Carbon dioxide sequestration in geologic formations with special reference to sequestration in deep coal seams

In an era of rapid economic development, increasing usage of fossil fuel has intensified the emission of greenhouse gases such as carbon dioxide. Reducing the amount of greenhouse gases (GHG) emission into the atmosphere has been a strenuous challenge for the industries and researchers around the world. Storing carbon dioxide in geological formations is an attractive method around the world to meet the demands of reducing carbon dioxide emission. The principal objective of this paper is to discuss three methods of carbon dioxide sequestration: saline aquifers, depleted/active gas/oil reservoirs and unmineable deep coal seams. The above three options are discussed in this paper with special attention to storage in deep unmineable coal seams. The very large capacity of sequestration in saline aquifers around the world increases the value of this option while it has a disadvantage of not being able to produce another commodity to offset the cost of injection when compared to sequestration in depleted or active gas/oil reservoirs and deep unmineable coal seams.