Introduction
Several studies have been done on energy life cycle analysis of soybean biodiesel. These include:
- a 1994 paper published by the National Soydiesel Development Board (Ahmed et al.);
- a 1998 study by the National Renewable Energy Laboratory (Sheehan et al.);
- a 2005 paper by Pimentel and Patzek;
- a 2006 study by the


Biodiesel is a diesel fuel substitute made from a variety of oils, fats, and greases.
