H3PW12O40, an efficient and reusable catalyst for biodiesel production related reactions. Esterification of oleic acid and etherification of glycerol.

J. SEPÚLVEDA; C. VERA; J. C. YORI; J.M. BADANO

QUíMICA NOVA

SOC BRASILEIRA QUIMICA

Lugar: Sao Paulo; Año: 2011 vol. 34 p. 601 - 606

0100-4042

Esterification of oleic acid with methanol and etherification of glycerol with tert-butanol was studied using H3PW12O40 (HPA); Cs2.5H0.5PW12O40 and Amberlyst 35W catalysts.  In esterification at 25 °C HPA displayed the highest activity.  While the resin needed 90 ºC to be active HPA had a similar activity level at 25 ºC.  Moreover the HPA catalyst could be reused after being transformed into its cesium salt.  However in etherification of glycerol HPA and Amberlyst 35W showed similar initial activity.  The acid properties of the catalysts were determined by means of the liquid phase reaction test of dehydration of 1,4-butanediol and by ammonia desorption.               The results demonstrated that HPA is a strong protonic acid and that both surface and bulk protons contribute to the acidity.  Because of its strong affinity for polar compounds, HPA is also seemingly dissolved in both oleic acid and methanol.  The reaction in this case proceeds with the catalyst in the homogenous phase.