(6a) Upgrading Low BTU Fuels to Reduce Emissions and Enhance Performance In IC Engines

Landfills are currently the most common system used for the final disposal of solid waste. They are projected to remain the most common system in the forthcoming years. The release of Landfill Gas (LFG), mainly composed by CH4 and CO2 in an average proportion of 50%-50%, to the atmosphere constitutes an important environmental issue as methane is a GHG 20 times more powerful than CO2 and 23% of the methane emissions in the US come from landfills.  On the other hand, LFG can be a free source of low BTU fuels. For these two reasons, LFG is in most cases being collected, and it can be used as IC engine fuel in order to generate electricity. However, because of the fluctuations in the composition of the gas, higher emissions of pollutants such as UHC, NOx, and CO are released. Thus the importance of lowering the emissions of these toxic gases whose expulsion is regulated by the EPA. One solution to this issue is the addition of Synthesis Gas (Syngas) -H2 and CO- to the input LFG.

Preliminary data has shown that by supplementing the input gas stream with as little as 5% Syngas,  Nox emissions can be reduced up to 40%, CO up to 67%, and UHC up to 80%. Both the amounts of CO and UHC are reduced because the Syngas increases the activity of the fuel due to its higher flame speed; t he Nox formation is mitigated as a consequence of a more stable combustion at lower temperatures. More detailed data needs to be collected for different Syngas, LFG, and total input gas compositions.  All the tests are being run in a Honda Engine GC160 with Maximum Power output of 2kW. Nevertheless, emission levels of 4 different engines with bigger capacity-Capstone CR200, Solar Centaur 40, Caterpillar G3516 LE-have been compared. It was observed that the results of the experiments can be extrapolated to an industrial scale as well.