Experimental investigation on the combustion, performance and pollutant emissions of biodiesel from animal fat residues on a direct injection diesel engine

Fat trap grease is a cheap source for biodiesel production, but until now its transformation into biofuel is not well studied. The effects of the use of biodiesel from degraded raw material on combustion in engines are not discussed by researchers. In this paper, engine tests were performed on biodiesel produced from AFR (animal fat residues) collected from fat traps. This fuel presents differences in chemical composition and on physical properties as compared to standard biodiesel produced from vegetable oils. Tests were performed on a single cylinder, air cooled, direct injection diesel engine at 1500 rpm, performance and pollutant emissions were measured and the combustion parameters were analyzed. The use of AFRBD in the engine resulted in similar performance with slight brake thermal efficiency decrease at low loads and a slight increase at high loads. A decrease of 9% of power output at 1500 rpm was also detected. As per pollutant emissions, a drastic reduction of unburned hydrocarbons between 32% and 45% was obtained with AFRBD (animal fat residue biodiesel). Particulate matter emissions were also reduced at low and medium load ranges, but no differences were detected at high loads. Nitric oxides emissions were also measured and slight increase was detected at low loads and a slight reduction was noticed at full engine load. (C) 2014 Elsevier Ltd. All rights reserved.