H3PW12O40 (HPA), an efficient and reusable catalyst for biodiesel production related reactions: esterification of oleic acid and etherification of glycerol

Abstract

Recebido em 4/5/10; aceito em 17/11/10; publicado na web em 14/3/11In esterification of oleic acid with methanol at 25 °C HPA displayed the highest activity. Moreover the HPA could be reused after being transformed into its cesium salt. In the reaction of etherification of glycerol HPA and Amberlyst 35W showed similar initial activity levels. The results of acid properties demonstrate 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.

Screening of Novel Materials for Biodiesel Production Through the Esterification of Oleic Acid

“…Finally, is worth noticing that the specific activity obtained in this contribution (6.4 µmol mg −1 h −1 ) is similar to the one reported for the 12-tungstofosforic acid H 3 PW 12 O 40 in the esterification of oleic acid with methanol (8.0 µmol mg −1 h −1 , OA:methanol molar ratio = 1:2.5) and ethanol (8.8 µmol mg −1 h −1 , OA:ethanol molar ratio = 1:6) [31,32].…”

Acidity and Characterization of 12-Tungstophosphoric Acid Supported on Silica-Alumina

“…This behavior of H 3 PW supported material is in agreement with others that have detected very low leaching under adequate preparation conditions. 59,60 To verify that the catalysis was truly heterogeneous, the optimized esterification reaction was repeated three times. The 30 wt.% H 3 PW/SiO 2 -Al 2 O 3 catalyst was recovered by centrifugation, washed with ethanol, dried in an oven at 100 °C and calcined at 200 °C before reuse.…”

Isomerization-cracking of n-octane on catalysts based on heteropolyacid H3Pw12O40 and heteropolyacid supported on zirconia and promoted with Pt and Cs

“…15 The Cs 2 CO 3 solution was added dropwise to an HPA solution at room temperature. The concentrations of both solutions were adjusted to get a precipitate with the nominal composition of Cs 2.5 H 0.5 PW 12 O 40 .…”