Journal of Membrane Science, Vol.415, 725-733, 2012
Development of alumina supported ternary mixed matrix membranes for separation of H-2/light-alkane mixtures
Ternary component mixed matrix membrane was prepared from PES, SAPO-34 and 2-hydroxy 5-methyl aniline on a macroporous alumina disk by the solvent evaporation method in order to investigate the effect of existence of an inorganic support. The membrane and its pure PES/Alumina counterpart were characterized by single gas permeability measurements of H-2, CH4, C2H6 and C3H8. The corresponding H-2/CH4 selectivities of membranes were 71.3 and 41. The membranes were also used to separate equimolar mixtures of H-2 with CH4, C2H6 and C3H8 over a temperature range of 35-90 degrees C. The separation selectivities of ternary component membrane were 73.4 for H-2/CH4, 242.9 for H-2/C2H6 and > 1000 for H-2/C3H8 at 35 degrees C, which are comparable to the separation selectivities of pure PES on alumina. The permeances of all gases through PES/SAPO-34/HMA/Alumina membrane were, however, higher than those through PES/Alumina membrane at 90 degrees C. Despite its very complex morphology, the PES/SAPO-34/HMA/Alumina membrane preserved its structure and quality during the separation of different gas mixtures over temperature cycles between 35 and 90 degrees C. The CO2 and CH4 adsorption isotherms of PES-SAPO-34-HMA system were also obtained at 25 degrees C. The adsorption capacity of ternary component system was 1.55 mmol CO2/g and 0.45 mmol CH4/g, which is appreciably higher than the adsorption capacity of pure PES. (c) 2012 Elsevier B.V. All rights reserved.