Our paper entitled “Enhancing the understanding of heat and mass transport through a cellulose acetate membrane for CO2 separation” has been accepted for publication in the Journal of membrane science.The work has been done in collaboration with PhD candidate Elisa Magnanelli, whom I am co-supervising together with Dr. Eivind Johannessen (Statoil) and Prof. Signe Kjelstrup (NTNU). In the paper, we present a detailed theoretical model to describe heat and mass transport across a cellulose acetate membrane for CO2 separation. Some of our findings contradict previous results in the literature, in that we document that the Joule-Thomson effect gives a negligible transmembrane temperature drop. However, The accumulated Joule-Thompson effect can be significant along the membrane unit. We use nonequilibrium thermodynamics to account for coupling between heat and mass fluxes in the system. In conventional membranes, the support limits the possibility of using a temperature difference to enhance the performance. With thinner or better conductive support layers, we estimate that is possible to exploit coupling effects to enhance both permeation and selectivity by 14% and 8% respectively with a transmembrane temperature difference of 20 K. The possibility of using a thermal driving force to enhance the membrane performance is appealing, as a large amount of waste heat is typically available at the natural gas extraction site.
