Patent GB-741062-A (GB)
Title: Improvements in or relating to heat balanced hydrocarbon conversion process
IPC: C10G35/14
Filed: 1953-08-06
Abstract: An endothermic hydrocarbon conversion process is carried out by contacting the reactants in zone 10 with a fluidized bed of a mixture of catalyst particles and inert heat transfer particles of greater size and/or density than the catalyst, withdrawing the mixture through orifice 20 into an elutriating zone 17 where a proportion of the catalyst particles is removed and returned to the reaction zone, passing the elutriated mixture via line 25 to regeneration zone 30 which operates at a higher temperature than the reaction zone, and returning the <PICT:0741062/IV(a)/1> regenerated mixture to the reaction zone via line 36.  Heat is transferred from the regeneration zone to the reaction zone by means of the heat transfer solids.  In a hydroforming process, the reaction temperature may be 850 DEG -1000 DEG  F., reaction pressure 50-1000 (e.g. 200) lb. per sq. in., and regeneration temperature 1050 DEG -1200 DEG  F.  Suitable catalysts are Group VI metal oxides or sulphides, e.g. oxides of molybdenum, chromium or tungsten, or vanadium oxide, supported on a carrier of activated alumina or zinc aluminate spinel; silica, calcium oxide, ceria, or potassium oxide may be present as stabilizers or promoters. Suitable inert solids in the form of spheroidal particles are corundum, mullite, fused alumina, or fused silica.  Preferably the inert solids have a bulk density of at least 1.5 times that of the catalyst; the size of the catalyst particles may be up to 200 micros, and that of the inert solids 300-500 microns.  The ratio by weight of heat transfer solids to catalyst in the reaction zone may be about 1 : 10, increasing after elutriation to 3 : 1-4 : 1.  Elutriation zone 17 may contain packing material, and elutriating gas such as steam or recycle gas is introduced at 21.  A further stripping zone 22 may be provided.  Carrier gas consisting of steam, flue gas, or air enters at 26, and additional air for regeneration at 28.  Regeneration may take place in the line 25, with the omission of the separate regeneration zone.  Before return to the reactor, the regenerated mixture may pass through a stripping zone or may be treated with a hydrogen-containing gas to reduce oxidized catalyst.  The temperatures in the reactor and regenerator may be controlled by burning fuel in the regenerator, by varying the amount at elutriating gas so that more or less catalyst passes to the regenerator, or by adjusting valve 24 to alter the total solids circulation.  The average residence time of the catalyst in the reactor is about 3-4 hours, and that of the inert solids about 20 mins.-1 hour; the mixture of solids remains in the regenerator about 3-15 mins. Reference is also made to hydrofining, cracking and coking processes.ALSO:<PICT:0741062/III/1> An endothermic hydrocarbon conversion process is carried out by contacting the reactants in zone 10 with a fluidized bed of a mixture of catalyst particles and inert heat transfer particles of greater size and/or density than the catalyst, withdrawing the mixture through orifice 20 into an elutriating zone 17 where a proportion of the catalyst particles is removed and returned to the reaction zone, passing the elutriated mixture via line 25 to regeneration zone 30 which operates at a higher temperature than the reaction zone, and returning the regenerated mixture to the reaction zone via line 36.  Heat is transferred from the regeneration zone to the reaction zone by means of the heat transfer solids.  In a hydroforming process, the reaction temperatures may be 850 DEG -1000 DEG F, reaction pressure 50-1000 (e.g. 200) lbs. per sq. in., and regeneration temperature 1050 DEG -1200 DEG F. Suitable catalysts are Group VI metal oxides or sulphides, e.g. oxides of molybdenum, chromium, or tungsten, or vanadium oxide, supported on a carrier of activated alumina or zinc aluminate spinel; silica, calcium oxide, ceria, or potassium oxide may be present as stabilizers or promoters.  Suitable inert solids in the form of spheroidal particles are corundum, mullite, fused alumina, or fused silica.  Preferably the inert solids have a bulk density of at least 1.5 times that of the catalyst; the size of the catalyst particles may be up to 200 microns, and that of the inert solids 300-500 microns.  The ratio by weight of heat transfer solids to catalyst in the reaction zone may be about 1:10, increasing after elutriation to 3:1-4:1. Elutriation zone 17 may contain packing material, and elutriating gas such as steam or recycle gas is introduced at 21.  A further stripping zone 22 may be provided. Carrier gas consisting of steam, flue gas, or air enters at 26, and additional air for regeneration at 28. Regeneration may take place in the line 25, with the omission of the separate regeneration zone. Before return to the reactor, the regenerated mixture may pass through a stripping zone or may be treated with a hydrogen-containing gas to reduce oxidized catalyst.  The temperatures in the reactor and regenerator may be controlled by burning fuel in the regenerator, by varying the amount of elutriating gas so that more or less catalyst passes to the regenerator, or by adjusting valve 24 to alter the total solids circulation.  The average residence time of the catalyst in the reactor is about 3-4 hours, and that of the inert solids about 20 mins.-1 hour; the mixture of solids remains in the regenerator about 3-15 mins.  Reference is also made to hydrofining, cracking, and coking processes.