United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/010 August 1995
&EPA ENVIRONMENTAL
RESEARCH BRIEF
Pollution Prevention Assessment for a Manufacturer of
Bourbon Whiskey
Marvin Fleischman*, Debra Cambron*,
and Gwen P. Looby**
Abstract
The U.S. Environmental Protection Agency (EPA) has funded
a pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the expertise to do so. Waste Minimization Assessment Cen-
ters (WMACs) were established at selected universities and
procedures were adapted from the EPA Waste Minimization
Opportunity Assessment Manual (EPA/625/7-88/003, July 1988).
That document has been superseded by the Facility Pollution
Prevention Guide (EPA/600/R-92/088, May 1992). The WMAC
team at the University of Louisville performed an assessment
at a plant that produces bourbon whiskey. Grains are ground,
cooked, and fermented using yeast. The resulting fermented
product is sent to a beer still for alcohol recovery. Overhead
vapors go to a doubler from which they flash yielding a new
whiskey. The new whiskey obtained is stored in charred wooden
barrels for several years and, after maturation, is shipped
offsite for bottling. The team's report, detailing findings and
recommendations, indicated that carbon dioxide and ethanol
are vented to the atmosphere in large quantities and that
significant cost savings could be realized through carbon diox-
ide and ethanol recovery.
This Research Brief was developed by the principal investiga-
tors and EPA's National Risk Management Research Labora-
tory, Cincinnati, OH, to announce key findings of an ongoing
research project that is fully documented in a separate report
of the same title available from University City Science Center.
"University of Louisville, Department of Chemical Engineering.
"University City Science Center, Philadelphia, PA.
Introduction
The amount of waste generated by industrial plants has be-
come an increasingly costly problem for manufacturers and an
additional stress on the environment. One solution to the
problem of waste generation is to reduce or eliminate the
waste at its source.
University City Science Center (Philadelphia, PA) has begun a
pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the in-house expertise to do so. Under agreement with EPA's
National Risk Management Research Laboratory, the Science
Center has established three WMACs. This assessment was
done by engineering faculty and students at the University of
Louisville's WMAC. The assessment teams have considerable
direct experience with process operations in manufacturing
plants and also have the knowledge and skills needed to
minimize waste generation.
The pollution prevention opportunity assessments are done for
small and medium-size manufacturers at no out-of-pocket cost
to the client. To qualify for the assessment, each client must
fall within Standard Industrial Classification Code 20-39, have
gross annual sales not exceeding $75 million, employ no more
than 500 persons, and lack in-house expertise in pollution
prevention.
The potential benefits of the pilot project include minimization
of the amount of waste generated by manufacturers and re-
duction of waste treatment and disposal costs for participating
plants. In addition, the project provides valuable experience for
graduate and undergraduate students who participate in the
program, and a cleaner environment without more regulations
and higher costs for manufacturers.
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Methodology of Assessments
The pollution prevention opportunity assessments require sev-
eral site visits to each client served. In general, the WMACs
follow the procedures outlined in the EPA Waste Minimization
Opportunity Assessment Manua/(EPA/625/7-88/003, July 1988).
The WMAC staff locate the sources of waste in the plant and
identify the current disposal or treatment methods and their
associated costs. They then identify and analyze a variety of
ways to reduce or eliminate the waste. Specific measures to
achieve that goal are recommended and the essential support-
ing technological and economic information is developed. Fi-
nally, a confidential report that details the WMAC's findings
and recommendations (including cost savings, implementation
costs, and payback times) is prepared for each client.
Plant Background
Manufacturing Process
Whiskey Production
The production of whiskey is described in this section. A
process flow diagram that depicts the process appears at the
end of this section.
Corn, rye, and malt grains received via railcars and trucks are
bottom-unloaded through a grate onto a screw conveyor. The
grains are carried to a vibrating screen where large foreign
material is removed, then transferred by bucket elevators to
storage silos.
As needed, the grain is transported by screw conveyor to mills
for grinding. The ground grain (also called meal) is then sent
via bucket elevator to the meal room where each type of grain
is stored in a separate bin. A small amount of malt meal is
added to bins of corn meal and rye meal to keep them from
hardening. The meal is then gravity fed to the scale room.
From the scale room, rye and malt are sent to separate slurry
tanks prior to being added to the cooker. Corn meal is con-
veyed to one of three mash cookers to which water and spent
stillage from fermentation are added. Steam is added to the
cooker directly in order to cook the corn at high pressure and
temperature. After the corn has been cooked, the vessel tem-
perature is lowered by releasing the tank pressure. The rye
slurry from the slurry tank is added to the cooking vessel where
the resulting mixture is cooked at lower pressure and tempera-
ture then used for the initial corn cooking. Next, the malt slurry
is added to the mixture (called the mash) in the vessel. The
cooking process releases the starches from the grain and the
malt provides the enzyme that converts the starch to sugar.
In a separate operation, yeast is prepared for the fermentation
process. An inoculum and a mixture of rye and malt meals are
combined in one of several yeast tubs. Once the yeast is
ready, it is mixed with the mash and cooled. The mixture is fed
to a fermentor where the yeast metabolizes the sugars to
produce alcohol.
The fermented product, beer that is approximately 9% alcohol
by volume, is sent to the beer well for storage. From the beer
well the product is pumped to the beer still for alcohol recovery.
The overhead vapors from the still go to a thumper (also called
a doubler) where they flash into the high wine condenser,
yielding a 145-proof new whiskey. The still bottoms or "slop"
are sent to the dryhouse for further processing into distillers'
dried grains for use as animal feed.
The new whiskey is sent to one of several storage tanks where
it is reduced in proof using demineralized water. Charred white
oak barrels are then filled with product. The filled barrels are
sent to a temperature- and humidity-controlled warehouse where
the product matures for several years.
Following the maturation process, the barrels are conveyed to
vacuum pumps which transfer the whiskey into storage tanks.
The whiskey is loaded into trucks and taken to an offsite
bottling facility.
A process flow diagram for whiskey production is shown in
Figure 1.
Dried Grains Production
The processing of the still bottoms begins with the initial sepa-
ration of "thin slop" from "thick slop" by passing the mixture
over a screen. A portion of the thin slop is sent to the mash
cookers. The remaining thin slop is sent to a small holding
tank. The thick slop is passed through a paddle screen and a
press for further recovery of thin slop. Remaining thick slop is
conveyed to a drier and then a storage tank. From the holding
tank the thin slop is sent through a four-stage multi-effect
evaporator and two finishing evaporators. The syrup is sent to
a dehydrator and then to storage. Dried grain from the thin and
thick slop is mixed and sold as animal feed.
A process flow diagram for production of distillers' dried grains
is shown in Figure 2.
Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes:
• A product, distillers' dried grains for animal feed, is made
from the distillation residue.
• Spillage of grain during unloading has been reduced by
funneling the grain into the delivery grate.
• Leakage of grain from the grain handling system has been
reduced through the use of relatively new and tight equip-
ment and through frequent routine maintenance.
Pollution Prevention Opportunities
The type of waste currently generated by the plant, the source
of the waste, the waste management method, the quantity of
the waste, and the annual waste management cost for each
waste stream identified are given in Table 1.
Table 2 shows the opportunities for pollution prevention that
the WMAC team recommended for the plant. The opportunity,
the type of waste, the possible waste reduction and associated
savings, and the implementation cost along with the payback
time are given in the table. The quantities of waste currently
generated by the plant and possible waste reduction depend
on the production level of the plant. All values should be
considered in that context.
It should be noted that the economic savings of the opportu-
nity, in most cases, result from the reduction in raw materials
and from reduced present and future costs associated with
waste treatment and disposal. Other savings not quantifiable
by this study include a wide variety of possible future costs
related to changing emissions standards, liability, and em-
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r
Unloading
Grains
Cleaning
Milling ; - ; '
Veasf Rye, Malt
Beer
f~ 1 Well
,: Corn Meal
" Bin
Scale
Rye Meal
1 Bin \
Scale
Malt Meal
Bin
t
Scale
Mash ^_
Cooker
Slurry
Tank
Still
Thumper
Condenser
High Wine _
Storage
Barrel
Filling
Grain Slop to
Byproducts Processing
Whiskey Shipped to
Offsite Bottling
Facility
Barrel I
Dumping I"™*"
I
Barrel
Warehousing
Figure 1. Abbreviated process flow diagram for whiskey manufacturer.
Grain Slop From
Bottom of Still
I
Screens
J Thick Stillage
' ' Tank
*» Screen
Thin Stillage lot-
Tank
Evaporators
Presses
t
Dryer
Dehydrators
Mixing
Dried Grain
Figure 2. Abbreviated process flow diagram for dried grain production.
ployee health. It also should be noted that the savings given for
each pollution prevention opportunity reflect the savings achiev-
able when implementing each waste minimization opportunity
independently and do not reflect duplication of savings that
would result when the opportunities are implemented in a
package.
Additional Recommendations
In addition to the opportunities recommended and analyzed by
the WMAC team, several additional measures were consid-
ered. These measures were not analyzed completely because
of insufficient data, minimal savings, implementation difficulty,
or a projected lengthy payback. Since one or more of these
approaches to pollution prevention may, however, increase in
attractiveness with changing conditions in the plant, they were
brought to the plant's attention for future consideration.
• Install a system to reduce the concentrations of BOD5 and
suspended solids in the wastewater currently sent to the
POTW.
• Use an enclosed filter on the off-gas of the granary cyclone;
direct the collected dust to the corn meal storage bin.
• Use high-pressure water spraying to clean cookers in order
to reduce the quantity of water required for cleaning.
• Reuse the evaporator scrubber effluent for cleaning of the
vent from the steam tube dryers.
• Recover ethanol emissions from the storage tanks in various
stages of the manufacturing process.
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• Reduce dust losses that occurduringthe loading of distillers'
dried grains into trucks.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-814903 by the University City
Science Center under the sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma
Lou George.
Table 1. Summary of Current Waste Generation
Waste Generated
Grain waste
Grain and water
Grain
Water and caustic
Wastewater
Carbon dioxide
Ethanol
Water and caustic
Ethanol
Water, acid, and caustic
Ethanol
Ethanol
Ethanol
Dried grains and water
Water and soluble grain
Other wastewater
Coal ashes
Spent oils
Source of Waste
Vibratory screens and cleaning
of conveyors
Water scrubber for cyclone
Granary operations
Cleaning of mashers, fermentors,
beer well, and mash lines
Rinsing of cooker and cleaning
of sight glasses on cookers
Fermentors
Fermentors
Cleaning of stills
Condensers
Regeneration of cation and
anion exchangers
Filling of storage tanks
Barrel breathing during maturing
process
Transfer of product for bottling
Cleaning of equipment used
for byproduct processing
Evaporator condensate from
byproduct processing
Various processes
Burning of coal for steam generation
Changing of lubricating oils
Waste Management Method
Given to employees for use
as animal feed
Sewered
Dust reduced using water scrubber
Sewered
Sewered
Vented to atmosphere
Vented to atmosphere
Sewered
Vented to atmosphere
Used for neutralization; sewered
Vented to atmosphere
Vented to atmosphere
Vented to atmosphere
Sewered
Sewered
Sewered
Shipped to landfill
Recycled offsite
Annual Quantity
Generated (Ib/yr)
6,350
33,259,000
Included in above
25,146,500
8,300
106,240,000
637,400
5,196,000
630,530
3,572,940
4,960
2,545,000
8,320
37,413,000
666,782,800
143,161,500
32,000,000
2,300
Annual Waste
Management Cost
0
4.6802
369,000
(lost material value)
3.3902
negligible
0
136,000
6802
134,400
1.2402
1,060
1,027,000
3,360
5.0802
90.6302
12.9152
98,700
1,500
' Includes waste treatment, disposal, and handling costs and lost materials values.
2 Estimated cost of individual waste stream. Additional surcharges of $113,410/yr are incurred for BOD and suspended solids.
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Table 2. Summary of Recommended Pollution Prevention Opportunities
Annual Waste Reduction
Pollution Prevention Opportunity
Waste Reduced
Quantity (Ib/yr)
Percent
Net Annual Implementation
Savings Cost
Simple
Payback (yr)
Install a packaged CC>2 recovery
plant to recover CC>2 and ethanol
vented from the fermentors. Sell
the recovered liquified CC>2 to a
CC>2 distributor. Recovered
water/ethanol can be sent to the
beer well to be further processed.
Recover ethanol vent losses from
the still condensers using a
refrigerated water-cooled condenser.
Use the recovered ethanol as a
supplemental fuel in the boilers.
Replace the currently used ion
exchange system with a reverse
osmosis unit that is available on-
site for demineralizing water.
Recover ethanol from the ware-
house exhaust air using carbon
adsorption and steam stripping
and distillation. Return the re-
covered ethanol to the beer well.
Ship coal ash to a nearby cement
kiln that can use the ash as a raw
material instead of shipping it to a
landfill.
Carbon dioxide
from fermentors
Ethanol from
fermentors
106,240,000
573,700
Ethanol from condensers 567,500
Water, acid, and caustic 3,572,940
Ethanol from barrel
breathing
Coal ash
2,375,191
32,000,000
100
90
90
100
93
100
$1,248,2001'2 $2,600,00
7,360
1,3
2,740
1,4
16,600
160
864,2101'3 831,000
68,300
2.1
2.3
0.1
1.0
1
Total annual savings have been reduced by the operating cost required for implementation.
If a tax is imposed on CC>2 emissions in the future, the savings from this WMO would be even higher.
If a tax is imposed on VOC emissions in the future, the savings from this WMO would be even higher.
It is possible that this plant will be reclassified as a hazardous waste generator in the future because of new regulations concerning the pH of regenerant material.
In that case, savings from this WMO would be even higher.
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United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-95/010
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