Electrospun Fibrous Carbon Molecular Sieve Membrane for the Separation of Aromatics and Cyclic Aliphatics.

Abstract

The separation of aromatic compounds from cyclic aliphatics has drawn decades of attention from researchers. Adsorption-based separation, an energy-saving recovery technology, can be efficiently carried out on various adsorbents. Developing cost-effective adsorbents with good selectivity and batch preparation capability is an inevitable trend. Carbon molecular sieves (CMSs) are promising, but controlling the pore size distribution is a major limitation. In this work, a series of phenolic resin-based fibrous CMSs with a concentrated distribution of ultramicropores and conjugated sp² carbon structures was synthesized by regulating electrospinning and heat treatment. Experimental and computational studies indicate that SCF2-1000 exhibits an adsorption amount ratio of 6.8 in static adsorption, comparable to those of reported framework materials and zeolites. In equimolar benzene/cyclohexane breakthrough experiments, it achieves a high adsorption amount ratio of 11.4 and a long separation window of 2000 min g^-1. FCF-1H demonstrates a dynamic adsorption selectivity factor of 30.14 and a long separation window of 8300 min g^-1 in a 1:9 toluene/methylcyclohexane separation experiment. The short-range and concentrated ultramicropores allow rapid, selective adsorption and easy regeneration without decline. This work offers a feasible pathway toward separating and purifying mixed gases containing aromatics and their hydrogenation products in industrial processes.