Challenges in biodiesel industry with regards to feedstock, environmental, social and sustainability issues: A critical review

This paper addresses the challenges in developing a sustainable biodiesel industry especially in Malaysia. The challenges discussed in this paper are divided into three main sections covering issues before, during and after biodiesel processing. The pre-processing problems concern the feedstock market, legislation through policies, fuel-food competition, deforestation issue and alternative feedstock conflict. Problems with regards to the uncontrollable glycerol production and its global market crisis are also reviewed. Besides, some suggestions on poising back the glycerol market stability are reviewed through several upgrading processes and methods that can convert glycerol to its functional chemicals. The last section covers the social issue of biodiesel in obtaining people׳s acceptance and capability of this industry to cultivate the sustainable practices along the processing line. Moreover, challenges in verifying its commercial value by fulfilling the global biofuel standards are also highlighted.