Controlling solids circulation in a gas-solids reaction system

Abstract

This invention provides a method for controlling solids circulation in a gas-solids reaction system. The method entails aerating solid particles in a standpipe. Aeration fluid is injected into the standpipe at the appropriate location to increase apparent density of the solid particles.

1 . A method of aerating solid particles in a standpipe of a gas-solids reactor system, comprising: 
 a) providing a standpipe having an internal wall and solid particles within the standpipe, and    b) injecting aeration fluid at a point away from the internal wall, wherein at least 25% of the aeration fluid is injected at a point away from the internal wall so as to aerate the solid particles in the standpipe.    
     
     
         2 . The method of  claim 1 , wherein at least 50% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         3 . The method of  claim 2 , wherein at least 75% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         4 . The method of  claim 1 , wherein the standpipe has a centerline and the aeration fluid is injected into the standpipe at a point such that at least a portion of the fluid is injected at a location r/R<0.75, with r being defined as the radial distance from the centerline of the standpipe to the point of aeration fluid injection, and R being defined as the radial distance from the centerline of the standpipe to the internal wall of the standpipe.  
     
     
         5 . The method of  claim 4 , wherein r/R<0.6.  
     
     
         6 . The method of  claim 5 , wherein r/R<0.5.  
     
     
         7 . The method of  claim 1 , wherein the solid particles in the standpipe have an apparent density of at least 50% of the maximum apparent density of the solid particles.  
     
     
         8 . The method of  claim 7 , wherein the solid particles in the standpipe have an apparent density of at least 60% of the maximum apparent density of the solid particles.  
     
     
         9 . The method of  claim 8 , wherein the solid particles in the standpipe have an apparent density of at least 80% of the maximum apparent density of the solid particles.  
     
     
         10 . The method of  claim 1 , wherein the solid particles flow through the standpipe at a velocity of from 0.25 m/sec to 5 m/sec.  
     
     
         11 . The method of  claim 10 , wherein the solid particles flow through the standpipe at a velocity of from 0.75 m/sec to 4 m/sec.  
     
     
         12 . The method of  claim 11 , wherein the solid particle flow through the standpipe at a velocity of from 1 m/sec to 3 m/sec.  
     
     
         13 . The method of  claim 1 , wherein the solid particles flow through a reactor portion of the gas-solids reactor system at a velocity of from 1 m/sec to 30 m/sec.  
     
     
         14 . The method of  claim 13 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 3 m/sec to 25 m/sec.  
     
     
         15 . The method of  claim 14 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 5 m/sec to 20 m/sec.  
     
     
         16 . The method of  claim 1 , wherein the standpipe is in an oxygenate to olefin reactor system.  
     
     
         17 . The method of  claim 1 , wherein the standpipe is in a fluidized catalytic cracking reactor system.  
     
     
         18 . The method of  claim 1 , wherein the standpipe is in a reactor system for oxidation of n-butane to maleic anhydride.  
     
     
         19 . The method of  claim 1 , wherein the standpipe is in a reactor system for ammonia oxidation of propylene or propane to acrylonitrile.  
     
     
         20 . The method of  claim 1 , wherein the standpipe has an internal diameter of at least 2 feet.  
     
     
         21 . The method of  claim 1 , wherein the solid particles in the standpipe have an apparent density of at least 20 lb/ft 3 .  
     
     
         22 . The method of  claim 1 , wherein aeration fluid is further injected through at least two orifices located at different azimuthal positions on the standpipe.  
     
     
         23 . The method of  claim 22 , wherein the aeration orifices are separated at a distance of from π/5 to π radians.  
     
     
         24 . The method of  claim 23 , wherein the aeration orifices are separated at a distance of from π/4 to 2π/3 radians.  
     
     
         25 . The method of  claim 22 , wherein the aeration fluid is injected through at least one orifice in an azimuthal direction around a circumference of the internal wall.  
     
     
         26 . A method of aerating solid particles in a standpipe of a gas-solids reactor system, comprising: 
 a) providing a standpipe having a centerline, an internal wall and solid particles within the standpipe; and    b) injecting aeration fluid into the standpipe at a point such that at least a portion of the fluid is injected at a location r/R<0.75, wherein r is defined as the radial distance from the centerline of the standpipe to the point of aeration fluid injection, and R is defined as the radial distance from the centerline of the standpipe to the internal wall of the standpipe, so as to aerate the solid particles in the standpipe.    
     
     
         27 . The method of  claim 26 , wherein r/R<0.6.  
     
     
         28 . The method of  claim 27 , wherein r/R<0.5.  
     
     
         29 . The method of  claim 26 , wherein the solid particles in the standpipe have an apparent density of at least 50% of the maximum apparent density of the solid particles.  
     
     
         30 . The method of  claim 29 , wherein the solid particles in the standpipe have an apparent density of at least 60% of the maximum apparent density of the solid particles.  
     
     
         31 . The method of  claim 30 , wherein the solid particles in the standpipe have an apparent density of at least 80% of the maximum apparent density of the solid particles.  
     
     
         32 . The method of  claim 26 , wherein the solid particles flow through the standpipe at a velocity of from 0.25 m/sec to 5 m/sec.  
     
     
         33 . The method of  claim 32 , wherein the solid particles flow through the standpipe at a velocity of from 0.75 m/sec to 4 m/sec.  
     
     
         34 . The method of  claim 33 , wherein the solid particles flow through the standpipe at a velocity of from 1 m/sec to 3 m/sec.  
     
     
         35 . The method of  claim 26 , wherein the solid particles flow through a reactor portion of the gas-solids reactor system at a velocity of from 1 m/sec to 30 m/sec.  
     
     
         36 . The method of  claim 35 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 3 m/sec to 25 m/sec.  
     
     
         37 . The method of  claim 36 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 5 m/sec to 20 m/sec.  
     
     
         38 . The method of  claim 26 , wherein at least 50% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         39 . The method of  claim 38 , wherein at least 75% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         40 . The method of  claim 39 , wherein 100% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         41 . The method of  claim 26 , wherein the standpipe is in an oxygenate to olefin reactor system.  
     
     
         42 . The method of  claim 26 , wherein the standpipe is in a fluidized catalytic cracking reactor system.  
     
     
         43 . The method of  claim 26 , wherein the standpipe is in a reactor system for oxidation of n-butane to maleic anhydride.  
     
     
         44 . The method of  claim 26 , wherein the standpipe is in a reactor system for ammonia oxidation of propylene or propane to acrylonitrile.  
     
     
         45 . The method of  claim 26 , wherein the standpipe has an internal diameter of at least 2 feet.  
     
     
         46 . The method of  claim 26 , wherein the solid particles in the standpipe have an apparent density of at least about 20 lb/ft 3 .  
     
     
         47 . The method of  claim 26 , wherein aeration fluid is further injected through at least two orifices located at different azimuthal positions on the standpipe.  
     
     
         48 . The method of  claim 47 , wherein the aeration orifices are separated at a distance of from π/5 to π radians.  
     
     
         49 . The method of  claim 48 , wherein the aeration orifices are separated at a distance of from π/4 to 2π/3 radians.  
     
     
         50 . The method of  claim 47 , wherein the aeration fluid is injected through at least one orifice in an azimuthal direction around a circumference of the internal wall.  
     
     
         51 . A method of aerating solid particles in a standpipe of a gas-solids reactor system, comprising: 
 a) providing a standpipe having an internal wall and solid particles within the standpipe, and    b) injecting aeration fluid at a point away from the internal wall so as to aerate the solid particles in the standpipe, wherein the solid particles in the standpipe have an apparent density of at least 50% of the maximum apparent density of the solid particles.    
     
     
         52 . The method of  claim 51 , wherein the solid particles in the standpipe have an apparent density of at least 60% of the maximum apparent density of the solid particles.  
     
     
         53 . The method of  claim 52 , wherein the solid particles in the standpipe have an apparent density of at least 80% of the maximum apparent density of the solid particles.  
     
     
         54 . The method of  claim 51 , wherein the solid particles flow through the standpipe at a velocity of from 0.25 m/sec to 5 m/sec.  
     
     
         55 . The method of  claim 54 , wherein the solid particles flow through the standpipe at a velocity of from 0.75 m/sec to 4 m/sec.  
     
     
         56 . The method of  claim 55 , wherein the solid particles flow through the standpipe at a velocity of from 1 m/sec to 3 m/sec.  
     
     
         57 . The method of  claim 51 , wherein the solid particles flow through a reactor portion of the gas-solids reactor system at a velocity of from 1 m/sec to 30 m/sec.  
     
     
         58 . The method of  claim 57 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 3 m/sec to 25 m/sec.  
     
     
         59 . The method of  claim 58 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 5 m/sec to 20 m/sec.  
     
     
         60 . The method of  claim 51 , wherein at least 50% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         61 . The method of  claim 60 , wherein at least 75% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         62 . The method of  claim 61 , wherein 100% of the aeration fluid is injected at a point away from the internal wall.  
     
     
         63 . The method of  claim 51 , wherein the standpipe has a certerline and the aeration fluid is injected into the standpipe at a point such that at least a portion of the fluid is injected at a location r/R<0.75, with r being defined as the radial distance from the centerline of the standpipe to the point of aeration fluid injection, and R being defined as the radial distance from the centerline of the standpipe to the internal wall of the standpipe.  
     
     
         64 . The method of  claim 63 , wherein r/R<0.6.  
     
     
         65 . The method of  claim 64 , wherein r/R<0.5.  
     
     
         66 . The method of  claim 51 , wherein the standpipe is in an oxygenate to olefin reactor system.  
     
     
         67 . The method of  claim 51 , wherein the standpipe is in a fluidized catalytic cracking reactor system.  
     
     
         68 . The method of  claim 51 , wherein the standpipe is in a reactor system for oxidation of n-butane to maleic anhydride.  
     
     
         69 . The method of  claim 51 , wherein the standpipe is in a reactor system for ammonia oxidation of propylene or propane to acrylonitrile.  
     
     
         70 . The method of  claim 51 , wherein the standpipe has an internal diameter of at least 2 feet.  
     
     
         71 . The method of  claim 51 , wherein the solid particles in the standpipe have an apparent density of at least 20 lb/ft 3 .  
     
     
         72 . The method of  claim 51 , wherein aeration fluid is further injected through at least two orifices located at different azimuthal positions on the standpipe.  
     
     
         73 . The method of  claim 72 , wherein the aeration orifices are separated at a distance of from π/5 to π radians.  
     
     
         74 . The method of  claim 73 , wherein the aeration orifices are separated at a distance of from π/4 to 2π/3 radians.  
     
     
         75 . The method of  claim 72 , wherein the aeration fluid is injected through at least one orifice in an azimuthal direction around a circumference of the internal wall.  
     
     
         76 . A method of aerating solid particles in a standpipe of a gas-solids reactor system, comprising: 
 a) providing a standpipe having an internal wall and solid particles within the standpipe; and    b) injecting aeration fluid into the standpipe in inwardly radial directions of the internal wall, through at least two orifices located within ½ foot of a horizontal baseline through the standpipe, with the orifices being separated at a distance of from π/5 to π radians.    
     
     
         77 . The method of  claim 76 , wherein the orifices are separated at a distance of from π/4 to 2π/3 radians.  
     
     
         78 . The method of  claim 76 , wherein the aeration fluid is injected through at least one orifice in an azimuthal direction around a circumference of the internal wall.  
     
     
         79 . The method of  claim 76 , wherein the standpipe has a centerline and additional aeration fluid is injected into the standpipe at a point such that at least a portion of the additional aeration fluid is injected at a location r/R<0.75, with r being defined as the radial distance from the centerline of the standpipe to the point of aeration fluid injection, and R being defined as the radial distance from the centerline of the standpipe to the internal wall of the standpipe.  
     
     
         80 . The method of  claim 79 , wherein r/R<0.6.  
     
     
         81 . The method of  claim 82 , wherein r/R<0.5.  
     
     
         82 . The method of  claim 76 , wherein additional aeration fluid is injected at a point away from the internal wall, and at least 25% of the additional aeration fluid is injected at a point away from the internal wall.  
     
     
         83 . The method of  claim 76 , wherein the solid particles in the standpipe have an apparent density of at least 50% of the maximum apparent density of the solid particles.  
     
     
         84 . The method of  claim 83 , wherein the solid particles in the standpipe have an apparent density of at least 60% of the maximum apparent density of the solid particles.  
     
     
         85 . The method of  claim 84 , wherein the solid particles in the standpipe have an apparent density of at least 80% of the maximum apparent density of the solid particles.  
     
     
         86 . The method of  claim 76 , wherein the solid particles flow through the standpipe at a velocity of from 0.25 m/sec to 5 m/sec.  
     
     
         87 . The method of  claim 86 , wherein the solid particles flow through the standpipe at a velocity of from 0.75 m/sec to 4 m/sec.  
     
     
         88 . The method of  claim 87 , wherein the solid particles flow through the standpipe at a velocity of from 1 m/sec to 3 m/sec.  
     
     
         89 . The method of  claim 76 , wherein the solid particles flow through a reactor portion of the gas-solids reactor system at a velocity of from 1 m/sec to 30 m/sec.  
     
     
         90 . The method of  claim 89 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 3 m/sec to 25 m/sec.  
     
     
         91 . The method of  claim 90 , wherein the solid particles flow through the reactor portion of the gas-solids reactor system at a velocity of from 5 m/sec to 20 m/sec.  
     
     
         92 . The method of  claim 76 , wherein the standpipe is in an oxygenate to olefin reactor system.  
     
     
         93 . The method of  claim 76 , wherein the standpipe is in a fluidized catalytic cracking reactor system.  
     
     
         94 . The method of  claim 76 , wherein the standpipe is in a reactor system for oxidation of n-butane to maleic anhydride.  
     
     
         95 . The method of  claim 76 , wherein the standpipe is in a reactor system for ammonia oxidation of propylene or propane to acrylonitrile.  
     
     
         96 . The method of  claim 76 , wherein the standpipe has an internal diameter of at least 2 feet.  
     
     
         97 . The method of  claim 76 , wherein the solid particles in the standpipe have an apparent density of at least 20 lb/ft 3 .