Waste Management to use landfill gas to power trucks

The nation's largest trash collector plans to power hundreds of trucks in its fleet on garbage.

Houston-based Waste Management Inc. and the Linde Group, a global natural gas producer and distributor, will build a plant to purify and liquefy landfill gas at the waste disposal company's Altamont site near Livermore. The plant is expected to open next year.

The company has a number of collection operations in the Sacramento area and runs a landfill in Reno.

The conversion of part of Waste Management's fleet of 3,000 trucks to run on biogas comes as conventional fuel prices are rising. California businesses also face mounting pressure by regulators to reduce greenhouse gas emissions and particulate pollution from sources such as passenger cars and diesel-powered trucks and buses.

"Natural gas is the cleansed fuel that is available for use in a heavy-duty truck," Waste Management spokesman Kent Stoddard said.

California's Air Resources Board and the state's Integrative Waste Management Board are among agencies that provided $1.6 million in grants to help fund the $15 million liquid natural gas plant, Stoddard said.

Waste Management already harnesses landfill gas to produce electricity at about 100 of its 280 landfills nationwide. This is the first time the company will convert landfill gas into liquid natural gas to power trucks.

Conventional natural gas is a fossil fuel, but natural gas derived from biomass, such as organic waste decomposing in landfills, is a renewable resource.

Landfill gas – a mixture of half methane and half carbon dioxide – is collected, purified, compressed and supercooled to form liquid natural gas. Only methane is used to form the fuel. As with all landfills, Stoddard said, some carbon dioxide is released into the air but under limits set by the state.

Producing energy from waste is the "best" scenario, said Patricia Monahan of the Union of Concerned Scientists, and the process also recycles methane, a potent greenhouse gas.

"It's the best we can hope for," she said.

Landfill gas from the Altamont site currently generates about 8 megawatts of electricity and feeds into the Pacific Gas and Electric Co. power grid, Stoddard said. Some of the additional landfill gas will power the plant, he added, while the rest will be converted to liquid natural gas.

The plant is expected to generate 13,000 gallons per day of the fuel, enough to power about 300 trucks. The company expects to reduce its greenhouse gas emissions by 30,000 tons a year using biogas.

Stoddard said several hundred other Waste Management trucks in California's fleet run on compressed or liquid natural gas, shipped in from Arizona.

"It becomes much better when you can avoid that long transportation trip, and produce (the liquefied gas) more locally and from a waste-derived source. That's extremely beneficial," he said.

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