Detail Mass transfer study of naphthalene in supercritical CO(2) Bibliografi Author: Salim, Paul Hartawan ; Trebble, M. A. (Advisor) Topik: ENGINEERING; CHEMICAL Bahasa: (EN )    ISBN: 0-612-20769-2     Penerbit: UNIVERSITY OF CALGARY     Tahun Terbit: 1997     Jenis: Theses - Dissertation Fulltext: NQ20769.pdf (0.0B; 2 download) Abstract Mass transfer of naphthalene in supercritical $CO/sb2$ is studied in a turbulent flow region of a packed bed (i.e., 55 $<$ Re$/sb[p] <$ 324). Experimental pressures vary from 89 to 172 bar, temperatures from 45 to 60$/sp/circ$C, Sc numbers from 3 to 7, and $Gr/sb[p]$ numbers from 9.8 $/times$ 10$/sp5$ to 8.2 $/times$ 10$/sp6.$ This study requires a theoretical approach (i.e., solubility and diffusion modelling), and an experimental one. Solubility modelling involves evaluations of several sets of mixing rules for use with the Trebble-Bishnoi-Salim equation of state (EOS). The new mixing rule preserves the quadratic nature of the predicted second virial coefficient and forces excess volumes to be zero at infinite pressure. It is observed that the more complex mixing rules are only of significant benefit in systems exhibiting large asymmetry or polarity effects. Then, the mixing rule is extended to solid-vapour equilibria in order to estimate the solubility of naphthalene in supercritical $CO/sb2.$ Diffusion modelling refers to the modification of the Interacting Sphere (IS) model by introducing a multiple hard-sphere term N into the probability function of molecular collisions. The modification corrects the probability function for multiple hard-spheres and is particularly beneficial for n-alkanes larger than n-triacontane. A generalized version of the modified IS model is presented. The new model is also used to correlate infinite dilution mutual diffusivity. The diffusion model developed for n-alkanes is also capable of predicting the diffusion of naphthalene at infinite dilution in $CO/sb2.$ The overall standard deviation for infinite dilution mutual diffusivity is 3.72% Experimental measurements are conducted in packed beds of naphthalene, contacted with supercritical $CO/sb2$ at isobaric and isothermal operation. Initially, measurements of solubility data of naphthalene in supercritical $CO/sb2$ were taken in order to test the reliability of the experimental apparatus. An EOS developed previously for solid-fluid equilibria reproduces the experimental solubility data of naphthalene in supercritical $CO/sb2$ within 21.94%. Mass transfer experiments were then conducted by increasing the flow through the extractor and measuring (1) the initial height of each layer in the extractor, (2) initial and final masses of the extractor, (3) pressure and temperatures, and (4) $CO/sb2$ flowrate and consumption. To model the dissolution of naphthalene into supercritical $CO/sb2,$ an unsteady-state differential mass balance was employed. The differential equation was solved implicitly using a dynamic solution. The convective mass-transfer coefficient, $k/sb[c],$ was then obtained iteratively using the Newton-Raphson procedure in order to match the weight loss of naphthalene. Published $Sh/sb[p]$ correlations developed in laminar flow regions are shown to overpredict $Sh/sb[p]$ numbers obtained in this work in a turbulent flow region. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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