Membrane Carbon Capture and the Critical Role of Process System Engineering

There is general consensus that when the concentration of target component (TC) in the membrane inlet feed is comparatively low, membranes tend to become an infeasible option for separation of TC. For this reason, there is a controversy in the literature on the feasibility of membranes for post-combustion carbon capture where the concentration of CO₂ in the power plant’s flue gas is usually less than 15%. Our recent study shows that, the main reason for inconsistency in analyses is due to the application of simple membrane models. Such simplifications become critical when the TC concentration is at threshold values (as for CO₂ in the flue gas) [1].

In this presentation, we will present a systematic methodology for analysis of membrane systems considering multicomponent flue gas with CO₂ as TC. We avoided simplifying assumptions namely multicomponent flue gas represented by CO₂/N₂ binary mixture or considering the co/counter current flow pattern of hollow-fibre membrane system as mixed flow. We found, via parametric analyses, optimal regions of flue gas pressure and membrane area within which a techno-economical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous.

[1] Khalilpour, R., Abbas, A., Lai, Z., Pinnau, I. 2011. Modeling and Parametric Analysis of Hollow Fibre Membrane System for Carbon capture from Multicomponent Flue Gas. AICHE Journal.