Esterification of oleic acid employing sulfonated polystyrene and polysulfone membranes as catalysts

Abstract

In the present study, catalytic activity of dense, porous, electrospun membranes of polysulfone (PSF) and polysulfone with sulfonated polystyrene (PSF_PSS) have been evaluated in reactions of esterification of oleic acid with methanol, in times that varied from 10 to 480 minutes. Conversion to biodiesel has been confirmed by FTIR and quantified through gas chromatography. The results showed the catalysts used were effective in the esterification reaction studied and the PSF_PSS electrospun membrane has presented the best conversion to methyl oleate, reaching 70.5% in a 10-minute reaction and 95.8% in a 240-minute reaction, when methanol:oleic acid molar ratio of 10:1, 5% of catalyst and temperature of 100 °C were used. Considering the performance of solid catalysts described in literature, mainly related to reaction times and conversion of the process, this study reveals a promising feasibility of using electrospun membranes of PSF_PSS for developing a heterogeneous acid catalyst aimed to biodiesel synthesis.

Keywords:
biodiesel; esterification; membranes; polysulfone; sulfonated polystyrene