TY - JOUR
T1 - Simultaneous removal of CO 2 and H 2S from pressurized CO 2-H 2S-CH 4 gas mixture using hollow fiber membrane contactors
AU - Marzouk, Sayed A.M.
AU - Al-Marzouqi, Mohamed H.
AU - Teramoto, Masaaki
AU - Abdullatif, Nadia
AU - Ismail, Zahoor M.
N1 - Funding Information:
The authors would like to thank JCCP (Japan Cooperation Center, Petroleum) for the financial support. They would also like to acknowledge the Office of Research Support and Sponsored Projects of the UAE University.
PY - 2012/2/15
Y1 - 2012/2/15
N2 - In the present paper, the simultaneous removal of CO 2 and H 2S from their pressurized mixture with CH 4 (5% CO 2-2% H 2S-93% CH 4) using custom made membrane contactors equipped with micro-porous polymeric hollow fibers is described. Two types of commercial hollow fibers were employed and compared, i.e., expanded poly(tetrafluoroethylene) (ePTFE) and poly(tetrafluoroethylene-co-perfluorinated alkyl vinyl ether) (PFA). The feed gas mixture composition was 2% H 2S, 5% CO 2 in balance of CH 4 to mimic the typical natural gas composition. Distilled water, aqueous sodium hydroxide and amine solutions of different concentrations were tested as absorption liquids to achieve the selective removal of the acid gases from the pressurized gas streams. The effect of pressure on the simultaneous CO 2 and H 2S absorption rates was investigated by the simultaneous pressurization of the absorption liquid and the feed gas (up to 50 bar) and monitoring the residual acid gases in the exit stream. The obtained experimental results indicated that the simultaneous CO 2 and H 2S fluxes were enhanced by increasing the inlet gas pressure for both physical and chemical absorption solvents. Up to the authors' best knowledge, this is the first report on (i) the experimental simultaneous removal of CO 2 and H 2S from pressurized gas streams using HFM contactors and absorption solvents up to 50 bar and (ii) the utilization of PFA fibers in custom made high pressure-membrane modules. PFA fibers exhibited impressive higher fluxes (9-10 times) for CO 2 and H 2S than those obtained with the common ePTFE fibers which could be attributed in part to the associated higher mass transfer coefficient. The anticipated CO 2/H 2S flux ratio of 2.5 (which matches the ratio of their inlet concentrations in the feed gas) was obtained whenever the co-absorption was unhindered into absorption solvent of sufficient capacity, e.g., 2.0 M NaOH solution. Analysis of the mass transfer coefficients showed that while the overall mass transfer coefficients are determined by the liquid phase mass transfer coefficients at low pressures, gas phase mass transfer resistance contributes considerably to the overall resistance at high pressures.
AB - In the present paper, the simultaneous removal of CO 2 and H 2S from their pressurized mixture with CH 4 (5% CO 2-2% H 2S-93% CH 4) using custom made membrane contactors equipped with micro-porous polymeric hollow fibers is described. Two types of commercial hollow fibers were employed and compared, i.e., expanded poly(tetrafluoroethylene) (ePTFE) and poly(tetrafluoroethylene-co-perfluorinated alkyl vinyl ether) (PFA). The feed gas mixture composition was 2% H 2S, 5% CO 2 in balance of CH 4 to mimic the typical natural gas composition. Distilled water, aqueous sodium hydroxide and amine solutions of different concentrations were tested as absorption liquids to achieve the selective removal of the acid gases from the pressurized gas streams. The effect of pressure on the simultaneous CO 2 and H 2S absorption rates was investigated by the simultaneous pressurization of the absorption liquid and the feed gas (up to 50 bar) and monitoring the residual acid gases in the exit stream. The obtained experimental results indicated that the simultaneous CO 2 and H 2S fluxes were enhanced by increasing the inlet gas pressure for both physical and chemical absorption solvents. Up to the authors' best knowledge, this is the first report on (i) the experimental simultaneous removal of CO 2 and H 2S from pressurized gas streams using HFM contactors and absorption solvents up to 50 bar and (ii) the utilization of PFA fibers in custom made high pressure-membrane modules. PFA fibers exhibited impressive higher fluxes (9-10 times) for CO 2 and H 2S than those obtained with the common ePTFE fibers which could be attributed in part to the associated higher mass transfer coefficient. The anticipated CO 2/H 2S flux ratio of 2.5 (which matches the ratio of their inlet concentrations in the feed gas) was obtained whenever the co-absorption was unhindered into absorption solvent of sufficient capacity, e.g., 2.0 M NaOH solution. Analysis of the mass transfer coefficients showed that while the overall mass transfer coefficients are determined by the liquid phase mass transfer coefficients at low pressures, gas phase mass transfer resistance contributes considerably to the overall resistance at high pressures.
KW - Gas-liquid membrane contactors
KW - PFA hollow fiber
KW - Physical and chemical absorption
KW - Simultaneous removal of CO and H S at high pressures
KW - e-PTFE hollow fiber
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U2 - 10.1016/j.seppur.2011.10.024
DO - 10.1016/j.seppur.2011.10.024
M3 - Article
AN - SCOPUS:84856319981
SN - 1383-5866
VL - 86
SP - 88
EP - 97
JO - Gas Separation and Purification
JF - Gas Separation and Purification
ER -