Blend membranes comprising polyetherimide and polyvinyl acetate with improved methane enrichment performance

Khuram Maqsood; Asif Jamil; Anas Ahmed; Burhannudin Sutisna; Suzana Nunes; Mathias Ulbricht

doi:10.1016/j.chemosphere.2023.138074

Blend membranes comprising polyetherimide and polyvinyl acetate with improved methane enrichment performance

Chemosphere. 2023 Apr:321:138074. doi: 10.1016/j.chemosphere.2023.138074. Epub 2023 Feb 11.

Authors

Khuram Maqsood¹, Asif Jamil², Anas Ahmed³, Burhannudin Sutisna⁴, Suzana Nunes⁵, Mathias Ulbricht⁶

Affiliations

¹ Department of Chemical Engineering, University of Jeddah, Jeddah, Saudi Arabia. Electronic address: kmaqsood@uj.edu.sa.
² Department of Chemical, Polymer and Composite Materials Engineering, University of Engineering and Technology (New Campus) Lahore, Pakistan.
³ Department of Industrial and System Engineering, University of Jeddah, Jeddah, Saudi Arabia.
⁴ Okinawa Institute of Science and Technology, Okinawa, Japan.
⁵ Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
⁶ Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen,Essen, Germany.

PMID: 36780999
DOI: 10.1016/j.chemosphere.2023.138074

Abstract

A clean and sustainable energy source, biogas is widely accessible worldwide. The caloric value of biogas is related to its methane content, and therefore removal of other gases is essential for reaping the benefits of this cleaner resource. In contrast to other classical techniques, membrane technology is relatively new yet extremely promising for methane enrichment. The methane enrichment performance of polymeric membranes is constrained, hence newer material combinations have been investigated to enhance membrane performance. In this study, blend membranes comprised of polyetherimide (PEI) and polyvinyl acetate (PVAc) in varying proportions were prepared by adopting the wet-phase inversion technique. The generated pure, and blend membranes were characterized for the morphological, thermal, and structural study. The interactions of PEI and PVAc in blend samples were verified by FTIR analysis. On the other hand, SEM investigation indicated that the membranes have an anisotropic porous structure with a dense skin layer at the top. Subsequently, a single glass transition temperature (T_g), as validated by DSC analysis, indicates that the blended polymers are miscible. Furthermore, membranes' performance for gas separation was assessed regarding selectivity and permeance at feed pressures ranging from 2 to 6 bar. The permeation results showed that the CO₂ permeance has increased by 40.47% with the addition of 4 wt % PVAc at 2 bar pressure. Furthermore, ideal selectivity improves as the blend ratio increases; nonetheless, the highest value for CO₂/CH₄ ideal selectivity was attained with a 2 wt % PVAc addition and at 2 bar pressure, which is approximately 26% greater than the pure PEI membrane. At 4 bar pressure, optimum CO₂/N₂ selectivity value of 22.50 was achieved. The findings indicate that PVAc is an excellent option for expanding the separation performance of blended polymeric membranes for biogas enrichment.

Keywords: Biogas; Blend membrane; Carbon dioxide separation; Gas permeation; Methane enrichment; Polyetherimide; Polyvinyl acetate.

MeSH terms

Biofuels
Carbon Dioxide* / chemistry
Gases / chemistry
Methane* / chemistry
Polymers / chemistry

Substances

polyetherimide
Carbon Dioxide
polyvinyl acetate
Methane
Biofuels
Polymers
Gases