改性VOx/MSU-1催化剂上CO2氧化异丁烷脱氢反应

以MSU-1为载体制备了一系列改性的VOx/MSU-1催化剂,并在CO2氧化异丁烷脱氢制异丁烯的反应中评价了催化剂的性能,发现稀土元素La、Ce的加入能提高催化剂的活性。采用XRD、H2-TPR及NH3-TPD方法对催化剂La2O3-VOx/MSU-1进行了深入的表征,发现La2O3的加入提高了载体MSU-1上活性组分VOx的分散度,同时也改善了催化剂表面的酸碱性,更加有利于异丁烷氧化脱氢反应的进行。优化了反应条件,在最佳反应条件下,异丁烷的转化率为63.6%,异丁烯的产率为52.3%。最后,通过8 h的稳定性实验,发现与VOx/MSU-1相比,催化剂La2O3-VOx/MSU-1具有更好的催化稳定性。     

异丁烷脱氢技术应用研究

异丁烷脱氢是一种重要的碳四高附加值利用技术,并且得到了广泛的工业应用。本文研究了三种异丁烷脱氢工艺,根据计算分析及相关资料,给出了这三种工艺的有关技术经济指标,从中反映出各种工艺的特点。     

VOx／SiO2催化剂上异丁烷催化脱氢制异丁烯

研究了使用负载法制备的VOx／SiO2催化剂上的异丁烷催化脱氢制异丁烯的反应。使用XRD和Raman光谱技术表征了催化剂的表面结构,考察了催化剂的钒氧化物负载量、反应温度和H2／n-C4H10比对反应性能的影响。研究结果表明：钒氧化物最大单层覆盖量为9％左右,大于9％催化剂表面开始形成V2O5晶体,堵塞载体孔道,使催化剂活性位减少;V2O5负载量9％为最佳钒氧化物负载景;反应温度在590-620℃,氢烷比为1-3为最佳反应条件。同时C1-C3裂解收率受反应温度影响较大,而与氢烷比及钒氧化物负载量影响不大。     

K2O-CuO-Cr2O3/Al2O3催化剂上异丁烷脱氢制异丁烯的催化性能研究

以Cr2O3为活性组分,K2O和CuO为助剂,γ-Al2O3为载体制备负载型催化剂,并考察了其对异丁烷直接脱氢制异丁烯的催化活性.探讨了活性组分Cr2O3及助剂K2O、CuO对催化剂活性的影响,结果表明,金属Cr含量与催化活性直接相关,K对催化剂选择性有改进作用.实验结果还表明了该催化剂适用于高空速下的催化反应.对含不...     

K_2O-CuO-Cr_2O_3/Al_2O_3催化剂上异丁烷脱氢制异丁烯的催化性能研究

以Cr2O3为活性组分,K2O和CuO为助剂,γ-Al2O3为载体制备负载型催化剂,并考察了其对异丁烷直接脱氢制异丁烯的催化活性。探讨了活性组分Cr2O3及助剂K2O、CuO对催化剂活性的影响,结果表明,金属Cr含量与催化活性直接相关,K对催化剂选择性有改进作用。实验结果还表明了该催化剂适用于高空速下的催化反应。对含不同助剂的Cr系催化剂进行了N2吸附-脱附、XRD等表征。N2吸附-脱附发现催化剂比表面积与异丁烷脱氢的初始活性存在一定的对应关系;XRD的表征说明各组分能很好地分散负载在载体上;其中,在优化的反应条件温度853 K、空速1000 h-1下,K2O-CuO-Cr2O3/Al2O3催化剂有最佳的异丁烷的转化率和异丁烯的收率,分别达64.76%和57.24%。     

钯复合膜反应器中异丁烷催化脱氢反应

引　言异丁烷脱氢反应是一个受热力学平衡限制的反应 ,平衡转化率很低 ,若将膜反应器用于该反应 ,则可以通过膜不断地从反应区选择性分离出氢气 ,克服了反应受热力学平衡制约的缺点 ,这样就可降低反应温度和减压程度的要求 ,改善反应的工艺条件 ,从而达到高效和节能的目的 .文献中已分别对钯 /陶瓷复合膜[1,2 ]和钯 -钌 (钌的质量分数为 2 % )合金膜[3]反应器中的异丁烷脱氢反应进行了初步研究 .前文[4 ]已对用改进的化学镀新工艺制备的钯和钯 -银 /陶瓷复合膜进行了表征 ,本文将用钯-银 /陶瓷复合膜反应器进行异丁烷脱氢反应的研究 .本工作…     

异丁烷脱氢技术开发

介绍了国内外异丁烷脱氢制异丁烯技术,和中国石化上海石油化工研究院(SRIPT)开发的基于铂系催化剂的成套技术,包括多段串联绝热固定床反应工艺、低压油吸收分离工艺等关键技术,该技术具有能耗和装置投资低的特点。     

异丁烷催化脱氢制异丁烯技术研究

介绍我国异丁烷和异丁烯资源的利用现状,重点对异丁烷脱氢制备异丁烯的反应机理、反应流程和催化剂类型进行了论述。最后,通过对我国异丁烷脱氢制异丁烯催化剂开发现状的总结,指出我国应大力合理开发利用丰富的异丁烷资源。     

高分散型钒氧化物催化剂上异丁烷催化脱氢的研究

采用V(t-BuO)3O与介孔SBA-15表面羟基反应的方法制备了高分散型钒氧化物催化剂,通过ICP-AES、BET、XRD和SEM对样品进行了表征,并考察了其在异丁烷直接脱氢、氧化脱氢以及直接脱氢与氧化脱氢相结合的条件下的脱氢反应催化性能。结果表明,相对于NH4VO3浸渍法,V(t-BuO)3O与载体反应的方法制备的催化剂具有更高的钒氧化物分散度,直接脱氢与氧化脱氢相结合的异丁烷脱氢反应中显示出高活性和高选择性,减少了COx的产生并抑制了积炭的生成。     

Propane Dehydrogenation over a Commercial Pt-Sn/Al2O3 Catalyst for Isobutane Dehydrogenation: Optimization of Reaction Conditions

The applicability of a commercial Pt-Sn/Al₂O₃ isobutane dehydrogenation catalyst in dehydrogenation of propane was studied. Catalyst performance tests were carried out in a fixed-bed quartz reactor under different operating conditions. Generally, as the factors improving propane conversion decrease the propylene selectivity, the optimal operating condition to maximize propylene yield is expected. The optimal condition was obtained by the experimental design method. The investigated parameters were temperature, hydrogen/hydrocarbon (H₂/HC) ratio and space velocity, being changed in three levels. Constrains such as the susceptibility of the catalyst components to sintering or phase transformation were also taken into account. Activity, selectivity and stability of the catalyst were considered as the measured response factors, while the space-time-yield (STY) was considered as the variable to be optimized due to its commercial interest. A STY of 16 mol·kg^-1·h^-1 was achieved under the optimal conditions of T 620℃, H₂/HC 0.6 and, weight hourly space velocity (WHSV) 2.2 h^-1. Single carbon-carbon bond rupture was found to be the main route for the formation of lower hydrocarbon byproducts.     

锂对二氧化碳气氛下乙苯脱氢催化剂铁(Fe)/活性炭(AC)的促进作用

研究了助剂Li对CO2气氛下活性炭负载的Fe氧化物(Fe/AC)催化剂上的乙苯脱氢性能的影响和CO2的作用。助剂Li的添加提高了Fe/AC催化剂在CO2气氛下的乙苯脱氢活性和稳定性;CO2气氛下的苯乙烯收率明显高于N2气氛下,表明CO2显著促进了乙苯脱氢反应。     

Deactivation of VMgO x Catalysts by Coke in the Process of Isobutane Dehydrogenation with Carbon Dioxide

The process of isobutane dehydrogenation in the presence or absence of carbon dioxide was carried out over VMgO _x catalysts with different vanadium loading. The performed tests show that both the reaction atmosphere and physicochemical properties of the catalysts (related to vanadium content) have a great influence on the activity decrease and the carbonaceous deposit formation. Despite small ability of carbon dioxide to remove coke in the Boudouard reaction, the amounts of carbonaceous species deposited on the catalysts after the isobutane dehydrogenation under CO₂ atmosphere were even twice greater in comparison to those deposited in helium stream. Moreover, the rate of coke deposition during the dehydrogenation in the inert gas flow was only slightly dependent on the reaction time, in contrast to the process in carbon dioxide atmosphere. The results show that the coke formation on VMgO _x is enhanced predominantly by surface acidity of the catalysts, which grows with the vanadium content and the presence of CO₂ in the feed.     

CO_2压缩机脱氢催化剂活性降低分析与对策

对中海石油华鹤煤化有限公司CO2压缩机脱氢槽运行情况进行简介,重点介绍脱氢催化剂的使用情况,催化剂装填要求,使用前后的数据对比,投运后的运行情况,以及氢含量增高的应对措施。     

离子液体催化异丁烷烷基化工艺条件

采用统计分析和回归正交实验方法,分析H2SO4,HF和离子液体烷基化工艺条件对异丁烷与丁烯的烷基化反应生成三甲基戊烷选择性的影响,并考察了离子液体烷基化循环使用性能.结果表明,由于离子液体呈Lewis酸性,在催化异丁烷和1-丁烯烷基化反应时,三甲基戊烷选择性很低.以离子液体为催化剂,在反应温度大于15℃,搅拌速率大于1 500 r/min,异丁烷与2-丁烯物质的量之比大于10,催化剂与反应物体积分别为50和150 mL的条件下进行烷基化反应,离子液体循环使用20次以上,三甲基戊烷选择性仍大于80%.通过中试烷基化实验验证反应温度、搅拌速率、烷烯比与三甲基戊烷选择性之间的多元线性回归方程,发现三甲基戊烷选择性的计算值与实验值吻合较好.表明所得的方程具有较好的预测能力.     

Oxidative Dehydrogenation of Ethylbenzene with Carbon Dioxide over Metal-Doped Titanium Oxides

Various metal-doped (Fe, V, Zr, Mg) titanium oxides were prepared by an acid-catalyzed sol–gel method and their properties as catalysts were investigated for oxidative dehydrogenation of ethylbenzene in the presence of carbon dioxide. The characterization techniques, XRD, BET, TGA were employed to analyze the features of catalyst. Fe₃Ti catalyst was found to be quite effective among the catalysts tested at 823 K, 39.8% ethylbenzene conversion and 98% styrene selectivity were acquired.     

1,4-丁二醇脱氢与顺酐加氢耦合催化剂

采用共沉淀法制备了不同配比的Cu-Zn-A1复合氧化物催化剂,利用XRD和TPR等表征技术及活性评价考察了催化剂各组分配比对催化剂性能的影响,并对各组分配比进行了优化。试验结果表明,Al的摩尔分数为20%,Cu/Zn摩尔比为0.5~2.0时,Cu-Zn-Al催化剂在常压下耦合法制备γ-丁内酯反应具有良好的活性。XRD表明灼烧后未经还原的催化剂活性组分为CuO。通过XRD、TPR及BET表征发现,适宜的Cu/Zn摩尔比可以提高催化剂比表面积,使CuO具有较高分散性及高的还原性能,从而有利于提高催化剂的选择性。     

La-V-O/粘土催化剂上丙烷氧化脱氢制丙烯

采用浸渍法制备了La-V-O/粘土系列催化剂,并对催化剂进行了丙烷氧化脱氢制丙烯反应活性评价和BET、XRD、H2-TPR和XRF表征。结果发现La-V-O/杭锦2#土催化剂的催化性能最好。     

Well-Defined Highly Active Heterogeneous Catalyst System for the Coupling Reactions of Carbon Dioxide and Epoxides

The poly(4-vinylpyridine)-supported zinc halide catalysts, prepared from a reaction of ZnX₂ and poly(4-vinylpyridine), exhibit high selectivity and activity for the coupling reaction of CO₂ and ethylene oxide or propylene oxide. Solid NMR characterization of the poly(4-vinylpyridine)-supported ZnBr₂ catalyst and its reaction product with propylene oxide and/or CO₂ show that a pyridinium-alkoxy ion-bridged zinc bromide complex is functioning as an active species, such as in the homogeneous catalysis with L₂ZnBr₂ (L = pyridine or methyl-substituted pyridine).