Aspects of Landfill Gas Collection and Utilization: Energy from Waste

Tej Gidda¹, Rick Mosher¹, Ed McBean², and Frank Rovers^1
1 Conestoga-Rovers & Associates, Waterloo, ON
² Conestoga-Rovers & Associates, and University of Guelph, Waterloo, ON

Landfill gas (LFG) is a byproduct of the anaerobic degradation of organic material placed in a landfill. In general, the composition of the gas is 50% methane and 50% carbon dioxide, with traces of other gases. LFG constitutes an odour and health problem, and thus technologies to mitigate landfill gas emissions are important. Gas collection technology is a fairly established field, and generally includes flaring of the extracted methane. Of late, utilization of the LFG for electricity generation has become more common as utilization technology has improved and the economics of such systems have become more viable. Utilization of landfill gas for electricity production is a renewable energy offering a clean, stable power supply for the long term.

Though electrical generation from LFG is ever-increasing, many factors relating to the production and collection of LFG affect the success of such systems. Power plants at landfills will not be successful unless a stable, consistent fuel supply is obtained. These issues will be explored in this presentation. The lifespan for gas utilization will be discussed in terms of landfill conditions, expected gas generation, and the market issues that control the viability of utilization systems. Factors affecting expected power generation will be outlined in the context of gas yields as a function of pre- and post-closure of the landfill. Further, the economics of LFG power plants will be outlined.

Several case studies will be explored to demonstrate successes and additional challenges relating to landfill gas utilization. These case studies will range from small to extremely large landfills in Canada.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005