Analytical solution for coupled heat and mass transfer in membrane-based absorbers

Abstract

Membrane-based absorbers have received much attention in recent years owing to their higher sorption rates compared to conventional absorbers. In this study, for the first time, two analytical solutions are proposed for membrane-based absorbers. These analytical solutions can be used for non-volatile liquid-based physical sorption applications, such as absorption heat pumps/chillers and some CO2 capture reactors. The Laplace transform method and similarity solution are used to develop these analytical models. The models’ results are validated with the experimental data available in the literature. It is shown that the analytical model obtained by the Laplace transform method is more accurate compared to the similarity solution approach. However, the similarity solution provides a more compact solution. Additionally, a comprehensive parametric study is conducted on the effect of the operating conditions and membrane physical properties on absorption rate. It is shown that the solution inlet concentration and membrane porosity are the most significant operating condition and membrane physical property, respectively.