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A hydrogenation reactor with palladium as a membrane selectively permeated by hydrogen was designed. This reactor has some advantageous characteristics: (1) Reaction by permeate hydrogen makes it possible to omit one separation process. (2) Reaction rate is controlled by changing the permeation rate through the hydrogen pressure. In the present study, it was elucidated that the reaction by permeate hydrogen was much faster than that by gaseous hydrogen when the other reactant affected the hydrogen adsorption strongly. 相似文献
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膜催化反应器的分析与模拟 总被引:2,自引:1,他引:2
分析了膜反应器的出现、发展和最新研究。论述了几种膜反应器中气体的传递机理,定量分析了膜反应器中控制传递与反应的模型方程式以及计算机模拟和实验研究结果。最后评价了两类膜反应器的操作特性,以⊿n<0、⊿n=0和⊿n>0三类不同的催化反应作为模型反应与传统的PFR 和 MFR 的操作特性作了对比。 相似文献
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引 言近年来 ,膜反应器研究已经成为化学反应工程领域的热点课题之一 .其中单侧的膜反应过程研究较多 ,而耦合膜反应过程的研究相对较少 .耦合膜反应过程是指在膜反应器中膜两侧都有反应发生 ,一侧反应的产物是另一侧反应的反应物 ,而膜可优先选择该物质透过 .耦合膜反应过程的研究首先是在前苏联开展的 ,主要以Gryaznov等[1,2 ] 对脱氢反应与加氢反应耦合过程的研究为代表 ,有关介绍参见Shu等[3] 、Zaman和Chakma[4 ] 以及Saracco和Specchia[5] 的综述 .研究表明 ,耦合膜反应过程有其特殊的优点 :通… 相似文献
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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… 相似文献
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J. W. Veldsink R. M. J. van DAMME G. F. Versteeg W. P. M. van SWAAIJ 《Chemical Engineering Communications》1998,169(1):145-166
A theoretical investigation has been presented for applications and features of a non-permselective, catalytic membrane reactor with separated feed of reactors [12-14, 17, 18]. Transmembrane fluxes were calculated from the dusty gas model as a function of a great number of parameters and operation conditions. This study shows that the non-permselective, catalytic membrane reactor with separated feed of reactants (CMRSR) has attractive features to use this reactor in fast and highly exothermic reactions and selectivity improvement in multiple reactions.
When the CMRSR is operated in the transport controlled regime, the process is easy to control and even possesses some self-controllability. Due to the transport conversion, thermal runaway cannot occur which allows operation with concentrated feed of reactants. Furthermore, a transmembrane pressure difference increases both the fluxes and the selectivity, because the reaction products are preferentially directed towards one side of the membrane. The simultaneous increase of both selectivity and fluxes is a remarkable feature of a CMRSR which is in contrast with conventional reactors. 相似文献
When the CMRSR is operated in the transport controlled regime, the process is easy to control and even possesses some self-controllability. Due to the transport conversion, thermal runaway cannot occur which allows operation with concentrated feed of reactants. Furthermore, a transmembrane pressure difference increases both the fluxes and the selectivity, because the reaction products are preferentially directed towards one side of the membrane. The simultaneous increase of both selectivity and fluxes is a remarkable feature of a CMRSR which is in contrast with conventional reactors. 相似文献
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针对列管式固定床F-T合成反应器的特点建立了一维拟均相数学模型。通过对模型计算与试验结果进行对比分析,表明该模型可以较好的描述反应过程。并从固定床反应器的操作热稳定性出发,对列管式固定床F-T合成反应器的最大允许管径和最大传热温差进行了计算。结合模型计算结果得出了合适的反应管直径与冷却介质温度范围,可以优化列管式固定床F-T合成反应器的设计。 相似文献
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无机膜催化反应器中的环己烷脱氢反应 总被引:2,自引:0,他引:2
无机膜催化反应器中的环己烷脱氢反应赵修仁,黄闻迪,陈淑兰(大连理工大学化工学院,大连116012)关键词:无机膜,膜催化反应,环己烷脱氢1前言由于无机膜具有耐温、耐化学腐蚀及轻度耐压的特点,因此有可能用于在高温下进行的催化反应而实现膜催化过程。Arm... 相似文献
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建立了加压三相鼓泡淤浆床环氧乙烷合成反应器的数学模型 ,计入了催化剂颗粒在床层中沉降形成沿床高浓度分布对反应的影响以及由于惰性液相载体部分返混对传递的影响 ,进一步利用经实验验证的上述数学模型模拟不同表观气速、床高、反应器直径 (扣除传热元件截面积 )、进口乙烯摩尔分数等参数对床层中催化剂浓度随床高的分布、出口环氧乙烷摩尔分数、环氧乙烷选择率以及单位质量催化剂环氧乙烷年产量的影响 .通过模拟分析预示了工业三相床环氧乙烷反应器的合理尺寸、表观气速、环氧乙烷选择率以及时空产率 ,为工业化提供必要的设计依据 相似文献
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中空纤维膜反应器的操作模式 总被引:3,自引:0,他引:3
通过对超滤、循环和反冲操作的中空纤维膜反应器流体力学状况的分析,推导出反应器内压力分布、通量因子与阻力因子λ的关系.超滤模式压力分布在对角线以下,循环模式在对角线1/2处呈轴对称分布,反冲式当λ较小时,压力分布较为均匀,λ大于5时接近超滤.三者的通量因子随λ的增大而减小,最大值分别为100%、50%和25%.单位膜面积的生产能力以反冲式最大,超滤式次之,循环式最小,且均随反应器的长度增加而减小. 相似文献
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Hui Zhang Ming Jiang Daobin Zhang Qiang Xia 《Chemical Engineering Communications》2013,200(3):377-386
The effect of initial pH, liquid flow rate, gas flow rate, and gaseous ozone concentration on the ozonation of 4-nitrophenol in a membrane reactor was investigated. The results showed that the disappearance of 4-nitrophenol increased with the increase of liquid flow rate, gas flow rate, and gaseous ozone concentration. The rise of the initial pH value led to an increase in 4-nitrophenol removal rate, but the increase became negligible after initial pH exceeded 9.5. The highest removal efficiency of 4-nitrophenol achieved was 94% after 100 min reaction when gaseous ozone concentration was 0.51 mmol L?1, gas flow rate was 57 mL min?1, liquid recirculation rate was 72 mL min?1, and initial pH was 10.3. The membrane reaction system could be modeled based on the lumped kinetics of 4-nitrophenol removal, and the corresponding rate constant of 4-nitrophenol removal was determined from the model. 相似文献
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Katica Sertić-Bionda Zoran Gomzi Marko Mužic 《Chemical Engineering Communications》2013,200(3):275-288
A five-lump kinetic model had been developed for modeling of gas oil catalytic cracking. The experiments were carried out in a standard fixed bed micro-activity test (MAT) reactor. Distribution of the cracking product components was determined as a function of temperature. The sequential step optimization method was used to estimate the kinetic constants. A MAT reactor nonisothermal and the unsteady-state model was proposed. The overall heat of the reactions was established from the macroscopic difference of the products' and the reactants' enthalpies. The influence of the feedstock and the reactor temperature was discussed. The reactor and the kinetic models were validated using the experimental MAT results. Simulation results were in good agreement with the experimental data. 相似文献
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膜反应器的理论分析 总被引:1,自引:1,他引:0
周忠清 《化学反应工程与工艺》1991,7(3):237-245
以化学反应工程的观点,对一级可逆反应的膜反应器进行了理论分析。建立了反应速率和分离速率偶合的联立动力学方程求解方法,得出关于膜反应器的几个基本结论。1.膜反应器能促进反应效果必须具备下列条件:(1)膜的选择性 S_m 要远大于反应平衡常数 K_o 的倒数S_,》K_c~(-1)(2)正反应的速率常数 k 比反应物 R 的分离速率常数 k_R 要大一些。2.膜反应器的理想最大转化率 X_mX_m=1/[1+(S_mK_c)~(-1)]3.当无因次参数 m 为7.9时,膜反应器的相对转化率η为99%,且应该在 m≥7.9附近进行操作。4.膜反应器的各种参数与促进反应效果的最适宜的操作条件有关。通过分析,确定了膜反应器的总转化率有某一个理想的最大值,可得到理想的最大转化率、膜的选择性和平衡常数之间的关系。在设计条件和操作条件下,这种关系对于所研究的膜反应器是有效的。 相似文献
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A new application of the fixed bed catalytic reactor with flow reversal for combustion of natural gas is investigated by mathematical modeling and computer simulation. Comparison between the results obtained for this new reactor and those for a classic catalytic fixed bed is made. Inexpensive perovskite type catalysts containing no noble metals were used. It is shown that an appropriate choice of operating parameters (concentration and temperature of input gas mixture, superficial gas velocity, size and shape of catalyst and inert material, volumetric ratio between catalyst and inert material in the bed) allows for a methane combustion at must lower temperatures in the reactor with flow reversal than in a classic catalytic reactor. Under such a low temperature combustion, no nitrogen oxides are produced. 相似文献
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膜分离式酶解反应器流体流动特性 总被引:3,自引:0,他引:3
讨论了膜分离式酶解反应器进行酶解反应操作时流体流动的特性。导出停留时间分布函数方程式,采用降阶法的阶跃方式进行了实验验证。结果表明:实验值与按分布函数方程式的计算值吻合良好,通过与连续釜式反应器(CSTR)停留时间分布的特征值的比较,显示出这种反应器的优越性。 相似文献