Biodiesel is an alternative fuel made from a number of different feedstocks – vegetable oils (such as soybean and canola oil), animal fats (such as beef tallow and chicken fat), waste cooking oils, and a host of others. Two chemical processes – esterification and transesterification – combine these fats/oils with methanol, and a caustic catalyst like sodium hydroxide, to create methyl esters. Methyl ester is the chemical name for biodiesel. This process also creates a byproduct called glycerin, which has many industrial uses.
Biodiesel is used in standard diesel engines. Biodiesel can be used alone, but it is normally blended with petro-diesel. Biodiesel is usually described based on its concentration in conventional petroleum diesel. The blends most commonly distributed for use in the retail diesel fuel market are:
- 100% biodiesel – referred to as B100;
- 20% biodiesel/80% petrodiesel – referred to as B20
- 5% biodiesel/95% petrodiesel - referred to as B5
- 2% biodiesel/98% petrodiesel – referred to as B2.
Rudolph Diesel, inventor of the diesel engine, envisioned the use of biodiesel in the engines. In fact, the first diesel engine was designed to run with peanut oil. In 1913, Diesel noted that “the use of vegetable oils for engine fuel may seem insignificant today…but such oils may become in course of time as important as petroleum and the coal tar products of the present time.”
Biodiesel provides significant economic, environmental and security benefits and is gaining greater market share worldwide.