Toluene impurity effects on CO2 separation using a hollow fiber membrane for natural gas

The performance of defect-free cross-linkable polyimide asymmetric hollow fiber membranes was characterized using an aggressive feed stream containing up to 1000 ppm toluene. The membrane was shown to be stable against toluene-induced plasticization compared with analogs made from Matrimid®, a commercial polyimide. Permeation and sorption analysis suggest that the introduction of toluene vapors in the feed subjects the membrane to antiplasticization, as the permeance decreases significantly (to less than 30%) under the most aggressive conditions tested. Separation efficiencies reflected by permselectivities were less affected. The effect of the toluene on the membrane was shown to be reversible when the toluene was removed.

Graphical abstractThis manuscript demonstrates the performance of an advanced cross-linked polyimide hollow fiber membrane for natural gas purification in the presence of a heavy hydrocarbon impurity – toluene. The results show that the membrane is resistant to plasticization compared to another commercial polyimide (Matrimid®), but shows evidence for antiplasticization.Figure optionsDownload full-size imageDownload high-quality image (177 K)Download as PowerPoint slideResearch highlights▶ Cross-linkable hollow fiber membranes were characterized with toluene in the feed. ▶ The membrane resisted toluene-induced plasticization compared to Matrimid® analogs. ▶ Analyses suggest toluene caused antiplasticization of the cross-linkable membrane. ▶ The effect of the toluene on the membrane was shown to be reversible.