Cyclic operation strategy for extending cycle life of trickle beds under gas–liquid filtration

The hydrodynamics of a trickle-bed reactor subjected to fines-contaminated feed flows was studied under cyclic operation to assess whether or not periodic flows are able to reduce fines deposition and hence to extend reactor operational life under filtration conditions. The bed was subjected to single-pass kaolin++kerosene suspension and air flows to study liquid–, gas– and alternating liquid–gas cyclic operation policies. It was found that fast- and slow-mode liquid cyclic operation policies were not be able to decrease either the pressure drop or the specific deposit; however, with adjusting carefully the parameters of liquid cyclic operation it would be possible to prolong the trickle-bed cycle life. The alternating gas–liquid cyclic feed was also found useful to reduce the levels of pressure drop and bed specific deposit and exhibited the same efficiency for both short and tall beds.