Coal gasification: an environmental viewpoint

In the process of coal gasification a number of substances which cause environmental pollution are produced. They are tars, oils, phenols, sulphur, NOx, particulate matter, ash, and carbon dioxide. Measures to deal with them are pointed out. Coal gas can be used to produce high temperature plasma required for MHD generators and to produce hydrogen for fuel cells. Bharat Heavy Electricals Ltd. has commissioned a coal gasification plant based on a moving bed gasifier coupled to wet gas clean up system and a pressurised fluidized bed gasifier plant designed for Indian coals. Their features are described. (M.G.B.)