Integrated CO₂ capture and enzymatic bioconversion in supported ionic liquid membranes

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• 作者：Lu¨ªsa A. Neves ; Carlos Afonso ; Isabel M. Coelhoso ; Jo?o G. Crespo
• 关键词：CO2 capture ; Supported liquid membranes ; Ionic liquids ; Carbonic anhydrase ; Enzymatic transport of CO2
• 刊名：Separation and Purification Technology
• 出版年：2012
• 出版时间：3 September, 2012
• 年：2012
• 卷：97
• 期：Complete
• 页码：34-41
• 全文大小：842 K

文摘

This work proposes an innovative concept for the removal of CO₂ from flue gas streams using supported liquid membranes with non-volatile ionic liquids (or solvents), comprising a thermoresistant enzyme that enhances the selective transport of CO₂.

Membrane stability, CO₂ and N₂ permeability and CO₂/N₂ ideal selectivity was determined in the membranes developed. The selected liquid phases - the ionic liquid [C₄MIM][Tf₂N] and the organic solvent PEG - were immobilized in a porous hydrophobic polymeric support. The effect of introducing the carbonic anhydrase enzyme, on the solubility and diffusivity of CO₂ and N₂ through these solvents, under controlled water activity conditions, was investigated.

These results show that the supported liquid membranes prepared were stable at high temperatures and selective towards CO₂ when compared with N₂. Depending on the water activity of the solvents, the presence of enzyme may increase the CO₂ solubility coefficient up to 30 % , even if a low enzyme concentration is used. These results illustrate the potential of using this approach to further enhance the performance of SLMs impregnated with ionic liquids for capture of CO₂.