Oxidation of Glucose on Immobilized Glucose Oxidase in a Trickle-Bed Reactor : Effect of Liquid-Solid Contacting Efficiency on the Global Rate of Reaction

抄録

Oxidation of glucose to gluconic acid using a catalyst consisting of glucose oxidase and catalase both immobilized on activated carbon was employed to study the liquid-solid contacting efficiency (f) in a trickle-bed reactor. The global rates of reaction were measured at 25°C and at atmospheric pressure, as a function of catalyst loading (1.0 to 9.0 g), catalyst partiole size (0.055 and 0.110 cm), superficial liquid velocity (0.044 to 0.337 cm/s), and superficial gas velocity (1.63 to 7.35 cm/s). The measured rate was considered to be the sum of the rates at the liquid-covered and gas-covered outer surfaces of catalyst particles. The value of f was determined by integrating numerically the mass balance equations for oxygen and the equation for the intrinsic rate of reaction simultaneously. The estimated value of f did not vary with catalyst loading. While f was independent of gas flow rates, it was influenced by both liquid flow rates and particle sizes. The effects of these operating parameters on f are discussed on the basis of the static and/or dynamic holdup.