含NH_3废气选择性催化氧化法研究进展

氨选择性催化氧化法(NH3-SCO)在含NH3废气污染控制技术研究方面具有良好的应用前景。介绍了现有的两种NH3-SCO反应机理,综合评述了NH3-SCO技术的主要影响因素载体、活性组分和助剂的研究近况,并对NH3-SCO技术研究领域的未来研究方向进行了展望。     

磷化氢在改性13X分子筛上的吸附行为

为回收工业废气中的磷化氢(PH3)并资源化,采用浸渍法制备了一种CaCl2改性13X分子筛吸附剂,通过容积法研究了25—70℃PH3气体在改性13X分子筛上的等温吸附行为。结果表明,在实验条件范围内25,40,55,70℃下PH3的饱和吸附量(质量分数)分别为2.528,1.901,1.591,0.925mg/g。Freundlich吸附等温方程很好地模拟了改性13X分子筛对PH3的等温吸附,Langmuir和Henry吸附等温方程对吸附平衡数据的拟合效果不佳表明了改性13X分子筛表面吸附位的不均匀分布。当初始吸附量为0.10mg/g时,等量吸附热值最大,为17.81353kJ/mol,即等量吸附热不超过18kJ/mol,过程为物理吸附,便于PH3气体的解吸。     

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。     

金属氧化物催化CO还原NO的研究进展

一氧化碳（CO）广泛存在于烧结/球团/焦化烟气或汽车尾气中,应用CO-选择性催化还原（SCR）技术同时脱除烟气中CO和NO是烟气治理的理想方案之一。目前,在NO-CO反应研究中较多的是贵金属催化剂,但由于其价格昂贵、高温失活、易中毒等问题难以在工业中实现应用。本文将近几年来金属氧化物催化CO还原NO的研究成果进行了系统的梳理与总结,重点介绍Fe基、Ce基、Co基、Cu基这4种金属氧化物催化剂的研究进展,分析催化剂的制备方法、掺杂助剂种类和比例、NO-CO反应条件等因素与催化活性之间的关系,总结催化剂抗水抗硫性能及可能的CO-SCR反应机理,并探讨O₂存在的条件下对催化剂活性的影响,为提高金属氧化物催化剂抗氧性研究提供理论参考。     

Ir基催化剂用于CO选择性催化还原NO的研究进展

针对具有烟温低、氧含量高和CO浓度大等特征的固定源烟气（钢铁烧结/球团烟气和焦化烟气等）脱硝领域,CO选择性催化还原NO _x （CO-SCR）技术具有良好的发展前景。Ir基贵金属催化剂因其在CO-SCR反应体系中表现出了良好的抗氧能力和较高的催化活性成为催化脱硝领域研究的热点之一。本文重点总结了单一载体、复合载体与复合活性组分三类Ir基催化剂在CO-SCR脱除NO _x 中的催化性能,同时从制备条件和反应条件两大方面归纳了其对Ir基催化剂的CO-SCR脱硝性能的影响,简要阐述了Ir基催化剂表面反应机理,并对未来研究工作进行了展望,指出采用多种手段对催化剂进行改性,并通过降低Ir负载量、反应温度窗口以及提升其催化活性等方式来降低成本,为实现Ir基催化剂CO-SCR工业化应用提供借鉴。     

变压吸附工艺的研究与进展

论述了国外变压吸附在气体分离研究及技术的最新进展 ,对其工艺流程设计存在的问题进行了阐述 ,并分析了变压吸附工艺的应用及发展方向。     

Effect of rare earth addition on Cu-Fe/AC adsorbents for phosphine adsorption from yellow phosphorous tail gas

Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous chemical industry tail gas,the concentration of which is always more than 80 vol.%,and it can be the feed gas to produce various valuable products such as formate,oxalate,and methanol and so on.But,PH3 is one of the important barriers,which is harmful to the following chemical process.In order to make use of the tail gas,PH3 should be removed firstly,and CO should be covered in the whole purified procedure at the same time.In this work,the modified activated carbon(MAC) was used as the adsorbent to separate PH3 from the mixture tail gas.Series of MAC adsorbents were prepared for the adsorption of PH3,which loaded Cu-Fe and Ce(La),or separately.The PH3 adsorption capacities,chemical and physical properties of MAC were all investigated.The results showed that over 99% PH3 adsorption efficiency was achieved when used MAC adsorbents.The removal efficiency and PH3 adsorption capacity of the Cu-Fe-Ce/AC(20:1:0.4) were both much higher than those modified activated carbons.The maximum PH3 adsorption capacity was 71 mg of PH3/g of MAC on the Cu-Fe-Ce/AC,which were much higher than literature data using CuO only for adsorbing hydride gases.     

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.     

农村沼气的净化及资源化利用研究进展

沼气的净化提纯技术是沼气资源化利用中非常重要的一个环节.介绍了农村沼气的组成,并总结了现有的沼气净化提纯的主要方法及其特点.目前沼气的净化提纯技术主要是脱硫、脱碳、脱水及脱除其它不助燃的杂质.其中,脱硫技术主要有干法、湿法及生物法脱硫等;脱碳主要有液体吸收法、固体吸附法和膜分离法等;脱除水分主要有冷凝法、溶剂吸收和固体...     

柔性负载型催化剂催化净化气态污染物研究进展

当前灰霾等大气污染问题备受关注，高效、廉价的催化净化材料作为污染治理技术的核心之一，其研发意义非凡。以柔性材料为基底制备的新型整体式催化剂因催化活性高、加工成型简单、应用灵活、易于实现催化剂原位再生等优点，成为环境催化领域发展的一个新兴热点方向。本文介绍了以金属泡沫、有机泡沫以及纤维等柔性材料为载体的催化剂特性和应用领域，重点阐述了上述柔性负载型催化剂的典型合成过程及其对气态污染物（如NO_x、甲苯、甲醛等）的催化性能和净化机制，综述了其在脱硝领域的应用研究成果，包括抗硫耐水机理、纤维滤布催化剂的协同除尘脱硝能力以及碳泡沫催化剂的高效催化性能等。通过总结分析柔性负载型催化剂阶段性研究成果、应用现状以及实际应用问题，进一步展望其在环境催化净化领域的研究方向、重点和难点。催化剂黏结性、活性、稳定性的提升以及移动床反应器-催化剂的匹配设计与优化都将是柔性高效一体式催化剂的研发重心所在，此类催化剂的成功研发将会为中小型燃煤炉窖尾气的催化净化提供技术核心与保障。