Presulfiding OCR catalyst replacement batches

Abstract

Catalyst particles are presulfided in a pretreatment zone separate from a hydroconversion reaction zone. The presulfided catalyst is then added to a moving bed of catalyst in the hydroconversion reaction zone at reaction pressure, so that the reactor is not shut down to replace catalyst. The presulfiding process is particularly beneficial for use in moving bed reactors for heavy oil conversion.

1 . A process for ex-situ sulfiding a catalyst employed in the hydroprocessing of a heavy hydrocarbon feed stream in a moving bed reactor system, the system possessing at least one reactor zone and at least one pretreatment zone, wherein the hydroprocessing occurs in the reactor zone and the catalyst is sulfided in the pretreatment zone before being added to the reactor zone.  
     
     
         2 . The process of  claim 1 , wherein the pretreatment zone of the moving bed reactor system comprises the equipment that is used to transfer the catalyst from storage to the reactor.  
     
     
         3 . The process of  claim 1 , wherein the feed stream is upflowing through the reactor zone of the moving bed reactor system, the moving bed reactor system being selected from the group consisting of (i) ebullated and expanded types of reactor systems which are capable of onstream catalyst replacement; (ii) a substantially packed-bed type reactor system having an onstream catalyst replacement system.  
     
     
         4 . The process of  claim 1 , wherein the pretreatment zone comprises at least one high pressure vessel and at least one low pressure vessel.  
     
     
         5 . The process of  claim 4 , wherein catalyst may be treated in the low and high pressure vessels in series.  
     
     
         6 . The process of  claim 4 , wherein catalyst may be treated in the low and high pressure vessels simultaneously, in parallel.  
     
     
         7 . The process of  claim 1 , wherein the catalyst is presulfided in the pretreatment zone by means of the following steps: a) adding a volume of hydroprocessing catalyst to the pretreatment zone, which volume includes fresh hydroprocessing catalyst; b) heating the volume of hydroprocessing catalyst until the catalyst has a temperature ranging from 90° C. to 370° C.; and c) adding a presulfiding agent to the pretreatment zone to prepare presulfided catalyst.  
     
     
         8 . The process of  claim 4 , wherein hydroprocessing catalyst is sulfided at a temperature of 125° C. to 325° C.  
     
     
         9 . The process of  claim 7 , wherein the step of adding a volume of hydroprocessing catalyst to the pretreatment zone comprises: a) preparing a slurry comprising a hydrocarbon liquid and a volume of hydroprocessing catalyst; b) adding the slurry comprising the hydrocarbon liquid and the hydroprocessing catalyst to the pretreatment zone; and c) removing at least a portion of the hydrocarbon liquid from the pretreatment zone.  
     
     
         10 . The process of  claim 7 , wherein the step of adding a presulfiding agent to the pretreatment zone comprises: a) pressurizing the pretreatment zone which contains the hydroprocessing catalyst with a presulfiding agent at a pressure in the range of 0.2 to 24.2 MPa and a temperature in the range of 90° C. to 370° C. to produce at least partially presulfided catalyst; and b) removing at least a portion of the presulfiding agent from the pretreatment zone.  
     
     
         11 . The process of  claim 7 , wherein the presulfiding agent comprises a sulfur containing material selected from the group consisting of H 2 S and sulfur-containing materials which decompose at temperatures below about 370° C.  
     
     
         12 . The process of  claim 11 , wherein the presulfiding agent comprises H 2 S.  
     
     
         13 . The process of  claim 11 , wherein the presulfiding agent comprises a gaseous recycle stream containing H 2  and H 2 S.  
     
     
         14 . The process of  claim 10 , wherein the at least partially presulfided catalyst is produced at a temperature in the range of 125° C. to 325° C. and at a pressure in the range of 5.0 MPa to 20 MPa.  
     
     
         15 . The process of  claim 10 , wherein the at least partially presulfided catalyst is produced in less than 24 hours.  
     
     
         16 . The process of  claim 14 , wherein the at least partially presulfided catalyst is produced at a temperature in the range of 150° C. to 285° C.  
     
     
         17 . The process according to  claim 7 , wherein the step of adding a presulfiding agent to the pretreatment zone comprises: a) adding a volume of hydroprocessing catalyst to the pretreatment zone, which volume includes fresh hydroprocessing catalyst; b) flowing a heated hydrocarbon liquid through the volume of hydroprocessing catalyst within the pretreatment zone until the catalyst has a temperature ranging from 90° C. to 145° C.; c) subsequently pressurizing the pretreatment zone at a pressure ranging from 0.2 MPa to 24.2 MPa; d) continuing to flow the heated hydrocarbon liquid through the catalyst in the pretreatment zone until the catalyst has a temperature ranging from 125° C. to 325° C.; e) flowing a presulfiding mixture through the catalyst in the pretreatment zone to prepare at least partially presulfided catalyst.  
     
     
         18 . A method for hydroprocessing a hydrocarbon feed stream that is upflowing through a hydroconversion reaction zone comprising the steps of: a) introducing a hydrocarbon feed stream in the presence of hydrogen at a reaction pressure into a hydroconversion reaction zone which contains particulate hydroprocessing catalyst to commence upflowing of said hydrocarbon feed stream through said catalyst and to recover a reaction effluent therefrom; b) presulfiding ex-situ a volume of hydroprocessing catalyst within a pretreatment zone to produce presulfided catalyst, wherein the catalyst is presulfided by means of the following steps: (1) adding a volume of hydroprocessing catalyst to the pretreatment zone, which volume includes fresh hydroprocessing catalyst; (2) heating the volume of hydroprocessing catalyst until the catalyst has a temperature ranging from 90° C. to 370° C.; and (3) adding a sulfiding agent to the pretreatment zone to prepare presulfided catalyst; and c) adding at least a portion of the presulfided catalyst into the hydroconversion reaction zone while maintaining the reaction zone at the reaction pressure.  
     
     
         19 . The process according to  claim 18 , wherein the reaction zone is maintained as a substantially packed bed of particulates hydroprocessing catalyst.  
     
     
         20 . The method of  claim 19 , wherein the step of introducing a hydrocarbon feed stream into a hydroconversion reaction zone comprises flowing upwardly said hydrocarbon feed stream into said substantially packed bed of hydroprocessing catalyst at a rate of flow such that said substantially packed bed of hydroprocessing catalyst expands to less than 10% by length beyond a substantially full axial length of said substantially packed bed of hydroprocessing catalyst in a packed bed state.  
     
     
         21 . A method for hydroprocessing a hydrocarbon feed stream comprising the steps of: a) introducing a hydrocarbon feed stream into a hydroconversion reaction zone having a substantially packed bed of particulate hydroprocessing catalyst to commence upflowing of said hydrocarbon feed stream through said substantially packed bed of the catalyst at a rate of flow such that said substantially packed bed of hydroprocessing catalyst expands to less than 10% by length beyond a substantially full axial length of said substantially packed bed of hydroprocessing catalyst in a packed bed state, and to recover a reaction effluent therefrom; b) withdrawing a first volume of the hydroprocessing catalyst from the hydroconversion reaction zone to commence essentially plug-flowing downwardly said substantially packed bed of hydroprocessing catalyst within said hydroconversion reaction zone; c) adding a second volume of a particulate hydroprocessing catalyst to a pretreatment zone, which second volume includes fresh hydroprocessing catalyst; d) presulfiding the second volume of hydroprocessing catalyst within the pretreatment zone to prepare presulfided catalyst; and e) adding at least a portion of the presulfided catalyst into the hydroconversion reaction zone to replace the withdrawn first volume of catalyst.