BioCycle July 2010, Vol. 51, No. 7, p. 14
As an Massachusetts Institute of Technology grad student, Purpose Energy, Inc. CEO Eric Fitch developed a passion for brewing beer. Now he’s building a biogas plant right next to the Magic Hat Brewing Co. in Burlington. The plant has already begun taking the brewery’s spent grains – and other by-products such as greywater and spent yeast – and filling up an anaerobic digester specially designed to process feedstock with a high solids content. “When we first started out we wanted to purchase a digester, and we found there weren’t really any capable of handling spent grains,” Fitch explains. “So we developed patented technology that’s really tailored to brewery by-products and other materials with a high solids content.” Much of that by-product is typically trucked offsite, he adds, “because it’s too expensive to put down the drain” in terms of processing.
Besides acting as CEO and R&D guy, Fitch also serves as the company’s (extreme) grease monkey. He recently donned climbing gear and a scuba regulator attached to a 30-foot umbilical hose, dropped in through the roof of the half-filled digester, traversed the inner chamber of a weir pipe 35 feet above ground, and suspended himself to access and reconfigure an effluent pipe in order to allow for increased working pressure – and thus the capacity for more stored gas – inside the tank.
Once the digester is fully operational, PurposeEnergy will begin selling biogas back to the brewery – with Green Mountain Power as a middleman in order to avoid being regulated as a public utility – which will power all systems traditionally run on natural gas. “Were going to deliver biogas to the brewery’s boilers, so instead of buying imported natural gas from Canada, they’ll be using ”homebrew’ from their own backyard,” says Fitch. The system will also be harvesting 1.3 million BTUs of power from the exhaust, engine coolant and engine oil in order to heat the digester and preheat water going into the brewery’s boilers. Any excess power will be sold back to the grid. “We probably will be done filling up the digester in about three weeks,” he adds. “Then it’s a matter of waiting for the microfauna to be happy. Right now we’re just accumulating biomass. It will probably take until October.” Operating under the mantra “Saving the Earth, one beer at a time,” PurposeEnergy has the financial backing of Vermont’s Clean Energy Development Fund and Green Mountain Power.
CEDAR GROVE COMPOSTING ANNOUNCES DIGESTER TECHNOLOGY SELECTION
Cedar Grove Composting, a long-time organics processor in the Seattle region, has been evaluating several anaerobic digestion technologies to process food waste and yard trimmings at its Everett, Washington facility. In early July, the company announced that it is working with BIOFerm Energy Systems, owned by the Viessmann Group in Germany, to integrate high solids digesters into its composting operation. The first phase is being designed to process 50,000 tons/year. Cedar Grove is in the engineering and design stage, and hopes to begin construction by the end of 2010. The permitting process with the Puget Sound Clean Air Agency and the Snohomish County Public Health Department is also underway.
The Everett facility receives about 225,000 tons/year of yard trimmings, wood and residential and commercial/institutional food waste and soiled paper. Cedar Grove utilizes the GORE Cover composting system, which is operated in three phases – two covered and one uncovered. Once operational, digested material will go directly into the second phase of the GORE system, creating more processing capacity on the composting pad. “Cedar Grove is moving into the next realm of its development, the creation of green energy from food scraps that were once destined for a landfill,” says Steve Banchero, CEO. “We are looking to secure contracts for sale of electricity or natural gas in order to complete our digester business plan.”
BLUE HEN COMPOSTING
The Blue Hen Organics Recycling Center, built, owned and operated by Blue Hen Disposal and Tunnell Companies L.P., opened in April in Sussex County. “It has taken nearly five years to permit, design and construct the facility which is the first of its kind in southern Delaware,” explains Robert Tunnell III of Blue Hen Organics. The 46-acre facility is permitted by the Delaware Department of Natural Resources and Environmental Control to process 50,000 cubic yards annually of clean, nontoxic, nonhazardous biodegradable materials such as yard trimmings, grass clippings, leaves, land clearing debris and poultry manure. Located in the heart of Delmarva’s agribusiness community and a short drive from Sussex County’s highly populated beach areas, it is open to the general public, landscaping contractors, commercial haulers and farmers.
“With the Delaware Solid Waste Authority implementing a yard waste ban in 2011 and landfill rates dramatically increasing July 1, 2010, Blue Hen Organics offers southern Delaware residents a low-cost option for their yard waste,” says Tunnell. “Our drop-off rates for most organic materials are $20 a ton.” These materials are recycled into compost, topsoil, and specialty compost-based soil blends.
Visit www.bluehenorganics.com for more information.
7th ANNUAL ROTARY IN-VESSEL GROUP MEETS IN SEPTEMBER
The 7th Annual Rotary In-Vessel Users Group meeting will be held September 16-17, 2010 in Sevierville. Project managers, equipment manufacturers and others involved with composting facilities that utilize rotary vessels will get a first-hand look at the Sevier Solid Waste, Inc.’s rebuilt MSW/biosolids cocomposting facility that was destroyed in a fire several years ago. The plant, which processes 250 tons/day of material, has five rotary vessels. Presentations on a variety of composting facilities, including ones in Australia and France, are scheduled for September 16 at the Inn at Christmas Place in Pigeon Forge. For more information, contact Tom Leonard, Sevier Solid Waste, at Leonard_t_2000@yahoo.com.
Millerton, New York
FARM COMPOSTER RETOOLS OPERATIONS
McEnroe Organic Farm in the Hudson Valley produces about 30,000 cubic yards of compost annually, with feedstock including leaves, cow and horse manure, and food waste coming to the 440-acre site from as far away as New York City. When a stray manhole cover inadvertently found its way into the farm’s horizontal grinder, causing $40,000 in repair bills, partners Ray McEnroe and Douglas Durst decided to rethink their operation, which included investing in an Allu screening bucket. “We compost in Ag Bags, and the food waste needs to be ground up – otherwise you will have a full orange or grapefruit or melon in there,” explains Ray McEnroe. “The Allu bucket serves the purpose of grinding the materials, and if there’s a big piece of metal it just kicks it out.” The bucket came in at a fraction of the cost of the now-retired grinder, he adds. Major fuel savings have also been realized.
Operating on more than 800 acres, McEnroe Organic Farm sells a variety of produce, farm-raised meats and nursery products out of a bustling roadside store as well as wholesale to other retailers, growers and landscapers. Soil products include bagged compost blends, topsoil, potting soil, a nursery mix and a perennial mix.
STUDY QUESTIONS ENVIRONMENTAL BENEFITS OF WOODY BIOMASS
A six-month Massachusetts Department of Energy Resources (DOER) commissioned study to assess the relative environmental benefits and costs of burning woody biomass for energy has raised some serious concerns. Questions addressed in the study included: 1) How much wood is available from forestland for biomass energy in Massachusetts; 2) What might be the impact of increased biomass harvests on forest ecosystems, and; 3) What are the carbon accounting (climate science) implications of using forest biomass for energy?
The study, drafted by the Manomet Center for Conservation Science, comes at the heels of a recent decision by the Massachusetts legislature not to vote into law an initiative that would have placed a cap on carbon dioxide emissions for any energy technology considered alternative (and, thus, eligible for the tax credits the designation affords). In recommending the “no” vote, an energy committee had cited studies in progress to evaluate greenhouse gas emissions and other concerns about woody biomass energy production. The committee said the proposed legislation was too broad in placing potential restrictions on other alternative forms of energy such as anaerobic digestion and that if the study in progress indicated that action need to be taken with regard to woody biomass then “it will take steps to enact the necessary restrictions at that time.”
A push to put the question to voters was rescinded July 7 after a letter from the Secretary of Energy and Environmental Affairs assured activists that the state would change the incentives provided to biomass energy to reflect the emerging science.
The Manomet study concluded that using wood to produce electricity is not “carbon neutral” and can result in more initial carbon “debt” than coal, oil or natural gas. But forests can grow back, the report states, so unlike with fossil fuels, the carbon debt can eventually be repaid if the forests are allowed to grow back. “Whether or not full carbon neutrality will be achieved in these circumstances will depend on if, when, and how the forest is harvested in the future,” a press release summarizing the study stated. A critical point of the study is that forest biomass for energy can increase greenhouse gases for a period of time – from years to decades depending on complex factors such as future forest management, type of biomass energy used (combined heat and energy was deemed most efficient) and type of fossil fuel being replaced – before it reduces them. The state is initiating a series of hearings about the report this month.
San Francisco, California
“RECYCLE OR ELSE” LAW WELL RECEIVED, SO FAR
The San Francisco Chronicle reports that the nation’s most stringent recycling law – responsible for diverting more than 400 tons a day of food scraps and other compostable materials away from disposal – is being generally well received. The law is part of the city’s goal to achieve zero waste by 2020. Currently, it’s recovering about 72 percent of the material generated, according to the City and County of San Francisco’s sfenvironment.org website. There’s more room for improvement, as compostable food and paper products still make up 36 percent of what the city sends to the landfill.
Some citizens and elected officials had initially expressed concerns that stiff fines for noncompliance – up to $1,000 – were too stringent, approaching the level of a recycling police state. But city officials promised to only enact fines for blatant and repeated noncompliance, and so far, according to the Chronicle, there haven’t been too many complaints. About 8,500 warnings have been issued; fines go into effect in July. The compostable fraction is collected and composted by Recology, Inc.
FOUR-DAY EVENT DIVERTS 36 TONS
The Georgia World Congress Center (GWCC) in Atlanta hosted a Microsoft Corporation event in April with a goal to divert as much of the waste generated as possible to food donations, recycling and composting. The four day meeting generated 57 tons of waste of which 36 tons were diverted. The GWCC baled and recycled over 1.4 tons of cardboard on site, in addition to 4.2 tons of plastic, aluminum, paper and glass. Levy Restaurants donated 1.5 tons of food to the Atlanta Union Mission and sent 29 tons of food waste and other compostable materials to Closed Loop Organics, a local composting facility.