Title of article :
Dense film polyimide membranes for aggressive sour gas feed separations
Author/Authors :
Brian Kraftschik، نويسنده , , William J. Koros، نويسنده , , J.R. Johnson، نويسنده , , Oguz Karvan، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Pages :
12
From page :
608
To page :
619
Abstract :
Dense film membranes of the copolyimide 6FDA-DAM:DABA (3:2) are studied for simultaneous removal of CO2 and H2S from sour natural gas streams. Pure and mixed gas permeation as well as pure gas sorption data are reported at 35 °C and pressures up to 62 bar. The H2S partial pressures used are representative of highly aggressive field operations. Penetrant-induced plasticization effects are evident at feed pressures below 1 bar in pure H2S feeds; sub-Tg thermal annealing is used to effectively mitigate this effect, and these annealed films are used throughout the study. Surprisingly, H2S/CH4 selectivity nearly doubles for mixed gas testing in comparison to the pure component ideal selectivity values and approaches the level of a state-of-the-art glassy polymer, cellulose acetate (CA), at H2S partial pressures above 2 bar. Furthermore, permeation experiments using a 9.95% H2S, 19.9% CO2, 70.15% CH4 mixture at low feed pressures give CO2/CH4 selectivity of up to 49—over 30% greater than the pure component selectivity for 6FDA-DAM:DABA (3:2). The overall sour gas separation performance of this polyimide is comparable to high-performance rubbery polymer membranes, which have been reported for only moderate H2S partial pressure feeds, and is superior to that for CA based on a practical combined acid gas separation efficiency metric that we introduce. Finally, methods for continued development of the current polyimide membrane material for aggressive sour gas separations are presented.
Keywords :
Sour gas , Polyimide membranes , Hydrogen sulfide , Natural gas purification
Journal title :
Journal of Membrane Science
Serial Year :
2013
Journal title :
Journal of Membrane Science
Record number :
1359458
Link To Document :
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