CO₂ separation has become an important global agenda because of the requirements of industrial products and CO₂-induced global warming. Membrane-based technologies have provided an alternative for CO₂ separation. To make membrane-based separation more competitive, membranes must have a high permeance and high selectivity. Herein, we have developed a new high-performance multiple-layer hollow fiber membrane of cellulose triacetate (CTA) and cellulose diacetate (CDA) blends for CO₂ separation. CTA and CDA blends were chosen because they have similar chemical structures, good separation performance, economical and green nature. Both single-layer and dual-layer hollow fibers were fabricated by various spinning strategies. The optimized dual-layer membrane spun at outer dope flow rate of 1 mL/min exhibits a CO₂ permeance of 45 GPU and an ideal CO₂/CH₄ selectivity of 30.3 at 2 bar. Comparing with the optimized single-layer hollow fiber spun at 5 cm air gap distance and 15 m/min take-up speed, the former has a 100% higher CO₂ permeance without compromising the selectivity. The as-produced hollow fibers display a plasticization pressure of about 10 bar. In addition, they have impressive mixed gas CO₂/CH₄ selectivity of >40 at 2 bar. Therefore, the newly developed dual-layer hollow fiber membranes may have great potential for CO₂/CH₄ separation.

由于工业产品的需求和由CO ₂引起的全球变暖，CO ₂分离已成为重要的全球议程。基于膜的技术为CO ₂分离提供了替代方法。为了使基于膜的分离更具竞争力，膜必须具有高渗透性和高选择性。在此，我们开发了一种新型高性能多层中空纤维膜，该膜由三乙酸纤维素（CTA）和二乙酸纤维素（CDA）共混物制成，用于CO ₂分离。选择CTA和CDA混合物是因为它们具有相似的化学结构，良好的分离性能，经济和绿色的特性。单层和双层中空纤维都是通过各种纺丝策略制造的。在外部浓液流速为1 mL / min时旋转的优化双层膜表现出的CO ₂渗透率为45 GPU，在2 bar下的理想CO ₂ / CH ₄选择性为30.3。与以5 cm气隙距离和15 m / min的卷取速度纺制的优化的单层中空纤维相比，前者的CO ₂渗透率高100％，而不会影响选择性。所生产的中空纤维表现出约10巴的增塑压力。此外，他们还有令人印象深刻的混合气体CO ₂在2 bar时> 40的/ CH ₄选择性。因此，新开发的双层中空纤维膜可能具有很大的CO ₂ / CH ₄分离潜力。