Biodistillate transportation fuels include biodiesel (produced via transesterification of animal fats and vegetable oils) and renewable diesel (produced via catalytic hydroprocessing of the same feedstocks). Production and use of biodistillates are increasing dramatically, both in the U.S. and globally. This paper describes the policy drivers prompting growth of biodistillate fuels in the U.S., Europe, and selected other countries. Trends in fuel production volumes and feedstocks supplies are presented for these fuels. Current feedstocks are dominated by soybean oil in the U.S. and rapeseed oil in Europe. However, there is much interest in developing alternative, non-edible feedstocks such as jatropha and microalgae.
Currently, biodiesel is the dominant biodistillate in use, though interest in renewable diesel is increasing. This paper describes different conversion processes used to manufacture these fuels, and discusses the pros and cons of each. Chemical and physical properties of biodistillates are presented, along with a discussion of the relevant fuel specifications established by ASTM and other organizations. Measures to assure satisfactory fuel quality are explained. Finally, in-use handling and performance of biodistillates are discussed, focusing on issues such as fuel stability and low-temperature operability where special precautions may be necessary to ensure satisfactory quality.
