硫元素对烟气中汞的形态和分布的影响  

Effect of Sulfur on the Speciation of Mercury in Flue Gases

作　　者：王泉海[1] 邱建荣[1] 吴昊[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《燃烧科学与技术》2003年第2期135-138,共4页Journal of Combustion Science and Technology

基　　金：教育部骨干教师资助项目(2202);国家自然科学基金资助项目(50176015).

摘　　要：采用化学热力平衡分析方法研究了在煤燃烧和气化过程中产生的烟气里痕量元素汞的形态及分布.在0.1MPa下,400～2000K温度范围里,研究了汞 煤系统、汞 煤 硫系统和汞 煤 硫 氯系统中汞在还原性气氛和氧化性气氛的烟气中的化学形态和分布,着重探讨了煤中的硫元素对汞在烟气中的形态和分布的影响.化学热力平衡分析结果表明,在煤燃烧和气化的最高温度区域里,单质汞是汞的主要形式;在气化的还原性气氛烟气中,汞的主要形式是单质汞,在氧化性气氛的燃煤烟气中,随着烟气温度的降低,单质汞将发生化学反应而生成二价汞的化合物;硫元素的存在可以促进汞元素以固相硫酸汞(HgSO4)的形式沉积,但烟气中高硫含量会抑制汞元素蒸气的氧化以及氯化汞的形成.By using chemical thermal equilibrium analysis method, the speciation of mercury in flue gases during coal combustion and gasification was studied.The system was HgCoal system,HgCoalS system and HgCoalSC1 system.Under the condition of 0.1 MPa and temperature between 400 K and 2 000 K,we studied the speciation of mercury in reducing atmosphere and oxidizing atmosphere,especially discussed the effect of sulfur on the speciation of Hg.The results show that in the high temperature zone of coal combustion and gasification elemental mercury is thermal stable form of Hg.In the reducing atmosphere flue gases of coal gasification,elemental Hg is main form of Hg; while in the oxidizing atmosphere flue gases of coal combustion,in low temperature zone,elemental Hg will react with other components in the flue gases to from bivalent mercury compound.Sulfur can promote deposit by solid HgSO4.The greater content of S in flue gases will inhibit mercury element from being oxidized and HgC12 formation.

关 键 词：煤燃烧 汞 形态 硫元素 烟气 硫酸汞 

分 类 号：TQ534[化学工程—煤化学工程]