Experimental Study of Direct Injection Diesel Engine Fueled with Two Types of Gas To Liquid (GTL)

In this study, the main properties of two types of gas-to-liquid (GTL) fuels were investigated. Then, performance and emission characteristics of a compression ignition engine fueled with GTLs were investigated by comparison with diesel fuel. GTL1 was composed of 100% paraffin by volume, and GTL2 was composed of 99.8% paraffin and 0.2% aromatics by volume. Most GTL fuel properties were comparable to those of diesel fuel, while both fuels have a higher cetane number and lower sulphur. A diesel engine could be operated with GTL fueling without any special engine modifications. Our tests showed that with the high cetane number of GTLs, the ignition delay was shorter, and combustion started earlier than with diesel fuel. With GTL1 operation, THC and soot emissions were lower than with diesel fuel operation, and even lower with GTL2 fueling. The combustion duration with GTLs was longer as compared with diesel fuel at early injection timings, but became shorter than with diesel fuel operation with retarding injection timing. In case of GTL2, the combustion duration was shorter than that of GTL1 at retarded injection timings. The THC and soot emissions with GTLs were lower than those of diesel fuel at all injection timings, especially, THC and soot emissions with GTL2 were the lowest among all fuels tested here.