Effect of catalytic hydrodynamics over microagglomerates of Mn2O3 and PdO supported on γ-χ-Al2O3 for dimethyl ether production. (1st June 2022)

• Record Type: Journal Article
• Authors: Armenta, M.A.; Maytorena, V.M.; Buentello-Montoya, D.A.; Arroyo, E.; Cota-Leal, M.; Yong, D.; Olivas, A.
• Is Part Of: Fuel. Volume 317(2022)
• Publication Date: 2022-06-01
• Subjects: Methanol dehydration process -- Palladium oxide -- Dimethyl ether -- Activation energy -- Heterogeneous catalysts -- Manganese oxide; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.123509
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: PdO and Mn2 O3 nanomaterials were prepared by wet impregnation. Methanol dehydration using PdO and Mn2 O3 /γ-χ-Al2 O3 microagglomerates. PdO/γ-χ-Al2 O3 reached selectivity to DME of 100%. Effect of microagglomerates surface and size on methanol dehydration. Abstract: In this study, we synthesize microagglomerates of PdO and Mn2 O3 supported over γ-χ-Al2 O3 via the impregnation method, for their application in the methanol dehydration to dimethyl ether, under reaction conditions of 240 °C to 290 °C and 1 pressure atm. It was determined by XRD, TEM and XPS that when PdO (Pd 2+ ) is present at 3% by weight over γ-χ-Al2 O3, conversions of 57% and selectiveness of 100% towards dimethyl ether can be reached at 250 °C due to at a higher density of moderate acid sites (a moderate acidity difference of 0.5276 mmol/g with respect to Mn2 O3 /γ-χ-Al2 O3 ). Additionally, our theoretical and experimental results between the correlation of the textural and morphological properties of the PdO/γ-χ-Al2 O3 and Mn2 O3 /γ-χ-Al2 O3 materials with the hydrodynamics and kinetics of the reaction, showed that when PdO agglomerates with a size of ∼79.2 µm are used, higher internal mass transfer rates predominate when compared to using Mn2 O3 agglomerates of a larger size, ∼124 µm. Finally, the relative stability shown by the PdO/γ-χ-Al2 O3 catalyst during 10 h of reaction was correlated with its low apparent activation energy (111 kJ/mol) and with its inactive phase change of PdO measured by XPS after the reaction.