Trickle-Bed Reactors: Porosity-Induced Hysteresis

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• 作者：Rabindranath Maiti ; Rajesh Khanna ; and K. D. P. Nigam
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2005
• 出版时间：August 3, 2005
• 年：2005
• 卷：44
• 期：16
• 页码：6406 - 6413
• 全文大小：202K
• 年卷期：v.44,no.16(August 3, 2005)
• ISSN：1520-5045

文摘

The role played by the porous nature of the packing material in the hysteretic behavior of trickle-bed reactors (TBRs) is presented based on a new framework that incorporates the currentunderstanding of fluid flow in TBRs, concepts of participating and nonparticipating particles,and principles of liquid spreading on porous and nonporous substrates. A method to characterizethe extent of hysteresis is also presented. The framework is applied to reported experiments(Ravindra, P. V.; Rao, D. P.; Rao, M. S. Ind. Eng. Chem. Res. 1997, 36, 5133-45) and is shownto be able to explain the difference in the hysteretic behavior of porous packings and of nonporouspackings (comparable particle size) under varying startup conditions and numbers of cycles. Inaddition to providing a basis for the general framework within which hysteresis in TBRs shouldbe studied, it provides explanations to specific questions such as (1) the existence of hysteresisin porous packings and its absence in nonporous packings under similar conditions and (2) whento expect open-loop or closed-loop hystersis. It is also a good illustration of how a framework,which is based on pore levels, can explain reactor level complex phenomena like hysteresis. Itis expected that this work will enhance our understanding about the variations of the hystereticbehavior as well as hydrodynamics in TBR. In the absence of a data bank in the literature, theproposed framework has been validated with available limited data.