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

Abstract

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.

High-Performance FAU Zeolite Membranes Derived from Nano-Seeds for Gas Separation

“…The peak intensity of as-synthesized FAU membranes increased with synthesis time, indicating the growth of the zeolite layer. However, when the synthesis time was prolonged to 10 h, some weak peaks were observed at 2θ= 12.5°, 17.7°, 21.7°, 28.2°, and 33.4°, indicating that NaP zeolite existed in the membrane as an impurity phase [31]. The formation of NaP impurity in preparing FAU zeolite membrane was similar to that of T-type zeolite in preparing LTA zeolite for a long synthesis time [32].…”

High-Performance FAU Zeolite Membranes Derived from Nano-Seeds for Gas Separation

“…The peak intensity of as-synthesized FAU membranes increased with synthesis time, indicating the growth of the zeolite layer. However, when the synthesis time was prolonged to 10 h, some weak peaks were observed at 2θ = 12.5 • , 17.7 • , 21.7 • , 28.2 • , and 33.4 • , indicating that NaP zeolite existed in the membrane as an impurity phase [31]. The formation of NaP impurity when preparing the FAU zeolite membrane was similar to that of T-type zeolite when preparing LTA zeolite over a long synthesis time [32].…”

Zeolite-based catalytic membrane reactors for thermo-catalytic conversion of CO2

“…The gas diffusion is promoted with more defects or an enlarged defect at the cost of selective permeation. To tune the defect concentration and size so as to balance the permeability and selectivity, linking agents are helpful by strengthening the zeolite-support interactions with hydrogen bonding or electrostatic force ( Zhu et al., 2020 ; Mubashir et al., 2020 ). Also, additive molecules can heal the defects and improve the effective porosity of zeolite membranes by filing the intercrystalline space ( van den Bergh et al., 2010 ; Aydani et al., 2021 ).…”