Synthesis and characterization of supported Phenolic resin/Carbon nanotubes Carbon membranes for gas separation

Abstract

In this work, separation performance of supported carbon membranes produced from Novolac Phenolic resin as the main precursor and carbon nanotubes as nanofiller were investigated for separation of CO₂ from N₂ and CH₄. Supports were produced by carbonization of Novolac Phenolic resin-activated carbon mixture, and selective layer was coated by dip coating of prepared supports into solutions with different concentrations of Novolac Phenolic resin/carbon nanotubes. The composite membranes were pre-oxidized and carbonized under vacuum condition up to 160°C and 700°C, respectively. Carbon membranes were characterized using FE-SEM, BET, and gas permeation test. Results revealed that the best proportion of Novolac Phenolic resin/activated carbon was 40/60 wt% to make a defect-free and applicable support, most pores of which had sizes less than 10 nm. Membranes were tested at different pressures, and the results showed that CO₂ permeability increased with pressure. The carbon membrane made with 40 wt% Novolak phenolic resin and 1 wt% carbon nanotubes showed the best separation performance with CO₂/CH₄ and CO₂/N₂ selectivity of 19.5 and 18.3 in 10 bar, respectively.