ABSTRACT
The unprecedented demand for diesel fuels and the inevitable health hazards caused by petrodiesel combustion has led to the substantial increase in the production and consumption of biodiesel as an alternate fuel. It mainly consists of long chain alkyl esters that are derived through the extraction of organic oils from plants or animal fats through the transesterification process. It is advantageous over alcohol biofuels because it does not require any modifications to the already existing diesel engines. It is often blended with petroleum diesel (2–20%) or is used in the pure form. Feedstock is the main economic factor that contributes to about 80 percent of the total input costs. At present, biodiesel is produced using feedstocks such as soybean, rapeseed, and palm oils; however, several oleaginous non-crop feedstocks also are tested for biodiesel production. Still, there exists a great deal of debate over the pros and cons of biodiesel usage. This chapter reviews the various processes and feedstocks that have been used for biodiesel production. Different factors affecting the transesterication process such as the reaction temperature, reaction time, catalyst, and reactant purity have been assessed in detail. In addition, the fuel properties and specifications required for biodiesel standards have been summarized.
