Biodiesel is produced from various feedstocks including soybeans, oilseed, algae, and animal fats. It can be blended with diesel fuel for use with diesel-powered vehicles. Scientists are looking for advantages of biodiesel use.
According to the Alternative Fuels Data Center:
There are advantages of biodiesel regarding energy security, air quality, engine operation, and safety.
The United States imported 11% of its petroleum, and transportation was responsible for nearly three-quarters of its use. Depending heavily on foreign petroleum supplies puts the United States at risk for trade deficits, supply disruption, and price changes. Biodiesel is produced in the United States and used in conventional diesel engines, directly substituting for or extending supplies of traditional petroleum diesel. Biodiesel has a positive energy balance, meaning that biodiesel yields 4.56 units of energy for every unit of fossil energy consumed over its life cycle. (See USDA study) Source: Alternative Fuels Data Center
Currently, the performance of vehicles with higher diesel/bio ratio run better with higher contents of diesel. The shelf-life of stored biodiesel is short compared to straight fossil fuel products which can create limitations in how it is used.
Biodiesel continues to show great promise as research at universities and in the private sector continues. Work continues on increasing the shelf life of biomasses and the performance capabilities of biodiesel.