Study on performance and emission characteristics of VCR diesel engine fuelled with palm fatty acid distillate biodiesel

Abstract

This work consider the use of PFAD oil for the production of renewable and environment friendly biodiesel fuel as an alternative to conventional diesel. Test quantities of PFAD oil biodiesel were produced through transesterification reaction, 20% methanol (vol% PFAD oil), 0.8% (wt%) potassium hydroxide catalyst at 60oC reaction temperature and 90 min reaction time. The PFAD oil biodiesel produced was subsequently blended with petroleum diesel and characterized as alternative diesel fuel through ASTM standard fuel test. Variable Compression Ratio (VCR) engine test rig was used to determine the effect of compression Ratio (CR) on the performance and emission characteristics of the test fuel. Test were carried out at compression ratios of 16:1, 17:1, and 18:1 at different load. The performance parameters like Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC) and Exhaust gas temperature (EGT) were studied. At higher compression ratio the increase in BTE is observed for PFAD20 blend when compared to diesel. BSFC of biodiesel blend is higher at all compression ratios due to lower heating value of the fuel. However the biodiesel exhibited lower emission at CR 18 compared to neat diesel except NOx. The NOx is increased due to higher compression and better combustion characteristics of the biodiesel blend. Thus B20 blend at CR18 can be effectively used in diesel engine with better performance and reduced emissions.