ABSTRACT
20Coal is a primary fossil fuel and it is being used continuously as a main source for the production of electricity. It is a heterogeneous fuel, which contains carbon, hydrogen, sulfur, oxygen, nitrogen, moisture, and ash. Coal on combustion releases several pollutants such as CO2, SO x , NO x , H2S, and fly ash into the environment leading to global warming. Exposure of these gases to the atmosphere directly affects human health by causing lung and heart diseases. Therefore, it is crucial to develop efficient technologies for the production of clean energy from coal. Currently, research and developments are more focused toward clean coal technologies for commercialization. This chapter deals with the recent developments of coal technologies for a sustainable and clean energy recovery from the existing coal resources. It provides an overview of several clean coal technologies such as precombustion-, postcombustion-, and oxy-fuel combustion-based carbon capture and storage; coal beneficiation; NO x and SO x removal technologies; chemical looping combustion technologies; coalbed methane; underground coal gasification; supercritical and ultra-supercritical boiler-based IGCC technologies; and coal to liquid fuels and hydrogen. Integration of a mixture of these clean coal technologies in the existing power-generating systems is necessary to achieve a minimal energy penalty for carbon capture and storage. Therefore, the chapter also briefly discusses the feasibility of potential hybrid systems on clean coal combustion for clean energy recovery.
