Beneficiation of Coal with Biochemical Method and Effect of Treated Coal on Boiler Efficiency in Power Generatation

Abstract

In India it has become a major challenging task in majority of thermal power stations to maintain heat rate as per design norms due to problems associated with coal quality and constraints in operation and maintenance practices. Heat rate refers to the amount of heat required to generate one unit of power which mainly depends upon coal quality. Boiler efficiency and heat rate are mainly influenced by key quality parameters of the coal that is ash, moisture, volatile matter, net calorific value of coal, ratio of fixed carbon to volatile matter and grindability of coal. In this research study an effort is being made to improve coal quality by using bio-extracts derived from leaves of citrus limon in combination with lower concentrations of Ethylene Diamine Tetra Acetic Acid (EDTA) and compare boiler efficiency/heat rate with raw and beneficiated coals. Phyto extract derived from citrus limon is effective in demineralizing Aluminium and Pyrite minerals in coal and EDTA is successful for removal of Calcium and Magnesium mineral components of coal and hence calorific value of coal is increased. Results suggesting that usage beneficiated coals improving the boiler efficiency and reducing the heat rate of the thermal unit there by crores of rupee can be saved.