Hydrocarbon conversion process with radial flow and controlled hydrogen

Abstract

A continuous process for hydrocarbon conversion wherein a hydrocarbon charge stock is catlytically converted in the presence of hydrogen at hydrocarbon conversion conditions including a first inlet temperature, a first hydrogen to hydrocarbon mole ratio and a first mass flow rate of hydrocarbon into a hydrocarbon product stream in a high space velocity moving bed radial flow reactor containing catalyst wherein at least a portion of the catalyst is pinned and thereby immobilized during high space velocity conversion which process comprises: (a) reducing the first inlet temperature of the reactor by about 10.degree. F. (5.5.degree. C.) to about 100.degree. F. (55.5.degree. C.) to a second inlet temperature thereby lowering the rate of the hydrocarbon conversion; (b) reducing the first hydrogen to hydrocarbon mole ratio to a second hydrogen to hydrocarbon mole ratio which is from about 10% to about 60% of the first hydrogen to hydrocarbon mole ratio and sufficient to unpin the catalyst from the reactor thereby ensuring uniform gravitational catalyst flow through the reactor while maintaining the first mass flow rate of hydrocarbon; (c) introducing a quantity of fresh catalyst into an upper portion of the reactor while removing a similar quantity of spent catalyst from a lower portion of the reactor; (d) increasing the second hydrogen to hydrocarbon mole ratio to essentially the first hydrogen to hydrocarbon mole ratio; and (e) increasing the second inlet temperature to essentially restore the hydrocarbon conversion.