Processing of vegetable oil for biofuel production through conventional and non-conventional routes

•Ever increasing demand for alternative fuel specially biofuel imputes economically viable process•The economic feasibility of biodiesel process depends on the glycerol market prices and its valorization•This paper reviews alternative routes and covers new path ways for biodiesel process development & sustainability

Ever growing world energy demands, depletion and price of petroleum reserves, and environmental concerns are enormous challenges in today's scenario. For meeting the demand, alternate fuels are considered as an obvious choice owing to their renewability and environmental friendliness. Among the possible alternatives, processing of vegetable oil for biofuel production has gained considerable attention due to its ease of operation and integration with existing oil refining processes. Typically, transesterification based processes have been developed for production of biodiesel whereas hydroprocessing routes are developed to convert vegetable oil to green diesel and Bio-aviation turbine fuel (Bio-ATF) fraction using non-edible/edible vegetable oils as a feedstock. Accordingly, the present review is aimed at understanding of process aspects of various available processes. Based on the reviewed processing options, the merits and demerits of the developed routes have been highlighted and possible approaches for development of glycerin free biodiesel routes are envisaged.