Market-Based Environment Friendly Solution to Low-Rank Coal of Thar Desert

Abstract

A Single Thar Coal Reserve of Sindh is about 850 trillion cubic feet, which is more than oil reserves of Saudi Arabia & Iran, about 30 times higher than Pakistan's proven gas reserves of 28 TCF. Meeting the energy needs of today requires exploitation of these coal reserves, but the high operating costs and high percentage of sulfur contents makes this approach economically and environmentally unfeasible. Coalbed methane (CBM) or coalbed gas is a form of natural gas extracted from coal beds. In recent decades coalbed methane has become an important source of energy in various parts of the world. Coalbed methane is considered as an unconventional resource in which methane gas is stored in micropores and bedding planes, as well as free gas within natural fractures or cleats in the coal reserves. Improved recovery of methane from coal beds can be achieved by the injection of a second gas, typically nitrogen or carbon dioxide. Producing coalbed methane through injection of CO₂ is more efficient than current techniques requiring production. Molecules of CO₂ preferentially sorb on to the surface adsorption sites, displacing methane. CO₂ sequestration used to enhance recovery of coalbed methane. The other big advantage of this technique is that it will greatly reduce the CO₂ concentration in the atmosphere thereby providing the basis for a market-based environment friendly solution to the present world which has been greatly affected by global warming. CBM production is accompanied by an enormous amount of water and the use of such water after treatment is the most favorable option from environmental viewpoint. This paper will include the description of CBM production using carbon dioxide sequestration, and its potential for sandy Thar coal fields of Sindh province in Pakistan. It will also cover the environmental issues and challenges in coal bed methane production.