Integrating SO2 and NO x control systems in Indian coal-fired power plants

Abstract

Coal-fired power plants are amongst the largest sources of air pollution in India. These power plants emit a number of gaseous pollutants, including sulphur dioxide (SO2), nitrogen oxides (NOx) and also particulate matter. Recent international as well as national studies show a rapid increase in SO2 and NOx emissions. Both these gases have harmful impact on human health and hence need to be controlled. Typically, these pollutants are controlled using the wet flue gas desulphurization (FGD) units (for SO2) and hot-side selective catalytic reduction (SCR) units (for NOx)—mostly absent in the coal-fired power plants in India. This paper attempts to understand the plant level implications of using Wet FGD and hot-side SCR systems in Indian coal-fired power plants. The impacts on the technical (efficiency, energy penalty), environmental (emissions, fuel use) and economic (cost of electricity) aspects have been estimated through simulation of a power plant with and without the emission controls. Effect of increasing use of high-sulphur imported coal has also been discussed.