Towards a sustainable approach for development of biodiesel from plant and microalgae

The production of biodiesel can be accomplished using a variety of feedstock sources. Plant and microalgae based feedstocks are prominent and are studied extensively. Plant based feedstocks cultivated as monoculture on wastelands and trees in forests can cater towards partial fulfillment of feedstock requirements for biodiesel industry. Synthesis of biodiesel from microalgal oil has gathered immense interest and has potential to cater to the increasing feedstocks demands of the biodiesel industry. The major advantage offered by microalgal oil, as compared to plant based oils, is its potential for culture on non-arable land. Despite of the advantages of microalgal oil as a feedstock for biodiesel, there are constraints that have to be overcome in order to make it economical and sustainable. Sustainable approaches for both the plant and microalgae as feedstocks have been drawn. Despite there being several plant species, few have been found to be desirable as feedstocks for biodiesel production based on their lipid profiles. Among the microalgae, there are thousands of species and several of these have been cultured for extracting the oil to explore their feasibility in utilization as biodiesel feedstocks. Though, several of the microalgal species have shown potential for high biomass growth and lipid productivity, only a few have been found to provide a high biodiesel yield and conversion. Due to the several steps involved in the extraction of oil which are energy intensive, the cost of biodiesel from microalgal oil is high as compared with that obtained from the plant oils. A sustainable approach for utilizing plant and microalgal oils as feedstocks for biodiesel have been discussed. The emerging cost effective methods in production of biodiesel have been described. The energy return and greenhouse gas emissions from biodiesel have been outlined. Together, the plant oil and microalgal oil can offer potential source of feedstocks for the production of biodiesel. (C) 2013 Elsevier Ltd. All rights reserved.