United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S6-84-008 Sept. 1984
Project Summary
Testing and Evaluation of On-
Farm Alcohol Production
Facilities
William Kuby, Robert Markoja, and Steve Nackord
This report gives the results of a
sampling and analysis program managed
by the Industrial Environmental Research
Laboratory in Cincinnati, Ohio (IERL-
Ci), to characterize the air emissions,
water effluents, and solid residuals
from two on-farm ethanol production
processes sampled in June 1980.
Gaseous emissions, both vented and
ambient, were analyzed in the field for
CO2, Oi, and hydrocarbons, including
some 21 alcohols and aldehydes. CO2
was the only compound identified in the
vents. No significant increase in con-
centration of CQz was found in the
ambient air. No other significant air
emission problems were identified.
Liquid and solid samples of the
feedstock, make-up water, distillation
feed, byproduct, beer bottoms, product,
and washout water were analyzed in the
laboratory for priority pollutants, metals,
herbicides and pesticides, and other
standard chemical parameters (e.g..
Biological Oxygen Demand, Chemical
Oxygen Demand). The most significant
result was the identification of very high
Biological Oxygen Demand, Chemical
Oxygen Demand, Total Organic Carbon,
and Total Suspended Solids levels in
both process and waste streams. The
streams were also acidic (i.e., pH less
than 4). The levels of priority pollutants
were below current promulgated Re-
source Conservation and Recovery Act
standards, but some metals exceeded
selected state standards.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory, Cincinnati, OH,
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The objective of this program was to
test and characterize the effluents and
emissions from two farm-scale (approxi-
mately 6,000 gallons/year) ethanol
production facilities. The two sites were
in Kansas (Site A) and Nebraska (Site B).
In both cases, the feedstock was corn and
the enzymes used were a carbohydrate
enzyme (brand name Taka-therm) and a
glucohydrolase enzyme (brand name
Diazyme L-100). Surfuric acid was added
as a pH control.
During the batch sampled at Site A, the
process produced 126 gallons of 88.6
percent (177 proof) ethanol from the 75
bushels of ground grain (56 pounds
per bushel) or a yield of 1 5 gallons of
anhydrous ethanol per bushel of ground
grain. Ten thousand and four hundred
pounds of byproduct for animal feed and
950 gallons of beer bottoms as waste
were computed from a mass balance
based on measured quantities and com-
position analysis. Section 5 of the full
report contains a detailed analysis of
these effluents.
During the batch sampled at Site B, the
process produced about 13 gallons of
approximately 73.6 percent (147 proof)
ethanol from the 15 bushels of ground
grain (56 pounds per bushel) or a yield of
0.6 gallon of anhydrous ethanol per
bushel of grain A total of 3,350 pounds of
byproduct for animal feed and 145
gallons of beer bottons as waste were
computed from a mass balance based on
measured quantities and composition
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analysis. The Analytical Results section of
the full report contains a detailed analysis
of these effluents.
The gaseous emissions, both vented and
ambient were sampled using an extractive
system. The sample gas was also split
into two streams: one going to a total
hydrocarbon monitor and the other to a
gas chromatograph. The total hydrocarbon
instrument monitored total hydrocarbons
in the gas stream while the gas chroma-
tograph speciated the components of the
gas stream. Table 1 lists the compounds
screened for by the gas chromatograph.
The gas velocity in the vent was measured
by using a hot wire anemometer flow
measuring device. The sensing probe
was inserted upstream of the gas
sampling probe. Liquid and solid samples
were taken of each of the solid and liquid
effluents at the appropriate points.
Methodologies used for organics
analysis are based on EPA Methods, the
FDA Pesticide Analytical Manual, and
Standard Methods lor the Examination of
Water and Wastewater 14th Ed. APHA,
AWWA, WPCF. Aqueous samples were
analyzed according to Table 2 and solid
samples were analyzed according to
Table 3.
Analytical methodologies used for the
general chemistry analyses were based
on Standard Methods for the Examination
of Water and Wastewater 14th Ed. APHA,
AWWA, WPCF, and Methods for the
Analysis of Water and Wastes, EPA,
March 1979. Aqueous samples were
analyzed according to Table 4. The
analytical procedures for high solid
samples were basically the same as for
the liquid samples (Table 4).
Metals were determined by atomic
absorption spectrophotometry. Samples
were digested with nitric acid. Mercury
was determined by the cold vapor
technique. Other metals were determined
by either flame or graphite furnace
atomization of the acid digest.
Analytical Results
The laboratory and field analytical
results are presented and discussed in
this section. A brief description of the
quality control procedures is also included.
The actual results for precision, accuracy,
and recovery experiments are given in
Appendix A of the full report.
The laboratory analytical sample matrix
is shown in Table 5. Table 6 gives the
ethanol content in the various streams.
The data are organized as follows:
• Conventional parameters
• Metals, cyanide, and phenols
Table 1. Species Screened for by Gas Chromatograph
Alcohols
Methanol
Ethanol
1 -propanol
2-propanol
1 -butanol
2-butanol
2-methyl 1-propanol
Formaldehyde
Propionaldehyde
Butyraldehyde
Isobutyraldehyde
Aldehydes
2-methyl 2 -propanol
1 -pentanol
2-pentanol
3-pentanol
2-methyl 1-butanol
3-methyl 1-butanol
2-methyl 2-butanol
Valeraldehyde
Isovaleraldehyde
Furfuraldehyde
Table2. Aqueous Samples
Analysis
Method
Extractable organics by GCMS
Volatile organics analysis
(purge and trap}
Herbicides
EPA 625
EPA 624
Standard
Method 509B
Table 3. Solid Organic A nalyses
Analysis
Method
Note
Pesticides
Herbicides
Volatile organics analysis
(purge and trap)
Base/neutral and acid
fraction
FDA 211 13e
FDA 222.13c
EPA 624
EPA 625
Dilute with organic-
free water
Soxhlet Extraction
Table 4. Aqueous General Chemical Analyses
Analysis
Method
BODs
COD
TOC
Total suspended
solids
Total solids
Phenols
Cyanides (total)
Ammonia
Nitrate
Sulfate
Phosphorous
Specific
conductance
Metals
pH
Total Kjeldahl
nitrogen
5-day incubation, sample analyzed for oxygen
depletion
Acid dichromate reflux, back titrate with ferrous
ammonium sulfate
Conversion to COz infrared quantitation
Gravimetric, 105°C, weigh residue on filters
Gravimetric, 105°C, weigh residue
Distill, amino antipyrine color, CHC/3 extraction.
Distill, barbituric acid colorimetry
Distill, followed by nesslerization
Brucine colorimetric
Turbidimetric
Nitric/sulluric acid digest, ascorbic acid
colorimetry
Wheatstone bridge conductivity
Atomic absorption spectrophotometry following
acid digestion. Analysis by cold-vapor flame-
less AA (Hg), flame and graphite furnace analy-
ses as appropriate for others
Electrometnc
Sulfuric acid mercuric oxide digestion, distillation,
nesslerization
Metals: Al, Sb, As. Ba. Be, Bi, Cd. Ca, Cu. Cr. Fe, Pb, Mg. Mn, Hg. Ni. Se, Ag, Tl, Ti, and Zn
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Priority pollutants
— Acid compounds
— Base/neutral compounds
— Volatile organics
— Pesticides and herbicides
The process waste streams (beer
bottoms and washout water) exhibited
certain common characteristics of high
BOD5, COD, TSS and TOC, and low pH
(acidic).
Solids and oxygen demand were
extremely high but decreased over time
through the system. The analytical values
for Site B are probably on the low side
because of the warming of the samples in
transit. Laboratory analyses indicated that
most of the substances contributing to
oxygen demand were biodegradable.
The discharge of the materials high in
free and bound nutrients (i.e., nitrogen
and phosporous) stimulate biological
activity. All process streams exhibit this
characterization. Nutrients are an impor-
tant limiting factor in the growth of all
plants. With all other factors being equal,
the rate and profuseness of plant growth
is proportional to the amount of nutrient
available. A high concentration of nutrients
will produce rapid plant growth first
becoming apparent as algae bloom. The
term "bloom" is used when the concen-
tration of individual species exceeds 500
individuals per milliliter of water.
The results from the metals analyses
indicate that the corrosivity (low pH)
problem might be significant. Metals (Ca,
Cu, Fe, Mg, Mn, and Zn) detected at
significant levels tended to increase in
concentration through the system; how-
ever, the metals did tend to concentrate in
the byproduct even though the pH of the
byproduct and liquid streams were
similar. The sources of metals throughout
the process included the valves and
general piping, squeezer trough, distilla-
tion columns, and holding and settling
tanks. The low pH of the process streams
may be leaching metals from equipment,
the majority of which were not stainless
steel. The increasing levels of copper,
iron, manganese, and zinc through the
process are indicative of this problem.
Only traces of a few priority pollutant
organics, herbicides or chlorinated
pesticides, were detected in any of the
samples. Except for the pesticides and
herbicides, these traces of compounds
seemed to be contamination problems in
the laboratory rather than actual residues
of the compounds. In the winter when
doors would be closed, it would be
advisable to vent fermentation tank and
product tank emission to the outdoors to
prevent dangerous accumulations of COj
and ethanol in the work place.
Conclusions and
Recommendations
The overall results indicate several
areas of concern regarding the environ-
mental impacts from on-farm alcohol
production. Although primary concern
should be with those normal discharges
from the process, one must additionally
be concerned with the "dumping" of poor
batches and disposal of the solid materials
other than by byproduct use, i.e., as a
feedstock.
For the process liquid and solid
streams, these concerns include high
oxygen demand, high nutrient content,
metals in the process streams and
wastes, low pH (acidity), herbicide and/or
pesticide residues from feed grain (but
this would be highly dependent upon the
feed grain supplier and the area of use).
Regarding air emissions, particularly
during the winter months, the only
apparent concerns are venting of C02for
safety reasons from the fermenter off-gas
and ethanol vapor from the product tank
to the outdoors.
Finally, a treatabihty study should be
performed on all effluents and off-
specification process waste to determine
appropriate waste treatment methods
and obtain treatment design criteria.
TableS. Analytical Matrix
Site
A
B
Sample type
Make-up
water
Feed grain
Distillation
feed
Beer bottoms
Washout
water
Byproduct
Product
Cooker
runoff
Make-up
water
Feed Grain
Distillation
feed
Beer bottoms
Washout
water
Byproduct
Product
Soil
Soil control
I
X
X
X
X
X
X
X
X
§
* 1 6
«> -S> +
QL 3C Uj
X X
X
X
X
X
X
X
X X
X
X
X
X
X
*AI. Sb. As, Ba. Be, Bi. Cd. Ca. Cu, Cn, Fe. Pb. Mg. Mn. Hg. Ni. Se. Ag. Ti. H Zn
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Table 6. Analysis Results — Percent Ethanol by Gas Chromatography3
Sample type
Distillation feed
Beer bottoms
Washout water
Byproduct
Cooker mash runoff
Product
Site A
6.9
0.9
1.2
0.08"
Less than 0.5
87.0 (88.6 f
Site B
3.9
2.4
1.1
0.08"
71 0(73.6 f
"Accuracy estimated at +10 percent.
"Percent by weight.
cNumbers in parentheses are results from hydrometer tests.
William Kuby, Robert Markoja. and Steve Nackord are with Acurex Corporation,
Mountain View. CA 94042.
R. £. Mournighan is the EPA Project Officer (see below).
The complete report, entitled "Testing and Evaluation of On-Farm Alcohol
Production Facilities," (Order No. PB 84-215 789; Cost: $11.50, subject to
change) 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:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati. OH 45268
S GOVERNMENT PRINTING OFFICE, 1984—759-015/7819
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
PS
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