Supported silicotungstic acid on zirconia catalyst for gas phase dehydration of glycerol to acrolein

Coking of Catalysts in Catalytic Glycerol Dehydration to Acrolein

“…95 Nevertheless, this can also be partly explained by the proposition that, due to the high density of acid sites, the intermolecular dehydration of glycerol activated on adjacent acid sites accelerate followed by the successive coupling of hydroxyl groups of glycerol and then formation of carbonaceous deposits or coke. 108 For instance, in 2009, Suprun et al 63 performed catalytic glycerol dehydration under atmospheric pressure and at 280 °C in a fixed-bed reactor, feeding the catalytic bed a 5 wt % aqueous glycerol solution over SAPO-11, SAPO-34, Al 2 O 3 −PO 4 , and TiO 2 −PO 4 catalysts (total acidity: 1.33, 0.5, 0.3, and 0.3 mmol g −1 cat −1 , respectively). After 10 h, the amount of the resultant coke was found in the order: SAPO-34 (>9%) > SAPO-11 (4.6%) > TiO 2 −PO 4 (3.1%) > Al 2 O 3 −PO 4 (2.4%).…”

Theoretical and experimental evaluation of mass transfer limitation in gas phase dehydration of glycerol to acrolein over supported HSiW catalyst

“…Nitrogen adsorption-desorption was utilized to determine the pore size and surface area by Brunauer-Emmett-Teller (BET) method. Details of different characterization results have been discussed in our previous studies [26,27]. Table 1 summarizes some of the physicochemical properties of bulk samples and 30HZ-20A catalyst.…”

“…Based on our knowledge, there is no study on internal and external mass transfer limitations on gas-phase glycerol dehydration to acrolein in a continuous packed-bed reactor (PBR) over heterogeneous catalysts. Various steps of catalyst synthesis, screening [26,27], and optimization and kinetic study [28] have been investigated in our previous research. The objective of this work is to evaluate the existence of internal and external mass transfer limitations by theoretical and experimental approaches.…”

Heteropolycompounds as catalysts for biomass product transformations

“…The authors found that, generally, all tungsten-containing catalysts showed outstanding performance with regard to activity and selectivity compared to Mo-and P-containing materials. The best results include a selectivity value of 75% at complete conversion, which was achieved using SiW supported on aluminosilicate at 548 K 231,232 The dehydration of glycerol using ZrO 2 -supported PW catalysts at 588 K gave acrolein with conversion and yield values of 76 and 54% respectively 233,234 , while using ZrO 2supported SiW catalysts at 573 K higher conversion of glycerol was achieved (92 %), however the selectivity to acrolein was similar 235 251 , and these catalytic materials were also tested for the catalytic gas-phase glycerol dehydration to acrolein.…”