Coordination crosslinked microporous polyimides for membrane‐based crude oil fractionation

Abstract Membrane technology could serve as an energy‐efficient alternative for heat‐based crude oil fractionation, yet membrane separation of liquid hydrocarbon mixtures puts forward strict requirements for membrane materials to tolerate hydrocarbon infiltration with simultaneously precise molecular differentiation. Herein, we designed a series of microporous polyimides coordinately crosslinked by copper ions for membrane‐based crude oil fractionation. The resulting membranes exhibit high toluene permeance up to 0.29 L m −2 h −1 bar −1 and >80% rejection to liquid hydrocarbons with molecular weights >170 Da. Through a two‐stage membrane process, the gasoline content is enriched from 54.5% in a real gasoline and diesel mixture to 96.8%. Importantly, our polyimide membrane demonstrates the ability to separate real light crude oil effectively. This study presents an effective approach for designing engineering‐polymer membranes for liquid hydrocarbon separation, boosting the development of membrane‐based crude oil fractionation.