Preliminary Design of Reactive Distillation Columns

A procedure that combines feasibility analysis, synthesis and design of reactive distillation columns is introduced. The main interest of this methodology lies on a progressive introduction of the process complexity. From minimal information concerning the physicochemical properties of the system, three steps lead to the design of the unit and the specification of its operating conditions. Most of the methodology exploits and enriches approaches found in the literature. Each step is described and our contribution is underlined. Its application is currently limited to equilibrium reactive systems where degree of freedom is equal to 2 or less than 2. This methodology which provides a reliable initialization point for the optimization of the process has been applied with success to different synthesis. The production of methyl-tert-butyl-ether (MTBE) and methyl acetate are presented as examples

Steady-state and dynamic mass transfer of gases in porous materials

The diffusion of binary gas mixtures through a porous asymmetric tubular membrane has been studied experimentally. A modified Wicke-Kallenbach diffusion cell consisting of two gas compartments separated by the membrane was used. Steady-state experiments with pure gases and binary mixtures were carried out in order to determine the transport parameters of the membrane with respect to the dusty gas model. To verify these parameters, the dynamic transport of binary mixtures was examined applying the dynamic diffusion cell technique proposed by Novak et al. The measured transients were in relative good agreement with the model predictions

An experimental study of combined gas phase and surface diffusion in porous glass

The diffusion of inert and adsorbable gases and binary gas mixtures through porous glass has been studied experimentally. A modified Wicke Kallenbach cell consisting of two gas compartments separated by a tubular mesoporous membrane was used. The scope of this paper is to quantify the contributions of gas phase and surface diffusion. Adopting the dusty gas model (DGM) for the description of gas phase mass transfer and a generalized Stefan Maxwell (GSM) theory to quantify surface diffusion a combined transport model has been applied. The DGM was found to be well suited for the description of transport through the pores. Surface diffusion of adsorbable gases was analyzed experimentally for different loadings. The obtained Fickian surface diffusivities were found to be strongly concentration dependent. Multicomponent surface diffusion is mainly affected by adsorption equilibrium. Reliable predictions require an accurate knowledge of the competitive adsorption isotherms