Abstract:

Demand on energy from alternative fuels are growing rapidly due to depletion of fossil fuels and global warming crises. Biodiesel instead of conventional petroleum diesel, is a non toxic, biodegradable and renewable fuels.  Therefore, biodiesel can be considered as a promising liquid fuel for transport sector. Among the routes of  biodiesel synthesis, the most commonly used are transesterification of oil feedstocks and esterification of free fatty acids, in which these are carried forward in the presence of a catalyst. In transesterification process, a large majority of feedstocks come from vegetable/edible oil, as the first generation biodiesel feedstocks, in many regions of the world. The use of edible oils is not convenient in production of biodiesel due to insufficient amount of edible oil feedstocks and demand for food materials in the world.  When it is thought that over 70% of price of biodiesel includes cost of feedstocks, use of cheaper and more sustainable resources have become inevitable.  Waste cooking oil and algae oil, which have not been used as food sources, are termed as second generation feedstocks and seem more attractive and promising for biodiesel production. In addition to raw material source, the type of alcohol and catalyst also affects to price  and quailty of biodiesel.  Since biodiesel is a process includes sustainable technology, all inputs are investigated in terms of usability, sustainability and eco-friendly. The aim of this study to give an overwive  on the biodiesel production in that select of the most effective and available feedstocks and summarize the recent development and innovation in the production process. 

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