Landfill could provide heating fuel

Study will test collection of methane gas from garbage

Once you get beyond the stench, the gases emitted by the Johnson County Landfill actually could be a good thing.

The Kansas Geological Survey, based at Kansas University, has begun a test project that would use gases created by the trash heaps to tease methane from coal beds that lie underneath the landfill. The methane then would be used for home heating and other purposes.

“It’s a win-win situation for everybody in the deal,” said Dave Newell, assistant scientist with the geological survey.

The Johnson County Landfill, operated by Deffenbaugh Industries, is the largest in the Kansas City metropolitan area. It covers about two square miles in northwestern Johnson County.

Deffenbaugh already collects the gas created when anaerobic bacteria break down the waste. About half the gas is methane; the rest is carbon dioxide and other waste gases, which account for the gas’ stench. The methane is purified and pumped into a nearby pipeline, while the carbon dioxide is burned into the atmosphere.

According to a Johnson County waste management Web site, the landfill produces about 3 million cubic feet of methane a day. That’s enough to heat between 600 to 1,200 average homes.

But KU scientists think they may be able to extract even more methane out of the landfill.

The thin coal beds beneath much of eastern Kansas contain methane molecules. The so-called coal bed methane has sparked development of hundreds of wells in eastern Kansas in the past five years.

If all works as planned, the coalbed methane production at the Johnson County site would work this way: The gas produced by the trash would be pumped into the coal layer, which is between 550 and 900 feet deep.

Graduate student Matt Brown works on a project with the Kansas Geological Survey, based at Kansas University. The project will collect methane gas from coalbeds underneath the Johnson County Landfill, which could then be used for home heating.

Since carbon dioxide makes the coal give off its methane molecules, the methane could then be captured and the carbon dioxide would be sequestered in the ground.

Geological survey researchers have collected samples of the coal to test how much methane it will give off. They also will determine whether the gas collected from the waste must be separated into its parts before being pumped into the coal, or whether it can be injected in the same form as it is extracted.

“Nobody’s ever done this with Kansas coals,” Newell said. “We don’t know how the coal is going to react.”

Whether Deffenbaugh officials pursue the project further largely will be determined by how much methane can be produced, Newell said. A Deffenbaugh geologist did not return a phone call seeking comment for this story.

The test project is expected to last another year. It is funded with a grant from the U.S. Department of Energy.

“If this works out, it could work in other places,” Newell said. “As it is with all natural gas wells, the profitability of this will very much be determined by how close the nearest pipeline is.”