Detail The effect of equilibrium/non-equilibrium thermodynamics on rate processes Bibliografi Author: Vuddagiri, Srinivas R. ; Hall, Kenneth R. (Advisor); Eubank, Philip T. (Advisor) Topik: ENGINEERING; CHEMICAL Bahasa: (EN )    ISBN: 0-599-00329-4     Penerbit: TEXAS A&M UNIVERSITY     Tahun Terbit: 1998     Jenis: Theses - Dissertation Fulltext: 9903223.pdf (0.0B; 0 download) Abstract My research is involved with two projects: (1) the modeling of equilibrium and non-equilibrium condensers and (2) the modeling of reaction pathways on the Gibbs energy surface. In a vertical condenser, a literal interface between thermodynamics and transport phenomena occurs in the steady-state condensation of mixed vapors in wetted-wall towers. The thermodynamics of condensation/vaporization of mixtures is first reviewed to understand why the ratio of pure-component fluxes at the liquid-vapor interface are different, in general, from the ratio of corresponding equilibrium mole fractions. Then the dynamics of steady-state condensation in wetted-wall towers are developed based upon the film theory of Colburn and Drew (1937). The temperature/composition diagram is used to trace both transport phenomena and thermodynamic variables at various tower heights. A correction to the Ackermann correction factor is made allowing more general use of the design equations when the vapor-phase is non-ideal. The liquid-film resistance to mass transfer, usually neglected, is examined and included. Two cases are considered: (1) a superheated vapor and (2) a saturated vapor; three subcases are considered with varying thermal resistances in the coolant water and the inner wall. Our results showed maximization in the interfacial temperature and minimization in the condensing composition $Z/ /[//equiv/ (N/sb1/(N/sb1+N/sb2))/]$, interfacial compositions, and the bulk liquid composition at an axial position close to the entrance of the column. In the second project, a new method to optimize selectivity in reaction processes (such as a batch reactor) is presented. Using the second law of thermodynamics and Gibbs energy in conjunction with kinetic rate theory, this method can optimize any number of reactions with any number of components. Two and three-reaction cases are presented using hypothetical values for thermodynamic and kinetic properties to show how selectivity optimization can be done on the Gibbs energy surface. In all of these cases, fast reactions are assumed instantaneous and, hence, slow reactions are rate limiting reactions. We restricted our analysis to two slow reactions (3D) since reaction systems with three slow reactions or more require a hyperspace for the Gibbs energy surface. This method can be used for any reaction system whose individual mechanistic steps can be represented by elementary reactions. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

Copyright © 2006, 2007 Unika Atma Jaya, all rights reserved