Bio Diesel - An Efficient Energy Source

What is Bio Diesel?

Bio Diesel is an alternative fuel that is an example of clean burning alternative fuel. This is produced from domestic, renewable energy resources. You will be surprised to know that Bio Diesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a Bio Diesel blend. This Bio Diesel can be used in compression-ignition based engines (almost every diesel engine) with slight or no modifications. There are several benefits of using Bio Diesel. It is simple to use, biodegradable, nontoxic, and essentially free of sulfur and other aromatics.

Making of Bio Diesel

Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil. The process leaves behind two products, methyl esters (the chemical name for biodiesel), and glycerin (a valuable byproduct) usually sold to be used in soaps and other petroleum based products.

There are different ways of making bio diesel or alkyl ester. Most importantly, there are thee basic ways of ester production from vegetable oils and fats:

1. Base catalyzed transesterification of the oil with alcohol
2. Direct acid catalyzed esterification of the oil with methanol
3. Conversion of the oil to fatty acids, and then to Alkyl esters with acid catalysis

However, the most popular way of bio diesel production is the first one. Major portions of bio diesel or alkyl esters produced these days are done with the base catalyzed reaction process, because it is the most economic process of making bio diesel. There are some fundamental reasons behind that:

1. Low temperature (150 F) and pressure (20 psi) processing
2. High conversion (98%) with minimal side reactions and reaction time
3. Direct conversion to methyl ester with no intermediate steps
4. Exotic materials of construction are not necessary

The detailed process goes like this - A fat or vegetable oil is reacted with an alcohol (like methanol for example), in the presence of a catalyst (usually sodium or potassium hydroxide which has already been mixed with the methanol) to produce glycerin and methyl esters or biodiesel. The methanol is charged in excess to assist in quick conversion and recovered for reuse.

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