N -Aryl–linked spirocyclic polymers for membrane separations of complex hydrocarbon mixtures

Abstract

The fractionation of crude-oil mixtures through distillation is a large-scale, energy-intensive process. Membrane materials can avoid phase changes in such mixtures and thereby reduce the energy intensity of these thermal separations. With this application in mind, we created spirocyclic polymers with N-aryl bonds that demonstrated noninterconnected microporosity in the absence of ladder linkages. The resulting glassy polymer membranes demonstrated nonthermal membrane fractionation of light crude oil through a combination of class- and size-based “sorting” of molecules. We observed an enrichment of molecules lighter than 170 daltons corresponding to a carbon number of 12 or a boiling point less than 200°C in the permeate. Such scalable, selective membranes offer potential for the hybridization of energy-efficient technology with conventional processes such as distillation.

“All Polyimide” Mixed Matrix Membranes for High Performance Gas Separation

“…It can be seen from the hysteresis curve that the micropores of TP and 6FDA-Durene are constructed by parallel plate-like packing particles. However, AP and BP display ink-bottle-shaped micropores [34]. NLDFT pore size distribution data (Figure 2b) confirmed that microporous PIs had a large number of micropores less than 2 nm.…”

Shape‐Selective Ultramicroporous Carbon Membranes for Sub‐0.1 nm Organic Liquid Separation

“…[71,72] Although we utilize the hexane isomers to illustrate our approach in this study, we believe our stable carbon molecular sieve OSFO membrane platform can be applied across a wide range of difficult organic liquid separations. For example, Thompson et al [35] recently reported rationally designed polymeric membranes with intrinsic microporosity capable of fractionating light crude oil with highly complex hydrocarbon mixtures. Therefore, a more efficient way of synergistically combining the benefits of both materials and process will make large-scale separation process more energy-efficient.…”

The refinery of today, tomorrow, and the future: A separations perspective

“…This distribution provides significant enrichment of molecules that are farthest away from the split point. We have recently demonstrated that polymer membranes have the potential to fractionate light crude oils without requiring phase change 23 . In these low stage‐cut (4%) experiments, the membrane successfully rejected molecules in excess of 170 Da and preferentially permeated aromatic molecules less than this molecular weight (Figure 5).…”

“…The membrane rejects molecules in the shale oil that have molecular weights over 170 Da, and preferentially permeates aromatic molecules below that value. From Reference 23. Reprinted with permission from AAAS…”