Potential of Hydrogenated Vegetable Oil (HVO) in Future High Efficiency Combustion System

The limited availability of fossil fuels and the increasing environmental pollution will lead to an increased demand for sustainable biofuels. The production of bio-based diesel fuels from vegetable oils is commonly accomplished using a process known as Trans-esterification. The product of Transesterification is Fatty Acid Methyl Ester ( FAME), commonly known as Biodiesel. An alternative process is Hydro-treatment of seed oils or animal waste fats to produce highly paraffinic renewable diesel fuel called Hydrogenated Vegetable Oil (HVO). Detailed investigations were carried out by the "Department of Advanced Diesel Engine Development" at FEV GmbH Aachen (Germany), to explore the potential of this biofuel compound as a candidate for future compression ignition engines. Engine results of pure HVO fuel are compared to petroleum based diesel fuel (B0) and rapeseed oil methyl ester (B100) at different part load and full load points with respect to combustion behavior, engine efficiency, combustion sound level (CSL) and emission performance. To ensure that the findings are relevant for modern automotive business, the testing program was carried out on a EURO 6 compliant High Efficiency Diesel Combustion System (HECS) designed for future passenger car applications. The results indicate that at lower part loads, the higher cetane number of HVO fuel leads to lower ignition delay periods, resulting in decreased soot reduction potential and improved CSL behavior. On the other hand, at medium and high part load operations, soot emissions with HVO reduced approximately 50%-60% due to almost aromatic free fuel composition. Furthermore un-burnt HC and CO emissions for HVO were observed to be lowest amongst all investigated fuels.