ABSTRACT
Fossil fuel–based petroleum diesel products have been fulfilling the world energy demand. Continues usage of petroleum diesel products in diesel engines results in fuel depletion. In addition, more exhaust emissions are coming out from diesel engines fueled with conventional diesel, which leads to environmental pollution. Biodiesel is a prominent alternative for diesel fuel due to its fuel properties, which are similar to those of conventional diesel; also it is environmentally friendly and non-toxic. Hence, literature studies concentrate on identifying the feedstock for biodiesel production from different feedstocks through transesterification process, study the various technical barriers to using biodiesel in diesel engines, and enhance the cold flow properties and diesel engine performance, emission, and combustion characteristics through fuel modifications like blending biodiesel with metal additives, lower alcohols such as methanol, ethanol, and propanol, and higher alcohols such as pentanol, hexanol, and oxtanol. Literature studies reveal that metal additives and alcohol blended with biodiesel and conventional diesel enhanced the combustion efficiency, which leads to improvement in diesel engine performance characteristics and reduction in emissions.
