Scalable fabrication of COF membranes for aliphatic/aromatic separation of crude oil.

Cao, Li; An, Shuhao; Yuan, Bingbing; Li, Zhen; Samaras, Vasilios G; Xu, Ting; Zhang, Xixiang; Zhang, Huabin et al. · Science · 2026

basic_science · Level V

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Abstract

Distillation has been the cornerstone of crude oil refining for more than a century, relying on boiling point differences for fractionation. Although effective, it is highly energy-intensive and lacks the precision to separate specific hydrocarbon classes. We report crystalline covalent organic framework (COF) membranes with well-defined micropores and alkyl-functionalized frameworks that combine molecular sieving with preferential affinity to enrich aliphatics. An electric field-assisted roll-to-roll process enabled scalable fabrication of continuous membranes. These COF membranes enriched aliphatics to >95% and delivered permeance orders of magnitude higher than amorphous polymers in Arabian Light crude oil. A crude oil permeance of 0.34 liters m<sup>-2</sup> hours<sup>-1</sup> bar<sup>-1</sup> with >90% aliphatics enrichment was achieved using industrial-standard 1812 membrane modules, demonstrating a lower energy demand than distillation.