Carbon Sequestration and Utilization—India’s Energy Woes

Abstract

India has approximately 0.5% of world’s Oil and Gas reserves and fifth highest coal reserves in the world. Renewables like solar, hydropower and wind are in plenty but considering the state of the technology and commercial issues, renewables can only make a significant contribution to India’s energy basket in the mid- to long term. Most of our power plants are coal-based and power requirements are growing exponentially. Energy analysts believe that in spite of huge coal reserves, India may overtake China and be the world’s highest importer of coal. It is therefore imperative that we start adopting clean coal technology. Carbon dioxide sequestration is one such technology where carbon dioxide emitted in power plants is captured and reinjected into the subsurface either in depleted oil, gas fields or coal seams or even in plain saline aquifers so that it remains entrapped. Carbon dioxide sequestration is also used as a tertiary recovery process to enhance recovery factor in discovered oil fields, both for light and heavy oil. USA, Canada and Brazil are champions in enhanced oil recovery projects through carbon sequestration with more than hundreds of projects worldwide. Sequestration in saline aquifers is relatively new and besides USA and Canada, South Africa has commenced a pilot project. Algeria is also exploring feasibility of using depleted gas fields for sequestration. Porosity, permeability, volume of reservoir and seal are the critical parameters for success of sequestration in a saline reservoir. China is the first country in Asia to take up sequestration in saline aquifers and is carrying out research and modelling work in a large scale to ensure technical feasibility. Enhanced coal-based methane production through carbon dioxide sequestration is an area of active global research. Coal rocks have higher affinity for carbon dioxide; hence methane is displaced increasing its mobility. Coal-based methane production is however low at present. This paper describes carbon dioxide utilization challenges for enhanced oil recovery, sequestration in saline aquifers and the success in Iceland on storing carbon dioxide within basalts. Reservoir modelling and simulation studies on the specific host reservoir rock have to be carried out before large volumes of carbon dioxide can be reinjected and stored in the subsurface.