Fuel of the future - Biofuel

As fossil fuels become increasingly scarce and expensive, the search for alternative energy sources is getting intensified. Till quite recently the low cost of petroleum products made most agro-based fuels uneconomic, but not any longer. Since taxes in most countries account for more than half the price the consumer pays, many countries lower the taxes on bio fuels to make them viable.

The world automotive industry is seriously worried because they know that the ever-increasing prices of fossil fuels will adversely impact their future sales. Their business is to sell vehicles, so unlike oil companies, they are quite serious about bio fuels.

Brazil was one of the first to introduce a mix of 25% ethanol, derived from sugarcane, with petrol to make Gasahol that was popularized with slightly lower retail prices over 30 years ago. 100% ethanol is used in Formula 1 cars as it does not catch fire but a 10% mix can be used in any petrol powered car without any modification to the engines or fuel systems.

Ethanol has a higher octane value than petrol but will result in slightly lower power and fuel efficiency. But since the Ministry of Petroleum was not interested in bio fuels and it was not a priority with the Ministry of Agriculture, no one pushed bio fuels in India till very recently. Now a 5% mix is being belatedly used in India but oil companies are reported to be dragging their feet in implementing the new mandate.

For trucks, buses and diesel cars, pure Jatropha oil with a small quantity of additives can be used instead of diesel without any modifications to the engines or fuel systems.

Earlier this biodiesel had been successfully tested on test beds and for many thousand kms on the plains but road tests at high altitudes have demonstrated that emissions and performance as well as power output is excellent when put to an extreme test on steep inclines in the rarified air and low temperatures of high altitudes.

Jetropha oil compares well with diesel. The Cetane number is about 15% better than diesel at around 58 to 60 resulting in smoother and quieter performance. But the calorie output is a little lower and should result in about 3% less power output.

However, as biodiesel contains a little oxygen it faces less oxygen starvation at high altitudes. The flashpoint though is about 160 degrees C as compared to 50 for diesel,making it much safer. On the emission front, bio diesel contains no Sulphur so there is no SOX while NOX continunes to be very low.

Jetropha by itself is a useless plant that came to India (originally it came from Mexico along with PL 480 wheat) from America in the 60’s. Animals and birds shun the berries and the stalks that are mildly poisonous. It cannot be used for food, fibre or fuel and its only use is as a hedge crop.