甲烷高温燃烧催化剂研究进展

催化燃烧具有环保、高效、节能等诸多优点.综述了甲烷高温催化燃烧的研究现状,对甲烷燃烧催化剂材料的研究进展做了较详细的介绍,并阐述了甲烷高温催化燃烧反应器的研究进展.     

甲烷高温催化燃烧研究进展

甲烷催化燃烧具有环保、高效、节能等诸多优点,引起人们广泛的关注。综述了甲烷高温催化燃烧的研究现状,对甲烷燃烧催化剂材料的研究进展作了介绍,阐述了甲烷高温催化燃烧反应器的概况。     

Simulation of Catalytic Combustion of Methane in a Monolith Honeycomb Reactor

1 INTRODUCTION Monolith honeycomb reactor plays an important role in catalytic combustion[1] such as combustion chambers for gas turbines used in power generation where methane is the main reactant. It contains hun-dreds of parallel channels that are often of the order of 1—2mm in diameter. The catalyst may be dispersed within a washcoat that is coated onto the surface of the channels[2] where catalytic combustion occurs. Com-pared to conventional gas-phase combustion, catalytic combusti…     

不同金属取代LaMAl11O19-δ催化剂的制备及甲烷催化燃烧的性能

采用溶胶-凝胶法制备了系列的LaMAl11019(M=Fe,Co,Ni,Mn,Cu)催化剂,并且用XRD、BET、TEM等技术对其进行表征.进一步研究了M对六铝酸盐催化剂的形成.比表面积、燃烧活性的影响.结果表明M促进了六铝酸盐催化剂的形成,其中Mn取代的六铝酸盐催化剂的热稳定性高,而且具有更高的甲烷催化活性.     

超细In2O3-SnO2复合催化剂的制备及其催化性能的研究

以InCl3·4H2O及SnCl4·5H2O为原料,用共沉淀法制备超细In2O3SnO2复合催化剂,用XRD、TEM、TPD等对所制备的样品催化剂进行表征.XRD、TEM测定结果表明,所制备的样品粒径20～30 nm,分布窄,用TPD测定了样品对O2及CH4的脱附情况.CH4的催化燃烧试验表明,所制备的In2O3-SnO2复合催化剂具有良好的催化反应活性.     

Catalytic combustion of methane over barium hexaferrites

Barium hexaferrite BaFe₁₂O₁₉ and iridium-containing barium hexaferrites have been prepared by the citrates gel method. Their catalytic activity in methane combustion has been evaluated. BaFe₁₂O₁₉ is an efficient catalyst for this reaction, and the introduction of iridium in the hexaferrite structure does not improve this activity. Mössbauer spectroscopy suggests that a part of the iridium ions are incorporated in the hexaferrite structure, however in crystallographic sites where they cannot interact with the gas phase. Infrared study of CO adsorption reveals the presence of two types of iridium particles in the surface: small Ir particles, in strong interaction with the hexaferrite structure, and some larger Ir particles which were not incorporated into the lattice.     

CrO_x/ZrO_2催化剂上甲烷催化燃烧性能

采用沉淀法制备了CrO_x/ZrO_2催化剂,考察800℃高温焙烧的CrO_x/ZrO_2催化剂对CH_4燃烧的催化性能。采用X射线衍射和拉曼光谱等技术对催化剂进行物相结构表征。结果表明,Cr物种以Cr_2O_3形式存在,随着焙烧温度升高,催化剂中ZrO_2和Cr_2O_3的晶粒明显增大。CrO_x/ZrO_2催化剂的比表面积大于相应的纯Cr_2O_3和ZrO_2。催化剂的CH_4燃烧活性随着Cr含量的增加而提高,Cr质量分数20%时活性最高,CH_4完全燃烧温度为450℃。     

甲烷催化燃烧催化剂催化理论与应用研究进展

概述了甲烷催化燃烧催化剂的研究现状,从组成甲烷燃烧催化剂的3个部分（基体、活性组分、氧化物载体）分别加以论述。通过掺杂一些金属和金属氧化物,不但可以提高高活性贵金属催化剂的热分解温度,还可以提高高温催化剂（如钙钛矿和六铝酸盐材料等）的催化活性。最后简要综述了甲烷催化燃烧反应机理。     

玄武岩催化甲烷裂解制 C2 烃

以天然玄武岩为甲烷裂解催化剂,通过XRF、XRD、SEM及XPS对催化剂组成、结构、表面活性物种进行了研究。利用固定床反应装置考察了不同反应温度、空速条件下玄武岩催化甲烷裂解制C_2烃的效果。结果表明,在气体空速为4 L·h-1条件下,当反应温度为1 225 K时,甲烷的转化率为7.66%,C_2烃的选择性为33.64%;当反应温度升至1 325 K时,甲烷的转化率可达17.13%,同时C_2烃的选择性为27.21%。相同温度下,气体空速越大,乙烷的选择性越高,乙炔的选择性越低。催化剂活性因表面积炭的产生而降低,积炭类型为芳烃积炭。     

Cd改性拉长石催化甲烷裂解制C2烃

以Cd改性拉长石(Cd/Lab)为甲烷裂解催化剂制C2烃,通过XRD、XPS、TEM及GC对催化剂的结构、形貌和催化性能进行了表征与测试。利用固定床反应装置考察了金属掺杂量、反应温度、原料气空速等因素对拉长石催化甲烷裂解制C_2烃的影响。结果表明,当原料气空速为1 L/h、反应温度1073 K时,天然拉长石和Cd质量分数为1.0%的Cd改性拉长石催化甲烷裂解的转化率分别为3.32%和6.41%,且C_2烃的选择性99%。XRD、XPS、TEM等表征和催化性能结果表明,Cd2+进入到拉长石的碱金属位点,证明拉长石催化甲烷裂解的有效活性位点是碱金属位点。     

The Activation of a Pd/γ-alumina Catalyst During Methane Combustion: Investigation of the Phenomenon and of Potential Causes

Activation phenomena of a Pd/γ-Al₂O₃ catalyst under methane combustion reaction conditions were studied. The activation of the catalyst with time-on-stream is not due to Cl removal from the surface but seems to be related to sintering of the palladium particles. This could induce structural changes in the palladium particle, which would favor the activation of O₂ on the surface of PdO.     

催化燃烧——稀薄气体脱氧剂研究

研制了廉价脱氧剂 ,反应温度为 2 50°C,空时为 6s,动态脱氧率可大于90 % ,尾气氧的质量分率可低于 1× 1 0 -4 ,脱氧容量为 1 0 0 0 m L/g左右。     

二氧化碳和富氧空气对甲烷与乙烯燃烧的影响

利用碳氢燃烧实验台,研究了二氧化碳和富氧空气对甲烷、乙烯层流燃烧火焰的特性影响,分析了不同气氛下火焰结构特性和温度分布规律. 结果表明,随氧浓度从21%增加到50%(j),甲烷、乙烯火焰高度下降70%,火焰温度和亮度同时增加,且发光区域呈向下收缩趋势;相同氧浓度下,乙烯火焰亮度高于甲烷. 随CO2浓度由0增加到20%(j),火焰高度增加28%,各高度处火焰边缘温度平均下降290℃,中心温度平均下降132℃. 火焰亮度降低,由黄色变为暗黄色,底部亮度更低,CO2浓度超过20%(j)后,火焰出现悬浮状态,最终被吹熄.     

甲烷催化部分氧化制合成气的研究进展

文章叙述了甲烷催化部分氧化制合成气研究的进展情况。介绍了两种主要的反应机理：间接反应机理和直接反应机理;对负载型镍系催化剂的研究现状进行了叙述,并简单介绍了非负载型催化剂;另外还对固定床、流化床、膜反应器以及一些新开发的反应器的特点进行了讨论。     

催化燃烧技术在石化企业VOCs处理中的进展

催化燃烧技术是目前工业上最有效的处理低浓度挥发性有机物（VOCs）技术之一.文章介绍了石化企业催化燃烧技术中常用催化剂活性和载体,综述了近年来VOCs催化燃烧催化剂的国内外研究近况,指出未来可以应用到工业化中的新兴催化剂.     

Ce-Zr-V-O复合氧化物对二氯甲烷催化燃烧性能

用共沉淀法制备不同铈锆比及V掺杂量的Ce-Zr-V-O复合氧化物催化剂,在常压固定床反应器上对复合氧化物催化剂用于二氯甲烷催化燃烧的活性进行评价,采用BET、XRD、XPS和H₂-TPR等方法对复合氧化物催化剂进行表征。结果表明,V与Ce-Zr形成了Ce-Zr-V-O固溶体,V掺杂提高了催化剂的比表面积和孔径,形成了更多的晶格缺陷和活性中心,使催化剂具有更高的催化活性和稳定性。n(Ce)∶n(Zr)∶n(V)=7∶3∶0.5时,Ce_0.7Zr_0.3V _0.05 O _2-λ催化剂活性最好,小于300 ℃,连续反应200 h,二氯甲烷转化率大于98%。     

丙烯腈尾气流向变换催化燃烧的实验研究

在固定床反应器中利用HPA型催化剂进行了丙烯腈尾气流向变换催化燃烧实验。考察了在不同尾气组成、不同空速及不同换向周期下流向变换催化燃烧反应系统的热波特性、可燃物的转化率等特性。结果表明,在广泛的操作条件变化范围内,可燃物的转化率均能维持在96％以上,即使空速、气体组成在一定范围内短期波动,流向变换催化燃烧反应系统仍然能够维持正常操作,但在可燃物浓度较低且空速、换向周期与可燃物浓度匹配不合理时反应系统将熄火,浓度较高时将飞温。     

甲烷氧化偶联制C2烃催化剂及催化反应机理研究进展

综述了甲烧氧化偶联制乙烷、乙烯催化剂及催化机理研究概况。重点介绍1989年以来对碱及碱土金属化合物、烯土氧化物、复合氧化物等各类催化剂的研究进展。对目前催化剂上甲烷活化途径、甲基自由基在反应过程中的作用机理、不同氧化物种及表面酸、碱位与催化性能的关系等方面的研究抉况及不同观点也作了简介。     

Catalytic combustion of methane on novel catalysts derived from Cu-Mg/Al-hydrotalcites

Novel Cu-Mg/Al mixed oxides (designated as i-CMAO-800) were prepared by calcinations of Cu-Mg/Al hydrotalcites [(Cu²⁺ +Mg²⁺)/Al³⁺= 3] at 800 °C. Their performance for the catalytic combustion of methane was investigated. The oxides and their precursors were characterized by XRD, TG-DSC, TPR and N₂ adsorption/desorption techniques. The results showed that BET surface areas and the stability of the resultant oxides were greatly influenced by the copper contents in hydrotalcite precursors, bringing about difference in their activities for methane catalytic combustion. XRD results indicated that Cu was highly dispersed in hydrotalcite precursors in case of low copper contents, (Cu 40 wt%). For higher Cu contents, Cu(OH)₂ was formed, and, consequently, a separate phase of CuO was detected in the oxide catalysts after calcination. As indicated by the TG-DSC results, different decomposition behaviors were observed for various hydrotalcites. Thermal calcination promoted the formation of copper aluminates and segregation of CuO from the bulk phases. TPR results showed 15CMAO-800 has the highest reduction rate, and the catalytic activities of iCMAO-800 mixed oxides depend on both the reduction rates and the amounts of copper ions in mixed oxides. The catalyst 15-CMAO-800 showed the best performance.