Engine performance, combustion, and emissions study of biomass to liquid fuel in a compression-ignition engine

Abstract

In this work, the effects of diesel, biodiesel and biomass to liquid (BTL) fuels are investigated in a single-cylinder diesel engine at a fixed speed (2000rpm) and three engine loads corresponding to 0bar, 1.26bar and 3.77bar brake mean effective pressure (BMEP). The engine performance, in-cylinder combustion, and exhaust emissions were measured. Results show an increase in indicated work for BTL and biodiesel at 1.26bar and 3.77bar BMEP when compared to diesel but a decrease at 0bar. Lower mechanical efficiency was observed for BTL and biodiesel at 1.26bar BMEP but all three fuels had roughly the same mechanical efficiency at 3.77bar BMEP. BTL was found to have the lowest brake specific fuel consumption (BSFC) and the highest brake thermal efficiency (BTE) among the three fuels tested. Combustion profiles for the three fuels were observed to vary depending on the engine load. Biodiesel was seen to have the shortest ignition delay among the three fuels regardless of engine loads. Diesel had the longest ignition delay at 0bar and 3.77bar BMEP but had the same ignition delay as BTL at 1.26bar BMEP. At 1.26bar and 3.77bar BMEP, BTL had the lowest HC emissions but highest HC emissions at no load conditions when compared to biodiesel and diesel. When compared to diesel and biodiesel BTL had lower CO and CO2 emissions. At 0bar and 1.26bar BMEP, BTL had higher NOx emissions than diesel fuel but lower NOx than biodiesel at no load conditions. At the highest engine load tested, NOx emissions were observed to be highest for diesel fuel but lowest for BTL. At 1.26bar BMEP, diesel had a higher smoke opacity than BTL and biodiesel. At 3.77bar BMEP, BTL had the highest smoke opacity with diesel fuel having the lowest opacity. This work also demonstrated the effectiveness of BTL as a renewable alternative fuel with characteristics comparable to regular diesel fuel.