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Effects of enzyme microcapsule shape on the performance of a nonisothermal packed‐bed tubular reactor
Author(s) -
Hassan Mirza M.,
Atiqullah Muhammad,
Beg Shafkat A.,
Chowdhury Mohammad H. M.
Publication year - 1996
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/(sici)1097-4660(199605)66:1<41::aid-jctb439>3.0.co;2-j
Subject(s) - biot number , péclet number , dimensionless quantity , packed bed , isothermal process , materials science , mass transfer , heat transfer , mechanics , thermodynamics , chemistry , composite material , chromatography , physics
The effects of enzyme microcapsule shape (spherical, cylindrical and flat plate) on the performance of a nonisothermal, packed‐bed reactor have been modeled as a function of Biot number and Peclet number for mass and heat transfer ( Bi m , Bi h , Pe m and Pe h ), and dimensionless heat of reaction α. Under the given simulation conditions, only higher values of Bi m and Bi h (>2·5) confirm the influence of microcapsule shape on the reactor performance such that the axial and overall conversion and bulk temperature decrease as follows: spherical > cylindrical > flat plate. In terms of the shape‐independent modified Biot number, Bi * = Bi /{( n + 1)/3}, this order is retained for 2 < Bi * < 8. The influence of increasing Pe m , Pe h , and α on conversion and bulk temperature also follows the above order. For the flat plate, the exit conversion and temperature are not influenced by Pe m and Pe h , that is, mass transfer and thermal backmixing effects, respectively. On the other hand, for the spherical and cylindrical microcapsules, overall backmixing effects are negligible only beyond a critical value of Pe m (∼7) and Pe h (∼1·75). The conversion and bulk temperature increase with the increase in α, independent of the microcapsule shape. The spherical and cylindrical microcapsules, unlike the flat plate, cannot be considered isothermal.