FAU zeolite membranes for dewatering of amine‐based post‐combustion CO 2 capture solutions

In amine‐based CO 2 capture processes, aqueous amine solvent is circulated between absorber (CO 2 absorption) and stripping (solvent regeneration) columns. To reduce solvent regeneration energy demand, a selective membrane can dewater and enrich the CO 2 concentration in solution prior to the stripper, lowering steam requirements for solution heating. In this work, a facile synthesis strategy was developed to prepare faujasite (FAU) zeolite membranes built upon polydopamine (PDA) modified α‐Al 2 O 3 substrates. PDA facilitated the attachment of zeolite phases onto the substrate surface to form a 3 μm membrane layer. Membrane permeation flux of 4.45 kg m −2 h −1 and 95% rejection rate calculated by either CO 2 loading or total alkalinity was achieved in dewatering of CO 2 loaded 30 wt% monoethanolamine (MEA) solution. The effects of temperature on membrane dewatering performance and stability were investigated. This study highlights the potential for process integration of membrane technology in amine‐based post‐combustion CO 2 capture operations.