A Review on Neem Oil as a Biodiesel and Its Effects on Engine Performance and Exhaust Emission

An increase in industrialization and mechanization leads to an increase in energy demands. Fossil fuels such as petroleum are the major sources of this energy. However, these fuels cause air pollution due to the emission of greenhouse gases. Therefore, raising a need for an alternative fuel that is ecofriendly. Biodiesel has been regarded as a substitute since it is friendly to the environment and it does not cause air pollution. The main methods applied in the production of biodiesel include transesterification, direct blending and use, and thermal cracking or pyrolysis together with micro-emulsions. Currently, researchers, policymakers, and investors have been persuaded to think of a fuel that will substitute fossil fuels. Therefore, this review paper addresses factors affecting production, the method used in producing this biodiesel, and the effects of biodiesel on the performance of the engine and emission of exhaust gases.