Abstract
The effect of GTL (Gas to Liquids) fuel on emission characteristics under steady-state conditions was studied using a 4-cylinder diesel engine. Soot, CO and THC of the GTL fuel were lower than those of diesel fuel. Then, emission improvement was tried with increasing a high pressure loop (HPL)-EGR rate. A low pressure loop (LPL)-EGR was also introduced to improve further emissions. Both EGR systems could take advantages of GTL fuel characteristics and had possibility of reducing NOx with keeping the same soot level as Diesel fuel. The LPL-EGR was effective at middle to high load, while HPL-EGR was effective at low load with less penalty of BSEC.