Effect of a heat pretreatment on the structure and properties of carbon supports for carbon membranes

Abstract

A heat pretreatment was developed to modify the microstructure and properties of the phenolic resin‐based carbon supports for the preparation of carbon membranes. The pore size distribution, porosity, surface functional groups, microstructure, and morphology of the supports were characterized by bubble pressure method, boiling method, infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy, respectively. Furthermore, the optimum preparation conditions of the as‐prepared supports were validated by the fabrication of supported carbon membranes. The results show that the heat pretreatment at 280 °C is helpful for the supports to tolerate the high temperature of subsequent pyrolysis and improve the adhesion to surface carbon membrane layers. When supported carbon membranes were prepared by the heat pretreated supports, spin‐coating of 4 times, and pyrolysis at 650 °C, the ideal selectivities of H2/N2 and O2/N2 can reach 52.8 and 8.0, respectively.

Preparation and characterization of CO2‐selective Pebax/NaY mixed matrix membranes

“…Single gas permeation of the MMMs was conducted by the traditional constant‐pressure variable‐volume technology. The detailed information on the test setup has been given in our previous report . Highly purified gas (i.e., CO 2 or N 2 , with purify ≥99.999%) supplied from gas cylinders was directly introduced to the feed side of the MMMs that was tightly fixed in a stainless steel membrane cell by rubber O‐rings.…”