Facilitated transport of carbon dioxide and hydrogen sulfide in ion exchange membranes
Steady-state fluxes of acid gases and mixtures with CH/sub 4/ were measured for ion exchange membranes (IEMs) containing and ethylene diamine (EDA) carrier. The IEMs were prepared by exchanging EDA/sup +/ in aqueous solution for counterions in 170 ..mu..m Nafion perfluorosulfonic acid ionomer films. Facilitation factors (F) of 26.7 to 1.44 were measured for CO/sub 2/ feed gases with 1% to 100% CO/sub 2/, respectively. The H/sub 2/S F value was 15.8 for a 5% feed gas, increasing to 24.1 at a 1% feed. Facilitation factors measured for both CO/sub 2/ and H/sub 2/S in IEMs were larger than those for immobilized liquid membranes containing 1 M EDA solution. Separation factors for acid gases over CH/sub 4/ of up to 552 and 1200 were observed for CO/sub 2/ and H/sub 2/S, respectively, during binary mixture experiments. In experiments with CO/sub 2//H/sub 2/S/CH/sub 4/ feed mixtures, separation factors ranged from 503 to 1170. The IEM separation factors compare very well with those for commercial cellulose ester membranes which range from 21-30. In competitive transport experiments, CO/sub 2/ was preferred over H/sub 2/S for all feed composition studied because the equilibrium constant (K/sub eg/) for the CO/sub 2//EDA reaction was 326 times that for the H/sub 2/S/EDA reaction. The CO/sub 2//H/sub 2/S flux ratios ranged from 2.85 to 103. The implication of these data is that an EDA IEM could separate and fractionate a CO/sub 2//H/sub 2/S mixture. The same competitive effect was observed during CO/sub 2//H/sub 2/S experiments. Analytical models based on constant carrier concentration predicted CO/sub 2/ and H/sub 2/S facilitation factors very well.
- Research Organization:
- Colorado Univ., Boulder (USA)
- DOE Contract Number:
- AI21-84MC21271
- OSTI ID:
- 6823080
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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CARBON DIOXIDE
REMOVAL
HYDROGEN SULFIDES
ION EXCHANGE MATERIALS
PERFORMANCE TESTING
METHANE
SEPARATION PROCESSES
EFFICIENCY
ION EXCHANGE
MATHEMATICAL MODELS
MEMBRANES
QUANTITY RATIO
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
MATERIALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TESTING
030300* - Natural Gas- Drilling
Production
& Processing