Waste Options pushes plan for a gasification plant at landfill
BY MARY LANCASTER
Waste Options president Whitney Hall recently submitted a flow chart of the landfill's waste stream to the town and is currently working on a business plan that proposes a gasification plant to handle construction debris, bulky trash items and tires.

On July 1 the Department of Environmental Protection (DEP) banned construction and demolition (c & d) from being deposited in any of the state's landfills. Prior to that the island's c & d was being placed in the dump's only lined cell. When notice of the upcoming ban was announced Waste Options began trucking the debris to the mainland for disposal at a designated site.

Hall said that in FY06 the landfill received 44,734 tons of solid refuse of which 38 percent was c & d. A total of 650 truckloads of the debris was transported in 2006 with an anticipated increase to 1,060 in FY07 at a cost of $130 per ton for shipping and disposal. The c & d is presently going off at 40 tons per day, seven days a week, said Hall.

Agasification plant such as one he viewed in Illinois made by SENREQ could process up to 60 tons of material a day, which would eliminate the need to transport c & d and also handle mattresses, furniture, the material already in the lined cell and potentially any undecomposed waste in the old landfill being mined. Items such as refrigerators would not go into the plant because they require grinding which Hall said is impractical.

Hall has already spoken to DEP officials about the gasification proposal and said they indicated it could be permitted for use on Nantucket, even though no other such plants are in operation in the state. The demonstration model Hall has seen is in Morris, Ill. and processes that town's waste.

"We try and make it so nothing needs to be landfilled," said Myron Brick, chairman of SENREQ.

Brick estimates it would cost approximately $7-to-$12 million to build a plant to fit the island's needs at a size comparable to the existing c & d building and at a location near that structure. Waste Options would own and run the plant with an agreed on per ton cost similar to tipping fees to cover the expenses of design, construction, permitting and operation.

Recycling and composting would continue. Beyond allowing for local waste processing, the plant would also generate enough electricity to run all the landfill's power needs plus more that could be sold to islanders and create a revenue stream for the town. Finance director Connnie Voges said it cost the town $263,000 in FY06 for the landfill's energy bills. The compost plant demands about $1,600 in electricity a month and the recycling facility uses $25,000 a month in power.

Brick confirmed that a plant the size of that suggested for the island would put out one megawatt of power

every hour, something Bob Schwarzenbach on the Nantucket Energy Committee finds very attractive. The committee is in the planning stages of forming an electric aggregate to provide residents energy at low prices. Power from the generator at the plant would go into the energy grid interface and be used on island first.

"It is unlikely any of this electricity would go off-island," said Schwarzenbach. "One megawatt is equivalent to 10 percent of all the island's winter power demand. The landfill is a customer like others here. By selling one megawatt an hour at approximately nine cents a kilowatt that would generate about $900,000 in power revenue in guaranteed cash flow to the community from power from garbage. This is very exciting if we can pull this off."

The SENREQ model is a sealed, multi-chambered unit. It needs an outside

source of power at initial start-up, but then would become self-sustaining. Called a "batch system," the waste is loaded into the chambers which operate in sequence and heat to about 600 degrees. About four percent of the trash would remain as an ash-like substance which can be used as an additive to concrete.

After 24 hours the chamber contents are gasified, the ash is removed and the chamber is reloaded so the technology runs continuously. The gas produced in the process is burned in a boiler, then goes to a heat exchanger and a turbine generator. The gas is utilized as fuel to generate electricity and burns cleanly like natural gas, said Hall.

Brick estimates it would take six to nine months to build Nantucket's plant.

"We're very excited about this project," he said. "We've had great support from the Massachusetts DEP. They are working with us to permit this one."