Bio-Diesel is an eco-friendly, alternative diesel fuel prepared from domestic renewable resources i.e. vegetable oils and animal fats. These natural oils and fats are made up mainly of triglycerides. These triglycerides when reacted chemically with lower alcohols in presence of a catalyst result in fatty acid esters. These esters show striking similarity to petroleum derived diesel and are called "Bio-Diesel".

In the US bio-diesels are mainly derived from Soybean oil and in Europe from the Sunflower oil. However, as India is deficient in edible oils, non-edible oils may be material of choice for producing Bio-Diesel like Jatropha, Karanjia and Rice bran oils, etc. Since, in India bio-diesel is in research phase, so, economics would only be generated later.

Bio-Diesel has been more attractive recently because of its environmental benefits and the fact that it is made from renewable sources and can be prepared locally. Since India is deficient in edible oils, therefore, the non-edible oil like Karanjia, Jatropha, etc. could be the desirable source for India for production of bio-diesel. These plants could be grown on wasteland, about 80 million hectare of which is available in India . These crops grow in arid and semi-arid region and require almost no post plantation management and care. Since, all most all the wasteland is available in rural and economically underdeveloped region, the large-scale bio-diesel production has an enormous potential for employment and development of these areas.

The major application of Bio-Diesel is in transportation sector as an alternate to mineral diesel. Many automobiles builders like Ford, John Deere, Massey-Ferguson, Mercedes, BMW, Volkswagen, Volvo, etc have accepted Bio-diesel as the fuel suitable for their vehicles in the existing diesel engines. However, mostly Bio-diesel is used in 10% or 20% blends rather than as neat Bio-diesel. This blending approach also avoids the need to build a separate & costly infrastructure for storing Bio-diesel. Though Bio-diesel is recommended for use in almost all diesels run vehicles, the fuel must meet the ASTM/DIN specifications.

The depletion of the world petroleum reserves coupled with the global environmental problems stimulated the search for the alternative source for petroleum fuel. Bio-Diesel is one of such candidates for the exploitation as an alternative to diesel fuel. In laboratory process, the Bio-Diesel prepared, has been evaluated for various physico-chemical properties. Subsequently, we have successfully scaled up the production of Bio-Diesel at pilot scale (60 lit) at IOC (R&D) Centre. The product obtained has been evaluated for various physico-chemical properties and it was found that the synthesized Bio-Diesel meets the ASTM bio-diesel specification. Field trials and emission testing of Bio-diesel is being pursued at IOC (R&D) Centre.

As discussed above, that Bio-Diesel will be manufactured in the rural areas because of the wasteland and cheap labor availability. More precisely, it will depend upon the wasteland locations in the country.

IOC (R&D) has examined and optimized the synthetic processes for the preparation of Bio-Diesel from various vegetable oils, which include oils from Rice bran, Jatropha curcas, Palm, Karanjia, Sunflower etc. using methanol and ethanol as alcohol. In laboratory process, the Bio-Diesel prepared, has been evaluated for various physico-chemical properties. Subsequently, we have successfully scaled up the production of Bio-Diesel at pilot scale (60 lit) at IOC (R&D) Centre. The product obtained has been evaluated for various physico-chemical properties and it was found that the synthesized bio-diesel meets the ASTM bio-diesel specification. Field trials and emission testing of Biodiesel is being pursued at IOC (R&D) Centre.

Indian Railways is the largest user of diesel, about two million MTPA. Indian Railway is also owner of very large area of land, which presently is without organized plantation. Railways have shown interest to plant the Bio-Crops along the rail tracks and other land available and it is estimated that the railways can produce enough Bio-diesel to replace about 5 to 10% of diesel required for their use. Introduction of bio-diesel in Railways may serve two objectives. Firstly, lowering of emissions and secondly providing enough lubricity to the diesel. The lubricity of low sulphur diesel is likely to cause concerns in near future when the sulphur level of diesel will fall below 500 ppm. Bio-diesel at 1-2% level in petrodiesel will retain the lubricity of the low sulphur fuel.

Conversion of vegetable oil to bio diesel

The extraction of oil can be done in any suitable oil extraction unit.
Commonly used oil extraction units can be used for extraction of oil from jatropha and karanja as well. The second step of conversion of vegetable oil to bio diesel requires chemical processing plant. The operation of this plant requires specific training and this can be done by well trained engineers/ diploma holders/chemists.

IIT Delhi, IICT Hyderabad, ITL Faridabad and Delhi College of Engineering, New Delhi have developed technology for production of Bio-Diesel from vegetable oil. These institutions can be approached for getting know-how about the process.

Plant can be set up by a group of people or by entrepreneurs on small scale. For terms and conditions, these institutes may be contacted.

Training is available at ITL Faridabad as part of technology package. Other institutes may also be contacted.

Exact details for resources shall be available at above mentioned institutes.

Detailed procedure is enclosed.

Trans-esterification also called alcoholysis, is the displacement of alcohol from an ester by another alcohol in a process similar to hydrolysis. This process has been widely used to reduce the viscosity of triglycerides. The transesterification reaction is represented by the general equation, which is the key reaction for Bio-Diesel production.
RCOOR’ + R” RCOOR” + R’OH
If methanol is used in the above reaction, it is termed methanolysis. The reaction of triglyceride with methanol is represented by the general equation.

Triglycerides are readily trans-esterified in the presence of alkaline catalyst (Lye) at atmospheric pressure and temperature of approximately 60-70 0C with an excess of methanol. The mixture at the end of reaction is allowed to settle. The excess methanol is recovered by distillation and sent to a rectifying column for purification and recycled. The lower glycerol layer is drawn off while the upper methyl ester layer is washed with water to remove entrained glycerol. Methyl esters of fatty acids are termed as bio-diesel.