Presentation on theme: "2008 ASABE Annual International Meeting Rhode Island Convention Center Providence, Rhode Island June 29 – July 2, 2008 On-Farm Anaerobic Digestion Biogas."— Presentation transcript:
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 farm- based 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 1000 Beef + 120,000 Poultry 1 industrial AD under construction @ a Swiss Cheese Plant 2 in Design phase7 in Planning phase 1 Beef & Poultry –
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 Heated to maintain optimum temperature 99 o F or 135 o F Biogas is produced (60% methane & 40% carbon dioxide) 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
Growing concern of greenhouse gas emissions Nutrient management concerns Why are digesters getting a lot of attention today continued: Heat recovery utilization Regulations for nutrient discharges from non-point sources Reduces pathogens and weed seeds
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 Sale of Carbon Credits and Renewable Energy Credits (REC) Green energy Why are digesters getting a lot of attention today continued:
Pennsylvania’s Governor Edward G. Rendell’s Energy Portfolio Standards and Net Metering laws have allowed Pennsylvania farm- based 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
These programs are in their infancy and long term success is unknown. Carbon Credits & Renewable Energy Credits (REC) 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 Other sources of capital to finance part of the digester system Sale of Renewable Energy Credits (REC)
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 Prevent clogging Brendle Farm – pre-heat tank Added early in operation as a limestone grit and feather removal mechanism
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. Brookside Dairy, Homer City, PA:
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.
In large pen swine houses, a dunging pattern is observed. Pine Hurst Acres Danville, PA 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.
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 and Biological Engineering Basics of Anaerobic Digestion Terminology Types of Anaerobic Digesters * Complete Mix * Plug Flow * Covered Lagoon * Other Types or ModificationsComplete MixPlug FlowCovered LagoonOther Types or Modifications Case Studies Common Digester Misconceptions Consultants, Equipment Dealers and Funding Safety with Biogas Resource Links Centralized Digesters PSU Digester Projects Contact Us Biogas Production Biogas production using anaerobic (oxygen free) digestion is a biological treatment process to reduce odor, produce energy and improve the storage and handling characteristics of manure. A biogas production system must be specially designed and requires regular attention by someone familiar with the needs and operation of the digester. Associated manure handling equipment and gas utilization components are also required. The digester does not remove significant nutrients and requires an environmentally responsible manure storage and handling system. A well designed and operated digester will require modest daily attention and maintenance. The care and feeding of a digester is not unlike feeding a cow or a pig; it responds best to consistent feeding and the appropriate environmental (temperature and anaerobic- oxygen free) conditions. The earlier a problem in operation is identified the easier it is to fix and still maintain productivity. Thinking about a digester for your operation? Ask yourself these questions.Ask yourself these questions Support for this website made possible by: Mid-Atlantic Regional Water Program Mid-Atlantic Regional Water Program Department of Agricultural and Biological College of Agricultural Sciences Engineering
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 95 o F 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)
Farm Name Year Operational Type of Digester Animal Type # Animals Contributing CHP Unit Rating Heat Recovery Utilization DAIRY Brookside Dairy 2006 Modified Plug Flow (Slurry Loop) Dairy42585 kWdigester & hot water Brubaker Farms 2007Complete MixDairy900160 kW digester & genset radiator air used to dry separated solids used for bedding Dovan Farm2006Plug FlowDairy400100 kW digester & hot water Four Winds2006Plug FlowDairy500130 kW digester & hot water Hillcrest Saylors Farm 2006Plug FlowDairy750100 kWdigester & hot water Main Farm2006Complete MixDairy50090 kW digester & hot water Mason Dixon Farm 1978 Modified Plug Flow (Slurry Loop) Dairy2985600 kW digester & home heating Oregon Dairy1986 Modified Plug Flow (Slurry Loop) Dairy38565 kW digester & farmhouse domestic hot water and home heating Penn England2006 Plug Flow (Mixed Loop) Dairy800160 kW digester & hot water for milk parlor, genset radiator air used to dry separated solids used for bedding Schrack Farms2006Plug FlowDairy650200 kW digester & hot water for milking parlor Wanner Pride- N-Joy Farm 2007 Plug Flow Circular (Slurry Loop) Dairy400130 kWdigester & hot water
Farm Name Year Operational Type of Digester Animal Type # Animals Contributing CHP Unit Rating Heat Recovery Utilization SWINE Beaver Ridge Farm Design 2008Complete Mix Finishing 3000130 kWdigester & hot water David High1998 Vertical Plug Flow Swine 120022 kWdigester & hot water Mathis FarmDesign 2008Complete Mix Farrow to Finish 27215 kWdigester & hot water Pine Hurst Acres 2004Complete Mix Finishing 440047 kWdigester Rocky Knoll LMD Partners 1985Complete Mix Farrow to Finish & food waste 1000130 kWdigester & hot water BEEF & POULTRY Brendle Farm1984Slurry LoopLayers7200065 kW digester, pre-heat egg wash water for egg processing, heat egg processing area & office Zimmerman2007Complete Mix Beef / Broilers 1000 / 120000 175 kWdigester & hot water FOOD WASTE Fairview Swiss Cheese Construction 2008 mobilized film technology cheese whey & cone batter NAUnknown 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