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Projeto de investigação
Advanced Membrane Design based on Metal-Organic Frameworks-Supported Ionic Liquids for CO2 Separation
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Design of Enzyme Loaded W/O Emulsions by Direct Membrane Emulsification for CO2 Capture
Publication . Mondal, Suchintan; Alke, Bhavna; de Castro, Aline Machado; Ortiz-Albo, Paloma; Syed, Usman Taqui; Crespo, João G.; Brazinha, Carla; DQ - Departamento de Química; LAQV@REQUIMTE; MDPI AG
Membrane-based gas separation is a promising unit operation in a low-carbon economy due to its simplicity, ease of operation, reduced energy consumption and portability. A methodology is proposed to immobilise enzymes in stable water-in-oil (W/O) emulsions produced by direct membrane emulsification systems and thereafter impregnated them in the pores of a membrane producing emulsion-based supported liquid membranes. The selected case-study was for biogas (CO2 and CH4) purification. Upon initial CO2 sorption studies, corn oil was chosen as a low-cost and non-toxic bulk phase (oil phase). The emulsions were prepared with Nadir® UP150 P flat-sheet polymeric membranes. The optimised emulsions consisted of 2% Tween 80 (w/w) in corn oil as the continuous phase and 0.5 g.L−1 carbonic anhydrase enzyme with 5% PEG 300 (w/w) in aqueous solution as the dispersed phase. These emulsions were impregnated onto a porous hydrophobic PVDF membrane to prepare a supported liquid membrane for gas separation. Lastly, gas permeability studies indicated that the permeability of CO2 increased by ~15% and that of CH4 decreased by ~60% when compared to the membrane without carbonic anhydrase. Thus, a proof-of-concept for enhancement of CO2 capture using emulsion-based supported liquid membrane was established.
Impact of Ionic Liquid Structure and Loading on Gas Sorption and Permeation for ZIF-8-Based Composites and Mixed Matrix Membranes
Publication . Ortiz-Albo, Paloma; Ferreira, Tiago J.; Martins, Carla F.; Alves, Vitor; Esteves, Isabel A. A. C.; Cunha-Silva, Luís; Kumakiri, Izumi; Crespo, João Goulão; Neves, Luísa A.; DQ - Departamento de Química; LAQV@REQUIMTE; MDPI AG
Carbon dioxide (CO2) capture has become of great importance for industrial processes due to the adverse environmental effects of gas emissions. Mixed matrix membranes (MMMs) have been studied as an alternative to traditional technologies, especially due to their potential to overcome the practical limitations of conventional polymeric and inorganic membranes. In this work, the effect of using different ionic liquids (ILs) with the stable metal–organic framework (MOF) ZIF-8 was evaluated. Several IL@ZIF-8 composites and IL@ZIF-8 MMMs were prepared to improve the selective CO2 sorption and permeation over other gases such as methane (CH4) and nitrogen (N2). Different ILs and two distinct loadings were prepared to study not only the effect of IL concentration, but also the impact of the IL structure and affinity towards a specific gas mixture separation. Single gas sorption studies showed an improvement in CO2 /CH4 and CO2 /N2 selectivities, compared with the ones for the pristine ZIF-8, increasing with IL loading. In addition, the prepared IL@ZIF-8 MMMs showed improved CO2 selective behavior and mechanical strength with respect to ZIF-8 MMMs, with a strong dependence on the intrinsic IL CO2 selectivity. Therefore, the selection of high affinity ILs can lead to the improvement of CO2 selective separation for IL@ZIF-8 MMMs.
Mixed matrix iongel membranes containing azo-porous organic polymers
Publication . Nabais, Ana R.; Ortiz-Albo, Paloma; Zhou, Jin Xiu; Huang, Mu Hua; Mecerreyes, David; Crespo, João G.; Tomé, Liliana C.; Neves, Luísa A.; LAQV@REQUIMTE; DQ - Departamento de Química; Elsevier
The effect of temperature, pressure, and humidity content in the gas separation performance of iongel membranes are crucial parameters that should be assessed to determine the real potential of these materials to be used in CO2 separation processes. In this work, we present a detailed study on the impact of temperature (303, 323 and 353 K), pressure (2 and 4 bar), gas composition and water vapour content (between 11 and 21% of relative humidity) on the performance of iongels containing azo-porous organic polymers (azo-POPs), for CO2/N2 and CO2/CH4 binary gas separations. The iongels combining 80 wt% of the ionic liquid (IL) [C2mim][TFSI], 20 wt% of poly(ethylene glycol) diacrylate (PEGDA) and 0.5 wt% of different azo-POPs were prepared by a solvent-free UV curing method. At the lower temperature, the pressure increase seems to have a negative impact on the CO2 permeability of the prepared mixed matrix iongel membranes (MMIMs). However, the opposite behaviour was found when the temperature increases. Moreover, the presence of humidity in the feed gas stream affects the gas separation performance of the studied iongels, since the CO2 permeability greatly increases with increasing humidity in the gas mixture, while the selectivity decreases, for both gas separations under study. In general, the high pressure and temperature, and the presence of humidity have a significant influence on the separation performance of the studied iongel membranes, due to induced alterations in their structure and overall stability.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
OE
Número da atribuição
SFRH/BD/139389/2018