Effectiveness factors and mass transfer in trickle‐bed reactors

Rates of hydrogenation of α‐methyl styrene were measured at 40.6°C and 1 atm in a recycle, trickle‐bed reactor using a palladium/aluminum oxide catalyst. Data for different hydrogen concentrations in the gas and liquid feed streams suggested that except, at high liquid flow rates, on part of the outer surface of the catalyst the mass transfer limitation was very small, indicating a gas covered type of surface. A procedure was developed for evaluating effectiveness factors for the nonuniform boundary conditions existing when part of the particle surface is covered by gas.