低温SCR在锂盐窑炉的应用问题研究

Research on the Application of Low Temperature SCR in Lithium Salt Kilns

在国家对工矿企业废气排放的严格要求下,窑炉排放的烟气中氮氧化物(NO_(x))须达到超低排放的要求(NO_(x)浓度≤30 mg/Nm^(3)),而目前大部分排烟温度低的窑炉均使用低温SCR脱硝工艺对NO_(x)进行处理,但现阶段低温SCR脱硝技术存在易堵塞、易腐蚀、催化剂易失活等问题。本研究针对某低温SCR脱硝工艺,通过调控催化剂有效组分配比,调整催化剂最佳空速,优化安装调试步骤和增加关键位置高温防腐能力等措施,使存在水、氟化物、氯化物、二氧化硫等烟气,最终满足超低排放的要求,有效避免了催化剂失活、反应器腐蚀、氨逃逸超标、床层阻力大等问题。在NO_(x)的超低排放要求下,应根据实际的烟气条件针对性制定SCR脱硝工艺方案,避免投用后不达标而重新设计建设的巨大损失。

In adherence to stringent state regulations on the emission of mining enterprises,the nitrogen oxides(NO_(x))from the stack of kiln must comply with ultra-low emission standards(NO_(x)≤30 mg/Nm^(3)).Presently,most kilns with low smoke exhaust temperatures employ the low-temperature SCR denitrification process to address NO_(x),however,this technology is susceptible to issues such as blockage,corrosion,and catalyst deactivation.In response to the challenges posed by an low-temperature SCR denitrification process,this study implemented measures including adjusting the effective component ratio of the catalyst,optimizing the optimal space velocity of the catalyst,refining installation and debugging procedures,and enhancing the high-temperature anti-corrosion capacity of critical locations.These efforts ensured that the flue gas,containing water,fluoride,chloride,and sulfur dioxide,ultimately met ultra-low emission requirements.Notably,issues like catalyst inactivation,reactor corrosion,ammonia escape exceeding standards,and high bed resistance were effectively circumvented.When designing the SCR denitrification process to achieve NO_(x) ultra-low emission targets,it is imperative to tailor the plan to the specific flue gas conditions to avert the substantial losses associated with redesign and construction after substandard operation.