Non-Conventional Feedstock and Technologies for Biodiesel Production
Increased consumption and energy security issues have led many developed and developing countries to seek methods to produce alternative fuels. Biodiesel is one such high-density alternative fuel that can increase the longevity of transportation fuels. Biodiesel can be produced from a wide range of feedstock using simple process schemes. In the past, edible oils were used as feedstock for biodiesel fuel production; however, use of non-traditional feed stock like waste cooking oil, non-edible oils, animal fats, and algae can make biodiesel production a sustainable process. The high free fatty acids content in the feedstock, longer reaction rates, high energy consumption, and the catalysts used in the conversion process pose some limitations for current biodiesel production. These limitations can be addressed by developing novel process techniques such as microwaves and ultrasound and by developing non-catalytic transesterification methods. Enhancing byproduct recovery seems to be an important strategy to improve the energy footprint and economics of current biodiesel production.