3 research outputs found
Catalytic Conversion of Guaiacol Catalyzed by Platinum Supported on Alumina: Reaction Network Including Hydrodeoxygenation Reactions
The conversion of guaiacol catalyzed by Pt/γ-Al<sub>2</sub>O<sub>3</sub> in the presence of H<sub>2</sub> was investigated with a flow reactor at 573 K and 140 kPa. Dozens of reaction products were identified, with the most abundant being phenol, catechol, and 3-methylcatechol. The kinetically significant reaction classes were found to be hydrogenolysis [including hydrodeoxygenation (HDO)], hydrogenation, and transalkylation. Selectivity–conversion data were used to determine an approximate quantitative reaction network accounting for the primary products, and a more detailed qualitative network was also inferred. Catalytic HDO was evidenced by the production of anisole and phenol. The HDO selectivity increased with an increasing H<sub>2</sub> partial pressure and a decreasing temperature. Products formed by transalkylation reactions match those produced in the conversion catalyzed by HY zeolite, in which no deoxygenated products were observed
Conversion of Anisole Catalyzed by Platinum Supported on Alumina: The Reaction Network
The conversion of anisole (a compound representative of bio-oils) in the presence of H<sub>2</sub> was investigated with a flow reactor operated at a temperature of 573 K and a pressure of 140 kPa with a platinum on alumina catalyst. Analysis by gas chromatography–mass spectrometry led to the identification of more than 40 reaction products, the most abundant being phenol, 2-methylphenol, benzene, and 2,6-dimethylphenol. The kinetically significant reaction classes were transalkylation, hydrodeoxygenation, and hydrogenation. Selectivity-conversion data were used to determine an approximate quantitative reaction network accounting for phenol, 2-methylphenol, 2-methylanisole, and 4-methylphenol as primary products. Pseudo-first-order rate constants for the formation of these products are 12, 2.8, 0.14, and 0.039 L/(g of catalyst × h), respectively. A more complete qualitative network was inferred on the basis of the observed products and the assumption that the reaction classes leading to the most abundant primary products were responsible for the minor and trace products. The removal of oxygen was evidenced by the production of benzene
Design of a High-Pressure Flow-Reactor System for Catalytic Hydrodeoxygenation: Guaiacol Conversion Catalyzed by Platinum Supported on MgO
A high-pressure once-through plug-flow-reactor
system is reported
for characterization of hydroprocessing reactions of biomass-derived
compounds. All of the reactants are liquids. Data are presented for
conversion of guaiacol catalyzed by Pt/MgO and, in much less detail,
CoMo/Al<sub>2</sub>O<sub>3</sub>. The data demonstrate the advantages
of high pressure in such reactions, determining a pseudo-first-order
rate constant for guaiacol conversion at 523 K and 69 bar of approximately
55 L of organic reactant solution (g of catalyst)<sup>–1</sup> h<sup>–1</sup>. This value is 2 orders of magnitude greater
than that observed at 573 K and 1.4 bar