CO2/N2 gas separation using Fe(BTC)-based mixed matrix membranes: A view on the adsorptive and filler properties of metal-organic frameworks

• Published in: Separation and purification technology Vol. 202; pp. 174 - 184
• Main Authors: Nabais, Ana Rita, Ribeiro, Rui P.P.L., Mota, José P.B., Alves, Vítor D., Esteves, Isabel A.A.C., Neves, Luísa A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-08-2018
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2018.03.028

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•Metal-Organic Framework (MOF) Fe(BTC) evaluated as an adsorbent for CO2/N2 adsorption.•Fe(BTC)-based mixed matrix membranes (MMMs) were prepared and characterized.•MMMs showed higher separation performance at high temperature.•At 353 K, Fe(BTC)-based MMMs surpass the Robeson upper-bound correlation.
The incorporation of a Metal-Organic Framework (MOF), Fe(BTC), into a polymeric membrane was assessed for CO2/N2 gas separation. The adsorptive and filler properties of the MOF in the Mixed Matrix Membranes (MMMs) produced were investigated as a strategy to separate CO2 from N2 and contribute to reduce CO2 emissions. Therefore, Fe(BTC) was firstly characterized by single-component adsorption equilibria measurements of CO2 and N2, to evaluate the MOF performance as an adsorbent for CO2/N2 separation and its adsorption role in the MMMs performance. Fe(BTC) was then incorporated in Matrimid®5218 at different loading percentages, and the MMMs produced were characterized by distinct techniques (SEM, TGA, puncture tests and contact angle essays). Finally, pure gas permeation experiments were carried out for CO2 and N2 at 303 K, 323 K and 353 K, to evaluate the temperature impact on both gas permeability and CO2/N2 ideal selectivity. The results show that an increase in CO2 permeability and CO2/N2 ideal selectivity can be advantageously achieved, especially at the higher operating temperature of 353 K. At these conditions, the Robeson upper-bound is surpassed, which is a clear indication of the high potential of using Matrimid®5218/Fe(BTC) MMMs in post-combustion streams at high-temperatures.