PORTLAND — Ecomaine has added a new composting service that the company expects could be key in a state push to reuse and recycle 50 percent of waste.
The new food waste recovery service, known as anaerobic digestion, will be offered to ecomaine communities through a five-year contract starting Wednesday with Exeter-based Agri-Energy and Agri-Cycle Energy.
Anaerobic digestion is different from regular backyard composting because it requires a moist organic material to aid the breakdown of food waste – in this case cow manure. The process is also done in a closed tank rather than in an open space to harness and reuse gases released during the process, ecomaine CEO Kevin Roche said Tuesday morning.
Ecomaine, a Portland-based nonprofit regional trash and recycling company at 64 Blueberry Road, processes about 175,000 tons of trash and recycling annually for 57 member communities. The business has been considering offering some form of composting service since 2007, Roche said.
Ecomaine sees the “biggest benefit” from anaerobic digestion, he said, because “you don’t lose the energy (from the) gas produced.”
In anaerobic digestion, not only is the gas collected in the heated, oxygen-free closed container as the material breaks down, but the solid materials are reused for energy, fertilizer, and for drying and padding the beds of the cows providing the manure, which facilitates the whole “closed-loop system,” Roche said.
The biogas collected is a combination of methane and carbon dioxide, “which is burned in a 1,500-horsepower generator, producing enough heat to replace an average 700 gallons of heating oil daily,” or “enough to heat 300 New England homes every year,” according to a Sept. 1 ecomaine press release.
That amount of energy also provides “22,000 kilowatt hours of electricity per year,” or enough to power 800 households.
Agri-Energy and Agri-Cycle Energy already use the biogas harnessed through their system to “power approximately 800 homes,” according to the release.
Greater Portland, until now, lacked the commercial and industrial infrastructure to accommodate the organic and sustainable breakdown of food waste on a large scale, Roche said – the area was “missing an outlet,” in terms of food waste recovery services offered to both individual consumers and big box grocery stores.
Considering that approximately 25 percent of all trash is food waste, the new infrastructure could really make a dent in processing organic matter, Roche said.
While big-box grocery stores are going to drive the new infrastructure, since about “90 percent” of what they generate is food waste, he said, it will also provide an outlet for municipal trash collection, for example, to offer the service to residents willing to collect eggshells, food scraps, grains, tea bags and the like.
Roche said ecomaine is in talks with many communities about implementing the new service at a rate of $55 per ton.
Food waste receptacles for use by individual consumers are small, bucket-sized countertop containers. The hope is to get consumers to pay for the municipal service.
Roche said it wouldn’t make sense for one user to pay for ecomaine services in a city or town that didn’t offer to pick up the waste: the amount of energy expended to drive the small bag of food waste to ecomaine would negate the energy harnessed from composting.
It makes more sense for consumers to contact their town or city to request the service alongside trash and recycling pick-up, Lisa Wolff, communications manager for ecomaine, said.
Roche expects that, to start, the new program will bring in about 50 to 100 tons of food waste a week.
When the food waste is brought in, it will be pushed to the side of nonfood trash that is collected and burned for steam. The food waste will then be packed and transported by Agri-Cycle Energy trucks to the Exeter facility, where it will be mixed with cow manure and processed.
The plastic food waste bags will then be returned to the ecomaine facility for incineration.
Since the program is in its nascent stages, so are discussions with municipalities interested in implementing the program.
Julie Rosenbach, sustainability coordinator for South Portland, said Tuesday morning that offering a service like this “is what we’re working toward.”
Because the city has its own goal of reaching a 40 percent recycling rate by 2019, Rosenbach said recycling organic material is “going to be a huge part of that. We just have to figure out how to do it.”
Offering to collect a completely new waste stream is a big step, she said, and one that would likely involve a pilot project before it is officially implemented.
In a city the size of South Portland, which has about 25,500 residents and produces about 6,000 tons of trash annually, offering a food waste pick-up service could divert about 2,400 tons of the total waste, Rosenbach said.
“We’d save around $40,000 a year just in tipping fees,” she said.
Ecomaine hopes communities like South Portland see the service as advantageous, not only in terms of the value choice, but fiscally, too.
“If you put the system in place, our feeling is that people will come,” Roche said.
Ecomaine’s new composting service offers consumers the option of collecting their food waste in countertop buckets designed to not produce odor.
Ecomaine CEO Kevin Roche stands in the waste-to-energy building where food waste, at right, is separated from nonfood waste. A new program gives consumers the option of composting food waste.