Cuboid Packed-Beds as Chemical Reactors?

Abstract

Columns are widely used as packed-bed or fixed-bed reactors in the chemical process industry. Packed columns are also used for carrying out chemical separation techniques such as adsorption, distillation, extraction and chromatography. A combination of the variability in flow path lengths, and the variability of velocity along these flow paths results in significant broadening in solute residence time distribution within columns, particularly in those having low bed height to diameter ratios. Therefore, wide packed-column reactors operate at low efficiencies. Also, for a column of a particular bed height, the ratio of heat transfer surface area to reactor volume varies inversely as the radius. Therefore, with wide columns, the available heat transfer area could become a limiting factor. In recent papers, box-shaped or cuboid packed-bed devices have been proposed as efficient alternatives to packed columns for carrying out chromatographic separations. In this paper, the use of cuboid packed-beds as reactors for carrying out chemical and biochemical reactions has been proposed. This proposition is primarily supported in terms of advantages resulting from superior system hydraulics and narrower residence time distributions. Other potential advantages, such as better heat transfer attributes, are speculated based on geometric considerations.

Special Issue on Feature Papers for Celebrating the Fifth Anniversary of the Founding of Processes

“…The second paper addresses the problem of minimizing fuel consumption in fuel gas networks through a superstructure-based method and mixed-integer nonlinear programming [2]. The interesting possibility of extending the favorable characteristics of cuboid packed-bed devices originally designed for chromatographic separations to packed-bed chemical reactors is explored in the third paper [3]. The fourth paper addresses the optimal design of ammonia production plants based on adsorption for unreacted nitrogen and hydrogen recovery and wind energy for electricity generation [4].…”

Modeling of the Continuous Dehydrogenation of Perhydro‐Dibenzyltoluene in a Cuboid Reactor

“…The average heat‐transfer distance can be modified by changing the ratio between length and width in a cuboid reactor. [ 19 ] Ghosh also proved theoretically and experimentally, that a cuboid reactor has a narrower residence time distribution than a tubular reactor. [ 19 ] Furthermore, the height equivalent to one theoretical plate in chromatography decreases by changing from a tubular to a rectangular cross section.…”

“…[ 19 ] Ghosh also proved theoretically and experimentally, that a cuboid reactor has a narrower residence time distribution than a tubular reactor. [ 19 ] Furthermore, the height equivalent to one theoretical plate in chromatography decreases by changing from a tubular to a rectangular cross section. As a result, rectangular columns have improved separation properties in chromatography.…”

Flow Field Simulation and Measurement in Packed Beds Based on 4D‐X‐Ray Computed Tomography

“…Packed beds are widely used in the chemical and the process industry. Packed bed reactors, for example, are very versatile and used in many chemical processing applications such as absorption, distillation, stripping, separation processes, and catalytic reactions [1][2][3][4][5]. Packed beds have been also proposed for several energy storage applications such as advanced-adiabatic compressed air energy storage [6], liquid-air energy storage [7] and thermal energy storage systems [8,9].…”