Utilization of Ventilation Air Methane in Indian Coal Mines: Prospects and Challenges

摘要

Methane is a by-product of coalification process and its emission in underground mine workings during mining operation poses a safety hazards on miners and machineries deployed in the mine. To ensure safety in underground mines, emitted methane is mixed with ventilation air below prescribed percentage and vented in the atmosphere. Methane content in ventilation air system is generally less than 0.02% but in huge quantity is vented into atmosphere. In year 2010, 0.24Tg of methane from underground coal mines was emitted in the atmosphere. But now-a-days, methane gas is recognized as a clean source of energy and a potent greenhouse gas. India is the third largest coal producer country in the world and about 12% of total coal production comes from underground mines up to a maximum depth of 600m and remaining from surface mines. Utilization of ventilation air methane is an option to reduce methane content in atmosphere and provide opportunities to earn carbon credits. This paper describes methane emission in the atmosphere from coal mining and handling activities, opportunity to utilize ventilation air methane as fuel to generate energy and challenges to be encountered in utilization. An economical benefit on the basis ventilation air methane utilization has also been presented.