Catalytic reactor with liquid recycle

A continuous multi-phase reactor column system for contacting reactant gas with liquid petroleum oil reactant in a series of successive fixed beds of catalytic solids comprising

• inlet means for feeding the liquid petroleum oil reactant and the reactant gas containing hydrogen above a first catalyst bed of porous catalyst particles for continuous concurrent downward flow through the catalyst bed,
• a liquid collection reservoir disposed beneath the first catalyst bed and beneath at least one succeeding catalyst bed to collect the treated petroleum oil, gas-liquid downcomer conduit means passing through the liquid collection reservoirs, gas-liquid redistribution means disposed below said liquid collection reservoirs to convey and uniformly distribute the gaseous hydrogen reactant and a portion of the petroleum oil in the reservoir directly to the succeeding catalyst bed of porous catalyst particles;
• withdrawal conduit means for withdrawing a portion of the treated liquid petroleum oil from the first catalyst bed liquid collection reservoir and recycle conduit means connected to the withdrawal conduit means for recycling the withdrawn treated liquid petroleum oil to a gas-liquid distribution means disposed above the first catalyst bed to uniformly distribute the treated liquid petroleum oil on the first catalyst bed, the recycle conduit means introducing the recycle liquid in a succeeding catalyst bed at a location between the collection reservoir of a preceding catalyst bed and the gas liquid redistribution means of the respective succeeding catalyst bed and recycle flow control means in operative relationship with the feed inlet means and the recycle conduit means to control the recirculation rate of the treated liquid petroleum oil withdrawn from the liquid collection reservoir at sufficient liquid flux rate to effect substantially uniform catalyst wetting by the inlet liquid petroleum oil feed and the recycle treated liquid petroleum oil feed.

A continuous catalytic reactor column for contacting oil and a treating gas in a multiphase fixed bed catalytic reactor having at least two operatively connected catalyst beds comprising

• inlet means for feeding the oil and treating gas above a first horizontal porous catalyst bed of catalyst particles for concurrent downward flow through the catalyst bed;
• a liquid collection reservoir disposed below the first catalyst bed and below at least one succeeding catalyst bed, a gas-liquid downcomer conduit means passing through the liquid collection reservoirs, gas-liquid redistribution means disposed below said liquid collection reservoirs and operatively connected to the gas-liquid downcomer conduit means to convey and uniformly redistribute the gaseous treating gas and a portion of the treated oil in the reservoirs directly to the succeeding horizontal porous bed of catalyst particles,
• withdrawal conduit means for withdrawing a portion of the treated oil from the collection reservoir in the succeeding catalyst bed, recycle conduit means and pump means for recycling the withdrawn treated oil to a gas-liquid redistribution means disposed above the catalyst bed from which the liquid came and for introducing the recycle liquid at a location between the collection reservoir of a preceding catalyst bed and the gas-liquid redistribution means of the succeeding catalyst bed;
• and
• sensing means disposed in the oil feed inlet means to the reactor to sense the oil feed rate to the reactor, recycle sensing means disposed in the recycle conduit means to sense the rate of treated oil recycle and control means capable of comparing the oil feed rate with a total desired flow rate and capable of adjusting the recycle rate of treated oil in at least one catalyst bed so as to maintain a total liquid flux rate in that catalyst bed sufficient to provide catalyst wetting.