Volume 9, Number 2, Summer 1997
Topics for this issue: ENVIRONMENTAL
Using solid-waste materials as boiler
fuels helps Cagle's Foods turn costs into savings
High-tech data acquistion
and control system can reduce wastewater treatment costs
Pilot-scale
DAF system helps identify and eliminate waste
New USDA guidelines for
water conservation and reuse to be released soon
Software program nears
completion to help processors save on water costs
Using solid-waste
materials as boiler fuels helps
Cagle's Foods turn costs
into savings
Solid waste is not a serious problem for the
poultry industry yet, but it could become a significant cost issue
as landfill disposal costs start
to go up. This article discusses an innovative solid-waste
recycling program implemented by Cagle's Foods that involves
burning waxed
cardboard boxes
and recovering the energy generated to produce steam.
Further
processing facilities have become more plentiful in recent years as
consumer demand for higher value-added
products has
increased. The industry
commonly uses plastic boxes or totes filled with ice
to move chilled product from a primary processing facility
to
a further
processing
facility. These
plastic boxes can be sanitized and reused; but eventually
they
wear out and have to be either disposed of as a solid
waste in a landfill or accumulated
for recycling. Corrugated totes are more popular in
facilities receiving
product from outside companies. These containers cannot
be reused and typically wind up as solid waste in a
landfill.
"
Solid waste is not a serious problem for the poultry industry yet.
But it could become a significant cost issue as landfill disposal
costs start
to go up," ATRP researcher Jim Walsh emphasizes.
At least one poultry processor has already taken steps
to reduce this exposure and cost and is
making it work to their cost advantage today.
Cagle's
Foods has implemented a program at three of its facilities,
where they have switched to wax-coated
corrugated
boxes that
are used one time
and then are burned to generate energy for the processing
operation. Solid waste boilers are used for burning
the boxes. According
to Ken Nix, projects
and ergonomics engineer for Cagle's, the value of
this waste is something on the order of 6,000 BTUs per pound
minimum (depending on how wet
the boxes are and how heavily coated with wax). Even
when the boxes
are wet, Nix notes,
they burn well because the wax is a tremendous source
of energy.
Nix compares their Collinsville, Alabama,
plant's waste-handling costs with those of another poultry processor
close
to the Collinsville operation: "Their
bill per week for waste handling is about $2200. Our
cost per week is about 10 percent of that ($240 a week).
We pay far less for waste removal and
don't pay anything for fuel for the boiler."
Cagle's Collinsville facility is burning about 18,000
pounds per day of cardboard waste in a low-pressure
boiler that
is run almost
entirely from the solid waste generated by the plant's
processes. However,
since
the further-processing area at the plant has the capability
to run more volume than the slaughtering operation,
outside birds from other
processors
are brought in to make up the difference. The Cagle's
plant also
burns the cardboard-box waste used to transport these
birds from other processors.
In addition, the plant receives waste cardboard boxes
from another poultry
processor in the area.
Walsh notes that "it's probably
an opportunity for any poultry processor to consider
when looking at plant modifications." He cautions that
plant personnel must examine the plant's whole operation
since wax-coated box burning may not be practical for
all operations. For example, a certain
minimum volume of waste is needed to make such an operation
viable. If this volume is not there, other water heating
methods, such as direct contact,
can prove more cost effective if supplemental boiler
fuel must be used.
If plants don't have enough waste
to meet their energy needs, they may have a supplier who can provide
additional waste
so that they
can implement
a process like the one at the Collinsville facility,
Nix emphasizes. For example, Cagle's feedmills in
Forsyth, Georgia, and Camilla,
Georgia, use
waste materials from other sources.
The Forsyth feed
mill uses boxes from Cagle's Macon plant to generate its energy. The
Forsyth mill is
currently receiving approximately 5,300 pounds
per day or around
30,000
pounds
per
week of the
wax-coated
boxes
from the plant. The Macon plant uses large boxes
that hold 1,000 or 1,200 pounds of chicken for
temporary storage. When the Macon
plant is
through
with the boxes, they are broken down, put into
a baler,
and then shipped to Forsyth.
Since the Macon facility
doesn't produce enough waste boxes to meet all of the Forsyth plant's
energy needs,
the Forsyth
mill supplements the Macon
shipments with box scraps from a Georgia Pacific
finishing plant
in southwest Georgia, which produces corrugated
boxes for the poultry industry.
During
production, the manufacturer has to punch out
holes, trim the boxes, and sometimes discard material
that is not suitable
or has not
been
coated properly.
Since the Forsyth mill can use this scrap material,
it does not end up as a solid-waste disposal
problem for the manufacturer.
The Camilla feedmill produces very little
burnable solid waste. Consequently, they are powering
their boiler almost
entirely with box waste from
the same Georgia Pacific supplier as the Forsyth
plant. The plant is burning about
180,000 pounds per week of this waste. The
plant also receives some box waste from a nearby firm
that does
custom printing
of corrugated boxes and
materials.
Ken Nix is enthusiastic about the
possibilities of using the waxed, corrugated boxes as a source
of energy: "Once you've established a consistent
supply of this material and you've worked
out all the details of the material handling
aspects,
it seems to be a very reliable source of
heat and a good
way to save money on fuel costs. Even in
these times, this can result in a significant
savings
in waste handling and disposal, and we all
know that
these costs are not likely to diminish in
the future."
Nix anticipates that these
sorts of solutions to solid-waste handling
and energy-generation
problems are going to
become more and more
important to processors in the future: "I
think this sort of thing is going to be very
much like the rendering business was many
years ago - we more or
less gave away chicken scraps to a renderer
to get rid of it. Now, there is such a demand
for rendering stock to support the expanding
petfood market,
it has become an income producer. Solid waste
that is generated by chicken processing will
take on that same character in the future.
Right now, people
are paying for solid waste to be taken away;
in the future it could have value just like
the rendered product has now. Processors
will recognize
it for its heat value, as a supplement or
a replacement for petroleum fuels.
Walsh
notes that using the boxes to generate
energy has multiple benefits: it solves sanitation
problems
(plants don't have
to worry about maintaining
plastic totes), solves solid-waste disposal
problems, and gives plants a way of generating
energy they
need for
processing
operations.
High-tech data
acquistion and control system can reduce
wastewater treatment costs. Poultry processing
facility managers rely upon dissolved-oxygen meters to manually
check that
the proper amount of
aeration is applied in
wastewater treatment. However, dynamic
changes in the waste stream frequently result
in overaeration that leads to sludge bulking
and excess electrical usage. Georgia Tech
researchers are currently
studying alternative
methods of measuring
plant operations that will provide facility
managers with real-time feedback. The system
is currently
being tested and should help
processing plants operate
more efficiently in the future.
Aerated
lagoons and stabilization ponds are commonly used for industrial wastewater
pre-treatment
in the food processing
industry as an
economic alternative for removing BOD5.
Mechanical surface aeration is the
key component in these systems, because
the amount
and rate of aeration influences
the
final treatment. But excess aeration
also generates sludge bulking and wasted electrical
costs.
While processing facility managers
have traditionally relied upon dissolved-oxygen
meters to measure
aeration
effectiveness
in
meeting the requirements of their discharge
permits, they also need to consider aeration
efficiency.
In order to make lagoon and
pond wastewater treatment systems at food processing
facilities more efficient,
Georgia Tech
researchers are
currently studying alternative methods
for measuring dissolved oxygen such
as incorporating oxidation-reduction potential
(ORP) sensors
and
programmable logic
controllers to:
automatically control aeration rates
and thus reduce energy usage
yield
optimum biological wastewater treatment and
provide flexibility to
adjust for process fluctuations.
These features will provide the facility
manager with feedback while the process
is going on.
Plant management and planning
should also
improve as presentation and integration
of plant process
data becomes more sophisticated.
Researchers have installed their
data acquisition and control system
at a
poultry processing
facility and
are currently
measuring energy
usage and lagoon removal efficiencies.
They anticipate completing the on-site
demonstration by July 1997; however,
monitoring will continue throughout
the year to evaluate
the system
under winter
conditions.
Pilot-scale
DAF system helps identify and eliminate
waste
Georgia Tech researchers have
found that processing plants are typically
using too high a concentration
of chemicals
in DAF treatment systems.
Researchers have developed a pilot-scale
DAF system that allows a plant
to determine how well they are performing.
They
believe
studies using this system can help
plants improve their
treatment performance.
The old adage "Less
is more" has been proven once
again. Researchers with Georgia
Tech's Agricultural Technology Research
Program
have discovered
that many poultry processors use
thirty to forty percent more chemicals
than necessary in their dissolved-air
flotation (DAF) primary waste treatment
systems. These researchers are
now working with a pilot-scale
DAF to identify process changes that
will
optimize the amount of chemicals
added. Improving
performance can lead to financial
savings, improved skimmings quality,
and enhanced effluent quality for
the company.
The DAF system works
by releasing tiny air bubbles into
the facility's
wastewater.
These
bubbles
lift solids and free-floating grease
to the surface, where it can be
skimmed off. Skimmings are
sent to a renderer
to produce
feed additives for the industry.
Chemicals
such as ferric sulfate and organic polymers can also be
added to the wastewater
to improve
treatment. However,
if
this chemical
dosage
is too much, the quality of the
skimmings can be affected. Skimmings
may contain
excessive concentrations of metals,
such as aluminum
or iron, which
are derived from the coagulant
used in the initial wastewater
treatment. These metals can
affect
the
color and toxicity
of the rendered
product. Because many renderers
will
not accept poor quality skimmings,
processors
are then forced to dispose of
the skimmings
as waste.
Improperly operated
DAF systems can also impact the overall treatment
process. Because DAFs
are essentially used
as primary waste treatment
systems, an excessive dosage
of chemicals
can affect the secondary waste
treatment system. The processor
may be forced
to
improve the
secondary system in order to
make up for deficiencies in
the primary
system.
Researchers have been
experimenting with a pilot-scale DAF system
to predict the
optimum range of chemical
dosing for
a system operation. Project
director John Pierson
states that the group
was
at first
concerned
that
they would not be able to
mimic the many varied processes found
at different
facilities.
However,
they found
that by concentrating on
reproducing the
initial chemical mixing process,
they could successfully replicate
the facility's operations.
Pierson
and his group have employed the system at Sylvest
Farms'
further processing plant
in Union City,
Georgia,
where they
discovered that
treatment efficiencies
for removals of
chemical oxygen demand
(COD), Total Suspended Solids, and
Total Kjeldahl
Nitrogen (TKN)
can be increased by seventy-five
percent, ninety percent,
and fifty percent, respectively.
Pierson states, "While
this facility diligently
monitors its process, the
method for initial chemical
addition
of ferric sulfate did not
allow for rapid dispersal,
so ferric
usage was thirty percent
higher than needed."
The
unit can also be used as
part of a broader program
to
keep an
eye on
in-plant processes.
The pilot-scale
system tracks
and records influent
and effluent wastewater
concentrations. Exploring
trends in
influent changes can help
identify likely upsets
in plant operations.
Understanding a company's
entire process system allows
better control
over fluctuations and upsets.
The
team plans to take the mobile pilot-scale
system to different plants,
where
they
will initially replicate
the
processor's
existing chemical
dosing and then vary
system parameters
to assess the effects.
This method allows the
processor to continue
normal operations
while testing new systems.
New
USDA guidelines for water
conservation and reuse
to
be released soon
Water-use laws and wastewater
restrictions may make
water conservation
a priority for many poultry
processors.
The USDA is in the
process of issuing
new guidelines for water
use
that will help
poultry processors
implement water-reuse programs.
Like other food industries,
the poultry industry
is dependent on water.
However, the demand
for water resources
is
increasing rapidly
as more
and more residential
and
industrial users tap
into existing
water
supplies each
day. So serious is
the problem that some
areas
of the country
are already
facing
potential regional
restrictions on new
water usage.
At the same
time, many municipalities
have also enacted increasingly
stringent
requirements
on
wastewater strength
being received by their
treatment plants from
industry.
These factors add up
to dollars - clean
water has
become,
and will continue to
be, an increasingly
expensive
commodity for
industry. Finding ways
to conserve water and
to reuse it where possible
provides
an opportunity
for poultry plants
to lower costs,
ensures that
an adequate
supply of water
is available for processing
needs, and enhances
a plant's abilities
to meet tightening
regional and national
water use restrictions
by reducing the
overall volume of water
needed.
The United States
Department of Agriculture
(USDA)
has recognized for
a number of years the
importance
of water
reuse. In the
June 1990 Guidelines
for the Safe Reuse
of Treated
Effluent
Water for Meat and
Poultry Processing,
the task
force that
wrote the
guidelines stated
that "the need to
conserve potable [drinking]
water is becoming critical."
The
USDA is in the process
of issuing
new guidelines
to encourage water
reuse, which
will affect
all food industries,
not just poultry.
The USDA anticipates that
the guidelines will
be released within
the next few months,
with final comments
due in January
1998.
Currently, most
plants can take almost as
much water as they
want. However,
in a growing
number
of areas,
water permits
are required. For
example, plants
in Georgia using
more than 100,000 gallons
per day
of
water must
have water withdrawal
permits. These permits
allow government
authorities
to
control
increases in water
withdrawal (even
for expansions), pending
the implementation
of sound water-conservation
measures
in existing
operations.
Similarly,
recent regional water
agreements, such
as the
compact between
Georgia,
Florida, and Alabama
on the
CFA - the Chattahoochee,
Flint, and
Apalachicola watershed
- also have the potential
to restrict water-usage
growth. The compact
mandates that in
the near future the
states have to
set up agreements
on how much
water can be withdrawn
by each state.
Plants that withdraw
their water from
aquifers could
also face
problems
with obtaining enough
water. In
some areas
of the country there
is concern that the
amount of water being
withdrawn from aquifers
exceeds
the ability
of
the aquifers to recharge
themselves, leading
to fears of infiltration
of seawater into
the aquifers or an overall
lowering of the water
table to unacceptable
levels.
ATRP researcher
Jim Walsh notes that "the
industry has been looking
for years at opportunities
for reusing water -
they just need guidance
on
what is acceptable
in order to implement
water
reuse programs." The
new guidelines should
help processing plants
implement water reuse
while meeting federal
requirements.
The Environmental
Protection
Agency (EPA), the Food
and Drug Administration
(FDA),
and the USDA's
Food
Safety and Inspection
Service do have
requirements that water
be "safe for the
intended use." These
requirements mandate
that plants reusing water
must
-
have an advanced wastewater-treatment
facility;
-
meet "safe
for the intended use" criteria;
-
have qualified
personnel for the wastewater-treatment
system;
-
have a quality-control
program that monitors
water reuse;
-
identify
potable and reuse water lines and
keep them
separate;
-
have alarms
and valves in place to keep reuse
water from
contaminating
the drinking
water
supply;
-
have a system
in place to prevent reuse water
from contaminating
product;
-
monitor and
test reused water daily and test
for heavy metals
at least once a
year;
-
apply a final
potable water rinse to any
edible product
and any
equipment that contacts
reuse
water.
The
current guidelines
on water reuse
(which the new guidelines
will replace) are
designed to help
plants meet the
requirements.
The current
guidelines are performance based:
plants have to prove
that what they are
doing is "safe for
the intended use." The
guidelines are not
a prescription requiring
plants to follow
certain procedures
- plants vary in the amount
and type of water they
use to produce birds
according
to the specific process
and type of equipment
in the plant. A plant
is responsible
for designing and implementing
a plan that will meet
the requirements of
producing birds in a sanitary
manner
and protecting worker
health.
Walsh anticipates
that
the new guidelines
will have a similar
performance-based
concept. However,
under
the new
guidelines,
plants may well have
more responsibility
to
make
sure that they are
processing in a
sanitary manner.
This could include
keeping more detailed
records.
Part of the
question for plants implementing
water-reuse
systems
is how safe the
water needs to be so
that it is acceptable
for a
particular process
or in a particular
area of the plant.
According to Walsh,
that could vary, depending
on how the water is
used
in
areas where product
is
processed,
and could even include
cleaning and treating
water to the
EPA's
drinking water standards.
The new
guidelines may
stress scientific-based
decisions
on what is safe. Plant
personnel may need
to base their decisions
on data
from university research,
agriculture-extension
research projects,
private
sources, and government
agencies. They also
may need to coordinate
with
and consult with researchers
to test
and analyze reuse water
to
ensure
that it meets
the conditions
for reuse.
"
Essentially, technology is available for 100 percent water reuse," says
Walsh. Other industries,
such as the pork industry, appear to have implemented large waste-reduction
and water-reuse projects. These projects involve a
combination of treatment
methods, for example dissolved air flotation and clarifiers. To meet
drinking-water standards, plants have to incorporate
other treatment methods
such as ozonization, ultraviolet irradiation, and microfiltration.
These other technologies are not inexpensive. Poultry plants
will have to make a
cost evaluation - what is the cost both of the raw water and of getting
the water treated and discharging it versus recycling some
or all of the water
in the plant.
Specific guidelines for the reuse of chiller
water have
existed for several
years
and include requirements
for
the water
pollutant levels,
such as turbidity
and bacteria. Other
types of
reuse have been approved
on a case-by-case
basis. Walsh hopes
that the "new guidelines
will make all types
of reuse easier to understand."
Walsh
notes that one of the
plant operations
where
personnel
might
investigate water
reuse is in the
area of transporting
inedible material from
the processing areas
to the offal
trucks. The
material is usually
sluiced from the area,
which requires a lot
of water. Water reused
for this
purpose
might need
less treatment than
that
in other areas of
the plant since it
doesn"t
touch the product.
Another place where
personnel might reuse
water is during
cleanup operations.
Personnel might be
able to use recycled water
for everything but
the
final cleanup, which
will need to use potable
(drinking)
water.
Walsh feels that
the
poultry industry
has made strides
in water reuse
but that further
conservation
measures
are needed.
Since
the goal
of the new USDA guidelines
is to provide the
industry with a road
map to
implement
water reuse programs,
Walsh believes that
the new guidelines
will
greatly
benefit the industry.
He
also hopes that equipment manufacturers
will become
more involved in
water-reuse programs when they
see the guidelines
and will
respond by modifying
existing processing
equipment or
making new equipment
to take
advantage of water
reuse.
Walsh states: "If
plants follow the new
guidelines to implement
water-reuse programs, they can: first, save in the cost of raw water
and the cost of
treating wastewater;
second, continue as a growth industry should water restrictions become
more of a problem; and third, reduce problems in meeting
the changing wastewater
discharge limits from different localities."
As soon as the USDA
issues the new guidelines,
ATRP
will be
sending out an environmental
PoultryFax to
alert processors.
Software
program nears completion
to help processors
save on water costs
Georgia Tech researchers
are ready to aid
processors faced
with the
rising cost
of
water-related expenses.
Researchers have
continued developing
a computer-based
product that will help plant
managers target
areas where water
efficiency needs improvement.
Five field
tests
are
scheduled
to take place this
summer to validate
the program
before final release.
The program runs
on both Windows
and Macintosh
computers and will
be distributed on
3.5-inch diskettes.
Many poultry processors
are faced with
rising water-related expenses
that can sometimes
exceed $300,000
annually. To
help them
reduce
these expenses,
Georgia Tech researchers
are completing
efforts to develop a
computer-based
consultation program
called
WaRP (Water Reduction
Performance Support
System). The program
allows poultry
processors to audit
their plant's water
usage without having
to call
for
external
assistance.
Researchers have
made improvements
to the
initial WaRP software
program completed
last fall (see
PoultryTech Fall 1996)
and introduced
at
the 1997 Poultry
Show.
The new
prototype can now
identify where
plants are
losing
water as well as
account for water
usage
in most areas of
the plant. WaRP
will help
identify opportunities
to reduce water
usage and
also recommend
ways to implement
these
changes, thus becoming
the starting point
for
identifying
water-related cost
savings.
WaRP was originally
designed to run
on a CD-ROM; however
researchers found
that some poultry
facilities do not
have computers
equipped with CD-ROM drives.
Since many poultry
processors
have at least one
computer that can
run standard-size
3.5-inch disks,
Georgia Tech
computer programmers
condensed the software
program
to fit on a single
3.5-inch
disk. The new disk
version will run
on either an
IBM-compatible
(Windows 3.1 or Windows
95) or
a Macintosh
computer.
The WaRP
designers used actual water-use
data
to structure the
software program
and continue to update
plant
data to improve the
basic WaRP model
for all users.
Currently two field
tests are in progress;
a total
of
five are scheduled
to help identify "real-world" challenges
that typically face
a poultry facility
in its daily operation.
Results from the
field
tests
will help the researchers
tailor WaRP for individual
poultry processors
to give more accurate
results
that can lead to
better cost savings. "The
more the program
is tailored to a
facility, the more accurate
the
results and, of course,
the savings," notes
project director
John Pierson.
Pierson is confident
that many Georgia
poultry facilities
will benefit from
WaRP's water-use
reduction strategies.
The 3.5-inch
disk version
of WaRP is scheduled
for release
in the fall.
Researchers
are also developing a stand-alone
database
version to gather
and store
monthly water-use
results for cumulative
data analysis.
This
historical data
will better assist the
facility
by
allowing plant
engineers to anticipate
water-usage levels
in future
months. The
database version
should also be
available in
the fall of 1997.
As
a special feature, Georgia Tech researchers
will be
available by
phone to assist
plant engineers
with any problems or concerns
regarding the WaRP
program.
Credits
Dara O'Neil, Editor
Rae Adams, Contributing
Editor and Photographer
Margie Brown, Contributing
Editor
Nancy Davis, Contributing
Editor
Caroline Fitzpatrick,
Contributing Editor
Kevin Marshall,
Contributing Editor |
