Gas permeability of combined membrane systems with mobile liquid carrier
Résumé
Gas transfer in a membrane system called a selective membrane valve (SMV) is studied. The SMV is a system consisting of two mobile gas phases, one mobile liquid phase, and two membranes acting as interfaces between gas and liquid. Such a membrane system has supplementary variable parameters and is designated for the separation of multicomponent gas mixtures. System permeability for individual gases (CO2, O2, and H2) and its dependence on a flow rate of a liquid phase are studied. Time dependences of the non-steady state transfer of CO2 through the immobile layer of chemisorbent (aqueous K2CO3 solution) at its different concentrations are studied for the first time. Two theoretical models are developed: the model of gas transfer through a selective membrane valve system with a mobile liquid absorbent (in the absence of chemical interaction) and the model of a non-steady-state transfer of CO2 through the immobile layer of aqueous potassium carbonate solution. The first model makes it possible to determine gas-to-liquid diffusion coefficients; the second model permits us to plot kinetic permeability curves and to calculate system permeability with allowance for the CO2 transfer accompanied by reversible chemical reaction with the carrier. The model dependences agree well with the experimental data.