(569dq) Modeling of Gas-Liquid Absorption with an Irreversible (M,N) Order Reaction in Film and Bulk in the Presence of Gas Film Resistance and Criteria for Regime Identification

A Hikita-Asai approximation-based analytical solution of the film model for gas absorption accompanied by an irreversible (m,n) order reaction with a solvent in the liquid film and bulk in the presence of a finite gas film resistance for a given set of values of bulk compositions of the solute in the gas phase and the solvent in the liquid phase is developed. The composition of the solute in the liquid bulk is estimated by neglecting the influence of reactor-specific bulk liquid phase solute material balance, thus enabling estimation of fluxes of solute at the gas-liquid interface and film bulk interface that are reactor independent. The film model equations are written in dimensionless form which results in a set of dimensionless numbers.. The approximate solution is obtained in terms of dimensionless concentrations and fluxes. The results of the approximate solutions for a (2,1) order reaction are validated by comparison with the numerical solution of the film model obtained by using COMSOL MULTIPHYSICS software. A typical comparison of the concentration profiles of the solute A and the solvent B in the liquid film are shown in Figure 1 that are obtained by solving the rigorous film model and the solution of the approximate model for a case where reaction in film and bulk, as well as gas film resistance are significant. Procedures are identified for screening different regimes based on criteria that can be evaluated from input data... Some of the criteria for validity of specific reaction regimes where the rate equations simplify on account of one or more of the resistances involved in mass transfer are not important are given.