December 19, 2011 | General

Anaerobic Digest

BioCycle December 2011, Vol. 52, No. 12, p. 18

Perris, California
Biogas To Transportation Fuel

In mid November, the city of Perris’ planning commission approved CR&R Waste and Recycling Services’ plans to build a 150-ton/day anaerobic digestion facility. The plant will be among the first California facilities using AD to convert municipal solid waste to produce renewable transportation fuels and power. It is supported by the Los Angeles County Conversion Technology project, $4.5 million in funding from the California Energy Commission (CEC) and various additional stakeholders.
While CR&R, which serves more than 2.5 million residential and 5,000 business customers across five southern California counties, will be bringing in some separated food waste and yard trimmings, most of the feedstock will be recovered at its materials recovery facility (MRF). “CR&R operates its own MRF and obtains the organic fraction from the mixed waste,” explains Norma McDonald of Organic Waste Systems (OWS), the technology provider. McDonald adds that this project is notable because “it is, for the most part, a privately funded project by a well-established company in the waste management business. The decision to include AD as part of its unit operations is a major step for this industry. I think it’s also a milestone from the standpoint that it shows that when sufficient incentives or requirements are in place for organics diversion, you see more companies considering AD. CR&R is trying to maximize the diversion it achieves, and AD is seen as essential to achieving that goal.” McDonald says the facility is designed to be sufficiently flexible to also handle source separated organics and/or yard trimmings.
Incentives include California’s AB 939 recycling law that mandated 50 percent municipal waste diversion by 2000 – and recently raised to 75 percent by 2020 – as well as AB 32, which includes a low-carbon fuel standard. “Going into domestic production of advanced alternative fuels that reduce emissions and improve air quality standards works hand-in-hand to facilitate projects like this,” McDonald adds.
Mount Joy, Pennsylvania
Fast-Tracked AD Project

When anaerobic digestion (AD) technology developer RCM, International, LLC came knocking on his door last February, Mount Joy dairyman Arlin Benner had heard about AD but didn’t think it would fit his operation. “RCM came to me and said, ‘You should think about a digester;’ and I said ‘No way, my farms are too spread out,'” recalls the fourth-generation Mennonite farmer with three contiguous Lancaster County farms housing a total of 900 milking cows and around 850 replacement heifers. RCM delivered a proposal anyway and convinced Benner to apply to multiple sources for funding. One catch was that the project needed to be under construction by December 31, 2011 in order to qualify for 30 percent funding from the U.S. Treasury under Section 1603 of the 2009 American Recovery and Reinvestment Act.
With an additional $500,000 from the USDA’s Rural Energy for America Program (REAP) and $838,000 from a Pennsylvania Renewable Energy grant, the $3 million project was scheduled to break ground as this issue went to press. “The whole thing happened real fast for me,” says Benner, adding that financing, township approvals of a land development plan and the logistics of the project were the three big hurdles that needed to be overcome. “At every step along way, it couldn’t have fallen into place any better than it did. I have to compliment the township; they were really great to work with.” Benner anticipates payback of his own investment, about $1 million, within five years.
Manure from free-stall barns at the three farms will be pumped about 4,000 feet to a mixed plug-flow digester with enough capacity to accommodate more than twice the amount of manure produced by the combined herd. Benner also plans to take in food waste from area grocery stores and restaurants, both for the tipping fees and to boost biogas production. Heat from the genset to be installed will be used to warm his farmhouse, an adjacent 10-bedroom bed and breakfast run by his parents and to provide hot water to both residences as well as for use in the dairy operation. Benner is currently buying dried digested solids for bedding from a neighboring dairy and plans to switch to his own.
Santa Barbara, California
County To Build Digester To Extend Landfill Life
After years of considering alternatives to expanding the Tajiguas Landfill, Santa Barbara County has decided to build a resource recovery park that will include a materials recovery facility (MRF); an anaerobic digester to process recovered organics and use biogas to make electricity and biofuel; a power plant; and continued operation of the landfill to accommodate the unrecoverable portion of a growing waste stream. The Santa Barbara County Resource Recovery & Waste Management Division will partner with Mustang Renewable Power Ventures out of San Louis Obispo County to build the facility that is expected to generate 1,000 kilowatts annually.
Having chosen a technology and a partner, the county will continue to solicit community feedback while drafting an environmental impact report (EIR) to move the project forward. “We have been studying this most intensively since 2007, but really it’s been going on since the last landfill expansion in 2002,” says Carlyle Johnston, project leader for the county. “At our current disposal rate, the landfill would close in 2023.” The target date for the new facility, which will utilize Bekon dry fermentation anaerobic digestion technology out of Germany, is late 2015 or early 2016. “The community has been part of the selection process, and we will continue that discussion,” he says, adding that a more typical scenario is for planners and developers not to engage the public until the EIR process is under way.
Syracuse, New York
When Walmart pledged to begin diverting all organic recyclables from stores in all 50 states and Puerto Rico away from landfills and toward more beneficial uses such as composting and anaerobic digestion by August 2010, the mega retailer knew its biggest challenge would be available infrastructure. It hired Quest Recycling Services in Frisco, Texas, and Quest contracted with regional environmental service professionals such as Environmental Products & Services of Vermont (EPSVT), Inc. to arrange for hauling and find outlets for the organics. Phil Holloway is Director of Sustainability Services for EPSVT, which is actually based in Syracuse. He manages the transportation of organics for around 500 grocery stores from South Carolina to Maine (about 2,000 tons/week).
“The majority of that is Walmart locations,” says Holloway, adding that the company tries to find a home for the organics within 50 to 75 miles of where it’s collected. Outside that range, he says, it’s just not economically feasible due to high fuel and transportation costs.
While EPSVT’s management options start with donation of edible food and some diversion of preconsumer food waste (no meat scraps) to animal feed, the majority of outlets are composting sites and anaerobic digesters. One AD facility is at Barham Farms in Zebulon, North Carolina, which is permitted to process 150 tons/day of food waste in a 750,000-gallon complete mix digester. Hog waste from 4,000 sows and piglets and crop waste from commercial greenhouses (heated via the digester) also are digested. About 40 stores within that workable 50 to 75 mile radius of Zebulon should be able to meet about a tenth of available digester capacity, says Holloway. Barham Farms runs a companion composting operation, therefore it could continue to take food waste if it needed to temporarily shut down its digester. EPSVT also delivers to two other composters in the area.
Marin County, California
The Central Marin Sanitation Agency’s (CMSA) Food to Energy (F2E) project has broken ground on a FOG (fats, oils and grease) processing facility, and its two existing anaerobic digesters at the San Rafael treatment plant should be accepting food waste well inside of a year. Food waste will be collected by Marin Sanitary Service (MSS), down the road from the wastewater treatment plant. MSS is investing in infrastructure to preprocess the food waste it collects from 247 commercial accounts as well as curbside residential food waste and green waste that currently gets transported to a composting facility. The food waste will be loaded onto a conveyor via a forklift and manually sorted for contaminants before being conveyed to a grinder and then to a 20-ton capacity transfer truck for delivery to CMSA.
Primary goals of the F2E project are diversion of organic waste from the landfill and creation of energy, says CMSA General Manager Jason Dow. Besides rehabilitating a pair of 80-feet in diameter digesters with new Dyster membrane covers and converting from a gas to a pumped mixing system, the FOG receiving facility will mix that material with liquid biosolids prior to loading in the digesters. Biogas is fed to an existing 750 kW Waukesha genset to produce electricity. Heat generated from the engine will be used to heat the facility and to maintain the temperature inside the digester. “We’re in full construction mode,” says Dow. “The FOG/F2E facility site has been graded, excavation has been done, it’s been shored and the concrete has been poured. The facility is near completion. Staff will receive training and we will hopefully be ready to receive some material by the end of 2012.”
Dow says CMSA will actively recruit contractors who haul waste grease from food service facilities and is hopeful its convenient location coupled with a reasonable tipping fee – likely to fall somewhere between 5 cent and 10 cents a gallon – will attract customers. The retooled facility will be able to handle up to 5,000 gallons of FOG and 15 tons of commercial food waste daily. “We’re anticipating that if Marin Sanitary Service starts a program of educating the public and restaurant owners about the benefits of separating food waste and placing it in collection bins, it will slowly ramp up,” he adds. “We’re anticipating 25 percent of that maximum capacity from the outset into the first year.”
Marion, Iowa
In 2003-2004, the Bluestem Solid Waste Agency (now the Cedar Rapids Linn County Solid Waste Agency or CRLC-SWA) and the Iowa Department of Natural Resources commissioned a report on the relative merits and feasibility of anaerobic digestion (AD) technologies to manage organic waste streams while creating renewable energy opportunities in the Midwest. That plan also explored potential funding sources for such projects. When the report was written, there were around 130 large AD plants converting the organic fraction of municipal solid waste and/or industrial waste worldwide. Since all but five of these were located in Europe, members of the agency’s board of directors and staff went on a fact-finding mission that included a tour of large-scale commercial AD facilities abroad.
Although a digester facility never evolved out of that analysis, the solid waste agency is once again exploring the option. CRLC-SWA is piloting a food waste composting program and accepts 8 to10 tons of produce each week at its yard trimmings composting site from area Walmart stores. A survey of area grocers conducted last summer indicates additional interest in food waste diversion and, recently, staff has fielded calls from cafeterias and restaurants inquiring about composting. “There has always been an interest in composting by agricultural industries here,” says CRLC-SWA Executive Director Karmin McShane, “but lately we are hearing from retailers who are interested in sustainability.”
In 2012, the agency plans on conducting another study that will assess composting and anaerobic digestion technologies, as well as available feedstocks. Due to composting site constraints, CRLC-SWA ceased taking most industrial material in 2006. Consequently, large agricultural industries such as Quaker Oats/Pepsico, Cargill and ADM had to find other outlets for their organics. “The landscape in this country is changing – alternative energy and sustainability have higher visibility than they did in 2003,” adds McShane. “We will examine the economic feasibility of AD again and see how it plays out.”
Newcastle, United Kingdom
Nestlé’s has been given the go-ahead by city councilors to build an anaerobic digestion plant for treating waste at its Fawdon site in Newcastle, UK. The facility will receive all of the solid food waste and wastewater generated by the factory, which makes candy under a variety of product names marketed in the UK and Europe. The plant will treat 21 million gallons/year of factory wastewater to generate biogas to heat and power the factory and facilitate recycling of grey water back into factory processes. It will also recover energy from the 1,300 tons of food waste that results from the confectionery production operation (currently, 550 tons are sent to landfill, with the balance used as animal feed). The digestate, an estimated 220 tons/year, will be used as an agricultural fertilizer.

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