Processes for minimizing catalyst fines in a regenerator flue gas stream

Abstract

Process for minimizing the amount of catalyst fines in a flue gas from a catalyst regenerator. Pyrolysis oil is injected into the reaction zone, preferably downstream from the feedstream inlet. The catalyst fines will be passed along with the hydrocarbon effluent stream and can be removed with a filter or other similar device. The amount of pyrolysis oil can be controlled, for example, based upon the opacity of the flue gas from the catalyst regenerator, or based upon the amount of catalyst injected into the reaction zone.

What is claimed is: 
     
         1 . A process for reducing an amount of catalyst fines in a regenerator flue gas, the process comprising:
 injecting a hydrocarbon stream into a reaction zone, the reaction zone including a stream of fluidized catalyst and configured to crack hydrocarbons and form an effluent stream;   injecting a biomass-derived pyrolysis oil stream into the reaction zone;   separating the effluent stream from the fluidized catalyst in a separation zone to provide a hydrocarbon effluent stream and a catalyst stream, the hydrocarbon effluent stream includes catalyst fines.   
     
     
         2 . The process of  claim 1  further comprising:
 regenerating the catalyst from the stream of fluidized catalyst to provide a regenerated catalyst; and, 
 introducing the regenerated catalyst into the reaction zone. 
 
     
     
         3 . The process of  claim 1  wherein an inlet for the biomass-derived pyrolysis oil stream is downstream of an inlet for the hydrocarbon stream. 
     
     
         4 . The process of  claim 1  further comprising:
 removing catalyst fines from the hydrocarbon effluent stream. 
 
     
     
         5 . The process of  claim 1  wherein the biomass-derived pyrolysis oil stream comprises between 30 to 55 wt % oxygen. 
     
     
         6 . The process of  claim 1  wherein an amount of biomass-derived pyrolysis oil injected into the reaction zone is based upon an amount of catalyst injected into the reaction zone. 
     
     
         7 . The process of  claim 1  wherein a ratio of biomass-derived pyrolysis oil carbon injected to catalyst injected comprises at least approximately 0.001 kg of pyrolysis oil carbon/kg of catalyst and is calculated by (A×B)/C,
 wherein A represents a pyrolysis oil weight fraction of total liquid feed, 
 and wherein B represents a non-oxygen weight fraction of the pyrolysis oil 
 and wherein C represents a catalyst to hydrocarbon oil mass ratio. 
 
     
     
         8 . The process of  claim 1  wherein an amount of the catalyst fines in the catalyst stream is reduced as compared to an amount of catalyst fines in the catalyst stream when no biomass-derived pyrolysis oil is injected. 
     
     
         9 . A process for reducing an amount of catalyst fines in a regenerator flue gas, the process comprising:
 injecting a hydrocarbon stream into a reaction zone, the reaction zone including a stream of fluidized catalyst injected therein and configured to crack hydrocarbons and form an effluent stream;   injecting a pyrolysis oil stream into the reaction zone;   controlling an amount of pyrolysis oil injected into the reaction zone in order to reduce the catalyst fines in a flue gas stream; and,   separating the effluent stream from the fluidized catalyst in a separation zone to provide a hydrocarbon effluent stream and a catalyst stream.   
     
     
         10 . The process of  claim 9  wherein an inlet for the pyrolysis oil stream is disposed downstream an inlet for the hydrocarbon stream. 
     
     
         11 . The process of  claim 10  further comprising:
 determining an opacity of the flue gas stream and controlling the amount of pyrolysis oil injected into the reaction zone based upon the opacity of the flue gas. 
 
     
     
         12 . The process of  claim 9  wherein the pyrolysis oil comprises between 30 to 55 wt % oxygen. 
     
     
         13 . The process of  claim 9  wherein a ratio of pyrolysis oil carbon injected to catalyst injected comprises minimally approximately 0.001 kg of pyrolysis oil carbon/kg of catalyst and is calculated by (A×B)/C,
 wherein A represents a pyrolysis oil weight fraction of total liquid feed, 
 and wherein B represents a non-oxygen weight fraction of the pyrolysis oil 
 and wherein C represents a catalyst to hydrocarbon oil mass ratio. 
 
     
     
         14 . The process of  claim 9  further comprising:
 removing catalyst fines from at least a portion of the hydrocarbon effluent stream. 
 
     
     
         15 . The process of  claim 14  wherein the catalyst fines are removed from the at least a portion of the hydrocarbon effluent stream in a filtration zone. 
     
     
         16 . The process of  claim 9  wherein the amount of pyrolysis oil injected into the reaction zone is controlled based upon an amount of catalyst injected into the reaction zone. 
     
     
         17 . The process of  claim 9  further comprising:
 passing catalyst from the stream of fluidized catalyst to a regeneration zone having at least one regeneration vessel and configured to remove coke from the catalyst and provide a regenerated catalyst. 
 
     
     
         18 . The process of  claim 17  further comprising:
 passing the regenerated catalyst to the reaction zone. 
 
     
     
         19 . The process of  claim 18  wherein the regeneration zone also provides the flue gas stream. 
     
     
         20 . The process of  claim 19  wherein the amount of pyrolysis oil injected into the reaction zone is controlled based upon an opacity of the flue gas.