Effect of Fatty Acid Methyl Ester on Fuel-Injector Wear Characteristics

Abstract

This paper presents the experimental results carried out to evaluate the fatty acid methyl ester (FAME) obtained from cotton-seed oil and palm oil on fuel-injector wear characteristics. The cottonseed oil methyl ester (COME) and palm oil methyl ester (POME) were produced in the laboratory using alkaline transesterification. Gas chromatography based on 'BS EN 14103:2011' standard was used to analyze the percentage of fatty acids in COME and POME. The physicochemical properties of the two methyl esters were measured based on ASTM and EN standards. Various unique blends using cottonseed–palm oil methyl ester (CPME) were tested. Thirteen (13) different types of fuel blends were prepared from COME, POME, and petroleum diesel fuel (DF100). The wear and lubricity characteristics were measured using a high-frequency reciprocating rig (HFRR) based on ASTM D6079 standard. The worn surfaces of the specimen plates were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The COME100, POME100, and CPME100 showed excellent lubricity properties for the fuel injector in terms of lower COF and wear coefficient when compared with DF100. COME100, POME100 and CPME100 showed lower average COF compared to DF100 by 16.9%, 13.9% and 16.1%, respectively. This may be due to the presence of unsaturated fatty acids in the methyl esters composition. Consequently, the fatty acid methyl esters can be used to reduce the friction and wear of the fuel injectors due to the improvement in the tribological properties of the fuel.