Countercurrent hydroprocessing

Abstract

A method for the hydroprocessing of a heavy hydrocarbonaceous feedstock in a reaction zone having a bed containing a fixed array of porous catalyst particles by contacting the feedstock with a hydrogen-containing gas under conditions which allow distributing the feedstock predominantly in liquid phase under super-atmospheric process conditions at elevated temperature over the catalyst bed for downward flow in contact with the catalyst particles and introduction of the hydrogen-containing gas in the reaction zone below the catalyst bed in order to establish countercurrent contact of the upwardly flowing gas with the downcoming liquid and withdrawing treated liquid below the catalyst bed and withdrawing fluid depleted in hydrogen above the catalyst bed, in which process the catalyst bed has a void volume fraction below 0.5, whilst the countercurrent liquid/gas contacting is carried out under conditions which allow the Peclet number of the liquid to be in the range between 0 and 10.

1 . A method for the hydroprocessing of a heavy hydrocarbonaceous feedstock in a reaction zone comprising: 
 a bed containing a fixed array of porous catalyst particles by contacting the feedstock with a hydrogen-containing gas under conditions which allow distributing the feedstock predominantly in liquid phase under super-atmospheric process conditions at elevated temperature over the catalyst bed for downward flow in contact with the catalyst particles;    introduction of the hydrogen-containing gas in the reaction zone below the catalyst bed in order to establish countercurrent contact of the upwardly flowing gas with the downcoming liquid;    withdrawing treated liquid below the catalyst bed; and,    withdrawing fluid depleted in hydrogen above the catalyst bed, in which process the catalyst bed has a void volume fraction below 0.5, whilst the countercurrent liquid/gas contacting is carried out under conditions which allow the Peclet number of the liquid to be in the range between 0 and 10.    
     
     
         2 . The method according to  claim 1 , in which the catalyst bed has a void volume fraction above 0.25.  
     
     
         3 . The method according to  claim 2 , in which the catalyst bed has a void volume fraction between 0.30 and 0.48, preferably between 0.35 and 0.47.  
     
     
         4 . The method according to  claim 1 , in which the countercurrent contacting is carried out under conditions which allow the Peclet number of the liquid to be in the range between 1 and 8.  
     
     
         5 . The method according to  claim 1 , in which treated liquid which has passed downwardly through the catalyst bed is passed in trickle flow mode through a further bed containing catalytic particles prior to its withdrawal from the process and/or fluid depleted in hydrogen which has passed upwardly through the catalyst bed is passed upwardly in vapour phase through a further bed containing catalytic particles prior to its withdrawal from the process as fluid depleted in hydrogen.  
     
     
         6 . The method according to  claim 5 , in which at least part of the upwardly flowing hydrogen-containing gas is introduced in the bottom of the reaction zone containing a further bed containing catalytic particles through which treated liquid is passed prior to its withdrawal from the process.  
     
     
         7 . The method according to claims  1 , in which at least part of the treated liquid and at least part of the fluid depleted in hydrogen are combined and subjected to a second hydroprocessing step which is carried out either cocurrently or counter currently.  
     
     
         8 . The method according to  claim 1 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         9 . The method according to  claim 8 , in which catalyst particles are used having a spherical, cylindrical or polylobal form and a largest diameter between 0.5 and 3.5 mm.  
     
     
         10 . The method according to  claim 2 , in which the countercurrent contacting is carried out under conditions which allow the Peclet number of the liquid to be in the range between 1 and 8.  
     
     
         11 . The method according to  claim 3 , in which the countercurrent contacting is carried out under conditions which allow the Peclet number of the liquid to be in the range between 1 and 8.  
     
     
         12 . The method according to  claim 2 , in which treated liquid which has passed downwardly through the catalyst bed is passed in trickle flow mode through a further bed containing catalytic particles prior to its withdrawal from the process and/or fluid depleted in hydrogen which has passed upwardly through the catalyst bed is passed upwardly in vapour phase through a further bed containing catalytic particles prior to its withdrawal from the process as fluid depleted in hydrogen.  
     
     
         13 . The method according to  claim 3 , in which treated liquid which has passed downwardly through the catalyst bed is passed in trickle flow mode through a further bed containing catalytic particles prior to its withdrawal from the process and/or fluid depleted in hydrogen which has passed upwardly through the catalyst bed is passed upwardly in vapour phase through a further bed containing catalytic particles prior to its withdrawal from the process as fluid depleted in hydrogen.  
     
     
         14 . The method according to  claim 4 , in which treated liquid which has passed downwardly through the catalyst bed is passed in trickle flow mode through a further bed containing catalytic particles prior to its withdrawal from the process and/or fluid depleted in hydrogen which has passed upwardly through the catalyst bed is passed upwardly in vapour phase through a further bed containing catalytic particles prior to its withdrawal from the process as fluid depleted in hydrogen.  
     
     
         15 . The method according  claim 2 , in which at least part of the treated liquid and at least part of the fluid depleted in hydrogen are combined and subjected to a second hydroprocessing step which is carried out either cocurrently or counter currently.  
     
     
         16 . The method according  claim 3 , in which at least part of the treated liquid and at least part of the fluid depleted in hydrogen are combined and subjected to a second hydroprocessing step which is carried out either cocurrently or counter currently.  
     
     
         17 . The method according  claim 4 , in which at least part of the treated liquid and at least part of the fluid depleted in hydrogen are combined and subjected to a second hydroprocessing step which is carried out either cocurrently or counter currently.  
     
     
         18 . The method according  claim 5 , in which at least part of the treated liquid and at least part of the fluid depleted in hydrogen are combined and subjected to a second hydroprocessing step which is carried out either cocurrently or counter currently.  
     
     
         19 . The method according to  claim 2 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         20 . The method according to  claim 3 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         21 . The method according to  claim 4 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         22 . The method according to  claim 5 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         23 . The method according to  claim 6 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.  
     
     
         24 . The method according to  claim 7 , in which the hydroprocessing is carried out under hydrocracking conditions, including a temperature in the range between 200° C. and 475° C. and a pressure between 20 and 250 bar.