Fluid cracking process and the method for separating a suspension discharged from a riser cracking zone
AssigneeMobil Oil Corporation
InventorsJames H. Haddad, Scott A. Heffley, Hartley Owen
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Abstract
A riser cracking-catalyst regeneration operation is described wherein a suspension discharged from a riser operation is separated by catalyst particle concentrating means which discharge a concentrated stream of catalyst separated from gasiform material into a downcomer zone and out of further contact with discharged gasiform material in the suspension. A stripping gas is used to particularly aid the separation of catalyst and hydrocarbon vapors.
Claims11
In a fluid catalyst process comprising cracking a suspension of hydrocarbon reactant and catalyst at a temperature above 950.degree. F. in a riser conversion zone and thereafter regenerating catalyst recovered from said riser conversion zone to heat said catalyst and remove carbonaceous deposits before return to said riser conversion zone, the improvement for separating the hydrocarbon-catalyst suspension upon discharge from the riser conversion zone which comprises,
- discharging the suspension outwardly through openings in the upper periphery of the riser beneath radially extending restricted catalyst collecting passageways open on the bottom side thereof and providing a substantial confined catalyst stream generally separate from hydrocarbon vapors discharged from the riser beneath the confined catalyst stream,
- said catalyst collecting passageways curved downwardly adjacent the outer end thereof to induce a downward moment on said confined catalyst stream in said passageway sufficient to direct said stream downwardly into the open upper end of a catalyst downcomer passageway positioned to maintain catalyst so collected and directed separate from said discharged hydrocarbon vapors, and
- employing stripping gas to further promote the separation of catalyst and hydrocarbon vapors discharged from said riser.
A method for separating a suspension of catalyst particles and gasiform material following traverse of a riser contact zone which comprises,
- discharging the suspension outwardly through openings beneath the upper closed end of said riser and beneath radially extending restricted catalyst collecting passageways open on the bottom side thereof and providing a substantially confined stream of collected catalyst particles generally separate from discharge gasiform material,
- said catalyst collecting passageways curved downwardly adjacent the outer end thereof to induce a downward moment on said confined catalyst stream in said passageway for discharge directly downwardly into the open upper end of a restricted catalyst downcomer passageway positioned to maintain catalyst so collected and directed out of further contact with discharged gasiform material, and
- recovering catalyst particles so collected from the bottom of said passageway for further use as desired.
Dependencies are inferred from the claim text.