Comparative study of biodiesel production from different waste oil sources for optimum operation conditions and better engine performance

Abstract

Biodiesel from waste sources can be considered as the cheapest and most viable fuel alternative to depleting mineral diesel. In this work, biodiesel has been produced from different sources of waste oil; grilled chicken waste oil (GCWO) which is animal based source and waste cooking oil (WCO) which is vegetable based using transesterification method. The impact of different variables such as temperature, transesterification time, and amount of catalyst on the conversion and yield of biodiesel were investigated. Produced biodiesel was characterizes using ASTM standard methods for biodiesel property testing to determine the fuel properties including; kinematic viscosity, specific gravity, flash point, pour point, cloud point and acid number. Engine test has been conducted at increasing speed and constant load to evaluate the engine performance using the produced fuel. The results obtained indicate that the yield and conversion of bio-diesel from grilled chicken waste oil are greater than waste cooking oil. Both produced biodiesel fuel properties are within the standard biodiesel fuel specifications ASTM D6751. The maximum conversion and yield of biodiesel obtained by 97.76% and 94.4% suing GWCO and WCO respectively at optimum operating variables of 600C temperature, 3 h reaction time, and 0.4 wt% potassium hydroxide. Engine test results show similar trends for both biodiesels compared to diesel in term of engine brake power (BP) and brake specific fuel consumption (BSFC) with increasing engine speed. The maximum reduction in BP is found to be about 19% at 2400 rpm and a maximum increase in BSFC of 17% is obtained at 1800 rpm engine speed with both biodiesels compared to diesel fuel. Accordingly, though both biodiesels show comparable engine performance, GWCO presents higher biodiesel yield.