FAU zeolite membranes for dewatering of amine‐based post‐combustion CO2 capture solutions

Abstract

AbstractIn amine‐based CO2 capture processes, aqueous amine solvent is circulated between absorber (CO2 absorption) and stripping (solvent regeneration) columns. To reduce solvent regeneration energy demand, a selective membrane can dewater and enrich the CO2 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‐Al2O3 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 CO2 loading or total alkalinity was achieved in dewatering of CO2 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 CO2 capture operations.