Preparation Of High Performance CO₂Separation Membrane By Modifying Polyvinylamine With Low Molecular Weight Amines Or MOFs

Membrane technology for CO2separation is a promising technology for CO2separation. Up to now, seldom CO2separation membranes that show high permance andselectivity for industrial application has been developed. In this work, polyvinylamine(PVAm) was modified by low molecular weight organic amines and metal-organicframeworks (MOFs) to prepare CO2separation membrane with high permance andselectivity.Firstly?modifying PVAm with low molecular weight organic amines, includingmethyl carbamate (MC) and alkanolamines, can introduce multi-permselectivy(diffusivity-selectivity, solubility-selectivity and reactivity-selectivity) into the membranethrough adjusting the polymer structure in mutil-levels (atom, group and molecularaggregation), which can improve the permeance and selectivity of the membrane. Theanalysis of ATR-FTIR spectra results showed that cross-linking framework can formbetween PVAm and these low molecular weight organic amines by hydrogen bond. Allmodified PVAm composite membranes prepared in this work were measured withCO2/N2mixture (containing20vol%CO2and80vol%N2). The PVAm-MC/PScomposite membrane showed an outstanding performance. CO2permeance of themembrane is1340and197GPU at feed pressure of0.11and2.0MPa, respectively, andthe corresponding CO2/N2selectivity is468and64.Secondly, PVAm was modified by MOFs, including IRMOF-1, IRMOF-3and ZIF-8,to improve the permance and selectivity of the membrane. All modified PVAmcomposite membranes prepared in this work were measured with CO2/N2mixture(containing15vol%CO2and85vol%N2). The PVAm-ZIF-8/PS composite membraneshowed an excellent performance. CO2permeance of the membrane is940and184GPUat feed pressure of0.15and2.0MPa, respectively, and the corresponding CO2/N2selectivity is112and78.