Engine performance and exhaust emissions of Garcinia gummi-gutta based biodiesel–diesel and ethanol blends

Abstract

The use of abundantly available Garcinia gummi-gutta seeds grown at forest lands and ethanol a by-product of sugar industries has led to resource conservation and their use as alternate fuel to diesel engines for pollution reduction. Garcinia gummi-gutta (GGG) oil-based methyl esters blended with 20% ethanol and diesel fuel composed of six fuel samples (D100, B20E20, B30E20, B40E20, B100E20 and B100) are tested at different engine loads (0%, 20%, 40%, 80% and 100%) for their practical usefulness in diesel engine. Six fuel samples are tested for fuel properties. Biodiesel–diesel–ethanol blends showed approximately closer fuel properties to standard diesel fuel. Tests are carried out experimentally to know their performance and emission characteristics of six test samples fuelled in diesel engine varied subjected to different loads. Brake specific fuel consumption for all biodiesel blends is slightly higher for diesel fuel and its proportion decreases with increase in engine load. At full load engine condition, the brake thermal efficiency (BTE) for diesel fuel is 26.25%, and for biodiesel blends vary in the ranges of 22.5 to 25.2%. Compared to diesel fuel there is a reduction in 32.56% of carbon monoxide (CO) emission and 35.71% of hydrocarbon (HC) emission for biodiesel fuel (B100E20). For all biodiesel blended fuels tested at all engine loads, the oxides of nitrogen (NOx) emissions are marginally higher than diesel fuel. At full load engine condition, B100E20 (100% diesel and 20% ethanol) reduces CO emissions by 6.45%, HC emissions by 6.64%, and increases BTE by 0.8%, compared to neat biodiesel (B100). GGG based biodiesel blended with ethanol resulted with better fuel properties, performance and emission characteristics to that of diesel fuel. Garcinia gummi-gutta seed yields 45% of oil with a high conversion ratio to biodiesel of 1:0.96, which help the industry for biodiesel production in large scale at reduced cost.