摘要
采用吸附-放电等离子体分解工艺去除NO_(x),考察吸附剂类型和放电方式以及循环操作对NO_(x)去除性能的影响.所考察的4种分子筛(ZSM-5、MOR、SAPO-34和SSZ-13)中SSZ-13具有较大的NO_(x)吸附容量和较低的吸附强度,有利于延长吸附时间并促进等离子体作用下NO_(x)的脱附和分解.程序升温脱附和红外光谱分析结果表明,NO_(x)主要以物理吸附或较弱化学吸附的形式吸附于SSZ-13表面,少量转化为NO_(3)^(-)和NO_(2)^(-)等强吸附物种.放电方式显著影响等离子体去除SSZ-13表面NO_(x)的性能,与N_(2)吹扫放电和封闭放电相比,采用先封闭放电后N_(2)吹扫放电的方式可同时获得较高的NO_(x)去除率和去除能效以及较低的NO_(x)残留率和N_(2)O选择性.吸附-等离子体分解循环操作时可获得稳定的NO_(x)去除性能,循环使用6次后SSZ-13晶相和孔结构无显著变化.
Effects of adsorbent type,operating conditions of discharge,and cyclic operation on the removal of NO_(x) in adsorption-discharge plasma decomposition process were investigated.Among the four kinds of zeolites(ZSM-5,MOR,SAPO-34 and SSZ-13)investigated,SSZ-13 showed the highest NO_(x) adsorption capacity and lowest adsorption strength,which were beneficial to prolong the adsorption period and promote the desorption and decomposition of NO_(x) by plasma.The results of temperature-programmed desorption and infrared spectroscopy showed that NO_(x) was mainly physically or weakly chemically adsorbed on the surface of SSZ-13,while a small amount of NO_(x) was converted into strongly adsorbed species such as NO_(3)^(−)and NO_(2)^(−).The removal of NO_(x) adsorbed on SSZ-13 by plasma is significantly affected by the operating conditions of discharge.Compared with N_(2)-purge discharge and sealed-discharge,higher NO_(x) removal efficiency and energy efficiency,less residual NO_(x) on the adsorbent,and lower N_(2)O selectivity can be obtained simultaneously by using sealed-discharge first and thenN_(2)-purge discharge.The removal performance of NO_(x) can be maintained during cyclic operation of the adsorption-plasma decomposition process,without significant changes to the crystal and pore structures of SSZ-13 after six cycles.
作者
杜孟威
樊星
陈莉
李佳
宋丽云
李坚
DU Meng-wei;FAN Xing;CHEN Li;LI Jia;SONG Li-yun;LI Jian(Key Laboratory of Beijing on Regional Air Pollution Control,Beijing University of Technology,Beijing 100124,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2022年第6期2541-2551,共11页
China Environmental Science
基金
国家自然科学基金资助项目(21707004)
北京市自然科学基金资助项目(8152011)。
