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Abstract
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In this work, by applying heat treatment the effect of heat treatment on PEI hollow fiber membrane contactors to control the structural parameters and evaluate the performance of the membranes for CO2 capture and also CO2 stripping was studied. The membranes were fabricated via a wet spinning into non solvent bath technique. Then, the heat-treated membranes were prepared by exposing them at 80,120 and 160 ?C for all period of 5, 15 and 30 min under air atmosphere. To investigate the influence of hot air on the membrane structural parameters and membrane performance the following characterization tests were performed: measurement of membrane pore size, effective surface porosity, membrane bulk porosity and density, liquid entry pressure of water (LEPw), performance of hollow fiber membranes in gas-liquid contacting process (absorption and stripping) and also long term of membranes in stripping operation. As a result, the membrane mass transfer resistance was calculated. The experimental results revealed that, the greatest effect on the membranes structure was observed in the shortest duration of time and the lowest temperature i.e. 80 ?C and 5 min, which posseses the pore size of 49.97 (nm) and maximum effective surface porosity of 26.81 (1/m) and the highest LEPw of 3.4 bar. Accordingly, the wettability of this membrane in comparison to the untreated and the other heat treated membranes had been reduced. Also, at all the time periods and the temperatures, density of fibers were reduced and LEPw and porosity of membranes were increased. As it was seen in CO2 absorption, the heat treated membrane at the temperature of 80 ?C and period of 5 min has shown the best efficiency and CO2 stripping flux. But, it should be mentioned that although, the heat treatment process improve the heated membrane stability in comparison with unheated membrane, a method should be looked for increasing this degree of stability. In conclusion, applying heat treatment on the PEI hollow fiber
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