Development of poly(amidoamine) dendrimer/ poly(ethylene glycol) hybrid membranes for CO₂ capture at elevated pressures

To improve CO₂ separation performance of Poly (amidoamine) (PAMAM) dendrimer at pressure difference conditions, hybrid membranes have been developed by immobilizing of PAMAM dendrimer into a cross-linked poly(ethylene glycol) dimethacrylate (PEGDMA) polymer matrix. A multifunctional cross-linker (MFX) such as trimethylolpropane trimethacrylate (TMPTMA) was used to enhance membrane separation performance at elevated pressures. The resulting hybrid membrane PAMAM dendrimer / PEGDMA/TMPTMA hybrid membrane exhibited an excellent CO₂/H₂ selectivity of 30 and above with CO₂ permeance of 2.1×10^-12m³(STP)/(m2 s Pa) at 660 kPa CO₂ partial under 820 kPa feed pressure with 80% relative humidity at 40 °C. The PAMAM dendrimer/cross-linked PEG hybrid membrane shows great potential for CO₂ separation from H₂ in high pressure applications, such as IGCC process. A compatible crosslinker (CPC) was used to prepare the composite membrane with a thin selectivity layer to enhance CO₂ permeance. An isopropyl alkyl hindered amine IAM, tertiary amine TA1 and TA2 were added to the formation solution of membrane for investigating the effect of additive on CO₂ separation performance.