A Review on Biodiesel Production, Analysis, and Emission Characteristics from Non-Edible Feedstocks

Biodiesel produced from different edible and non-edible feedstocks is a viable alternative option for fueling a combustion engine. However, the widespread use of edible sources for biodiesel production may lead to food versus fuel controversy. Oil from non-edible feedstock is best possible solution for problems that inhibits biodiesel production on commercial scale. This study presents the potential of different non-edible feedstock for biodiesel production. Several aspects such as extraction technologies used for extracting oil from non-edible sources and biodiesel production pathways from non-edible feedstocks are discussed. The quality of biodiesel should be assured before its commercialization by different physical and chemical characterization techniques are used. In particular, the emission comparison of biodiesel derived from the different non-edible feedstocks is discussed. Based on this study, the non-edible feedstocks have the potential to produce biodiesel but still it has a long way to go. This is due to non-edible feedstock is in the R & D phase and needs more research to eliminate additional treatment steps compared to edible feedstock for economic aspects. Furthermore, there has been a trade off in emission properties of biodiesels produced from non-edible feedstocks which must be removed or evaluated for pilot scale investigations before commercialization.