Coal gasification operations

Abstract

high ash content and low calorific value. Use of coal gasification has the potential to eliminate the environmental hazards associated with ash, with open pit mining and with greenhouse gas emissions if UCG is combined with re-injection of the CO{sub 2} fraction of the produced gas. With respect to carbon emissions, India's dependence on coal and its projected rapid rise in electricity demand will make it one of the world's largest CO{sub 2} producers in the near future. Underground coal gasification, with separation and reinjection of the CO{sub 2} produced by the process, is one strategy that can decouple rising electricity demand from rising greenhouse gas contributions. UCG is well suited to India's current and emerging energy demands. The syngas produced by UCG can be used to generate electricity through combined cycle. It can also be shifted chemically to produce synthetic natural gas (e.g., Great Plains Gasification Plant in North Dakota). It may also serve as a feedstock for methanol, gasoline, or diesel fuel production and even as a hydrogen supply. Currently, this technology could be deployed in both eastern and western India in highly populated areas, thus reducing overall energy demand. Most importantly, the reduced capital costs and need for better surface facilities provide a platform for rapid acceleration of coal-gas-fired electric power and other high value products. In summary, UCG has several important economic and environmental benefits relevant to India's energy goals: (1) It requires no purchase of surface gasifiers, reducing capital expense substantially. (2) It requires no ash management, since ash remains in the subsurface. (3) It reduces the cost of pollution management and emits few black-carbon particulates. (4) It greatly reduces the cost of CO2 separation for greenhouse gas management, creating the potential for carbon crediting through the Kyoto Clean Development Mechanism. (5) It greatly reduces the need to mine and transport coal, since coal is used in-situ.