A study on performance and emissions of a 4-stroke IC engine operated on landfill gas with syngas addition

The aim of this study is to investigate the suitability of landfill gas (LFG) as an alternative fuel for an internal combustion (IC) engine and how to reduce pollutants emissions from LFG operations by adding syngas to LFG. The effect of CO2 fractions in LFG on the engine performance and exhaust emissions such as CO, UHC and NOX are experimentally determined, and a simulated LFG (50% CH4 and 50% CO2) mixed with a simulated syngas consisting of H2 and CO (H2/CO = 2) is also studied. The Honda GC160E engine connected with a small generator which functions as different electrical loads is used for this study. When CO2 fraction in LFG changes from 0% to 50% at 0.8 kW load condition, CO and UHC emissions increase from 241.8ppm to 802.1ppm and from 35.6ppm to 113.4ppm respectively, while NOX emission decreases from 126.7ppm to 99.8ppm. In case of LFG (50% CH4 and 50% CO2)-syngas (H2/CO = 2) mixtures, 5% addition of syngas to LFG at 0.8 kW load condition reduces CO, UHC and NOX emissions from 802.1ppm to 203.1ppm, from 113.4ppm to 11.1ppm and from 99.8ppm to 64.5ppm, respectively. However, when more syngas is added to LFG (10% and 15% syngas in fuel mixture) it does not measurably reduce these emissions any further.