(788g) Pvam-PIP/PS Composite Membrane with High Performance for CO2/CH4 Separation

Polyvinylamine(PVAm)-piperazine(PIP)/polysulfone(PS) composite membrane was prepared in our previous work [1]. The membrane exhibits high CO2/N2 separation performance and could well meet the requirement of flue gas separation [1]. In this work, CO2/CH4 separation performance of the PVAm-PIP/PS composite membrane was investigated. The membrane was developed by coating PVAm-PIP mixed solutions with different mass ratios of PIP/PVAm (mPIP/mPVAm) on the PS ultrafiltration membrane. The effects of mPIP/mPVAm in the coating solutions and wet coating thickness on the CO2/CH4 performance of the PVAm-PIP/PS composite membrane were investigated. The PVAm-PIP/PS composite membrane prepared in this work showed higher CO2/CH4 performance than other membranes reported in the literature due to the large increase of the introducing carrier concentration and low crystallinity. For CO2/CH4 gas mixture (10/90 by volume), the PVAm-PIP/PS composite membrane with the mPIP/mPVAm of 1.430 and wet coating thickness of 30µm showed CO2 permeance of 4510 and 697 GPU [1 GPU = 10-6 cm3 (STP)/ (cm2 s cmHg) = 3.35×10-10 mol/(m2 s Pa)] at feed pressure of 0.11 and 3.0MPa, respectively, and the corresponding CO2/CH4 selectivity of 121 and 29, respectively. Moreover, the separation performance stability of the PVAm-PIP/PS composite membrane was investigated and no deterioration in the membrane perm-selectivity was observed. Finally, the economic evaluation of the membrane with the highest CO2/CH4 performance prepared in this work was carried out. PVAm-PIP/PS composite membrane could well meet the requirement of CO2/CH4 separation. [1]Qizo ZH, Wang Z, Zhang CX, Yuan SJ, Zhu YQ, Wang JX, Wang SC. AIChE Journal.2012; doi: 10.1002/aic.13781.

Keywords: fixed carrier membrane, piperazine, cross-linking, polyvinylamine, CO₂ permeance, CO₂/CH₄ selectivity