An evaluation and screening device for granular catalyst is designed

and an example of acetoxidation of ethylene in gas phase on hollow cylindrical catalyst with active constituent maldistributed on the outside and inside surface is given. In this example

the reactor is designed as “U”shape

and five thermocouples are set to measure the axial temperature profile of the catalyst bed.The reactor and the preheat pipe are both put into an oil bath kept at constant temperature.Each granular catalyst ( 5mm×1.8mm×5.5mm) is split into eight smaller pieces of the same size

thus the equivalent diameter d s of the smaller pieces is equal to 2.2mm

the inner diameter d t of the reactor is 16mm

dt/ds is equal to 7.3

so that the wall effect is considered to be eliminated.The length of packed bed

including the catalyst and the inert carrier

is 145 times than d s

so the reactor is a plug flow reactor. The global kinetics equation is studied in a CSTR.It is found that the kinetics parameters of split catalyst is same as the full granular catalyst

so the active constituent distribution remaines unchanged with the catalyst split into uniform small pieces. The reaction-heat transfer models are applied to the multiple reactions net of gas phase acetoxidation of ethylene to synthesis of vinyl acetate.The results of model simulation and experimental data indicate that 30mL catalyst bed in 1∶2 dilution ratio(catalyst:inert carrier)is appropriate

it practically achieves isothermal operation inside the bed and presents good comparable results for screening and evaluating hollow cylindrical catalyst with active constituent maldistribution.