A generation 0 poly(amidoamine) (PAMAM) dendrimer in the immobilized liquid membrane (ILM) configuration was studied using flat films and hollow fibers for CO2-N2 separation. This dendrimer as a pure liquid functions as a CO2-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 (RHf) 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 RHf substantially while maintaining the CO2 permeance and the selectivity (αCO2/N2) 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 αCO2/N2'S. This behavior is explained in terms of the charged environment in the dendrimer liquid membrane under humidified feed conditions and facilitated transport of CO2.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering