共查询到18条相似文献,搜索用时 140 毫秒
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介绍了几种丙烷脱氢制丙烯技术:催化脱氢、氧化脱氢、膜反应器脱氢。综述了丙烷催化脱氢制丙烯催化剂的研究现状,虽然丙烷催化脱氢生产丙烯虽已实现了工业化,但其催化剂的性能需进一步提高;综述了丙烷氧化脱氢制丙烯反应催化剂的研究现状及膜反应器在丙烷脱氢反应上所具有的优越性,认为研发具有高稳定性和高透氢性能的氢分离膜,将有望能大幅度提高丙烯的收率。 相似文献
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《化工进展》2017,(5)
与已经工业化的丙烷直接脱氢制丙烯技术相比,丙烷氧化脱氢制丙烯因其放热反应的特点,可以在较低的温度下完成反应从而降低了能耗,且氧气的存在抑制了催化剂的积炭等优点而备受关注。然而,在过去三十年的研究历程里,丙烯的低选择性和低收率始终是该技术工业化面临的主要问题。本文从钒基催化剂上丙烷氧化脱氢的反应机理入手,对比了有氧和无氧条件下的丙烷氧化脱氢反应,分析了氧气的存在对丙烯选择性造成的不利影响,介绍了近几年所采用的提高丙烯选择性和收率的新的工艺方法,简述了颇具工业化前景的流化床反应器和膜反应器在丙烷氧化脱氢反应中的应用。氧气的存在是造成丙烯选择性低的重要原因,实现无氧条件下的丙烷氧化脱氢反应过程和催化剂的循环再生过程同时进行有望成为新的研究趋势。 相似文献
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卜婷婷杨利斌孔维杰周金波 《工业催化》2021,29(9):21-28
丙烯作为仅次于乙烯的重要化工原料,需求量非常大,丙烷氧化脱氢反应可克服热力学平衡限制,延长催化剂使用寿命,备受关注.综述了丙烷氧化脱氢制丙烯催化剂的研究进展情况,重点介绍了不同金属组分掺杂/负载的多孔材料催化剂对丙烷氧化脱氢制丙烯反应的催化性能,并对催化剂的发展方向进行了展望.指出开发性能更加优异的催化剂,从催化剂的微... 相似文献
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针对丙烷高效脱氢制丙烯的多孔膜反应器构建了无量纲数学模型并进行了模拟研究,考察了催化剂活性、透氢膜性能、操作条件对多孔膜反应器中丙烷脱氢的转化率、丙烯收率、氢气收率和纯度的影响。结果表明,移走产物氢气可以有效提升膜反应器的性能,其性能的提升程度由不同温压条件下催化剂和透氢膜性能共同决定。高活性催化剂是丙烷高效转化的基础,催化剂活性越高,膜反应器内的产氢速率越快;其次,膜的选择性和渗透通量越高,氢气的移除效率越高,可在最大程度上打破热力学平衡的限制,使反应向生成丙烯的方向移动。当多孔透氢膜的氢气渗透率在10-7~10-6 mol·m-2·s-1·Pa-1,H2/C3H8选择性达到100时,其丙烷转化率可以与Pd膜反应器内的转化率相当,但分离的氢气纯度低于Pd膜反应器。与传统的固定床反应器相比,膜反应器由于促进了化学平衡的移动,可以在较低的反应温度下获得相当高的丙烷转化率,且丙烷转化率随着反应压力的增加呈现出一个最大值。该模拟研究可为实际生产过程中膜反应器用于PDH反应的高效强化提供有益的技术指导。 相似文献
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丙烯是一种重要的有机化工原料和石油化工原料中间体,近年来在国内外市场的需求量持续增长。丙烷直接脱氢制丙烯技术具有收率高、技术成熟、经济环保等优点,备受研究者们的广泛关注。文中综述了丙烷直接脱氢制丙烯用单原子催化剂的研究进展,介绍了单原子催化剂的丙烷脱氢反应机理,探讨了单原子催化剂的失活行为,总结了活性组分、助剂及载体对单原子催化剂催化丙烷脱氢性能的影响,并分析讨论了单原子催化剂在当前研究中存在的问题。最后针对单原子催化剂虽具有优异的丙烯选择性和稳定性,但存在丙烷脱氢活性依旧不足的问题,提出了调控单原子催化剂电子结构促进丙烷脱氢活性的设计思路,为未来丙烷脱氢制丙烯高效单原子催化剂的设计提供了指导方向。 相似文献
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丙烷氧化脱氢反应不受热力学平衡限制,焓变小于零,为放热反应,可节省能源。但氧化脱氢制丙烯因为有O2存在,导致丙烷和丙烯深度氧化,使丙烯选择性下降。可通过以下途径改进:(1)通过添加助剂或改变活性组分限制丙烯的深度氧化;(2)改变反应气氛,用氧化性较弱的氧化剂(如CO2和N2O等)代替O2。近年来,在低碳烷烃脱氢领域以CO2为氧化剂的研究较多,CO2可以避免深度氧化。综述在丙烷氧化脱氢反应中通过引入CO2,将丙烷直接脱氢反应与逆水煤气反应进行偶合,打破了丙烷直接脱氢反应平衡,消除积炭,提高催化剂稳定性,推动反应向生成丙烯的方向进行,丙烯收率提高;在低温(270℃)区域,副反应可提高丙烷CO2氧化脱氢反应的丙烯平衡收率,丙烷二氧化碳脱氢反应的催化剂体系主要包括铬系催化剂、镓系催化剂、钒系催化剂及其他催化剂。 相似文献
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开发新型丙烯制备工艺对于满足人们日益增长的丙烯需求具有重要意义。由于商业化无氧脱氢技术存在热力学平衡限制、反应温度高、催化剂易积炭等不足,近年来,人们将研究重心转向了丙烷氧化脱氢技术。本文简述了丙烷氧化脱氢制丙烯的发展现状,综述了近年来文献报道的丙烷氧化脱氢催化剂体系(V基、Cr基、Co基、Ni基、Mo基、Pt基、Ce基和非金属基催化剂)、机理研究和不同氧化剂选择,并对各自的优势和不足进行了简单分析。分析发现,虽然目前丙烷氧化脱氢催化剂的种类非常广泛,但产物丙烯的收率仍有待提高,机理研究也需要更加系统和深入。最后指出,系统研究丙烷氧化脱氢机理,并在此基础上开发先进催化剂,进一步提高丙烯的选择性和收率是未来丙烷氧化脱氢研究的重要方向。 相似文献
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Comparison of different catalysts in the membrane-supported dehydrogenation of propane 总被引:4,自引:0,他引:4
Dehydrogenation of propane is studied in a high temperature packed bed catalytic membrane reactor with a hydrogen-selective silica membrane. The silica membrane is prepared by a two-step sol–gel process. The removal of hydrogen in the membrane reactor results in higher propane conversion and higher propene yields in comparison to an equivalent fixed-bed reactor. Unfortunately, as a result of the H2 removal coking is favoured in the membrane reactor. Therefore, the higher propene yields are found only for the first 100–120 min time on stream. However, the lower selectivity of the membrane reactor due to coking is compensated to some extend by a reduced hydrogenolysis. Two commercial dehydrogenation catalysts of different activity were tested in the membrane reactor: Cr2O3/Al2O3 and Pt–Sn/Al2O3. The two catalysts show a different activity, coking, and regeneration behaviour in the membrane-supported propane dehydrogenation. 相似文献
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Rui Zhou Yong Cao Shirun Yan Jingfa Deng Yuanyan Liao Bifeng Hong 《Catalysis Letters》2001,75(1-2):107-112
Vanadium-containing mesoporous HMS catalysts have been prepared and characterized for the oxidative dehydrogenation (ODH) of propane. It is demonstrated that the vanadium supported HMS catalysts exhibit a much higher catalytic activity than the literature results obtained over the vanadium supported MCM-41 catalysts in the ODH of propane. The improved catalytic activity of the V-HMS catalysts has been attributed to the presence of high concentration of well-dispersed vanadium species on the surface of the mesoporous HMS materials. 相似文献
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《分离科学与技术》2012,47(2):224-233
Newly reported integrated processes are discussed for aliphatic (paraffin) hydrocarbon dehydrogenation into olefins and subsequent polymerization into polyolefins (e.g., propane to propylene to polypropylene, ethane to ethylene to polyethylene). Catalytic dehydrogenation membrane reactors (permreactors) made by inorganic or metal membranes are employed in conjunction with fluid bed polymerization reactors using coordination catalysts. The catalytic propane dehydrogenation is considered as a sample reaction in order to design an integrated process of enhanced propylene polymerization. Related kinetic experimental data of the propane dehydrogenation in a fixed bed type catalytic reactor is reviewed which indicates the molecular range of the produced C1-C3 hydrocarbons. Experimental membrane reactor conversion and yield data are also reviewed. Experimental data were obtained with catalytic membrane reactors using the same catalyst as the non-membrane reactor. Developed models are discussed in terms of the operation of the reactors through computational simulation, by varying key reactor and reaction parameters. The data show that it is effective for catalytic permreactors to provide streams of olefins to successive polymerization reactors for the end production of polyolefins (i.e., polypropylene, polyethylene) in homopolymer or copolymer form. Improved technical, economic, and environmental benefits are discussed from the implementation of these processes. 相似文献
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Elaine Gomez Zhenhua Xie Jingguang G. Chen 《American Institute of Chemical Engineers》2019,65(8):e16670
The catalytic reduction of CO2 by propane may occur via dry reforming to produce syngas (CO + H2) or oxidative dehydrogenation to yield propylene. Utilizing propane and CO2 as coreactants presents several advantages over conventional methane dry reforming or direct propane dehydrogenation, including lower operating temperatures and less coke formation. Thus, it is of great interest to identify catalytic systems that can either effectively break the C C bond to generate syngas or selectively break C H bonds to produce propylene. In this study, several precious and nonprecious bimetallic catalysts supported on reducible CeO2 were investigated using flow reactor studies at 823 K to identify selective catalysts for CO2-assisted reforming and dehydrogenation of propane. 相似文献
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E. V. Shelepova A. A. Vedyagin A. S. Noskov 《Combustion, Explosion, and Shock Waves》2011,47(5):499-507
Mathematical modeling of a catalytic membrane reactor was performed for thermodynamically coupled processes using as an example
the endothermic dehydrogenation of propane and the exothermic combustion (oxidation) of hydrogen. Benefits of using the membrane
reactor to increase the yield of target products by shifting equilibrium was demonstrated theoretically. The effect of hydrogen
combustion on the main characteristics of the endothermic dehydrogenation process was studied. The hydrogen combustion reaction
makes it possible to further increase the conversion of propane and compensate for the energy consumption in the endothermic
dehydrogenation process. 相似文献
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Catalytic activities of magnesium molybdates were investigated for the oxidative dehydrogenation of propane with and without molecular oxygen under atmospheric pressure. Catalytic properties drastically changed with the catalyst composition, and it turned out that Mg0.95MoOx catalysts having slight excess molybdenum showed the highest activity in the oxidative dehydrogenation of propane, which gave 61% selectivity to propene at 22% conversion of propane at 515°C. The catalytic activities strongly depended on the acidic properties of the catalysts. It was also revealed that the lattice oxide ions of the catalysts participated as an active oxygen in the oxidative dehydrogenation of propane. 相似文献
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Masoud Hasany Mohammad Malakootikhah Vahid Rahmanian Soheila Yaghmaei 《中国化学工程学报》2015,23(8):1316-1325
A two-dimensional non-isothermal mathematical model has been developed for the ethane dehydrogenation reaction in a fixed-bed catalytic membrane reactor. Since ethane dehydrogenation is an equilibrium reaction, removal of produced hydrogen by the membrane shifts the thermodynamic equilibrium to ethylene production. For further displacement of the dehydrogenation reaction, oxidative dehydrogenation method has been used. Since ethane dehydrogenation is an endothermic reaction, the energy produced by the oxidative dehydrogena-tion method is consumed by the dehydrogenation reaction. The results show that the oxidative dehydrogenation method generated a substantial improvement in the reactor performance in terms of high conversions and significant energy saving. It was also established that the sweep gas velocity in the shell side of the reactor is one of the most important factors in the effectiveness of the reactor. 相似文献