Experimental investigation of fast-mode liquid modulation in a trickle-bed reactor
Experimental investigation of fast-mode liquid modulation in a trickle-bed reactor
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滴流床反应器中快速模式液体调制的实验研究
DOI：
10.1016/j.ces.2004.03.048
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发表时间：
2004
影响因子：
4.7
通讯作者：
A. Ferri
中科院分区：
文献类型：
--
作者：
M. Banchero;L. Manna;S. Sicardi;A. Ferri
滴流床反应器的非稳态操作是改善反应器性能的一项重要技术，特别是当传质过程受速率控制时。在不同的技术中，液体流速的快速模式调制似乎是最成功的技术之一。事实上，在非常低的频率下循环液体流速可以诱导反应器在高相互作用状态下工作，在该状态下，传质和传热现象被强烈增强。快速模式的周期性操作，然后，可以被认为是自然的高相互作用制度在平均范围内的气体和液体流量通常与滴流制度在稳态条件下的延伸。在TBR反应器中，采用“开-关”快模式液相调制，在Pd/C催化剂上进行了α-甲基苯乙烯加氢的非稳态实验。在相应的平均液体流速下，将结果与稳态实验进行了比较，发现转化率提高了60%。所有实验都是在等温条件下进行的，因此转化率的提高只能归因于传质的增加，而不是热效应。气液流量和液体循环参数的变化对最佳工作条件提出了几个重要的含义。
Unsteady-state operation of trickle-bed reactors (TBRs) is a promising technique to improve reactor performances especially when mass transfer phenomena are rate controlling. Among the different techniques, fast-mode modulation of the liquid flow rate seems to be one of the most successful. In fact cycling the liquid flow rate at very low frequencies can induce the reactor to work at the high-interaction regime where mass and heat transfer phenomena are strongly enhanced. Fast-mode periodic operation, then, can be considered an extension of the natural high-interaction regime at a mean range of gas and liquid flow rate normally associated with trickling regime in steady-state conditions. Experimental tests have been performed in a TBR employing α-methyl styrene hydrogenation on Pd/C catalyst in unsteady-state conditions by “on–off” fast-mode liquid modulation. Results have been compared with the steady-state experiments at the corresponding average liquid flow rate, revealing a conversion rate improvement up to 60%. All experiments have been performed in isothermal conditions, so conversion improvement can be ascribed only to mass transfer increase and not to thermal effects. The variation of gas and liquid flow rates and liquid cycle parameters presented several important implications about the optimal working conditions.