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

Abstract

The catalytic liquid-phase hydrogenation of a-metylstyrene to give cumene over Pd/Al2O^2-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 (1/kLab) can be evaluated independently, but the mass transfer resistance at liquid-solid interface (lIksas) 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 liksas can be evaluated individually using the values of 1/kLab and chemical reaction rate previously estimated when chemical reaction is rate-controlling in stirred vessel with hydrogen bubbling.
The correlations between 1/kLas, liksas 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.