2008 ASABE Annual International Meeting
Rhode Island Convention Center
Providence, Rhode Island
June 29 – July 2, 2008
On-Farm Anaerobic Digestion
Biogas Production
in Pennsylvania – 30 Years
Deborah A. Topper Research Technician
Patrick A. Topper Sr. Research Technologist
Robert E. Graves Professor
The Pennsylvania State University
Pennsylvania has the distinction:
Four of the oldest continuously operating farmbased anaerobic digesters
30 years – Mason Dixon Farm
(Gettysburg, PA)
1984 First poultry digester up and running
(24 years)
Combined operating experience of these
four digesters is 99 years
Sixteen (16) known operating farm-based
anaerobic digesters (AD) in Pennsylvania
11 Dairy - 8695
3 Swine - 6600
1 Poultry (layers) – 72,000
1 Beef & Poultry – 1000 Beef + 120,000 Poultry
2 in Design phase
7 in Planning phase
1 industrial AD under construction @ a Swiss
Cheese Plant
What is an anaerobic digester?
Air tight, oxygen free container, usually concrete
Continues the digestion process of organic
materials such as animal manure and food
wastes
Biogas is produced (60% methane & 40% carbon
dioxide)
Heated to maintain optimum temperature
99oF or 135oF
Biogas can be used to run an engine generator
set creating electricity and waste heat
Why are digesters getting a lot of attention today?
Odor complaints - encroachment of housing
developments bordering farm land
Energy crisis (as in the late 1970’s)
Completion of de-regulation of Pennsylvania
electrical utility companies
Biogas used for power production: decrease,
meet or eliminate electricity purchases from
power companies
Why are digesters getting a lot of attention
today continued:
Heat recovery utilization
Nutrient management concerns
Regulations for nutrient discharges
from non-point sources
Growing concern of greenhouse gas emissions
Reduces pathogens and weed seeds
Why are digesters getting a lot of attention today
continued:
Dried separated solids - bedding for animals
Separated solids - sold as bedding or soil
amendments
Nutrient-rich effluent – lowers or eliminates
fertilizer costs
Improved storage and handling characteristics
of manure
Green energy
Sale of Carbon Credits and Renewable Energy
Credits (REC)
Pennsylvania’s
Governor Edward G.
Rendell’s Energy
Portfolio Standards
and Net Metering laws
have allowed
Pennsylvania farmbased digester
electrical generators to
produce “renewable
energy” for the grid
profitably. Net
metering basically
allows the farmer to
sell its excess power
to the grid at the retail
generation rate.
Power production adds significant costs to the overall
digester project, but without the power production capability
these anaerobic digester systems would not be cost
effective at the current $1M plus price tag.
Grants & loans from various agencies and programs
for Pennsylvania farmers installing an anaerobic
digester manure handling system
• United States Farm Bill
• Pennsylvania Department of Environmental Protection
(PADEP) Energy Harvest Grants
• United States Department of Agriculture (USDA)
Environmental Quality Incentives Program (EQUIP)
• Pennsylvania Department of Agriculture’s Machinery
and Equipment Loan Fund (MELF)
• Pennsylvania Governor Rendell’s Renewable Energy
Portfolio Standards
Carbon Credits & Renewable Energy Credits (REC)
Other sources of capital to finance part of the digester system
Sale of estimated carbon credits for a 20 year period
(received a lump sum payment)
Environmental Credit Corporation, certifies the farm’s
methane destruction and trades the carbon credits on
the Chicago Climate Exchange
Sale of Renewable Energy Credits (REC)
These programs are in their infancy and long term success is unknown.
ACT 38 of 2005
Agriculture, Communities and the Rural Environment
ACRE
Creates a process for farmers to seek judicial review of
ordinances believed to be restrictive of normal agricultural
operations. Farmers will have the ability to request the
Pennsylvania Attorney General to review an ordinance
restricting agriculture that the farmer believes to be illegal.
The Pennsylvania Secretary of Agriculture and the Dean of
the College of Agricultural Sciences at Penn State will
provide expert consultation regarding the nature of normal
farming operations and practices in the Commonwealth.
Unique items and problems that have occurred on
PA farms installing digesters
Brendle Farm - liquid chicken manure
•Water is added and mixed with the manure to make a
slurry
•Irrigate the digested manure slurry
Brendle Farm – pre-heat tank
• Added early in operation as a limestone grit and
feather removal mechanism
• Prevent clogging
Brookside Dairy, Homer City, PA: Pressure relief
valve attached to
the flexible
cover.
The designer of this
AD system uses an
emergency biogas
relief assembly that
is attached
directly to the
flexible cover to
prevent over
pressurization in
the event the
biogas piping gets
clogged.
Penn England Farm, Williamsburg, PA:
designed with a flat flexible cover to prevent
wind damage.
Penn England Farm, Williamsburg, PA: heat
recovered from the engine radiator is directed through the
concrete floor to dry the separated digested solids.
Schrack Farms (Dairy)
This plug flow digester is designed with an offal pit for
additional feedstock to boost methane production.
Schrack Farms - concrete and bolt delay (1 yr.)
A major problem with the concrete sub-contractor
building the plug-flow digester tank on Schrack
Farms delayed the entire project for almost a year.
The groove along the entire top edge of the
digester was not cast properly. Also, bolts of two
different sizes were not cast in the proper
locations.
Pine Hurst Acres
Danville, PA
In large pen swine houses,
a dunging pattern is
observed.
Swine do not like to
defecate where they
sleep. These piglets show
they prefer to sleep along
the wall and defecate in
the center of the pen.
Pine Hurst Acres
Complete Mix Digester
Pine Hurst Acres, Danville, PA
Manure Pits
1,100
pigs
1,100
pigs
3m
6m
Raw Manure
6m
6m
3m
Digested Manure
(Meinen 2008)
(Meinen 2008)
Gases: ammonia, hydrogen sulfide, methane and carbon
dioxide concentration levels were monitored and revealed
not to exceed recommended maximum concentrations for
either animals or humans (Meinen 2008).
A biogas website to communicate farm-based
anaerobic digester information to the public
(www.biogas.psu.edu) has been created at
The Pennsylvania State University.
What is an Anaerobic Digester, History of Anaerobic
Digestion, Types of Digesters (with case study examples from
across the United States), AD Safety, Resource Listings of
equipment, designers, financing and most recently, six
Pennsylvania farm-based AD case studies were added to
the biogas website.
Department of Agricultural Biogas Production
and Biological Engineering Biogas production using anaerobic (oxygen free) digestion is a biological treatment
process to reduce odor, produce energy and improve the storage and handling
Basics of Anaerobic
characteristics of manure. A biogas production system must be specially designed
Digestion
and requires regular attention by someone familiar with the needs and operation of
Terminology
the digester. Associated manure handling equipment and gas utilization components
Types of Anaerobic
are also required. The digester does not remove significant nutrients and requires
Digesters
an environmentally responsible manure storage and handling system.
* Complete Mix
* Plug Flow
A well designed and operated digester will
* Covered Lagoon
require modest daily attention and maintenance.
* Other Types or
The care and feeding of a digester is not unlike
Modifications
feeding a cow or a pig; it responds best to
Case Studies
consistent feeding and the appropriate
environmental (temperature and anaerobicCommon Digester
oxygen free) conditions. The earlier a problem
Misconceptions
in operation is identified the easier it is to fix and
Consultants, Equipment
still maintain productivity.
Dealers and Funding
Thinking about a digester for your operation? Ask yourself these questions.
Safety with Biogas
Support for this website made possible by:
Resource Links
Mid-Atlantic Regional Water Program
Department of Agricultural and Biological
Centralized Digesters
College of Agricultural Sciences
Engineering
PSU Digester Projects
Contact Us
Brendle Farm
Type of farm: Belted, Caged Layer
Name of farm: Brendle Farm
County: Somerset
Feasibility Study: 1982 by Wayne Bogovich of USDA Natural Resources
Conservation Service (NRCS) (Bogovich 2004)
Digester designer: Bert and Dick Waybright, Gettysburg, PA
Digester installer: Brendle Farm
Construction start date: Spring 1984 (designed in 1983)
Date Digester became operational: June 1984
Number of animals contributing manure to the digester: 72,000 laying hens
Manure handling system: caged layers manure belt, augered to liquid mix tank
Type of digester: slurry loop
Digester cover: flexible
Digester temperature: mesophilic 95oF
Biogas uses: operate the CHP unit to produce electricity and heat
Biogas utilization equipment: engine generator
Heat Recovery Utilization: engine generator water jacket to heat the digester,
pre-heat wash water for egg processing and to heat the egg processing area and
the office.
Power Purchase Agreement: Yes
2008 status of digester: operational
Information provided by: Robert and Michael Brendle, (2006 & 2007)
Year
Operational
Type of Digester
Animal
Type
# Animals
Contributing
CHP
Unit
Rating
Brookside
Dairy
2006
Modified Plug
Flow (Slurry
Loop)
Dairy
425
85 kW
digester & hot water
Brubaker
Farms
2007
Complete Mix
Dairy
900
160 kW
digester & genset radiator air used to
dry separated solids used for bedding
Dovan Farm
2006
Plug Flow
Dairy
400
100 kW
digester & hot water
Four Winds
2006
Plug Flow
Dairy
500
130 kW
digester & hot water
Hillcrest
Saylors Farm
2006
Plug Flow
Dairy
750
100 kW
digester & hot water
Main Farm
2006
Complete Mix
Dairy
500
90 kW
digester & hot water
Mason Dixon
Farm
1978
Modified Plug
Flow (Slurry
Loop)
Dairy
2985
600 kW
Oregon Dairy
1986
Modified Plug
Flow (Slurry
Loop)
Dairy
385
65 kW
Farm Name
Heat Recovery Utilization
DAIRY
digester & home heating
digester & farmhouse domestic hot water
and home heating
Penn England
2006
Plug Flow
(Mixed Loop)
Dairy
800
160 kW
digester & hot water for milk parlor, genset
radiator
air used to dry separated solids used for
bedding
Schrack Farms
2006
Plug Flow
Dairy
650
200 kW
digester & hot water for milking parlor
2007
Plug Flow
Circular (Slurry
Loop)
Dairy
400
130 kW
digester & hot water
Wanner PrideN-Joy Farm
Farm Name
Year
Operational
Type of
Digester
Animal
Type
Heat Recovery Utilization
# Animals
Contributing
CHP Unit
Rating
3000
130 kW
digester & hot water
1200
22 kW
digester & hot water
272
15 kW
digester & hot water
4400
47 kW
digester
1000
130 kW
digester & hot water
SWINE
Beaver Ridge
Farm
David High
Mathis Farm
Pine Hurst
Acres
Design 2008
Complete Mix
1998
Vertical Plug
Flow
Design 2008
Complete Mix
2004
Complete Mix
Finishing
Swine
Farrow
to Finish
Finishing
1985
Complete Mix
Farrow
to Finish
& food
waste
Brendle Farm
1984
Slurry Loop
Layers
72000
65 kW
digester, pre-heat egg wash water for
egg processing, heat egg processing
area & office
Zimmerman
2007
Complete Mix
Beef /
Broilers
1000 /
120000
175 kW
digester & hot water
Construction
2008
mobilized film
technology
cheese
whey &
cone
batter
NA
Unknown
Rocky Knoll
LMD Partners
BEEF &
POULTRY
FOOD
WASTE
Fairview Swiss
Cheese
Boiler to produce steam and electricity
for processing milk into cheese
Questions?
On-Farm Anaerobic Digestion Biogas Production
in Pennsylvania – 30 Years
Deborah A. Topper Research Technician
Patrick A. Topper Sr. Research Technologist
Robert E. Graves Professor
The Pennsylvania State University