High-performance PDMS/ZIF-8 tubular membranes for efficient 1,3-butadiene purification from C4 mixtures

The 1,3-butadiene (C₄H₆) purification currently relies on complex extractive distillation, which uses large amounts of organic solvents and excessive energy consumption. Developing new membrane separation technology for C₄H₆ purification can effectively reduce energy consumption and be more environmentally friendly. However, there are few studies on membrane separation processes for C₄H₆ purification, especially in terms of the feasibility of larger membrane areas for industrial separations, which limits their application. Herein, high-performance PDMS/ZIF-8 tubular membranes were developed and assembled into 3-channel modules to form a 7-step membrane for C₄H₆ purification from industrial C4 fraction mixtures. The prepared high-quality PDMS/ZIF-8 tubular membranes performed outstanding separation for C₄H₆ and other C4 gas mixtures at different feed temperatures, pressures and compositions. The separation mechanism was also revealed by introducing molecular geometry factors and molecular dynamics (MD) simulations. Based on the fact that the C4 fractions are generally liquid phases in the industry, the pervaporation performance of PDMS/ZIF-8 tubular membranes for industrial C4 mixture purification was further evaluated. The variation in the C₄H₆ purity on the permeate side of the PDMS/ZIF-8 tubular membrane was further revealed by introducing Stage-Cut. Thus, the C₄H₆ purity was increased from 43.1 % to 96.1 %, showing promising application prospects.