Application of hydrotreated vegetable oil from triglyceride based biomass to CI engines - A review

This review will be concentrated on the application of hydrotreated vegetable oils (HVO) produced from the triglycerides based biomass such as vegetable oil, animal fat, waste cooking oil and algae to compression ignition (CI) engines. Main problem in the application of HVO to CI engines is the poor low-temperature properties. The upgrading technology of cold flow properties of HVO reported in the literature can be categorized with four ways as isomerization, addition of flow improver, reaction temperature control and co-processing with petroleum derived raw materials. The advantages of hydrotreating over transesterification are lower processing cost, compatibility with infrastructure, NOx emission reduction, and feedstock flexibility. Combustion and emission characteristics of neat HVO, blends of HVO with petrodiesel and HVO with additives were widely investigated by many researchers. The use of HVO enables appreciable reductions in NOx, PM, HC and CO emissions without any changes to the engine or its control in heavy-duty engines. HVO could play an important role in providing an sustainable source of transportation fuels during the coming decades. In addition, HVO obtained from inedible vegetable oil and application of it to CI engine will be the subjects of future research in the production and application of HVO. The technologies for the reduction of NOx and PM in CI engines fuelled with HVO can be categorized with engine optimization and fuel optimization. The engine optimization technology is more effective than the fuel optimization technology. (C) 2013 Elsevier Ltd. All rights reserved.