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2008 ASABE Annual International Meeting Rhode Island Convention Center Providence, Rhode Island

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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. - PowerPoint PPT Presentation

Text of 2008 ASABE Annual International Meeting Rhode Island Convention Center Providence, Rhode Island

  • 2008 ASABE Annual International MeetingRhode Island Convention Center Providence, Rhode Island June 29 July 2, 2008On-Farm Anaerobic Digestion Biogas Production in Pennsylvania 30 YearsDeborah A. Topper Research Technician Patrick A. Topper Sr. Research Technologist Robert E. Graves ProfessorThe 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 Pennsylvania11 Dairy - 86953 Swine - 66001 Poultry (layers) 72,0001000 Beef + 120,000 Poultry1 industrial AD under construction @ a Swiss Cheese Plant2 in Design phase7 in Planning phase1 Beef & Poultry

  • What is an anaerobic digester?Air tight, oxygen free container, usually concreteContinues the digestion process of organic materials such as animal manure and food wastesHeated to maintain optimum temperature 99oF or 135oFBiogas 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 1970s)Completion of de-regulation of Pennsylvania electrical utility companiesBiogas used for power production: decrease, meet or eliminate electricity purchases from power companies

  • Growing concern of greenhouse gas emissionsNutrient management concernsWhy are digesters getting a lot of attention today continued:Heat recovery utilizationRegulations for nutrient discharges from non-point sources Reduces pathogens and weed seeds

  • Dried separated solids - bedding for animalsSeparated solids - sold as bedding or soil amendmentsNutrient-rich effluent lowers or eliminates fertilizer costs Improved storage and handling characteristics of manureSale of Carbon Credits and Renewable Energy Credits (REC)Green energyWhy are digesters getting a lot of attention today continued:

  • Pennsylvanias Governor Edward G. Rendells 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 Agricultures Machinery and Equipment Loan Fund (MELF) Pennsylvania Governor Rendells 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 farms methane destruction and trades the carbon credits on the Chicago Climate ExchangeOther sources of capital to finance part of the digester systemSale of Renewable Energy Credits (REC)

  • ACT 38 of 2005 Agriculture, Communities and the Rural EnvironmentACRECreates 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 manureWater is added and mixed with the manure to make a slurryIrrigate the digested manure slurry

    Prevent cloggingBrendle 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.

  • Pine Hurst Acres Complete Mix Digester

  • Raw ManureDigested Manure1,100 pigs1,100 pigs3 m3 m6 m6 m6 mPine Hurst Acres, Danville, PA

    Manure Pits (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 ( 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 TerminologyTypes of Anaerobic Digesters * Complete Mix * Plug Flow * Covered Lagoon * Other Types or ModificationsCase Studies Common Digester Misconceptions Consultants, Equipment Dealers and FundingSafety with BiogasResource LinksCentralized Digesters PSU Digester ProjectsContact Us Biogas ProductionBiogas 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. Support for this website made possible by:Mid-Atlantic Regional Water Program Department of Agricultural and BiologicalCollege of Agricultural Sciences Engineering

  • Brendle Farm Type of farm: Belted, Caged LayerName of farm: Brendle Farm County: SomersetFeasibility 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 FarmConstruction start date: Spring 1984 (designed in 1983) Date Digester became operational: June 1984Number of animals contributing manure to the digester: 72,000 laying hens Manure handling system: caged layers manure belt, augered to liquid mix tankType of digester: slurry loopDigester cover: flexible Digester temperature: mesophilic 95oFBiogas uses: operate the CHP unit to produce electricity and heat Biogas utilization equipment: engine generatorHeat 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: Yes2008 status of digester: operationalInformation provided by: Robert and Michael Brendle, (2006 & 2007)

  • Farm NameYear OperationalType of DigesterAnimal Type# Animals ContributingCHP Unit RatingHeat Recovery UtilizationDAIRYBrookside Dairy2006Modified P