Patent GB-636401-A (GB)
Title: An improved process for contacting finely divided solids with gases
IPC: B01J8/18
Filed: 1947-02-28
Abstract: <PICT:0636401/III/1> In processes in which finely divided solids are maintained in a fluidized state in a treating zone by means of an upflowing suspending gas and in which the buoyancy of the solids changes within the zone due to, for example, deposition of carbon thereon, the zone is partly or completely filled with solid non-fluidized packing elements and the solids which have undergone a change of buoyancy are withdrawn, treated to restore their original buoyancy and returned to the zone.  The packing elements may take the form of balls, spheres, cylinders, U-shaped elements, saddles, coils, metal turnings or helices and when cylindrical or hollow elements are used they may be employed as heat transfer tubes.  Elements of different sizes may be employed in different sections of the treating zone.  The process is particularly applicable to the catalytic reaction of carbon monoxide and hydrogen to produce hydrocarbons, but is also applicable to the carbonization of finely divided coal, the production of synthesis gas and the catalytic cracking and polymerization of petroleum oils.  As applied to the Fischer-Tropsche process, synthesis gas from line 2 is mixed with finely divided catalyst from line 3 and passed through reactor 1, the upper part of which contains non-fluidised packing elements supported on screen 5. A fluidized bed of catalyst particles is maintained within the reactor.  The reaction products pass off through separator 6 and line 7 to condenser 8, the condensed product being separated at 10 and uncondensed gas being removed through line 11 and recycled to the reactor through line 4.  The carbonized and therefore more buoyant catalyst particles concentrate in the packed area of the reactor and are withdrawn through line 13 to regenerator 14, regenerated catalyst being then returned through lines 19 and 4 to the reactor. Modifications are described wherein, in one case, the reactor, and in another case, the reactor and regenerator are completely filled with packing elements.ALSO:<PICT:0636401/IV (b)/1> In the catalytic production of hydrocarbons from mixtures of carbon monoxide and hydrogen wherein the finely-divided catalyst is maintained in a fluidized state by the upflowing reactant gases and wherein the buoyancy of the catalyst particles changes due to carbonization, the reaction zone is partly or completely filled with solid non-fluidized packing elements and the catalyst particles which have undergone a change of buoyancy are withdrawn, treated to restore their original buoyancy and returned to the zone.  The packing elements may take the form of balls, spheres, cylinders, U-shaped elements, saddles, coils, metal turnings or helices and when cylindrical or hollow elements are used they may be employed as heat transfer tubes.  Elements of different sizes may be employed in different sections of the reactor. Synthesis gas from line 2 is mixed with finely-divided catalyst from line 3 and passed through reactor 1, the upper part of which contains packing elements supported on a screen 5.  A fluidized catalyst bed is maintained within the reactor.  The reaction products pass off through separator 6 and line 7 to condenser 8, the condensed product being separated at 10 and uncondensed gas being removed through line 11 and recycled to the reactor through line 4.  The carbonized and therefore more buoyant catalyst particles concentrate in the packed area of the reactor and are withdrawn through line 13 to regenerator 14, regenerated catalyst being then returned through lines 19 and 4 to the reactor.  Modifications are described wherein, in one case, the reactor, and in another case, the reactor and regenerator, are completely filled with packing elements.