Oil extraction from plant seeds for biodiesel production

Energy is basic for development and its demand increases due to rapid population growth, urbanization and improved living standards. Fossil fuels will continue to dominate other sources of energy although it is non-renewable and harm global climate. Problems associated with fossil fuels have driven the search for alternative energy sources of which biodiesel is one option. Biodiesel is renewable, non-toxic, environmental-friendly and an economically feasible options to tackle the depleting fossil fuels and its negative environmental impact. It can be produced from vegetable oils, animal fats, waste oils and algae. However, nowadays, the major feedstocks of biodiesel are edible oils and this has created food vs fuel debate. Therefore, the future prospect is to use non-edible oils, animal fats, waste oils and algae as feedstock for biodiesel. Selection of non-expensive feedstock and the extraction and preparation of oil for biodiesel production is a crucial step due to its relevance on the overall technology. There are three main conventional oil extraction methods: mechanical, chemical/solvent and enzymatic extraction methods. There are also some newly developed oil extraction methods that can be used separately or in combination with the conventional ones, to overcome some disadvantages of the conventional oil extraction methods. This review paper presents, compare and discusses different potential biofuel feedstocks, various oil extraction methods, advantages and disadvantages of different oil extraction methods, and propose future prospective for the improvement of oil extraction methods and sustainability of biodiesel production and utilization.