BACKGROUND In this work, a pervaporation membrane bioreactor (PVMBR) with the novel ethanol permselective membrane was used to achieve ethanol production with high yield. For this purpose, ethanol produced by Saccharomyces cerevisiae from glucose and pervaporation was performed via dense hydrophobic polydimethylsiloxane (PDMS) having carbon nanotube‐graphene oxide (CNT‐GO) mixed matrix membrane. Different percentages of CNT‐GO (0, 0.25, 0.5, 0.75, and 1) were loaded in polymer matrix. Synthesized membranes were analyzed using FESEM, AFM, FTIR and XRD. RESULTS The bonding of groups in CNT‐GO, that was synthesized in this work, and membranes was characterized and confirmed using FTIR test. Considering the existence of 0.75 wt% of CNT‐GO in PDMS showed the highest ethanol selectivity of 22.5 in synthetic ethanol‐water solution, this incorporation was selected to use in PVMBR. The high ethanol selectivity was proved using XRD patterns. Also, FESEM indicated the optimum dispersion of nanoparticles at 0.75% of loading and AFM proofed the optimum surface roughness at this percentage. CONCLUSIONS The results showed that maximum ethanol production in PVMBR was achieved after 44 h with productivity of 0.5g.l−1.h−1 in feed side and 9.89 g.l−1.h−1 in permeate side. In fact, PVMBR enhanced the ethanol concentration up to 26 times. © 2020 Society of Chemical Industry