Study on the performance and emissions of a compression ignition engine fuelled with Fischer-Tropsch diesel fuel

Fischer-Tropsch (F-T) diesel fuel is characterized by a high cetane number, a near-zero sulphur content, and a very low aromatic level. In the present paper, the performance and emissions of an unmodified single-cylinder direct injection diesel engine operating on F-T diesel fuel are studied and compared with those of conventional diesel fuel operation. The results show that F-T diesel fuel exhibits a slightly longer injection delay and injection duration, displays an 18.7 per cent average shorter ignition delay, and has a lower peak value of premixed burning rate and a higher peak value of diffusion burning rate than conventional diesel fuel. The engine with F-T diesel fuel has a slightly lower peak combustion pressure and a far lower rate of pressure rise, and consequently a lower mechanical load and combustion noise compared with conventional diesel fuel. In addition, the brake specific fuel consumption is lower and the brake fuel conversion efficiency is higher for F-T diesel fuel operation. The CO2, HC, CO, NOx, and smoke emissions with F-T diesel fuel are reduced at all operating conditions when compared with conventional diesel fuel. On average, NOx and smoke emissions are reduced by 16.7 and 40.3 per cent respectively with F-T diesel fuel. The study demonstrates that F-T diesel fuel is an excellent clean alternative fuel for diesel engines.