Wednesday, July 16, 2008
A Green Gas
Methane extracted from coalfields to be used as clean fuel for vehicles
A proposal to supply coalbed methane to Kolkata to replace the city’s diesel-dependence is being welcomed in all quarters, since it would reduce pollution levels in the area. Methane will be extracted from coalfields in Jharia, Jharkhand, by using converters imported from France. The gas will be transported by road to Kolkata in steel containers until such time as new pipelines are laid and distribution networks worked out. Initially, methane will be used to power autos, taxis and buses that currently run on diesel, often adulterated. Eventually, the plan is to extend gas supply for household cooking purposes as well.
ONGC-The Oil and Natural Gas Corporation has signed an agreement with a private company for distribution to commence in January 2009. Coalbed methane as a source of clean natural gas has immense potential for India, especially since there are rich sources in the Jharkhand and West Bengal regions. Methane gas is found trapped in fissures in coal and extraction reduces explosion hazards in mines, thereby reducing safety risks for miners. When burnt as fuel, methane has zero emission, whereas when released into the atmosphere its global warming potential is 21 times that of carbon dioxide over a span of 100 years. There are, however, several factors that have hampered the realisation of this clean fuel potential in India. Though the country is rich in reserves of bituminous coal containing methane, the reserves are at depths of up to 1,200 metres and need appropriate drilling equipment apart from know-how for extraction. In the process of coalbed methane extraction, water from the coalbed is first pumped out and since the water is usually rich in sodium, its salinity makes it unfit for irrigation or drinking purposes. So, waste-water disposal from coalbed methane deposits is something that needs looking into in order not to adversely affect the local water table or stunt plant growth. Unless it is diluted sufficiently with normal water, saline content will be far too high. This, and the fact that converters to extract methane from coalbeds are not available locally, makes it imperative for India to have ties with other countries for technology and know-how transfer. China is on the job, showering tax breaks and subsidies on coalbed methane extraction companies and having an agreement with the US for technology inputs. India should speed up its coalbed methane projects in order to generate clean fuel in areas easily accessible from coal-bearing zones.