Mass Transfer Resistance in Catalytic Gas-Liquid Reaction in Bubble Column with Suspended Catalyst† —Hydrogenation of α-Methylstyrene with Palladium/Alumina Catalyst—

Abstract

The catalytic liquid-phase hydrogenation of α-metylstyrene to give cumene over Pd/Al2O3-catalyst suspended in a bubble column has been studied to evaluate the resistances to the mass transfer. The mass transfer resistance at gas-liquid interface (l/kLab) can be evaluated independently, but the mass transfer resistance at liquid-solid interface (l/ksac) must be separated from the overall resistance on the basis of the hydrogen concentration at catalyst surface which is related to that at gas-liquid interface with the ratio of chemical reaction rate to overall rate. Thus l/ksas can be evaluated individually using the values of 1/ksas and chemical reaction rate previously estimated when chemical reaction is rate-controlling in stirred vessel with hydrogen bubbling. The correlations between l/kLas, l/ksas or contribution of individual resistance to overall resistance and operating variables such as gas flow rate and catalyst loading were obtained as shown in Figs. 4, 5 and 6. In addition, correlations of gas hold up, bubble diameter, gas-liquid interfacial area and mass transfer coefficients with operating variables were obtained as shown in Figs. 7, 8, 9 and 10. © 1977, The Chemical Society of Japan. All rights reserved.