Browsing by Keyword "Portuguese Foundation for Science and Technology (FCT)"
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Item Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part II: Effect of the carbonization temperature on the gas permeation properties(2015-03-02) Llosa Tanco, Margot A.; Pacheco Tanaka, David A.; Mendes, Adélio; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe influence of carbonization temperature on the permeation properties and aging of thin (4 μm) supported carbon molecular sieve membranes (c-CMSM), prepared from in house synthesized novolac phenolic resin loaded with boehmite nanoparticles, were studied. Just after membrane carbonization (fresh membrane), high permeance to N2 and O2 and low O2/N2 permselectivities were observed; the highest permeations were observed for carbonization end temperatures between 500 °C and 700 °C. After leaving the c-CMSM 1 day in the air, a large decrease in the permeation and considerable increase in the permselectivity were observed due to the reduction of the pore size by oxygen chemisorption and water physical adsorption; the permeability to H2 and H2/N2 ideal permselectivity for a membrane carbonized at 550 °C are close to palladium membranes for low temperature (<100 °C). The effect of the permeation characteristics of the membranes carbonized at various temperatures and the removal of water adsorbed in the pores by heat treatment were studied.