External catalyst rejuvenation system for the hydrocarbon synthesis process

A process for practicing catalytic hydrocarbon synthesis and reactivation rejuvenation of deactivated hydrocarbon synthesis catalyst on a continuous basis, said process comprising combining catalyst and synthesis feed and hydrocarbon liquid in a hydrocarbon synthesis first vessel means to produce a reactor slurry comprising catalyst, synthesis feed and synthesis product, collecting deactivated catalyst from the top of the reactor slurry by means of a first downcomer - conduit means the top of which is fitted with gas disentrainment means and which is located just below the top surface of the reactor slurry, passing the deactivated catalyst down this first downcomer - conduit means from the top of the first vessel means to the bottom of a reactivation - rejuvenation second vessel means, said second vessel means having rejuvenating gas introduction means located at its bottom, forming a reactivating slurry of catalyst in reaction product and rejuvenating gas, wherein the deactivated catalyst is reactivated - rejuvenated in said second vessel means, collecting reactivated - rejuvenated catalyst from the top of the reactivating slurry by means of a second downcomer - conduit means the top of which is fitted with gas disentrainment means and which is located just below the top surface of the reactivation slurry and passing the reactivated - rejuvenated catalyst down the second downcomer - conduit means from the top of the second vessel means to the bottom of the first vessel means, all catalyst downward flows on both the first and second downcomer means occurring solely under the influence of gravity.