Search Results

Landfill gas (LFG) is a waste-product resource composed primarily of methane and carbon dioxide that can be collected and used to produce power either by extracting the methane or using the landfill gas directly in an internal combustion engine in what amounts to a net-negative greenhouse gas emission process. The carbon dioxide component of LFG dilutes the fuel and absorbs some of the heat of combustion, but also suppresses knock. A model is developed, using KIVA-4 code, to simulate engine performance at various operating conditions and evaluate the benefits of methane purification and direct use of LFG as a fuel. It was found that landfill gas used directly at higher compression ratios than can be used for pure methane fuel produces higher fuel efficiency than can be achieved using pure methane.

Ever increasing price of the fossil fuels, and fast depletion of the petroleum reserves world wide, have greatly encouraged the utilization of the alternative and renewable fuels for the production of electricity and motive power. Among the alternative renewable fuels, landfill gases which were produced by the anaerobic decomposition of organic waste in the landfills and solid waste dump sites were underutilized and overlooked in the past. Lately, there has been an increased interest in this research as the utilization of the landfill gas would provide energy independence, generate revenue and create environmental benefits. They are used both in the internal combustion engines and gas turbines for energy production needs. However because of the low heating value (Btu) content in the landfill gases, competitive energy market and other issues, they were not considered for the energy production in the past in most of the cases.

The recent interest to use Alternative Fuels for power generation and or mobile power is mainly driven by the serious environmental concerns and energy security of the nation. In this context, the utilization of the landfill gases which are generally low heating valve (Btu) content fuels and normally produced from municipal and city solid waste such as in landfills or garbage dump sites has been increasingly used due to the two fold benefits; firstly, the proper utilization of the gas will avoid the green house gas effect and other environmental concerns and secondly it can produce revenue for the local governments or industries at the same time. The paper describes the results of the investigation of the utilization of landfill gases in a spark ignition (SI) engine. Methane and landfill gas compositions were tested and their performance and combustion characteristics are studied and compared.