Engine’s behavior on hydrogen addition of waste cooking oil fueled light duty diesel engine - A dual fuel approach

Abstract Foremost aim of this paper is to study the influence of hydrogen induction on tail pipe exhaust emissions of a compression ignition engine fueled with waste cooking oil biodiesel (WCOB). Waste cooking oil biodiesel was mixed with mineral diesel fuel by a volume fraction of 50% (WCOB50). In addition to this pure hydrogen was inducted into the intake along with air at the volume flow rate of 2, 4 and 6 lpm. The test was conducted in a single cylinder agricultural based direct injection light duty diesel engine at various load conditions. At first, test results were correlated with neat diesel fuel and WCOB50 fuel at all loads. WCOB50 fuel indicates an insignificant reduction in BTE when compared to neat diesel fuel. Emission study revealed that WCOB50 usage moderately increases NOx emission and depreciates CO, HC and smoke opacity. However, hydrogen enrichment significantly decreased exhaust emissions such as smoke opacity, HC and CO except for NOx emission. Also, the BTE of the engine gradually improved with the increasing volume flow rate of hydrogen in the intake. At maximum power output in cylinder pressure and heat release rate were found to be higher for maximum hydrogen flow rate.