The Chemical Proof for Zero-Emission of Coal Combustion

摘要

Coal combustion causes serious pollution due to emission of SO_2 and NO_x, and the emission of CO_2 also attracts world attention. While removal of SO_2 and NO_x already doubled the power generation cost, capture of CO_2 is equivalent to double the market price of power coal. It is theoretically and experimentally shown that coal-fired power plants can be made emission free. All products of coal combustion including SO_2, NO_x, CO_2 and H_2O react with carbon to form either a gas mixture suitable for chemical synthesis or inoffensive substances and the conversion is theoretically completed at 900°C. A set of proving experiments was carried out using carbon sample and simulated flue gases (SFG) of coal combustion for 750 to 950°C. Complete conversion of CO_2 was observed at 950°C without existence of water in SFG, but the conversion of CO_2 and H_2O dropped to 50-60% of theoretical at presence of water in SFG. However, SO_2 and NO_x were converted to inoffensive substances at above 750°C for all cases. A possible technical route to realize zero emission of coal combustion is proposed based on experiments.