Biodiesel—Technical Viability for India

Abstract

The aim of the article is to investigate the different technologies for the production of biodiesel, which includes process description, pre-treatment of raw feedstock, esterification/transesterification and product purification/standardization. Further, technology comparison has been carried out for homogeneous acid/alkaline catalysis process, heterogeneous acid/alkaline catalysis process, supercritical methanol process and enzymatic (biochemical) process. In a technology viewpoint, the homogeneous (acid/alkaline) catalyst is mostly used for commercial production of biodiesel from batch and continuous processes. In India, sodium-based catalyst (e.g. NaOH) is preferred for a small-scale commercial production as it is inexpensive and easy to handle in transportation and storage. Presently, Indian commercial producers are using a two-stage homogenous process. The market price of biodiesel is Rs. 55 ({\textpm}2), excluding tax. This price is a little high in the market due to the cost of feedstocks which makes up to 80--90{\%} of the total production cost, operating cost and the capital cost in the view of business experts. The market price is almost near to the petroleum diesel price (approximately Rs. 60). However, in using biodiesel, there are enormous benefits towards the environment-friendly factors such as fewer emissions of CO, SO2, NOxand less particulate matter.