Dendrimer Liquid Membranes:  CO₂ Separation from Gas Mixtures

Abstract

A generation 0 poly(amidoamine) (PAMAM) dendrimer in the immobilized liquid membrane (ILM) configuration was studied using flat films and hollow fibers for CO 2 -N 2 separation. This dendrimer as a pure liquid functions as a CO 2 -selective molecular gate with highly humidified feed gas (Kovvali et al. J. Am. Chem. Soc. 2000, 122, 7594). The present work broadens the range of relative humidity of the feed gas stream (RH f ) by adding a small amount of glycerol to the pure dendrimer liquid. A 75% dendrimer-25% glycerol ILM was found to increase the operating range of RH f substantially while maintaining the CO 2 permeance and the selectivity (R CO 2 /N 2 ) close to the levels observed with a pure dendrimer ILM. The performances of pure and 75% dendrimer ILMs were found to be superior or comparable to the highest reported R CO 2 /N 2 's. This behavior is explained in terms of the charged environment in the dendrimer liquid membrane under humidified feed conditions and facilitated transport of CO 2 .

New Macromolecular Architectures for Permselective Membranes—Gas Permselective Membranes from Dendrimers and Enantioselectively Permeable Membranes from One-handed Helical Polymers—

“…Some liquid membranes using porous membranes containing dendrimers in the pores were reported. [34][35][36] A dendrimer membrane was prepared by the immersion of porous a hydrophilized polyvinylidene fluoride flat membrane (porosity 0.7; pore size 0.1 mm; thickness 100 mm; tortuosity 2.58; Millipore) into pure G0 PAMAM dendrimer or glycerol solution of G0 PAMAM dendrimer. 34,35 The CO 2 /N 2 permeation performance through the liquid membranes was measured under various humidity.…”

“…[34][35][36] A dendrimer membrane was prepared by the immersion of porous a hydrophilized polyvinylidene fluoride flat membrane (porosity 0.7; pore size 0.1 mm; thickness 100 mm; tortuosity 2.58; Millipore) into pure G0 PAMAM dendrimer or glycerol solution of G0 PAMAM dendrimer. 34,35 The CO 2 /N 2 permeation performance through the liquid membranes was measured under various humidity. The separation factor CO 2 /N 2 was almost 19000 at a low CO 2 partial pres-sure (Áp CO 2 ¼ 0:36 cmHg) under the completely humidified condition, while it was around 700 at the higher Áp CO 2 (> 30 cmHg).…”

A Review of Carbon Dioxide Selective Membranes: A Topical Report

“…It was suggested that the permeance of CO 2 could be increased by increasing CO 2 carrier solubility in the ILM liquid and by preparing ILMs with thinner hydrophilic supports. In another study by the same authors [202,203], they used polyamidoamine (PAMAM) generation 0 dendrimers having ethylenediamine as the CO 2 carrier in porous hydrophilic polyvinyldine fluoride supported ILM. Dendrimer immobilized liquid membranes containing a high concentration of primary and tertiary amine provided a facilitated CO 2 transport and also nearly eliminated the other gases.…”

【Original Contribution】 Effect of Ionic Liquid Additives on CO2Permeation and CO2/N2Selectivity through Facilitated Transport Membranes

“…Various FTMs for CO2 capture have been developed and many efforts have been made to enhance the CO2 permeability and selectivity. The specific performances of the FTMs have been widely investigated and it was empirically determined that the CO2 permeability and selectivity of FTMs under humid conditions were quite high 4,6,8,9,11,12) . Especially, the CO2 permeabilities of the FTMs containing amino acid as the CO2 carrier were strongly affected by humidity in the gas stream 6,8) .…”