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王涛李伯东程彦虎王学明彭召静焦桂萍 《工业催化》2020,(7):1-6
通过对当前含氮化合物废气治理技术的对比分析,总结选择性催化氧化的相关技术优势。根据对含氮化合物的种类及来源分析,介绍氨气、腈类、胺类及其他含氮化合物的催化净化技术。重点总结催化剂的种类、研发进展和在实际使用中可能遇到的问题,同时展望含氮化合物废气选择性催化氧化技术的研发方向。 相似文献
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制药行业在我国快速发展,带来经济增长与生活便利的同时也带来了大量挥发性有机污染物(VOCs)的排放。针对制药行业废气排放量大、排放节点多、污染物种类复杂等特点,催化燃烧因经济环保、应用灵活,成为处理制药VOCs的合适选择。本文总结了制药行业排放的典型VOCs及常见医用药品生产过程中的特征污染物,并着重从催化燃烧催化材料研发及应用的角度,总结了近年来制药行业典型VOCs催化燃烧技术的研究现状,同时对我国制药行业有机废气治理作了展望,即需进一步加深制药行业VOCs排放特征、VOCs实验室治理等基础研究来保证实际治理过程中的经济有效性;同时在原有催化氧化催化剂研究的基础上,研发多技术耦合工艺,实现制药行业废气的达标排放。 相似文献
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受绿色生态和可持续发展战略理念的驱动,废气排放对环境造成的危害备受关注。NO x 作为废气的主要污染物之一,是废气污染物控制的重点与难点。基于此,本文介绍了传统后处理脱硝技术的优缺点及应用现状,回顾了介质阻挡放电(DBD)基础研究,分析了DBD脱硝性能,重点阐述了DBD协同催化剂脱硝及脱硝机理。分析指出:①DBD驱动电源与反应器结构是制约脱硝性能的关键因素;②单独DBD技术脱硝性能较差,而DBD协同催化填充床技术展现出优异的脱硝性能和较高的N2选择性;③等离子体协同催化脱硝机理研究主要包括等离子体特征参数诊断、流体模型验证、等离子体传播机制分析以及原位表征,而在等离子体催化理论计算方面的研究较为缺乏。因此,未来DBD协同催化脱硝技术应立足如下几个方面发展:研发高功率、低能耗电源,提升废气NO x 处理量;优化反应器结构,提升脱硝的效率与选择性;设计与构筑适宜于DBD环境的脱硝催化剂;深入全面分析DBD协同催化剂脱硝机理。 相似文献
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介绍了NO_x废气的处理技术及选择性催化还原法处理的特点;详细分析了该处理方法应用于治理NO_x废气的情况及其效果。 相似文献
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Copper-manganese spinel is a low-cost VOCs catalytic combustion catalyst with good performance. Oxygen vacancy has excellent properties for oxygen activation and VOCs dehydrogenation activation, which is beneficial for the catalytic combustion of VOCs. In this study, a large number of oxygen vacancies were introduced on the copper-manganese spinel surface by selective dissolution method (acid treatment and alkali treatment) for catalytic combustion of toluene. Furthermore, the effects of acid treatment and alkali treatment on the catalytic performance, oxygen vacancy amount, physical and chemical properties, and toluene catalytic combustion mechanism of copper-manganese spinel were studied. Both acid treatment and alkali treatment can produce large quantities of oxygen vacancies on the copper-manganese spinel surface. The generation of surface oxygen vacancies can greatly improve the catalytic combustion activity of copper-manganese spinel. At 240 °C, the combustion rate of toluene increased by 8.8 times for the acid-treated catalyst and 11.2 times for the alkali-treated catalyst. The numerous surface oxygen vacancies, Mn3+/Mn4+ at the ratio of 1.11 and appropriate acidity result in the alkali-treated catalyst exhibiting excellent catalytic activity and stability for toluene combustion. This strategy provides a new method to further improve catalytic combustion activity of copper-manganese spinel and a reference for the development of the surface oxygen vacancy engineering of transition metal oxides. 相似文献
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Template synthesis of various nitrogen containing carbon nanotubes using different nitrogen containing polymers and the variation of nitrogen content in carbon nanotube (CNT) on the behaviour of supported Pt electrodes in the anodic oxidation of methanol in direct methanol fuel cells was investigated. Characterizations of the as-prepared catalysts are investigated by electron microscopy and electrochemical analysis. The catalyst with N-containing CNT as a support exhibits a higher catalytic activity than that carbon supported platinum electrode and CNT supported electrodes. The N-containing CNT supported electrodes with 10.5% nitrogen content show a higher catalytic activity compared to other N-CNT supported electrodes. This could be due to the existence of additional active sites on the surface of the N-containing CNT supported electrodes, which favours better dispersion of Pt particles. Also, the strong metal-support interaction plays a major role in enhancing the catalytic activity for methanol oxidation. 相似文献
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就目前国内各环保公司引进的几种国外烟气氮氧化物控制技术:低氮燃烧技术、选择性催化还原技术(SCR)、选择性非催化还原技术(SNCR)分别介绍其控制原理、工艺流程及系统组成,为有关专业技术人员选择烟气脱硝方案提供依据。 相似文献
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Xiao-Ning Guo Ru-Jing Shang Dong-Hua Wang Guo-Qiang Jin Xiang-Yun Guo KN Tu 《Nanoscale research letters》2010,5(2):332-337
Nanoditches from selective etching of periodically twinned SiC nanowires were employed to hinder the migration and coalescence
of Pd nanoparticles supported on the nanowires, and thus to improve their catalytic stability for total combustion of methane.
The results show that the etched Pd/SiC catalyst can keep the methane conversion of almost 100% while the unetched one has
an obvious decline in the catalytic activity from 100 to 82% after ten repeated reaction cycles. The excellent catalytic stability
originates from the limitation of the nanoditches to the migration and growth of Pd nanoparticles. 相似文献
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甲烷催化燃烧是一种清洁高效的甲烷燃烧技术,在节能减排中具有重要的应用价值。从催化剂、反应工艺和过程强化等方面对近年来甲烷催化燃烧技术进行综述,重点介绍颗粒催化剂固定床反应工艺、整体式催化剂反应工艺、流化床反应工艺和吸放热耦合反应工艺研究进展。用于固定床反应器的颗粒催化剂主要为负载型贵金属催化剂和非贵金属氧化物催化剂。贵金属催化剂活性好,起燃温度低,适合低浓度甲烷的催化燃烧。非贵金属氧化物催化剂耐高温性好,适合较高浓度甲烷燃烧体系。整体式催化剂的甲烷催化燃烧反应工艺中,最常用的是蜂窝陶瓷和金属合金等整体式催化剂的多段式催化燃烧反应器的设计。设计直接采用多段式整体催化剂,催化剂的位置不同,发挥的催化作用也不同。流化床催化燃烧装置具有燃烧过程接触面积广、热容量大和换热效率高等特点,可有效避免传统的固定床催化燃烧反应工艺存在的问题,非常适合应用于低浓度甲烷的催化燃烧过程。利用甲烷催化燃烧强放热的特点,将催化燃烧产生的热量进行时间或空间的耦合,可以开发出吸-放热耦合反应工艺。其中,固定床催化反应器中的流向变换强制周期操作作为一种高效的过程强化技术,在节约反应器成本的同时,可以提高反应热量的利用率。 相似文献
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相比于传统动力系统,基于燃料电池的动力系统具有很多优点,但在实际运用中仍有许多亟需解决的问题,其中包括燃料电池系统的低温启动问题。本文对比了各种燃料电池低温启动方案的工作机理及其优缺点,归纳并分析了氢气催化燃烧所用催化剂和催化燃烧反应过程以及燃料电池低温启动过程等方面的相关研究成果,研究了影响催化燃烧的主要因素,得出以下结论:基于氢气低温催化燃烧的燃料电池低温启动策略具有较高的可行性;在不同反应模型的情况下,氢气都可以在微尺度管道内实现稳定的燃烧;表面催化反应对空间气相反应有抑制作用;空间气相与表面催化的耦合反应能得到最高的温度;氢气/空气预混合气体入口流速、导热壁及导热壁材料、管径和当量比均对催化燃烧有着重要的影响。 相似文献
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Jamal Chaouki Danilo Klvana Christophe Guy 《Korean Journal of Chemical Engineering》1999,16(4):494-500
Turbulent Fluidized Bed (TFB) reactors appears to be ideal for exothermic and fast reactions such as catalytic oxidation of
methane. In this paper, a use of TFB reactor for two catalytic oxidation of methane: catalytic combustion of methane and catalytic
selective oxidation of methane for the ethylene synthesis is described. Catalytic fluidized bed combustion of methane is shown
to be an emerging technology capable of meeting all environmental constraints as far as nitrogen oxides and carbon monoxide
are concerned. This reaction carried out in both the bubbling and the turbulent regimes at 450-500 ‡C shows that the turbulent
regime is more favourable. A self-sustained combustion with complete conversion and a zero emission of NOx and CO was achieved with a mixture of 4% methane in air at 500 ‡C. The two-phase model of Werther [1990], which phenomenologically
introduces the enhancement factor due to chemical reaction, predicts quite well the combustor performance. The same model
but without enhancement factor (slower reactions) predicts satisfactorily the experimental data for the oxidative coupling
of methane and can be used to quantify the influence of homogeneous and catalytic reactions. 相似文献
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微尺度燃烧存在热量损失大、易熄火、燃烧不完全、转化效率不高等问题,因此对微型燃烧器内甲烷的燃烧采取预混催化燃烧方式来提高燃烧的稳定性和转化效率,为微型发动机碳氢燃料燃烧技术奠定基础。采用连续介质层流有限速率模型和二阶离散方法对微型燃烧器微流道内的催化燃烧、流动和传热进行了三维数值模拟。结果表明,甲烷质量流量和过量空气系数对催化转化效率有一定影响,壁面温度是影响催化转化效率的主要因素。甲烷质量流量、壁面温度与最佳过量空气系数之间具有一定的变化关系。可根据催化温度选择富燃料或富氧燃烧方式来提高微尺度催化转化效率。恒壁温边界条件下,催化燃烧主要发生在燃烧腔的下壁面。 相似文献