Application of Computational Mass Transfer (IV) Fixed-Bed Catalytic Reaction

• Published in: Introduction to Computational Mass Transfer pp. 175 - 201
• Main Authors: Yu, Kuo-Tsung, Yuan, Xigang
• Format: Book Chapter
• Language: English
• Published: Singapore Springer Singapore Pte. Limited 2016; Springer Singapore
• Series: Heat and Mass Transfer
• Subjects: 3D graphics & modelling; Concentration profile; Engineering thermodynamics; Exothermic catalytic reaction; Industrial chemistry; Simulation of chemical reactors; Turbulent mass transfer diffusivity profile
• ISBN: 9811024979; 9789811024979
• ISSN: 1860-4846; 1860-4854
• DOI: 10.1007/978-981-10-2498-6_5

In this chapter, an exothermic catalytic reaction process is simulated using computational mass transfer (CMT) models as presented in Chap. 10.1007/978-981-10-2498-6_1. The difference between the simulation in this chapter from those in Chaps. 10.1007/978-981-10-2498-6_2–10.1007/978-981-10-2498-6_4 is that chemical reaction is involved. The source term Sn in the species conservation equation represents not only the mass transferred from one phase to the other, but also the mass created or depleted by a chemical reaction. Thus the application of the CMT model is extended to simulating the chemical reactor. The simulation is carried out on a wall-cooled catalytic reactor for the synthesis of vinyl acetate from acetic acid and acetylene using both c′2¯-εc′\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{{c^{{{\prime }2}} }} - \varepsilon_{{c^{\prime}}}$$\end{document} model and Reynolds mass flux model. The simulated axial concentration and temperature distributions are in agreement with the experimental measurement. As the distribution of μt\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mu_{\text{t}}$$\end{document} shows dissimilarity with Dt and αt\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha_{\text{t}}$$\end{document}, the Sct\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Sc_{\text{t}}$$\end{document} or Prt\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Pr_{\text{t}}$$\end{document} are thus varying throughout the reactor. The anisotropic axial and radial turbulent mass transfer diffusivity are predicted where the wavy shape of axial diffusivity Dt,x along the radial direction indicates the important influence of catalysis porosity distribution on the performance of a reactor.