Effect of oil blends derived from catalytic pyrolysis of waste cooking oil on diesel engine performance, emissions and combustion characteristics

The purpose of this study is to study the effect of pyrolysis oil from economical feedstock waste cooking oil on engine performance, emissions and combustion characteristics. Effect of potassium and sodium hydroxide catalysts concentrations of 0.5, 1, 3, 5, 7 and 10% by weight on the oil yield was investigated. NaOH catalyst achieved the highest oil yield of 70% wt. at concentration of 1% wt. Pyrolysis oil was mixed with diesel oil in volume percentages of 0, 20, 40, 60, 80 and 100%. Oil blends were tested in a diesel engine at variable loads and rated speed of 1500 rpm. The higher oil blend ratio decreased the thermal efficiency, NOx and CO emissions about diesel oil. Increase of oil percentage in the blends led to the increase of specific fuel consumption, smoke and HC emissions about diesel oil. The oil blend B100 achieved the maximum decreases in thermal efficiency, CO and NOx emission by 29, 45 and 65%, respectively about pure diesel. Also, pure pyrolysis oil B100 showed the maximum increases in specific fuel consumption, HC and smoke emissions by 28.3, 33 and 11%, respectively related to diesel oil. Pyrolysis WCO could be alternative fuels in diesel engines.