Sunday, October 19, 2008

PROSPECTS OF COAL BED METHANE GAS IN JHARKHAND STATE OF INDIA.

PROSPECTS OF COAL BED METHANE GAS IN JHARKHAND STATE OF INDIA.

By
Dr. Nitish Priyadarshi


Coal contains methane gas as an inherent component but in widely variable proportions depending on the rank of coal and depth of occurrence. Its presence in coal has so far been considered a hazard as it is an inflammable and explosive gas and there have been many fire accidents in coal mines throughout the world due to this gas. In recent years, coal bed methane has become a good source of clean thermal energy for its easy inflammability and it has come up as an additional energy resource from the coal basins especially in the countries like USA, Australia and China.

Deep seated coal seams of comparatively high rank contain considerable volume of methane adsorbed on coal surfaces.

Unlike much natural gas from conventional reservoirs, coal bed methane contains very little heavier hydrocarbons such as propane or butane, and no natural gas condensate. It often contains up to a few percent carbon dioxide.
India is struggling to find enough energy sources to meet up the growing energy demand coupled with economic growth. Indian government is now exploring alternative sources too. Indian government has received 54 bids to extract coal-bed methane (CBM) from various domestic and foreign energy companies. This is the highest amount of bids the government has ever received. 18 domestic companies and 8 foreign companies have submitted their bids to extract methane from ten areas. It shows CBM has a good prospect in India.

At present, many foreign companies are setting up their plants in India. In addition, Indian companies are targeting the global market. This rapid industrialization has made India an energy hungry country. As the price of oil continues remain high in the international market, CBM can be a good source of energy for India in future. In fact, India is going to start commercial production of CBM from 2007. Some states of India contains good reserve of coal.

The prospect for coal bed methane is mainly related to the coal resources of the country. India has huge Gondwana (mainly Permian, 99.5%) and Tertiary (Eocene and Oligocene) coal deposits distributed in several basins located in peninsular and extra-peninsular regions. About 204 billion tons of coal reserves have been established and approximately 200 million tons or so are likely to be added in the near future by further explorations.

CBM IN JHARKHAND:

In India prospects of Coal Bed Methane (CBM) is not very bright, as most of the Indian coals are of inferior quality and of low rank. However, some of the coal basins contain high rank coal where sizeable reserves of CBM may be expected. A recent assessment has identified certain areas of Gondwana coalfields where gas -in-place reserves of 564 billion cubic meters have been indicated.

In 1990, efforts to exploit coal bed methane were initiated by Essar Oil (a private oil company) under the advice of American experts. The methane emission and desorption studies on Gondwana coal samples from Jharia Coalfield (Jharkhand) were carried out by Central Mine Planning and Design Institute Limited (Ranchi) and Central Mining Research Institute (Dhanbad). The content of gas and gas emission rate from these samples were found to be 1.8–2.3 m3/1000 m2 of surface and 12.7–17.3 m3/min, respectively. The studies carried out by Bharat Coking Coal Limited in the same area with the help of French experts indicated 0.68–1.45 m3/min gas emission rate.

In Jharkhand State areas identified for CBM are Jharia, East Bokaro, West Bokaro, North Karanpura and Rajmahal Basins.

The estimate reserves in Jharia coalfield is 4.82 trillion cubic feet, in East Bokaro it is 3.2 trillion cubic feet and West Bokaro it is 0.38 trillion cubic feet. Some of the new areas has also been identified like North Karanpura coalfield for the CBM which needs more survey.

Potential of CBM production in Jharia coalfield is 3.5 million cubic metres/day , East Bokaro has the potential of 2.5 million cubic metres /day, North Karanpura has the potential of 6.0 cubic metres /day and the Rajmahal Basin has the potential of 4.5 cubic metres/day.

Thick Tertiary coal of Makum area, Assam, and thick lignite seams of Tamil Nadu and Gujarat may also be positive areas for methane prospects. These factors need to be considered in future.

Reference:

Acharyya, S.K. Coal and Lignite Resources of India,2000, 41-43.
Biswas, S. K., Indian J. Petrol. Geol., 1995, 4, 1–23.
http://www.cmpdi.nic.in/cbm.htm
http://www.iisc.ernet.in/currsci/jun25/articles15.htm

http://envfor.nic.in/cpcb/newsletter/coal/cmetha.html

http://www.indianraj.com/2006/07/coalbed_methane_cbm_indias_fut.html
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