燃煤烟气中SO_3控制研究进展

Research Progress of SO_3 Control in Coal-fired Flue Gas

本文论述了燃煤电厂烟气中SO_3的主要来源为炉膛中SO_2与原子氧结合、省煤器中SO_2被飞灰中金属催化氧化和SCR催化剂的作用下SO_2与O_2发生反应,整体转化率为2%~3%;深入探讨了燃煤锅炉烟气中SO_3的危害,如空预器堵塞设备腐蚀、烟气酸露点升高、蓝色烟羽等;最后,对比分析了燃煤烟气中SO_3的控制方法,如喷入碱性吸收剂、湿式静电除尘器(WESP)、低低温电除尘、脱硫废水耦合脱除SO_3等技术的脱除效率及优缺点,得出结论,现有技术脱除效果较高但对SO_3的选择性差,脱硫废水耦合脱除SO_3技术同时解决多个环境问题,具有重要的研究价值。

The main sources of SO3 in coal-fired power plant flue gas is discussed in the paper,which include that SO 2 and atomic oxygen bond in the chamber of the furnace,catalytic oxidation of SO 2 by metals in fly ash in economizer,SO 2 and O 2 react in the action of the SCR catalyst.The total conversion rate is about 2%to 3%;The harm of SO 3 in flue gas is analyzed in detail,such as air preheater clogging,corrosion,increasing the acid dew point of the smoke,blue smoke plume,et al;Finally,the control methods of SO 3 in coal-fired flue gas are analyzed comparatively,such as the removal efficiency and the advantages and disadvantages of injecting alkaline absorber,WESP,low temperature electric precipitation,and The combining of desulfurization wastewater evaporation and SO 3 removal.Results show that the existing technologies have a high removal efficiency but lack of selective for SO 3,because it can can solve multiple environmental problems simultaneously,and has important research value in future.