Experimental Investigation of Diesel Combustion and Exhaust Emissions Fuelled with Fischer-Tropsch-biodiesel Blends: Part-I

This paper reports on experimental investigation of diesel combustion and exhaust emissions with Fischer-Tropsch (F-T) - biodiesel (BD) blended fuels. F-T fuel was used as a reference fuel for its superior properties to diesel fuel (DF). BD from non-edible jatropha oil was blended with F-T fuel. Using non-edible jatropha oil as a feed-stock, jatropha BD eliminates the food versus fuel conflict. The experimental results showed that exhaust emissions including carbon monoxide (CO), total unburnt hydrocarbon (THC), smoke, total particulate matter (TPM) and oxides of nitrogen (NOx) were reduced with F-T fuel compared to DF. CO, THC, smoke and TPM emissions were reduced significantly, while NOx emissions were somewhat higher with BD blended fuels compared to F-T fuel. The reductions in CO, THC, smoke and TPM emissions with BD blends were mainly due to the oxygen content in the BD blended fuel, while the increases in NOx emissions with BD fuels were due to advance in injection timing, higher percentages of fatty acids with double bonds in the carbon chain and higher heat release in the premixed combustion. Concerning engine performance and emissions, non-edible renewable BD blends can be excellent competitors of alternative fuel for diesel engine.