Mid-Missouri Energy to use landfill gas

By Timothy Charles Holmseth | August 04, 2008
Web exclusive posted August 7, 2008 at 4:51 p.m. CST

Minneapolis-based U.S. Energy Services Inc.; Johnson County Landfill, based in Shawnee, Kan.; and Chicago-based Integrys Energy Group Inc. have entered into an agreement that will supply renewable landfill gas to Mid-Missouri Energy Inc., a 40 MMgy ethanol plant in Malta Bend, Mo.

The gas will displace more than 90 percent of the natural gas used to produce ethanol at the Malta Bend facility.

Casey Whelan, vice president of strategy initiatives for U.S. Energy Services Inc., said negotiations have been underway since April, and the arrangement will benefit Mid-Missouri Energy. The Energy Policy Act of 2005 allows any ethanol plant that replaces 90 percent of its direct fossil fuel use with a waste derived fuel source to be eligible to receive an extra 1.5 renewable identification numbers (RINs) per gallon of ethanol produced.

"U.S. Energy Services was able to negotiate a price that allows Mid-Missouri Energy, which included an economic use impact analysis, off-take agreement negotiation, and thermal value management services," said Greg Bower, general manager for Mid-Missouri Energy.

Whelan said the operation will move pipeline quality gas from the landfill about 150 miles to the ethanol plant. "We are physically moving the gas from the landfill into Panhandle Easter Pipeline, which is an interstate pipeline. And then, moving the gas on the Panhandle system into the Mid-Missouri energy site," he said.

Whelan said it's his understanding that the U.S. EPA is not aware of any other ethanol plant that is displacing 90 percent of its fossil fuel with a waste derived fuel. "There are other plants displacing a part of their thermal requirements, but this is the first where there has been more than 90 percent," he noted.

The gas created at a landfill has to be dealt with because if released into the atmosphere it is damaging, Whelan explained. "Untreated methane that is vented to the atmosphere is a much more potent greenhouse gas than carbon dioxide, and when you burn methane you get carbon dioxide," he said.

In describing the process, Whelan said the system of capturing the gas involves little sink-wells that are made in the landfill. "You sink perforated plastic pipe into the landfill and then you connect each of the wells within the gathering system. Then you attach a blower system that creates a negative pressure so that the methane from the landfill percolates up the pipe and into the gathering system to a central collection area and then the gas is processed and cleaned up and essentially becomes the same as natural gas and then the gas is put into the pipeline system," he said.

The arrangement between the companies is expected to create up to 3,300 million British thermal units per day of pipeline quality biogas.