Glucose Oxidation in Slurry Reactors and Rotating Foam Reactors

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• 作者：Roman Tschentscher ; Tjeerd Alexander Nijhuis ; John van der Schaaf ; Jaap C. Schouten
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：February 1, 2012
• 年：2012
• 卷：51
• 期：4
• 页码：1620-1634
• 全文大小：1267K
• 年卷期：v.51,no.4(February 1, 2012)
• ISSN：1520-5045

文摘

Glucose oxidation using platinum promoted by bismuth was studied as a three-phase model reaction. Using catalyst nanoparticles and measuring the oxygen concentration in the bulk liquid, the kinetic parameters and mass transfer characteristics were determined at a temperature of 333 K. The overall reaction rate was studied experimentally using three different support types: slurry catalysts, pellets, and a solid foam stirrer. The glucose conversion rate and the deactivation rate of the catalyst depend strongly on the ratio between mass transfer and reaction rate. At low catalyst concentrations, the glucose oxidation process is liquid鈥搒olid mass-transfer-limited. The block stirrer shows a superior performance over the slurry catalysts due to the high liquid鈥搒olid volumetric mass transfer coefficient. The bimodal pore size distribution of the catalyst layer further increases the conversion rate. Using slurry catalysts, a loading of 1 wt % in combination with pure oxygen feed is required to achieve acceptable conversion rates. Under these conditions, the gas鈥搇iquid mass transfer and partially the liquid鈥搒olid mass transfer are the rate-limiting steps. The foam block stirrer shows good gas鈥搇iquid mass transfer rates and high liquid鈥搒olid mass transfer rates, which still increase at high power input. Working under external mass transfer control and using this stirrer type, the catalyst loading can be strongly reduced to loadings less than 0.4 wt %, while the conversion rate remains comparable to slurry particles with loadings of 1 wt %. As the catalyst is fixed, attrition and agglomeration in high viscosity liquids are circumvented. There is further no need for filtration, and the catalyst can simply be reused.