Harnessing of Coal Energy Through Underground Coal Gasification (UCG) in India – Opportunities and Challenges in Processing and Utilisation of Syngas

Abstract India is blessed with large reserves of deep seated coal which cannot exploit economically with the available technology. The gap in demand and supply of energy is on rise for the nation. Underground coal gasification (UCG) is a way of accessing the un-mineable coal for its energy contents and as a chemical feed stock. The coal is converted into syngas insitu and the gas is produced on the surface. Coal mines in Gujarat in association with GIPCL the technology for UCG is being acquired from a Mining Institute of Russia. The site is selected through a process of detailed characterization of lignite seams. Detailed design for the surface layout, already been accomplished. Like surface gasification, the syngas in a UCG trial also needs to be cleaned up to make it usable. The extent of cleaning required depends on end use of the gas. The prevailing emissions and waste disposal regulations at location concerned also determine the equipment & process to be used for cleaning. The design of surface facilities for the Vastan pilot is aimed at maintaining the optimal parameters essential for stabilized gas composition and calorific value (CV). The ultimate goal is designing an environment friendly commercial plant. Major challenges in gas processing for the successful trial include identification of end usage of low CV syngas, separation of sticky condensate from gas, handling of CO2, ultimately turning it into an economical proposition. Opportunities during pilot run are securing technical and economic parameters of syngas processing and determination of economic utilization and most vital being the indigenization of the technology. The paper deals at length with likely difficulties to be handled and benefits to be accrued in the syngas processing in the trial. It covers pilot specific UCG process and facilities required at surface to refine the syngas.