Investigation on the Gas Absorption with Reversible Chemical Reaction by Digital Computer

Abstract

It was considered that a gaseous species A dissolves into the liquid phase and then reacts reversibly with species B according to the mechanism A+B⇔2C, that is a mol of the reaction product C is reversibly produced which is more frequently the rate controlling step than the case of A+Bg⇔2C. The effect of the second order reversible reaction on the rate of gas absorption for the unsteady state diffusion theory has been computed numerically by the NEAC-2203 digital computer. To solve the non-linear partial differential equation, it was converted to dimensionless form through various parameters and the solutions for the wide ranges of the parameters K and q were computed for the case of the same diffusivities of each species. The computation results were compared with previous investigations, and the following results were obtained.1. The fundamental differential equations were solved in the conditions of M=4, y=0.1 and y∞=4.Then, the dimensionless concentration gradients of a, b and c in the liquid phase were given as functions of dimensionless distance y and time θ.These numerical calculations have shown good convergence and stability.2. By comparison of the β-values which are calculated by the numerical and analytical method in the case of the gas absorption with pseudo 1st order & 2nd order irreversible reaction, the accuracy and convergency of the calculating method were confirmed to be fine. And our assumptions that the reaction with K=100 and q=100 corresponds to the infinite irreversible were proved to be sufficient.3. In the gas absorption with 2nd order reversible chemical reaction, the reaction coefficients have been calculated for arbitrary value of K and q. It was confirmed that the reaction has become psudo 1st order for the larger values of q than 20 and irreversible for the larger values of K than 20, respectively. Further, the empirical Eq.(22) which denotes each values within 10% accuracy have been derived and the correction factor ψ(γ')(23) has also been shown in Fig.8 to give the correct values of β'.