Anaerobic Digestion Of MSW Organics 2011 ASTSWMO Solid Waste Managers Conference Kansas City, Missouri Nora Goldstein, BioCycle www.biocycle.net
Presentation Roadmap Background on OFMSW Anaerobic Digestion Drivers European Union Comparison Common Permitting/Regulatory Themes State Examples
AD of MSW Fundamentals Organic Fraction of Municipal Solid Waste (OFMSW) AD Systems Dry fermentation: Most similar to composting Varying degrees of wet, from high solids AD to low percent solids Wet AD systems for OFMSW most similar to manure and WWTP anaerobic digestion systems Typically require a preprocessing step to make a slurry Post-Treatment step Pathogen destruction
Drivers Food Waste Diversion By weight, largest category of MSW disposed Vegetative waste has very high water content Generators looking for alternatives to landfill disposal Can pay significant sewage surcharges because of high BOD High BOD = bio methane potential Renewable Energy Renewable Portfolio Standards Renewable Energy Goals Methane Emissions Reduction Compatibility With Composting
Project Realities Difficult to procure financially attractive power purchase agreements with utilities (no feed-in tariff type incentives) Capital Costs New concept in U.S.: First OFMSW plant just in start-up now Permitting confusion what is this animal? However, numerous operating digesters are receiving food waste streams so not a totally new animal! From permitting perspective, states do have rules regarding addition of food waste streams to digesters
BY CONTRAST, IN EUROPE About 200 OFMSW plants operating in Europe Average size plant in Europe is about 30,000 tons/year Drivers: European Union Landfill Directive Renewable Energy Incentives, e.g. Feed-In Tariffs More widespread implementation of biowaste (source separated organics) collection programs for households Incentives to use renewable energy in transport About one-third of EU s 2020 target can be met using biogas from biowaste as vehicle fuel Permitting, Regulations, Standards: Animal By-Products Rules Very restrictive on end product utilization
Pasteurization Step 70 C for one hour
Common Permitting, Regulatory Themes Who s In Charge? Solid Waste? Surface Water/Wastewater Have one agency take lead or.. Divvy it up Air/Emissions regarding methane, flares
Integrated Benefits
FOG receiving station at Millrae, CA WWTP
Ground material: 50-60% wet wt. Paddle finisher at EBMUD WWTP East Bay Munc. Util. Dist.: 100-200 tons/wk of food waste Central Contra Costa Solid Waste Authority (CA) commercial organics collection pilot
Univ. of Wisconsin, Oshkosh Dry Fermentation Digester Food Waste & Yard Trimmings Capacity of 8,000 tpy 28-day retention in digester Composting of digestate Totally enclosed, with biofilter for air treatment Biogas combusted in CHP unit Flare for gas vented prior to opening digester Solid Waste Permit Extensive air quality review for air permit Site on top of closed landfill so historical review not required
Cedar Grove Composting, Everett, Washington Dry fermentation digester in permitting Anaerobic digestion of food waste, with yard trimmings Existing composting operation over 90,000 tpy of food and green waste In WA State, local health department is permitting authority for solid waste regulations Because Cedar Grove already permitted for composting facility by local health dept, that permit is being revised to include digester No specific MSW digester language in existing state Dept of Ecology rules; anticipating rule making down road; for now, digesters regulated by rules using other category in existing rules Cedar Grove is required to get separate air permit because combusting biogas need permit like any facility with flare
Massachusetts Normally, solid waste facility required to obtain site assignment from local board of health, and solid waste permit from MassDEP Draft regulations establish new exemption from site assignment for anaerobic digesters receiving source separated organics Three categories being proposed: Farm AD Unit: exempt from solid waste regulations as long as complies with Dept of Agricultural Resources regulations Non-Farm Unit: obtains Permit By Rule if <60 tons/day and complies with performance standards Non-Farm Unit > 60 tons/day taking source separated organics must apply for recycling, composting or conversion permit which would exempt unit from site assignment and solid waste permitting. Would need to obtain permit to manage SSO www.mass.gov/dep/public/committee/adtf.htm
New York State Digesters not located on farms must get Part 360 solid waste permit unless located at site where the waste is generated (and thus exempt) Revising solid waste rules and will have section on regulating anaerobic digesters. Draft language for AD facilities not located on farm creates registered facility category (not Part 360 permit). Defined as facility that accepts only one or more the following wastes: Animal manure & bedding Crop residues and similar farm wastes Food processing wastes Food-derived FOG and other readily degradable wastes without sanitary content Composting facility for dewatered solids falls under same registration AD facility must operate in mesophilic or thermophilic temperature range and achieve volatile solids reduction of at least 40 percent
www.americanbiogascouncil.org
Nora Goldstein BioCycle noragold@jgpress.com