Selective Removal of Carbon Dioxide from Wet CO₂/H₂ Mixtures via Facilitated Transport Membranes containing Amine Blends as Carriers

Abstract

The selective separation of carbon dioxide (CO 2 ) from a wet gaseous mixture of CO 2 /H 2 through facilitated transport membranes containing immobilized aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), ethylenediamine (EDA) and monoprotonated ethylenediamine (EDAH + ) and their blends was experimentally investigated. The effect of CO 2 partial pressure, amine concentration, feed side pressure and amine species on the CO 2 and H 2 permeances were studied. The CO 2 permeability through amine solution membranes decreased with increasing CO 2 feed partial pressure but the H 2 permeance was almost independent of the H 2 partial pressure. A comparison of experimental results showed that single or blended amines with low viscosity and a moderate equilibrium constant, i.e., large forward and reverse reaction rate of CO 2 -amine, are suitable for effective separation of CO 2 . The permeability of CO 2 generally increased with an increase in amine concentration, although this increase may be compromised by the salting out effect and decrease in diffusivities of species. The results obtained indicated that CO 2 permeance across a variety of amines are in the order of DEA (2 M

Polyethylene Glycol (PEG) Addition to Polyethylenimine (PEI)-Impregnated Silica Increases Amine Accessibility during CO2 Sorption

“…Viscosity plays an important role in the diffusion of CO 2 in the bulk of the polymer phase in solid sorbents and influences sorption performance , as well as the permeability of membranes . The increases in viscosity during CO 2 sorption have been widely observed in solid amines, amine solutions, , and ionic liquids, , due to the formation of carbamate ion pairs that leads to cross-linking among PEI chains.…”

Carbon Dioxide: Capturing and Utilization

“…Separation of olefin/paraffin gases are very attractive and cost effective (Takht Ravanchi, 2008a, 2008b, 2008c, 2008d, 2009c, 2010a, 2010b, 2010c. CO 2 removal from gas streams especially natural gas is important for increase the heating value of the natural gas and limiting the CO 2 emission in the combustion systems (Heydari Gorji, 2009aGorji, , 2009b.…”

Investigation mechanism of DEA as an activator on aqueous MEA solution for postcombustion CO2 capture

“…Hagewiesche et al 8 shows the reaction behavior of MEA-MDEA absorption CO 2 experimentally and theoretically. In the work of Gorji et al, 10 it was founded that the blended system shows the high selectivity in the separation of CO 2 from CO 2 / H 2 . 9 Recently, some researcher founded that the use of blended of MEA and DEA shows some advantages in comparison with the single amine in the gas treatment process.…”