanalysis. 2d ed. New York,
Academic Press, 1961. p. 221-275.
7. Treadwell, H. Determination of carbon. Analytical Chemistry ,
7 (2): 349-370, 1930.
8. National Lead Co. of Ohio. General methods for the deter-
mination of carbon in metals, volumetric method. Method
no. 1.3.3.2. Fernald, Ohio 1968.
9. Bell, J. M. Characteristics of Municipal Refuse. In
American Public Works Association Special Report.
Chicago, American Public Works Association, Dec. 1963.
p. 28-38.
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10. Hamilton, L. F., and S. G. Simpson ed. Determination of
Carbon Dioxide, 19:10-19:11. InQui titative chemical
analysis. 11th ed. New York, New York, The Macmillan
Company, 1958. p. 382-387.
11. Horwitz, N. ed. Carbon Dioxide-Official , First Action,
11.048-11.054. In Official methods of analysis of the
association of official agricultural chemists. 10th ed.
Washington, D. C., Association of Official Agricultural
Chemists, 1965. p. 176-179.
12. Juvet, R. S., and Jen Chiu. Determination of carbon in
organic substances by an oxygen-flask method. Analytical
Chemistry , 32:130-1, 1960.
13. Personal cormiunication. I. R. Cohen, Research Chemist,
Research Services Laboratory, Bureau of Solid Waste
Management, U. S. Public Health Service, Cincinnati,
Ohio. 45213.
14. Personal cormiunication. A. J. Klee, Statistician,
Operational Analysis, Bureau of Solid Waste Manaqe-
ment, U. S. Public Health Service. Cincinnanti, Ohio.
45213.
15. Personal communication. C. A. Golden, Biologist,
Research Services Laboratory, Bureau of Solid Waste
Management, U. S. Public Health Service. Cincinnati,
Ohio, 45213.
16. Personal communication. J. F. Kopp. Group Leader-
Research Chemist, Division of Water Quality Research,
Federal Water Pollution Control Administration. 1014
Broadway, Cincinnati, Ohio.45202.
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VI. Appendix
A. Figures and Tables
B. Cost
C. Sample Preparation Procedures
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I
it
F ,
ja — * S
— i
- S
t ___
FIGURE 1.
The carbon-hydrogen train
- n
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CARBON—
MAIN SECTIONS TEMPERATURE HYDROGEN PURPOSE OF UNITS
TRAIN
OXYGEN
4,
CONCENTRATED H 2 S0 4 J REMOVES WATER AND SULFUR DIOXIDE
OXYGEN
ROOM
PURIFICATION IMAGNESIUM PERCHLORATEI REMOVES WATER
TEMPERATURE
SECTION Ir
F ASCARITE WITH 1
IACTIVATED ALUMINAI REMOVES CARBON DIOXIDE
[ FLOWMETER ] MAINTAINS OXYGEN FLOW
______________ (250 cc./mln.)
— SAMPLE WITH
COMBUSTION ACCELERATOR
SAMPLE 1
o COMBUSTION PRODUCTS
COMBUSTION 950 C AND EXCESS OXYGEN
ZONE I
CONVERTS CONDENSED RINGS WITH
IPLATINIZED ASBESTOS ANGULAR METHYL GROUPS TO CARBON
_______________ ________________ AND DIOXIDE AND REMOVES FLUORO-
ALUMINUM OXIDE COMPOUNDS
4,
[ LEAD CHROMATE J REMOVES OXIDES OF SULFUR
PURIFICATION 800°C [ OPPER OXIDE CONVERTS CARBON MONOXIDE TO
CARBON DIOXIDE
OF ________
GASEOUS ILEAD CHROMATE REMOVES OXIDES OF SULFUR
COMBUSTION
PRODUCTS ________________
SILVER WOOLj REMOVES HALOGENS AND CONVERTS
ZONE OXIDES OF NITROGEN TO FREE
4 , NITROGEN
200°C hEAD DIOXIDEI REMOVES OXIDES OF NITROGEN
ISILVER WIREJ REMOVES HALOGENS AND CONVERTS
OXIDES OF NITROGEN TO FREE
_____________ ______________ NITROGEN
FMAONESIUM PERCHLORATE I
ABSORBS WATER
IMAGNESIUM PERCHLORAT!J
ABSORPT ION j ABSORBS WATER
OF ROOM
F INDICARB AND ]
WATER AND TEMPERATURE IACTIVATED ALUMINA ] ABSORBS CARBON DIOXIDE
CARBON DIOXIDE
[ INDICARB AND
SECTION IACTIVATED ALUMINA ABSORBS CARBON DIOXIDE
_____ ‘4,
BARIUM HYDROXIOEI INDICATES CARBON DIOXIDE
p IN EXIT OASES
ATMOSPHERE
FIGURE 2. General outline of carbon-hydrogen train.
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21/2 1 Space
PACKEO
COMBUST ON
TUBE
8”
Furnace
(950°C)
12”
Furnace
(800°C)
‘ 2 Space
4,,
Furnace
(200°C)
Position Mark
Barge
PbCrO 4 (12—20 mesh)
“ Asbestos Plug
PbCrO 4
3 ” Silver Wool
Pb0 2 (12—20 mesh)
Silver Wire
B&S gauge)
FIGURE 3. Packed combustion tube
ScaIe ““
Size
‘2 Asbestos Plug
CuO
1 “ Space
13 ” Special Mixture
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TABLE 1
VARIABLES INVESTIGATED IN THE ESTABLISHMENT OF
THE CARBON-HYDROGEN METHOD
1. Type of baffles, glass versus ceramic
2. Sample insertion procedure
3. Temperature of each furnace
4. Amount and position of each packing ingredient
5. Position of each furnace
6. Flow rate of oxygen
7. Time for each sample analysis
8. Conditioning procedure for packed combustion tube
9. Type of boats or sample containers
10. Type of absorption bulbs
11. Position and type of combustion aids
12. Kind of solution for detecting carbon dioxide in exit gas
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TABLE 2
PERCENT ACCURACY OF CARBON AND HYDROGEN DETERMINATIONS OF STANDARD COMPOUNDS
aSince graphite is not pure, it was ignited in air at 1150 C to determine the
percent ash impurities.
Compound
No. of
determ .
%Element calcd. %Element found. %Recove .
C H C H C H
Sucorse, NBS
6
42.10
6.48
42.07
6.39
99.93
98.61
Sucrose, ACS
6
42.09
6.48
42.02
6.39
99.83
98.61
1-Naphthol, ACS
3
83.31
5.59
82.72
5.86
99.29
104.83
Urea
3
19.99
6.71
19.38
6.66
96.95
99.25
Calcium Carbonate
3
11.97
12.04
100.58
Graphitea
3
83.28
84.01
100.88
- ( .3 —
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Raw Garbage-A
aw Garbage-A
Fluorine (F)
Sulfur (Sf 6 )
Chlorine (Cl i
+3
Nitrogen (N
Carbon as:
Sucrose
Urea
Graphite
Calci urn-
Carbonate
43.51
43.38
10.09 to 0.13
10.99
TABLE 3
EFFECT OF ADDED INTERFERING SUBSTANCES ON PERCENT CARBON
CONCENTRATION IN SOLID WASTESa
Sample Percent additive in
Type Additive Analyzed Samples
Percent Carbon Concentration
Observedb
Changed
Possible Observed
Compost-A
Compos t-A
Compost-B
Compost-B
0.58
1.06
1 .41
0.94
Fluorine (F)
Sulfur (Sf 6 )
Chlorine (C1)
+3
Nitrogen (N )
Carbon as
Sucrose
Ure a
d
Graphi te
Calcium -
Carbonate
23.96
24.10
26.35
0.29 -
0.52 -
0.69 -
0.46 -
6.57
0.76 -
2.96 -
0.41 -
3.53
7.19
12.91
26.52
to 0.14
to 0.26
— 21.96
1.19
5.02
0.79
0.89
1.61
2.16
1 .44
8.83
2. 38
7.33
Raw Garbage-A
0.82 -
1.48 -
1.98 -
1.32 -
2.68 -
1.85 -
5.95 -
43.46
12.01 to 0.05
19.95
0.70 - 1.41
- 24 -
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TABLE 3 CONT’D
Resi due-A
(Fines)e
Resi due-A
(Fines)
Residue-B
(Organics)
Fluorine (F)
Sulfur (S 6 )
Chlorine (C1)
• +3
Nitrogen (N
Sulfur (Sf 6 )
Chloride (C1)
• +3
Nitrogen (N )
Carbon as:
Sucrose
Urea
Graphite
Calcium-
Carbonate
8.78 to 0.15
10.15
12.17 to 0.12
16.72
Sample
Type
Percent additive in
Additive Analyzed Samples
Percent Carbon Concentration
Observedb
Changed
Possible Observed
9.94
9.67
0.57
-
0.60
7.00
to
0.17
1.02
-
1.08
7.38
1.37
-
1.44
0.92
-
0.97
4.78
-
5.79
9.91
13.38
to
0.03
1.33
-
1.70
15.88
4.60
-
8.64
Residue-A
(Fines)
Resi due-B
(Organics )f
Residue-B
(Organics)
Carbon as:
Sucrose
Ure a
Graphite
Calcium-
Carbonate
Fluorine (F)
0.61 - 1.29
0.71 - 0.82
1.29 -
1.72 -
1.15 -
1.49
1.99
1.33
30.52
30.37
30.40
3.35 - 7.99
1.31 -
5.73 -
2.23
7.98
0.65 - 1.00
— 25_
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TABLE 3 CONT’D
Fly Ash-A _____ _____ 11.39 _____ _____
Fly Ash-A Fluorine (F) 0.55 - 0.87 11.40
Sulfur (Sf 6 ) 0.99 - 1.57
Chlorine (CY) 1.32 - 2.09
Nitrogen (N 3 ) 0.89 - 1.40
Carbon as:
Sucrose 3.61 - 6.24 14.69 to 0.10
16.77
Urea
Graphite
Calcium -
Carbonate
aHydrogen values are not shown because no extra precautions were taken against the
complex samples collecting moisture during weighing.
bValueS represent the average of at least three individual determinations.
Concentration of carbon in solid wastes material after substracting theoretical
amounts of carbon added.
dRepeat of “a” of Table 1.
e , ,Fines ,I are materials remaining after most of the readily combustible substances
have been removed by manual sorting.
“organics” are mostly the readily combustible materials.
Sample Percent additive in
Type Additive Analyzed Samples
Percent Carbon Concentration
b
Observed
Changed
Possible Observed
Fly Ash - A
6.77 to 0.01
10.69
11.29
1.53
7.79
- 2.09
- 9.42
0.85 - 0.92
- 26 —
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TABLE 4
STANDARD DEVIATIONa OF THE CARBON AND HYDROGEN DETERMINATI S
ON SUCROSE AND SOLID WASTES
Type
Sam
of
pie
Number of Carbon Hydrogen
Samples Duplicates Triplicates Duplicates Triplicates
Sucroseb 2 _____ 0.17 _____ 0.15
SucroseC 2 _____ 0.15 _____ 0.19
Compost 26 _____ 0.29 _____ 0.10
Compost 56 0.22 ____ 0.14 ____
Raw Garbage 17 0.18 0.19 0.19 0.18
Residue 16 0.04 0.06 0.04 0.03
Residue 8 0.21 0.23 0.22 0.18
Fly Ash 9 0.04 0.08 0.06 0.04
aCalculated on a pool basis for solid wastes samples
bNt.1 Bureau of Standards Grade.
CAmerican Chemical Society Grade.
_27 -
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TABLE 5
EFFECT OF SAMPLE PREPARATION TECHNIQUES UPON CARBON-HYDROGEN ANALYSES
Type of Preparation
Individual
percent Conc.
CARBON
Average
Percent Conc.
Correctedd
Avg. Percent
H
Individual
Percent Conc.
Y DROGEN
Average
PercentConc.
Correctedb
Avg. Percent
normal procedure for
residue (fines) 29.18 29.06 2.22 2.40
30.16 2.69
27.83 2.29
fluffy f
raction ( 172 %c)
37.10
37.08
6.38
3.56
3.47
0.60
residue
in Wiley
(fines) ground
Mill using lm
36.63
3.36
sieve
37.52
3.50
heavy fraction (81.4%)
of residue (fines)pul-
verized in liver Pulver-
izer, passed through #60
sieve
18.90
18.90
18.97
18.89
15.38
1.17
1.20
1.43
1.27
1.03
remaininq fraction (1.4%’
could not be ground or
pulverized or nassed
through #60 sieve
29.69
27.36
I
28.41
28.49
0.40
total 22.16
3.01
2.87
2.64
2.84
0.04
total 1.67
aCorrected using the percent fraction values, to correlate average carbon value of fraction to original residue
(fines) sample.
blbid for hydrogen.
CAll percents are on a dry basis.
-------
B. Cost.
The cost of performing the newly developed carbon-hydrogen method
was estimated assuming that: (1) the life expectancy of the glassware
and heating elements is five years and of the furnace is ten years;
(2) continuous operating conditions (3-hr. day, 40-hr. week, 8 holi-
days per year); (3) combustion tube will need repacking once every
six months; (4) duplicate analyses of each sample; and (5) cost of
sample preparation not included.
On a year y basis the minimum cost of the apparatus and çhemi-
cals needed for this method is $606.00; the approximate number of
analyses which can be performed is 1500 (or 750 samples); the number
of man hours required is approximately 1560 hours.
The performance of this method requires only periodic attention
by the analyst. Analyzing, at best, six samples a day, the analyst
will have approximately two hours of free time. The cost of the labor
for this method can only be expressed as man hours needed, since the
salaries of analysts vary too greatly.
Since the combustion tube requires a conditioning period before
a sample can be analyzed, the cost of this method is greatly reduced
by continuous operation. With a conditioned combustion tube, 14
similar samples can be analyzed in duplicate before reconditioning
is needed. Any number of similar samples less than 14 will require
the same amount of time for preparation of the train.
The cost of the chemicals needed for each combustion tube packing
is $64.79. Since the cost of lead chromate and lead dioxide is $50.40
- 29 -
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per tube packing, a study of purification schemes for cheaper grades
was performed. The lead chromates cost was greatly reduced from $18.50
to $0.90 per bOg by purchasing powder grade and preparing it for use.
However, the method required to convert cheaper lead dioxide into
usable material was found difficult and impractical.
In summary, this newly developed carbon hydrogen method if
employed in a continuous operation, is not expensive for the equip=
ment and chemicals needed. The initial cost of the special built
furnace is $1000; however, each additional furnace will cost $850.
The major cost of this method is the labor required to perform the
test. As yet, no quicker method has been developed which will give
satisfactory precision with solid waste materials.
C. Sample Preparation Procedures
All incinerator effluent samples employed in the development of
this method were collected by personnel in Technical Assistance Branch
Division of Technical Operations, Bureau of Solid Waste Management as
part of their evaluation of incinerators studies. These samples were
prepared for analyses by the personnel of the Analytical Task Group,
now part of Research Services Laboratory.
The laboratory personnel received the incinerator residue samples
in triple plastic bags, one inside the other. Residue samples were
manually separated, requiring the visual judgement of the separator,
into 9 organics , fines 1 , and the discarded “glass-ceramic—metal”
portions. (The terminology used for these portions is defined in
Table 3 ).
- 30 -
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The “organics” portion is dried at 70 C to a constant weight,
then ground in the Wiley Mill with the 2mm sieve attached. The
‘fines” portion is dried at 105 C to a constant weight, then pulver-
ized in the Iler Pulverizer until the sample passes through a #60
sieve. The “glass-ceramic-metal” portion is weighed before being
discarded.
With the Atlanta, Georgia, Incinerator Study in December 1968
even greater care has been exercised during sample preparation. Now
all residue “fines” samples are further separated. With the aid of a
magnet and a one-fourth inch sieve, more glass, ceramic,and metal
materials can be removed before pulverizing the samples. During the
pulverization step, a #20 sieve is employed to detect and remove any
more unwanted materials.
Incinerator fly ash samples are prepared for analyses in the
same manner as residue “fines” samples; but, since they contain very
little glass, ceramic,or metal materials, fly ash samples were easy
to prepare for analyses.
Raw refuse from incinerators was prepared as the residue “organics”
samples. However, these samples were delivered in plastic bags to the
laboratory as bulky samples which must first be put through a W-W
hammermill to reduce the particle size. Even before these samples can
be put into the hanimermill, all noticeable glass, ceramic, and metal
materials must be removed.
- 31 -
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Almost all compost samples originated at the PHS-TVA Compost
Plant, Johnson City, Tennessee and, except for a few samples prepared
by the author, were prepared for analyses by the personnel at the
plant site. These compost samples were shipped to the Research Ser-
vices Laboratory in sealed plastic bags.
Compost samples were prepared for analyses by drying the samples
in an oven, usually forced air, at 70 C to a constant weight, normally
overnight. These samples were ground using a Wiley Mill with a lm
sieve attached and stored in a tight, screw top container until the
analyses. As previously mentioned, (in Sectionlil. Results) all samples
were redried within a few days of the analyses.
All samples were tumbled for complete mixing before analyses.
In the development of this method, every samples was mixed with a
spatula before a portion was removed for the analyses.
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