Ethanol: Biofuelled debate: Down to Earth, Jan., 2007


The West Asian Crisis, rising prices and global warming are pushing large oil users to rethink energy alternatives and biofuel has become the buzzword. Various options are being tried out to produce ethanol in laboratories as well as in industry.

The US with 5 per cent of global population and 25 per cent of global oil use is in trouble. The Energy Act of 2005 defined gasoline standards to include a component of renewable fuel, giving rise to biofuel demand. 15 billion litres of biofuel was mixed with gasoline in 2006. This is expected to rise to 28.3 billion litres by 2012.

Meanwhile production of ethanol has increased significantly, from 14.7 billion litres in 16 plants in 2005 to 18 billion litres in 2006, in 33 plants. In the next years, production is projected to be 28.3 billion litres.

Ban on methyl tertiary butyl ether has also pushed demand for ethanol, because it is used as octane booster in gasoline

Yet, with such growth, ethanol production represents only 3 per cent energy equivalent of total US gasoline consumpton

95 per cent of ethanol produced in the US is processed from corn, other options being sugarcane, soyabean, and other plants.

The drive for corn ethanol is seen as a plant-based benign activity by green groups and corporates have hailed the effot

Demand for ethanol has created a domino effect in neraby Latin America, as well as in far away Indonesia, while farmers are busy raising crops for ethanol. Though ethanol has been touted as a green fuel, serious uestions are being asked from different standpoints

Corn has been selected as the kernels contain starch and it can be turned into sugar, which can be fermented to be turned into ethanol. But it takes a lot of energy to distil ethanol from corn.

Corn is one of the most energy-inefficient crops. It uses a high amount of chemical nitrogen fertiliser derived from natural gas. Farmers use atrazine, a petroleum-based pesticide. Add diesel for tractor, transport and coal/natural gas for distillation process. All things taken together, production of a litre of corn ethanol needs a three-quarter equivalent of ethanol

A litre of ethanol give 66 per cent energy of a litre of gasoline. It reduces greenhouse gas emissions by only 13 per cent when compared to gasoline

Large-scale corn production cannot be taken as benign activity because it creates soil erosion and contaminates water with pesticide and fertiliser run off. Demand for ethanol has pushed corn price and farmers are taking up corn momoculture replacing corn-soya rotation, causing severe damage to soil. More farmers are spreading to dry areas to cultivate corn

Analysts fear that feedcrop for ethanol will compete with foodgrain production. On the other hand, farmers do not stand to gain much as all financial benefits go to enterprises that blend ethanol with gasoline If all produced in the US were turned into ethanol, it would repalce only 15 per cent of gasoline use. The same can be achieved easily by increasing fuel efficiency by only 1.7 km per litre. The drive for ethanol has clouded the logic of fuel efficiency and reducing car use.