Unsteady-state operation of trickle-bed reactors
Unsteady-state operation of trickle-bed reactors
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滴流床反应器的非稳态运行
DOI：
10.1016/j.ces.2004.09.007
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发表时间：
2004
影响因子：
4.7
通讯作者：
M. Grünewald
中科院分区：
文献类型：
--
作者：
R. Lange;M. Schubert;W. Dietrich;M. Grünewald
本文对滴流床反应器的强制非稳态操作与稳态操作进行了实验和理论研究。众所周知，控制变量的变化会影响滴流床反应器的工况和性能。在本研究中，作为滴流床反应器的强制周期性操作的一个例子，使用了非稳态技术，其中催化剂床与不同的液体流速周期性地接触。非稳态操作被认为是在反应器入口处的方波循环液体流量。以α-甲基苯乙烯在钯催化剂（0.7%Pd/γ-Al_2O_3）上加氢制异丙苯：C_6H_5（CH_3）= CH_2（L）+H_2（G）→ C_6H_5CH（CH_3）_2（L）为模型反应。在实验室规模的滴流床反应器上进行的α-甲基苯乙烯加氢反应的实验结果表明，通过调节进料液流量可以显著改善滴流床反应器的性能。模拟研究表明，液体流量的变化有很大的影响，对液体的振荡和催化剂的润湿效率。因此，时间平均α-甲基苯乙烯转化率将增加，因为相（气-液、气-固和液-固）之间的传质阻力影响总反应速率，因此转化率将提高。
An experimental and theoretical study of forced unsteady-state operation of trickle-bed reactors in comparison to the steady-state operation is the subject of this paper. It is well known that changes in the control variables influence the regime and the performance of trickle-bed reactors. In this study as one example for a forced periodic operation of a trickle-bed reactor an unsteady-state technique was used in which the catalyst bed is contacted periodically with different liquid flow rates. The unsteady-state operation was considered as square-waves cycling liquid flow rate at the reactor inlet. The hydrogenation of alpha-methylstyrene to cumene: C6H5(CH3)=CH2(L)+ H2(G)→C6H5CH(CH3)2(L)over a Palladium-catalyst (0.7% Pd/γ-Al2O3) was selected as a model reaction. The experimental results of the alpha-methylstyrene hydrogenation in a laboratory-scale trickle-bed reactor showed, that the reactor performance can be significantly improved by feed liquid flow modulation. The simulation studies demonstrate that the liquid flow variation has a strong influence on the liquid hold-up oscillation and on the catalyst wetting efficiency. Consequently the time average alpha-methylstyrene conversion will be increased, because the mass transfer resistance between the phases (gas–liquid, gas–solid and liquid–solid) affect the overall reaction rate and consequently the conversion will be improved.