The Hindu Business Line : Bio-diesel — a compelling alternative

Will the excise duty exemption for bio-diesel, given in the latest Budget, kick-start the use of this alternative fuel that has everything going for it?

One of the provisions of Budget 2007-08 extends the benefit of excise duty exemption to bio-diesel. Now, many of us know bio-diesel to be some kind of alternative fuel. But what exactly is it? What is it got out of and how good an alternative is it to the regular fuels? Will vehicles need considerable alterations to run on bio-diesel? These are the questions many will be asking after Mr P. Chidambaram put bio-diesel in the spotlight last month.

What is bio-diesel?

Bio-diesel is a clean burning alternative diesel fuel that is obtained from natural, renewable sources such as vegetable oils and fats. The most common source of bio-diesel is soybean. Soya oil is the base vegetable oil from which all the bio-diesel in the US is processed. On the other hand, in Europe, most of the bio-diesel is processed from rapeseed oil.

In India, a mix of these two and also the oil extracted from the nuts of the Jatropha plant have been used to obtain bio-diesel. Around the world other oils of plant origin, such as canola oil, cottonseed oil, mustard oil and palm oil, have also been tried.

Bio-diesel is a cleaner burning fuel than the regular fossil fuel, not just in India, where the quality of regular diesel is relatively speaking poor, but also in the advanced automobile markets. Bio-diesel, as the name suggests, is also renewable as it is derived from plant sources and is less harmful to the environment.

How is bio-diesel obtained?

Bio-diesel, or alkyl/methyl esters as it is also known, is produced through a chemical process called transesterification, which usually involves the addition of alcohol. The process leads to the separation of glycerine from the oil and the end product is methyl esters or bio-diesel.

Bio-diesel burns better than conventional diesel and is extremely low on sulphur content, one of the biggest problems oil companies producing fossil fuel have to deal with. Since bio-diesel is plant derived, it is also high on oxygen content.

As a result, bio-diesel is less toxic and less polluting than regular diesel. When used in conventional diesel engines the improved quality of emissions with bio-diesel include lower levels of carbon-monoxide, sulphates, particulate matter and unburned hydrocarbons.

Can it substitute regular diesel?

This alternative fuel can be used in all the compression-ignition engines (as diesel engines are called), in which the regular fossil fuel is used. Most modern-day diesel engines can handle a blend of the regular fuel that contains up to 20 per cent of bio-diesel. At that level of blending, engines do not need major modifications or adjustments.

Bio-diesel blends, for example B20 (which is the nomenclature for a 20 per cent blend) and for than matter B100 (which is pure bio-diesel), have pretty much the same performance properties as the regular diesel fuel.

So, there is no reduction in the torque characteristics of the engine and the other performance parameters also remain unaffected.

Even when pure bio-diesel is used, many diesel engines will not require modifications, though car manufacturers are still studying the impact of the use of B100 on engine durability.

Viability

Unlike the other alternative fuel — bio-ethanol from sugarcane — bio-diesel has not picked up that much in terms of production volumes. It continues to be attempted only on a small scale for experimental purposes. The Government has cleared ethanol blending with regular petrol, but it is yet to take off due to a number of reasons, including arriving at a viable price for the fuel manufacturers and the worries about the possibility of adulteration at the blending stage. The government's blending norms already exist for B20.

As for bio-diesel, since production of fuel alone may not render the enterprise profitable and therefore sustainable, processors of this alternative fuel will have to also consider generating revenue from by-products such as glycerine, seed cake, fertiliser, etc.

So far, the only stumbling block for the adoption of bio-diesel, as was the case with the other alternative fuel, was the non-availability of any fiscal incentives for increased production. With increased public awareness, there will be no hesitancy among diesel car owners to fill up B20 at the local pump. Will the Budget sop kick-start the process?

More Stories on : Non-conventional Energy | Cars | Auto Focus | Environment

Article E-Mail :: Comment :: Syndication :: Printer Friendly Page