低温工况下SCR催化剂中毒的分析

Analysis of SCR Catalyst Poisoning at Low Temperature

低温工况下SCR脱硝催化剂使用寿命短、易中毒,为实现低温工况下SCR脱硝效果稳定达标,延长低温脱硝催化剂的使用寿命,利用X射线荧光光谱对唐山某焦化厂低温SCR脱硝中的钒钛系列催化剂进行测试,分析了低温含硫工况下SCR脱硝催化剂中毒现象。试验表明:在低温含硫工况下SCR催化剂表面主要的中毒物质为硫酸氢铵,硫酸氢铵质量分数为2.8%(热重法),另外表面还存在少量中毒物质CaO,质量分数约0.769%。结合实际工程经验,提出在脱硝反应器进口烟气管道上加装燃烧器升温装置,定期对催化剂表面的硫酸氢铵进行高温分解,从而对催化剂进行在线再生,延长催化剂使用寿命。

SCR denitration catalyst under low temperature conditions is short service life and easy poisoning,in order to achieve stable and up to standard SCR denitration effect under low temperature conditions and prolong the service life of low temperature denitration catalyst.A series of vanadium and titanium catalysts used in low-temperature SCR denitrification at a coking plant in Tangshan were tested by X-ray fluorescence spectrum.The results showed that the main toxic substance on the surface of SCR catalyst was ammonium bisulfate with a content of 2.8%(thermogravimetric method).In addition,there was a small amount of toxic substance CaO on the surface with a content of about 0.769%.Based on the practical engineering experience,the on-line regeneration of catalyst is suggested to install a burner heating device on the flue gas pipe at the inlet of denitration reactor to decompose ammonium bisulfate on the catalyst surface at high temperature regularly,so as to regenerate the catalyst on line and prolong the service life of the catalyst.