With reference to two non-conventional energy sources called ‘coalbed methane’ and ‘shale gas’, consider the following ‘statements:
- Coalbed methane is the pure methane gas extracted from coal seams, while shale gas is a mixture of propane and butane only that can be extracted from fine-grained sedimentary rocks.
- In India abundant coalbed methane sources exist, but so far no shale gas sources have been found.
Which of the statements given above is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Explanation
Statement 1 is incorrect
- Coal Bed Methane (CBM) is a natural gas that is extracted from coal seams.
- It is primarily composed of methane (CH4) with smaller amounts of other hydrocarbons such as ethane, propane, and butane, as well as carbon dioxide, nitrogen, and hydrogen sulphide.
- Coalbed methane is now becoming an important source of natural gas.
- Russia has the largest CBM reserves, followed by the USA, China, Canada, and Australia.
- Shale gas consists mainly of methane, with small amounts of ethane, propane, butane, & trace levels of carbon dioxide, nitrogen, and hydrogen sulfide.
- Shales are fine-grained sedimentary rocks formed of organic-rich mud at the bottom of ancient seas.
Statement 2 is incorrect
- In India, the sedimentary basins that hold prospects for shale oil and gas are Cambay Basin, Gondwana Basin, Krishna Godavari (KG) Basin, Cauvery Basin, Indo-Gangetic Basin, and Assam-Arakan Basin.
- ONGC predicts 187.5 TCF of shale gas in five basins (Cambay Onland, Ganga Valley, Assam & Assam-Arakan, KG Onland, & Cauvery Onland). India, with the world’s fifth-largest proven coal reserves, has significant prospects for CBM exploration and exploitation.
