Seminars and thesis defenses
Thin film enzyme - poly(ionic liquid) – free ionic liquid composite membranes for enhanced CO2 absorption with carbonate aqueous solutions
By Cristhian Molina Fernandez (iMMC / IMAP)
Carbonic anhydrase (CA) has been extensively studied in literature as CO2 hydration kinetics enhancer in CO2 absorption since the hydration reaction is the limiting step when using aqueous benign solvents. To protect the enzyme from the harsh conditions in the stripper, CA is usually immobilized. However, depending on the immobilization method, this procedure can lead to the reduction of enzyme activity or the increase of mass transfer limitations. Room temperature ionic liquids (ILs) have been proven as potential solvents in biochemical reactions, increasing in many cases the enzyme activity and stability. Furthermore, polymerized ILs (PIL) present high CO2 solubility. The present study focus on the elaboration, characterization and testing of CA integrated poly(ionic liquid) – free ionic liquid composite membranes in CO2 absorption using aqueous benign solvents. To reduce diffusional mass transfer limitations, thin film PIL-IL membranes with high free IL content were prepared by bulk free radical polymerization on top of a porous PVDF support. The enzyme was dissolved in the free IL before polymerization ensuring immobilization by physical entrapment inside of the cross-linked polymeric matrix.