(579a) A Polystyrene Sulfonate Assisted Polyethylenimine Membrane for Stable, Scalable and Highly Effective CO2/N2 Separation
AIChE Annual Meeting
2021
2021 Annual Meeting
Separations Division
Membranes for CO2 Capture
Thursday, November 11, 2021 - 8:00am to 8:25am
Greenhouse effect, largely caused by CO2 release, has become a critical concern for global climate change. The post-combustion CO2 capture is one of the major strategies to mitigate this issue. Membrane technology for carbon capture has drawn significant attention due to cost and energy efficiency and scalability. Many membranes for CO2 capture are limited by the tradeoff between CO2 permeance and CO2/N2 selectivity, poor long-term stability under actual operating condition (vacuum in permeate side). Facilitated CO2 carriers within the membrane structure help to overcome the permeance-selectivity tradeoff. However, these carriers are often lost under operational conditions. Herein, we fabricate a polystyrene sulfonate (PSS) assisted polyethylenimine (PEI) membrane by simple membrane casting where the carriers (amine groups in PEI) are stabilized electrostatically, providing long-term stability (>50 h) under varying vacuum condition. The CO2 permeance and selectivity could be tuned effectively by optimizing PEI loading. Our membrane shows a superior CO2/N2 separation performance with CO2 permeance >1,000 GPU and CO2/N2 selectivity over 250. Scalability of our membrane was demonstrated by preparing membrane with area ~70 cm2 while maintaining similar CO2 separation performances.