Kinetics of the esterification of palmitic acid with methanol catalyzed by 12-tungstophosphoric acid supported on ZrO2

Abstract

A series of catalysts containing 5-25 wt% 12-tungstophosphoric acid supported on hydrous zirconia were prepared and their catalytic activity evaluated for the esterification of palmitic acid with methanol. These catalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, surface area (BET method), and potentiometric titration for the estimation of acidity. The catalyst with 20 wt% TPA calcined at 300°C exhibited the highest activity. The effects of reaction variables such as catalyst loading, methanol to acid molar ratio and reaction temperature were studied. The pseudo-homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic models were applied to correlate the experimental kinetic data and kinetic parameters were evaluated. The LHHW model gave the best fit.

Recent progress on supported polyoxometalates for biodiesel synthesis via esterification and transesterification

“…Sai Prasad and co-workers reported TPA supported onto hydrous zirconia for the esterification of palmitic acid with methanol. 76 The catalyst with 20 wt% TPA calcined at 300 °C exhibited the highest activity. The pseudo-homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic models were applied to correlate the experimental kinetic data and kinetic parameters were evaluated.…”

Biomass Derivative Valorization Using Nano Core-Shell Magnetic Materials Based on Keggin-Heteropolyacids: Levulinic Acid Esterification Kinetic Study with N-Butanol

“…where n = 0 for the pH model, n = 1 for the ER model, and n = 2 for the LH model. This equation has been described by various authors in the esterification of organic acids [36][37][38][39]. Assuming that for the esterification of LEA, there is a weak sorption of reaction components on the catalyst surface (equilibrium constants of adsorption are low) so that the term ∑k i C i in the denominator is almost negligible [40]; the expression of the pH model is reduced to…”

Review on Biodiesel Production from Various Feedstocks Using 12-Tungstophosphoric Acid (TPA) as a Solid Acid Catalyst Precursor

“…In the case of catalysts with no pores, the active sites are believed to be exposed outside and therefore, the flowpath was considered to be three-dimensional (Scheme ). The metal oxide supports reviewed in this study (case numbers 3, 6–8, 11, 15, 16, 17, 19, 20, 23, 24) were readily available supports or synthesized as simple metal oxides following standard synthesis procedures. ,,− ,,− ,− Therefore, it was appropriate to assign flowpath 1 for these supports (column 3 of Supporting Information Table S.2). Silica based MCM-41 and SBA-15 (case number 4, 26) were synthesized using templates following well established procedures, for which the two-dimensional pore systems were confirmed. ,, The zeolite supports reviewed in this study (case number 1, 2, 25) were commercial supports or synthesized following well established conditions, ,, for which the pore systems are three-dimensional .…”