低温焦化烟气脱硝催化剂制备与中试验证研究

Production and pilot-scale test of honeycomb DeNO_x catalyst for low temperature flue gas from coking plant

为满足低温脱硝催化剂应用需求,优化脱硝催化剂配方,采用偏钛酸水热法成型工艺,实现了低温蜂窝体脱硝催化剂的中试和连续化工业生产,并完成5 000 m^3/h焦炉烟气脱硝中试性能验证。结果表明,催化剂产品具有较好的低温活性、强度、耐磨性以及成本优势,可分别满足300℃高硫含量(>500×10^(-6))和250℃低硫(<200×10^(-6))的高水(体积分数18%)烟气氮氧化物达标(<250×10^(-6))和超低(<75×10^(-6))排放要求,氨逃逸低于3×10^(-6),催化剂连续运行两周以上未见明显失活。270℃高硫含量(>500×10^(-6))烟气连续运行一周发现催化剂存在缓慢失活现象,表征证明催化剂失活是由硫铵类物质覆盖催化剂表面造成的,失活催化剂可通过高温焙烧再生。

The composition was optimized to obtain effective denitration catalyst for industrial application. The corresponding honeycomb catalyst was successfully produced in the continuous industrial production line by hydrothermal process of metatitanic acid,and the performance of the product was evaluated through 5 000 m3/h pilot-scale test over flue gas from coking plant.The results demonstrate that the catalyst product have good low-temperature activity,strength,abrasion resistance as well as low cost.The catalyst exhibited excellent activity and stability with high SOxcontent（ 〉 500×10-6） at 300 ℃ or with low SOxcontent（ 〈 200×10-6） at 250 ℃ for two-week test in coking plant,respectively.NOx emission concentration can be controlled below 250× 10-6or 75× 10-6with the ammonia escape less than 3×10-6by modulation of ammonia nitrogen ratio.For the flue gas with high SOxcontent（ 〉 500×10-6） at 270 ℃,the catalyst is deactivated slowly during the one-week test,owing to the coverage of catalytic surface by ammonium sulphate species.The deactivated catalyst can be regenerated by high-temperature roasting.