Reaction mechanism for glycerol dehydration in the gas phase over a solid acid catalyst determined with on-line gas chromatography

Catalytic Dehydration of Glycerol to Acrolein over a Catalyst of Pd/LaY Zeolite and Comparison with the Chemical Equilibrium

“…In the case of acrolein, even though recently values have been reported for ΔH°f by means of computational chemistry methods by Vasiliu et al [73], and later by Lewars and Liebman [84], the subsequent calculations in this work were carried out with data obtained with the Joback method due to its result (ΔH°f = −65.4 kJ·mol −1 ) which is in very good agreement with the value reported by Lewars and Liebman [84] (ΔH°f = −65 kJ·mol −1 ). Although 1,3-DHP, 2,3-DHP, vinyl alcohol, and 3-HP are not final reaction products in glycerol dehydration, they have been proposed as intermediate compounds by other authors [25][26][27]53] but there is a lack of their thermodynamic properties in the literature. From the equations of the Joback method in Table A1 and the values of Table A3, the values for ΔH°f, ΔG°f, and Cp were calculated for each species involved in the reactive system and presented in Table A5.…”

“…The thermodynamic data for water, methanal, and ethanal were obtained from the literature [75]. In the case of acrolein, even though recently values have been reported for ∆H • f by means of computational chemistry methods by Vasiliu et al [73], and later by Lewars and Liebman [84], the subsequent calculations in this work were carried out with data obtained with the Joback method due to its result (∆H [25][26][27]53] but there is a lack of their thermodynamic properties in the literature. From the equations of the Joback method in Table A1 and the values of Table A3, the values for ∆H • f , ∆G • f , and C p were calculated for each species involved in the reactive system and presented in Table A5.…”

“…Meanwhile, acetol is produced by the keto-enol tautomerization of 2,3-DHP promoted by the protonation of glycerol at the oxygen atom of the secondary hydroxyl group in the zeolite. Martinuzzi et al (2014) [53], proposed the reaction mechanism of glycerol dehydration and the subsequent transformation of its products by conducting the reaction over a solid acid catalyst in a fixed bed reactor, taking into account process variables such as temperature, glycerol concentration, gas hourly space velocity (GHSV) and oxygen concentration using nitrogen as carrier gas while the reaction products were analyzed by gas chromatography.…”

Catalytic Cracking of Biodiesel Waste Using Metal Supported SBA-15 Mesoporous Catalysts

“…In this study, the distribution of the volatile liquid phases was selective for 1-hydroxy-2-propanone and 2-propen-1-ol for all of the catalysts when using the pure glycerol. When the reaction temperature was above the boiling point of glycerol (290 • C), the liquid fraction was transformed to 1-hydroxy-2-propanone by dehydration [33][34][35]. This was then reduced and dehydrated to 2-propen-1-ol, as shown in Scheme 1 for the transformation pathway of glycerol into liquid products.…”

“…This was then reduced and dehydrated to 2-propen-1-ol, as shown in Scheme 1 for the transformation pathway of glycerol into liquid products. Usually, the harvested products in the liquid fraction are mainly produced via dehydration followed by H-transfer or aldol condensation [34,35]. Therefore, several researches have tried to reduce the gas phase production in order to enhance the yield of desired liquid compounds.…”