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Screening and characterization of catalytic composite membranes for ethyllactate production

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2004
Oğuzer, Özge
In this research, molybdophosphoric acid (PMo) was blended with polysulfone polymer (PSF) and form a film catalyst by using a common solvent dimethylformamide (DMF). Kinetic and mass transfer parameters were evaluated for catalytic films in ethanol lactic acid esterification reaction as film surface area, film thickness and catalyst loading were varied at 50?C, 1 atm and 1:1 ethyl alcohol to lactic acid mole ratio conditions. Also prepared films were characterized by DSC, TGA, FTIR, X-ray and SEM analysis. It was observed that the catalytic films showed higher activities with respect to the unloaded form of PSF and activities were increased with the increasing loading levels. The stabilities of the loaded catalysts were tested by means of deactivation experiments. A decrease was observed after 5th trial for 10wt% PMo loaded PSF film and at 4th trial for 15wt% PMo loaded PSF film. However, activities of the loaded films gave still higher conversion results than the unloaded PSF film. Also it was proved that with increasing film thickness conversion was decreased and increasing surface area conversion was increased. It was observed from the characterization studies that PMo catalysts have no chemical interaction with the PSF polymer and there was trace amount of DMF solvent was observed in the PMo-PSF catalytic film. Particulate structure of the PMo catalyst was observed and there is no catalyst agglomeration in the membrane network. However, along the thickness, catalyst particles were not homogeneously but finely dispersed in amorphous film structure.