Hydrocarbon synthesis reactor employing vertical downcomer with gas disengaging means

Abstract

The operation of a hydrocarbon synthesis reactor and catalyst distributed in the reaction slurry therein are improved by the presence in said reactor of one or more vertical downcomers open at both ends with gas disengaging areas located at their top end. The downcomer which circulates catalyst from the top of the reaction slurry to the bottom of said slurry is fully immersed in the reaction slurry and preferably extends from just above the bottom of the reaction zone of the reaction vessel to just below the top surface of the reaction slurry. The bottom end of said downcomer is shielded from intrusion of rising synthesis gas by the placement of a baffle which blocks rising gas entry but facilitates the exit of catalyst and liquid from the bottom of said downcomer and distributes them radially throughout the adjacent reactor slurry.

What is claimed is:  
     
       1. A method for uniformly redistributing particulate catalyst in a slurry phase reactor, said method comprising using a substantially vertical conduit means open at both ends, fully submerged in the slurry of the slurry phase reactor, the bottom end of the substantially vertical conduit means is near the bottom of the slurry phase reactor and the top of the conduit means is topped by gas disengaging means which are below the top surface of the slurry in the slurry phase reactor and wherein the bottom of the substantially vertical conduit means is shielded by a baffle means which diverts gases rising from the bottom of the slurry phase reactor from entering into the bottom of the substantially vertical conduit whereby catalyst in slurry enters at the top of the substantially vertical conduit and is disengaged from gases present therein thereby becoming a more dense mixture of catalyst in slurry which passes down the substantially vertical conduit and is ejected from the bottom of said conduit near the bottom of the slurry phase reactor. 
     
     
       2. The method of claim  1  wherein the baffle at the bottom of the substantially vertical conduit means is in the form of an inverted cone whereby downwardly moving catalyst-liquid stream exiting the bottom of the substantially vertical conduit impinges on the inverted cone and is diverted away from the bottom of the substantially vertical conduit at an angle. 
     
     
       3. The method of claim  1  wherein the substantially vertical conduit means comprises one or more downcomers. 
     
     
       4. The method of claim  3  wherein the cross sectional surface area of the substantially vertical conduit means occupies from 0.1 to 5% of the available cross sectional surface area of the reaction zone of the slurry phase reactor. 
     
     
       5. The method of claim  4  wherein when a multiple downcomer array is employed no single downcomer within the array constitutes more than 50% of the total cross sectional area of the multiple downcomer array. 
     
     
       6. A method for simultaneously uniformly redistributing and rejuvenating particulate catalyst in a slurry phase reactor, said method (1) comprising using a substantially vertical conduit means open at both ends, fully submerged in the slurry in the slurry phase reactor, the bottom end of the substantially vertical conduit means is near the bottom of the slurry phase reactor and the top of the conduit means is topped by gas disengaging means which are below the top surface of the slurry in the slurry phase reactor whereby catalyst in slurry enters at the top of the substantially vertical conduit means and is disengaged from gases present therein thereby becoming a more dense mixture of catalyst in slurry which passes down the substantially vertical conduit and is ejected from the bottom of said conduit near the bottom of the slurry phase reactor, thereby redistributing the catalyst, and (2) comprising using a substantially vertical draft tube means open at both ends, fully immersed in the slurry containing the catalyst and injecting hydrogen containing gas at or substantially near the bottom of said draft tube means thereby lifting catalyst in slurry from the bottom of the slurry phase reactor into and through the open bottom end of the draft tube means, rejuvenating catalyst in the presence of said hydrogen containing gas in the vertical draft tube means and ejecting the rejuvenated catalyst into the top of the slurry phase in the slurry phase reactor through the open top of the draft tube means. 
     
     
       7. A method for producing hydrocarbons utilizing said particulate catalyst which is redistributed in said slurry phase reactor in accordance with the method of claim  1 , comprising reacting synthesis gas in said reactor in the presence of said redistributed particulate catalyst. 
     
     
       8. The method of claim  7  wherein said slurry comprises C 5+    hydrocarbons produced by said method.   
     
     
       9. The method of claim  8  wherein said C 5+    hydrocarbons comprise C   5   -C   10    hydrocarbons.   
     
     
       10. The method of claim  8  wherein said C 5+    hydrocarbons comprise Fischer - Tropsch waxes.   
     
     
       11. A method for producing hydrocarbons utilizing said particulate catalyst which is redistributed and rejuvenated in said slurry phase reactor in accordance with the method of claim  6 , comprising reacting synthesis gas in said rector in the presence of said redistributed and rejuvenated particulate catalyst. 
     
     
       12. The method of claim  11  wherein said slurry comprises C 5+    hydrocarbons produced by said method.   
     
     
       13. The method of claim  12  wherein said C 5+    hydrocarbons comprise C   5   -C   10    hydrocarbons.   
     
     
       14. The method of claim  12  wherein said C 5+    hydrocarbons comprise Fischer - Tropsch waxes.