Biodiesel, a renewable fuel, is produced from vegetable oils and animal fats by a process called Transesterification Process. It breaks down the molecules of vegetable oils into constituents molecules forming biodiesel as the main product, and glycerin as the byproduct.
Sources of Biodiesel
Biodiesel is manufactured from the vegetable oils like soya, canola, jatropha, sunflower seed, algae etc. and animal fats. The chemical name for biodiesel is fatty acid alkyl esters. There are a few methods for production of biodiesel, but the most commonly used method for production of biodiesel is called as transesterification. It is the chemical conversion process of vegetable oil or animal fats to biodiesel.
Chemical Components of Vegetable Oil
The main components used for production of biodiesel are vegetable oil or animal fats. Vegetable oils are the triglycerides that comprise of three chains of fatty acids all connected together by a glycerin molecule. The triglycerides are not the individual atoms, they are rather esters. The esters in turn are the acids, say like fatty acids, which have been combined with alcohol. The chemical name for glycerin is glycerol, which is a form of alcohol.
Process of Transesterification
Transesterification is a chemical reaction for conversion of vegetable oil to biodiesel. In this process vegetable oil is chemically reacted with alcohol like methanol or ethanol in presence of catalyst like lye. After the chemical reaction various components of vegetable oil break down to form new compounds.
The triglycerides are converted into alkyl esters, which is the chemical name of biodiesel. If methanol is used in the chemical reaction, methyl esters are formed, while if ethanol is used then ethyl esters are formed. Both these compounds are biodiesel fuels with different chemical combination. In the chemical reaction alcohol replaces glycerin.
Glycerin that has been separated during transesterification process is released as the byproduct of the chemical reaction. Glycerin will either sink to the bottom of reaction vessel or come to the surface depending on its phase. It can be easily separated by the centrifuges. This whole process is called as transesterification.
The biodiesel produced by process of transesterification has much lesser viscosity, which makes it capable to replace petroleum diesel in the diesel engines. In the earlier years when process of transesterification was not known the viscosity of vegetable oil was the major hindrance for its use as the fuel for engine. Transesterification process has been able to remove this hindrance.
The byproduct of the transesterification chemical reaction is glycerin that originally formed bond between the chains of fatty acids. Glycerin can be used for various purposes. Thus during transesterification process nothing goes wasted, all the products and byproducts are utilized for various purposes.
Biodiesel: Alternate Fuels (Alternate Fuel for Vehicles)
Biofuels are obtained from renewable energy sources like vegetable oil and animal fats. Biofuels can be used as alternate fuel for vehicles. There are two popular blends of biofuels: B20 and B100. Biodiesel can be used easily in the engines in place of petroleum diesel.