Biodiesel production via transesterification reaction

Abstract

Global warming, climate change, local air pollution, ozone depletion, acid rain and depletion of fossil fuel are the major global environmental issues. Presently, non-renewable fossil fuels meet up to 80% of the world’s energy demand. Rapid consumption of fossil fuels as well as rising environmental pollution caused by extreme CO2 emissions, sulphur dioxide, and aromatic hydrocarbons has become crucial in searching for a clean and renewable energy source such as biodiesel. With continuous growth in the world’s population, rapid industrialization, urbanization, and economic growth, fossil fuel consumption is escalating to meet the global energy demand. Biodiesel is renewable, non-toxic, environment-friendly and an economically feasible options to tackle the depleting fossil fuels and its negative environmental impact. Biodiesel is an alternative fuel made by transesterification reaction of oil and alcohol under the influence of catalyst. Biodiesel is an alcoholic ester of various fatty acids, also known as FAME (Fatty Acid Methyl Esters). In the process of transesterification, the performance of the catalyst is the key factor of the biodiesel yield. Catalysts used in biodiesel production are classified as homogeneous, heterogeneous, and enzymatic catalysts. The incorporation of a catalysis-based transesterification reaction generally increases the rate of reaction and enhances the yield of the end product. In case of homogeneous catalysts, there are problems of catalyst poisoning and contamination. Heterogeneous acid catalysis has a lesser toxic effect and gives rise to fewer environmental problems compared to the homogeneous mode. The cost of each specific catalyst depends on various factors, including the source, synthesis method, and its reusability. Generally, using waste or biomass as sources of catalysts may reduce the price of commercially available solid catalysts.