Carbon dioxide absorption in a gas-liquid membrane contactor: Influence of membrane properties and absorbent chemistry

• Published in: Chemical engineering journal advances Vol. 18; p. 100601
• Main Authors: Khumalo, Nomcebo P., Mamba, Bhekie B., Motsa, Mxolisi M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2024; Elsevier
• Subjects: Carbon dioxide absorption; Gas liquid membrane contactor; Hollow fibre membranes; Hydrophobicity; Gas liquid membrane contactor; Hollow fibre membranes; Hydrophobicity; Carbon dioxide absorption
• ISSN: 2666-8211; 2666-8211
• DOI: 10.1016/j.ceja.2024.100601

•A gas liquid membrane contactor was used for CO2 absorption using nano-enabled amine solutions.•Custom-made porous hollow fibre membranes were prepared from waste polystyrene blended with polyvinyl chloride.•Polymer blending resulted in improved structural and chemical properties of the membranes.•Recirculating the liquid absorbent resulted in an increase in CO2 absorbed in the liquid/nanofluid.•The ethylene diamine solution and nanofluid achieved high CO2 absorption compared to MEA solutions/nanofluid. The present work demonstrates the performance of hollow fibre membranes fabricated using polyvinyl chloride, polystyrene (EPS) and polydimethylsiloxane (PDMS) coupled with 30% monoethanolamine (MEA) in a gas liquid membrane contactor (GLMC) for the absorption of carbon dioxide. A gas mixture with a composition of (50/50 v/v%) methane (CH4) and (CO2) was used to assess the efficiency of the prepared membranes in the removal of carbon dioxide. Then HFM 3 which showed high CO2 removal was used to separate a mixture of nitrogen (N2)/oxygen(O2)/carbon dioxide (CO2) with a composition of (73/18/9 v/v%), respectively. Four different absorption liquids: 30 % MEA solution, 30 % EDA solution, 30 % MEA – graphene oxide (GO) and 30 % EDA-GO nanofluids were coupled with HFM3 to analyse the efficiency of the different amine liquids in CO2 absorption in GLMC. The 30 % EDA-GO solution showed an increase in the efficiency of CO2 absorption. The nanofluids showed an enhancement factor for CO2 absorption in the nanofluid was 121 % and 117 % for MEA-GO and EDA-GO, respectively. This enhancement was attributed to the hydrodynamic effects and Brownian motion of graphene oxide in the amine liquids. 30 % EDA solution infused with 0.2 mg/ml graphene oxide nanoparticles achieved the highest loading of carbon dioxide 0.25 mol/ cm3.