Comparative Study of the Performance and Emission Characteristics of Biodiesels from Different Vegetable Oils with Diesel

This paper is concerned with the comparison and analysis of the performance and emission characteristics of methyl esters of sunflower oil, palm oil, pungam oil, Jatropha oil, Rice bran oil and waste cooking oil with those of diesel. The need to select the biodiesels source for standardization of biodiesels blends necessitates this comparison. In addition to the various vegetable oils, sunflower oil that has been hydrogenated after cooking has also been considered for this comparison. All the above mentioned vegetable oils are transesterified with methanol in presence of alkaline catalyst to obtain the respective methyl esters. The above obtained ‘biodiesels’ are tested on a single cylinder Direct Injection CI engine. The engine is loaded with an electrical dynamometer. The performance parameters, namely Brake Thermal Efficiency (BTE) and Specific Fuel Consumption (SFC) are calculated form brake power and total fuel consumption. Emissions of Carbon Monoxide (CO), Oxides of Nitrogen (NOX) and Unburnt Hydrocarbons (HC) are measured using MRU delta 1600 L Exhaust Gas Analyzer. The emissions of soot are measured by AVL smoke meter. The measured performance and emissions of the biodiesels are compared with that of diesel.

It is found that sunflower oil methyl ester (SUME) has highest BTE across the range of loads while Palm oil methyl ester (PAME) has the lowest specific fuel consumption among the biodiesels. NO_X emissions are highest for SUME. All biodiesels record lesser CO, HC and soot emissions compared to diesel.