面向烟气NO_(x)净化与回收的新型吸附工艺

A new adsorption process for flue gas NO_(x) purification and recovery

合理高效的吸附工艺是决定吸附法净化和回收烟气中NO_(x)工业可行性的关键工艺环节。提出一种通过外部补充气体实现固定床循环体空间内多次循环解吸NO_(x)的新型吸附工艺(GVTSA)。基于该工艺,采用Na-ZSM-5分子筛作为吸附剂,以某钢厂烧结机脱硫后烟气为原料(组分)进行了NO_(x)吸附回收实验研究。结果表明,GVTSA工艺相较传统吸附工艺(TSA工艺、VSA工艺)可获取更高的NO_(x)回收量,在优选条件下(220℃,-50kPa),NO_(x)回收率达到90%,解吸气中NO_(2)浓度由原料气的36 mg·m^(-3)提升到2%以上,NO_(x)循环吸附量可达0.10mmol·g^(-1),16次吸脱附循环稳定。研究结果可为烟气NO_(x)治理与资源化工业应用提供参考。

Reasonable and efficient adsorption process is the key process link that determines the industrial feasibility of the adsorption method to purify and recover NO_(x)in flue gas.In this paper,a novel adsorption process(GVTSA)with NO_(x)desorption using multiple hot gas circulations(GC)within the enclosed fixed bed through extra gas replenishment was proposed.Based on Na-ZSM-5 zeolites as sorbents,experimental studies on NO_(x)adsorption and recycling from desulfurized iron-ore sintering flue gas of a steel plant were conducted.The results show that the GVTSA obtained a higher NO_(x)recovery compared with traditional adsorption processes(e.g.TSA,VSA),reaching90%under the optimal conditions(220℃,-50 kPa).The concentration of desorbed NO_(2) was more than 2%,significantly enhanced from merely 36 mg·m^(-3) in the feed gas.The NO_(x)cyclic adsorption capacity reached 0.10 mmol·g-1 for up to 16 cycles.This work can provide references for industrial engineering application of flue gas ultra-low emission control and resource utilization.