Bio-diesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Bio-diesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a bio-diesel blend, it can be used in compression-ignition (diesel) engines with little or no modifications. Bio-diesel is simple to use, biodegradable, non-toxic, and essentially free of sulphur and aromatics. Experiments in using bio-diesel in heating boilers are already underway.
Bio-diesel is made through a process called transesterification whereby the glycerine is separated from the fat or vegetable oil. The process leaves behind two products -methyl esters (the chemical name for bio-diesel) and glycerine (a valuable by-product usually sold to be used in soaps and other products). The transesterification process involves mixing at room temperature methanol (50% excess) with NaOH (sodium or potassium hydroxide) (100% excess), then mixing vigorously with vegetable oil and letting the glycerol settle (about 15% of the bio-diesel mix). The supernatant is bio-diesel and contains a mixture of methylated fatty acids and methanol, the catalyst remaining dissolved in the glycerol fraction. Bio-diesel replaces the exhaust odour of petroleum diesel with a more pleasant smell of popcorn or chips.
NO. Fuel grade bio-diesel must be produced to European specifications (PrEN 14214:2001) in order to insure quality and proper performance. British Standard EN 590 does not meet the requirements for Bio-diesel Blends over 5%. Raw vegetable oil cannot meet bio-diesel fuel specifications. It is not a legal fuel.
The concept of using vegetable oil as an engine fuel dates back to 1895 when Dr Rudolph Diesel developed the first engine to run on unmodified peanut oil. Which he demonstrated at the World Exhibition in Paris in 1900. Unfortunately he died in 1913 before his vision of a vegetable oil powered engine was fully realized. Modern diesels arc now designed to run on a less viscous fuel than vegetable oil but, in times of fuel shortages, cars and trucks were successfully run on preheated peanut oil and animal fat.
A well known make of pressure jet burner in a central heating boiler is being run on WVO (waste vegetable oil) by a Biofuel Refining company in Cornwall, the proprietor also runs his motor vehicles on the same product. Central heating boilers that normally run on class 2 kerosene are also being run and tested on Biokerosene.
The development of a special form of class C2 fuel has been underway at the University of Glamorgan for some time. The aim of the research and development is to produce a renewable "green" fuel that is a direct replacement for class 2 fuel.
Bio-Gas is also used, but is unknown in comestic application.