SCR脱硝催化剂的发展、应用及其成型工艺综述

介绍了国内外钒钛系SCR脱硝催化剂的应用现状,阐述了低温锰系SCR脱硝催化剂的研究进展与工程探索情况,总结了商用蜂窝状、板式和波纹式SCR催化剂的成型工艺,并针对不同行业特性提出了脱硝催化剂研究方向。     

Effect of Ce-doping on catalysts derived from hydrotalcite-like precursors for COS hydrolysis

In order to investigate the effect of Ce-doping on the catalysts derived from hydrotalcite-like precursors for carbonyl sulfide(COS) hydrolysis,a series of Zn-Ni-Al-Ce hydrotalcite-like compounds were prepared by co-precipitation method and the catalytic activity of their derived composite oxides were studied at 50 oC.The effect on the structural properties caused by Ce doping was studied by the X-ray diffractometer(XRD),scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS).The catalytic activities results showed that addition of Ce enhanced the catalytic activities significantly,but excessive Ce-doping had a negative effect on COS hydrolysis.XRD,SEM and EDS results illustrated that,compared with the Ce-free sample,the particle size of oxide solids decreased and the degree of dispersion increased due to Ce doping.     

浸渍次序对低温脱除Hg~0和CO性能的影响

采用单次浸渍、两次浸渍、多次浸渍制备了系列Cu-Co/AC_N催化剂,并考察其同时脱除Hg~0和CO的催化活性。结果表明,催化剂脱Hg~0效率和脱CO效率依次为:两次浸渍>多次浸渍>单次浸渍。综合考量两种污染物的脱除效率,将200℃作为Cu-Co/AC_N催化剂同时脱Hg~0,脱CO的最佳反应温度。氧气对于两种污染物的脱除是至关重要的,16%的氧含量为同时脱Hg~0和脱CO的最佳条件。     

被动NOx吸附剂在柴油车冷启动排放控制中的研究进展

机动车尾气是氮氧化物（NO_x）重要来源之一,常见柴油车尾气NO_x处理技术对冷启动阶段NO_x减排效果较差,被动NO_x吸附剂（PNA）应运而生。PNA可低温吸附存储NO_x、高温脱附释放NO_x,释放的NO_x经过下游NO_x处理单元[选择性催化还原（SCR）或NO_x储存还原（NSR）]被彻底净化。本文综述了近年来PNA材料在低温冷启动过程中净化NO_x的研究进展,对不同类型PNA材料进行结构及性能比对,其中Pd/分子筛表现出良好的低温NO_x吸附-脱附性能、抗硫性以及水热稳定性,成为PNA优选。深入讨论了Pd/分子筛存储NO_x机制以及影响因素。此外,分析了PNA在低温吸附-脱附NO_x中面临的问题并展望其前景,指出提高具有优异抗水性能的NO_x吸附位点数量及Pd物种分散程度是开发高性能PNA的重要前提。     

铁合金煤气处理技术进展

铁合金是钢铁行业的重要组成部分,近几年在钢铁行业的带动下,铁合金产业也获得了一定的发展。生产铁合金会产生大量煤气,其主要成分包括烟尘、CO和CH₄等温室气体,不仅破坏生态环境,同时威胁人类健康。铁合金煤气存在高温、气量大、烟尘浓度高和粒径小等特性。因此,其煤气净化比较困难、复杂。随着国家对环保问题的日益重视,铁合金煤气的回收与净化成为铁合金行业发展的重点与难点。介绍了铁合金煤气净化技术的发展历程,铁合金煤气湿法净化及干法净化的几种典型工艺,以及净化技术的发展趋势。     

Carbon disulfide hydrolysis over Fe-Cu/AC catalyst modified by cerium and lanthanum at low temperature

A series of coal-based active carbon(AC) catalysts loaded by Fe-Cu,Fe-Cu-Ce and Fe-Cu-La were prepared by the sol-gel method for carbon disulfide(CS2) hydrolysis and their performances for CS2 hydrolysis in a fixed-bed reactor were investigated in this work.The results showed that the kind of rare earth oxide and its content had obvious effect on hydrolysis removal of CS2.The effects of temperature,space velocity,CS2 concentration and O2 concentration were also discussed respectively.Furthermore,the suitable operating conditions were obtained.It was found that the poisoning of hydrolysis active sites could result in the formation of sulfuric acid on the catalyst surface.     

低温催化水解二硫化碳技术的研究进展

对低温下二硫化碳的催化水解技术进行了总结,包括水解催化剂的研究与开发、催化水解的反应机理和反应动力学、催化剂失活机理3方面.指出通过提高催化剂的碱性来制备高活性的水解催化剂,在低温条件下一步脱除二硫化碳是未来这一领域的研究热点.     

新型核壳材料的性能及其在环境相关领域的研究进展

随着新型环境材料领域研究的不断深入和发展,纳米核壳材料因其独特的结构及其在诸多性能上的独特优越性,受到广大环境相关领域研究者的关注。详细归纳和总结了纳米核壳材料优良的光学性能、催化性能、电化学性能、吸附性能及其作用机理,并阐述了相关性能在解决日益加剧的环境污染问题及能源危机问题等相关领域的研究和应用,同时对纳米核壳材料未来的研究重点进行了展望。进一步加强对纳米核壳材料作用机理的研究,优化材料的制备方法,以及利用合理的办法尽快使其投入到工业化运行,可使核壳材料获得更好的研究价值和利用价值。