Effect of single and blended amine carriers on CO2 separation from CO2/N2 mixtures using crosslinked thin-film poly(vinyl alcohol) composite membrane

This article reports effect of different single and blended amine carriers on binary gas (20% CO2 balance N2) separation using novel CO2-selective crosslinked thin-film poly(vinyl alcohol) composite membranes. The characterization of the thin-film active layer had been carried out by Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The transport properties of CO2 (CO2 and N2 fluxes, CO2 and N2 permeability, and CO2/N2 selectivity) across the membrane were examined using counter flow flat sheet membrane module. The effects of active layer thickness (41 to 84 micron), feed absolute pressure (1.7 to 6.2 atm), temperature (90 to 125 °C), and sweep side water flow rate (0.02 to 0.075 cm3/min) on transport properties of CO2 across the membrane were analyzed. The dense layer containing amine carrier displays both high selectivity and permeability. It has been seen that the composite membrane of 25 wt% poly(allylamine) and 15 wt% 2-amino-2-hydroxymethyl-1,3-propanediol with 44 micron active layer thickness is having maximum CO2/N2 selectivity of 434 and CO2 permeability of 1826 Barrer at 2.8 atm feed side absolute pressure and 100 °C temperature.