Blocked operation for group ii and group iii lubricant production

Abstract

Systems and methods are provided for block processing of a feedstock to produce multiple viscosity grades of lubricant base stocks with substantially different viscosity index values. The systems and methods can involve the use of a sweet stage hydrocracking catalyst that can maintain good aromatic saturation activity under conditions that produce substantially different levels of viscosity index uplift. Optionally, the reactor including the sweet stage hydrocracking catalyst can include additional aromatic saturation catalyst. The systems and methods can further involve using a combination of aromatic saturation catalyst and dewaxing catalyst in a second sweet stage reactor, so that additional aromatic saturation activity is available for saturation of aromatics for products that undergo lower amounts of conversion in the sweet hydrocracking stage. The systems and methods can also allow for increased control over the relative temperatures of reactors within a reaction system.

1 . A method for producing lubricant boiling range product using blocked operation, comprising:
 fractionating a hydroprocessed feedstock to form at least a first lubricant boiling range fraction comprising a 343° C.+ portion and a second lubricant boiling range fraction having a T10 distillation point of at least 343° C. and a kinematic viscosity at 100° C. of 6.0 cSt or more, the 343° C.+ portion of the first lubricant boiling range fraction having a kinematic viscosity at 100° C. of 1.5 cSt to 6.0 cSt;   hydrocracking at least a portion of the first lubricant boiling range fraction in the presence of hydrocracking catalyst under first hydrocracking conditions comprising a first hydrocracking inlet temperature and a first hydrocracking outlet temperature in a first reactor to form a first hydrocracked effluent, the first hydrocracking conditions comprising 10 wt % to 80 wt % conversion relative to 370° C. of the at least a portion of the first lubricant boiling range fraction;   dewaxing at least a portion of the first hydrocracked effluent under first catalytic dewaxing conditions in a second reactor to form a first dewaxed effluent;   hydrocracking at least a portion of the second lubricant boiling range fraction in the presence of the hydrocracking catalyst under second hydrocracking conditions in the first reactor to form a second hydrocracked effluent, the second hydrocracking conditions comprising 1 wt % to 25 wt % conversion relative to 370° C. of the at least a portion of the second lubricant boiling range fraction, the second hydrocracking conditions comprising a second hydrocracking inlet temperature and a second hydrocracking outlet temperature, the conversion relative to 370° C. for the first hydrocracking conditions being at least 10 wt % greater than the conversion relative to 370° C. for the second hydrocracking conditions;   dewaxing at least a portion of the second hydrocracked effluent under second catalytic dewaxing conditions in the second reactor to form a second dewaxed effluent;   fractionating at least a portion of the first dewaxed effluent to form at least a first fuels boiling range product and a first lubricant boiling range product; and   fractionating at least a portion of the second dewaxed effluent to form at least a second fuels boiling range product and a second lubricant boiling range product, a viscosity index of the second lubricant boiling range product being lower than a viscosity index of the first lubricant boiling range product by at least 5.   
     
     
         2 . The method of  claim 1 , wherein the second catalytic dewaxing conditions comprise a second dewaxing inlet temperature that is greater than the second hydrocracking outlet temperature, or wherein the first catalytic dewaxing conditions comprise a first dewaxing inlet temperature that is less than the first hydrocracking outlet temperature; or a combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the second lubricant boiling range fraction comprises a viscosity index that is greater than the viscosity index of the first lubricant boiling range fraction 
     
     
         4 . The method of  claim 1 , wherein the second catalytic dewaxing conditions comprise introducing a heated hydrogen-containing stream into the second reactor. 
     
     
         5 . The method of  claim 1 , further comprising hydroprocessing a feedstock under hydroprocessing conditions to form the hydroprocessed feedstock. 
     
     
         6 . The method of  claim 1 , wherein one or more of the hydroprocessed feedstock, the first lubricant boiling range fraction, and the second boiling range fraction comprise 100 wppm or less of sulfur; or wherein the hydrocracking catalyst comprises 0.1 wt % to 5.0 wt % of a noble metal supported on the hydrocracking catalyst; or a combination thereof. 
     
     
         7 . The method of  claim 1 , wherein fractionating the hydroprocessed feedstock further comprising forming a fuels boiling range fraction. 
     
     
         8 . The method of  claim 1 , i) further comprising storing the at least a portion of the first lubricant boiling range fraction prior to the hydrocracking of the at least a portion of the first lubricant boiling range fraction, ii) further comprising storing the at least a portion of the second lubricant boiling range fraction prior to the hydrocracking of the at least a portion of the second lubricant boiling range fraction, or iii) a combination of i) and ii). 
     
     
         9 . The method of  claim 1 , wherein the first reactor further comprises an aromatic saturation catalyst, wherein the second reactor further comprises an aromatic saturation catalyst, or a combination thereof. 
     
     
         10 . The method of  claim 1 , wherein the hydrocracking catalyst comprising USY zeolite having a unit cell size of 24.30 Å or less, a silica to alumina ratio of at least 50, and an Alpha value of 20 or less, the hydrocracking catalyst further comprising 0.1 wt % to 5.0 wt % of a Group 8-10 noble metal supported on the hydrocracking catalyst. 
     
     
         11 . The method of  claim 1 , wherein the first lubricant boiling range product comprises a viscosity index of at least 125. 
     
     
         12 . The method of  claim 1 , wherein the second lubricant boiling range product comprises a viscosity index of at least 80. 
     
     
         13 . The method of  claim 1 , wherein the viscosity index of the second lubricant boiling range product is lower than the viscosity index of the first lubricant boiling range product by at least 15. 
     
     
         14 . The method of  claim 1 , wherein the first dewaxing conditions are substantially similar to the second dewaxing conditions. 
     
     
         15 . The method of  claim 1 , wherein the first hydrocracking inlet temperature is greater than the second hydrocracking inlet temperature by at least 10° C. 
     
     
         16 . The method of  claim 1 , further comprising:
 exposing at least a portion of the first dewaxed effluent to an aromatic saturation catalyst in a third reactor under first aromatic saturation conditions to form a first saturated product comprising the first lubricant boiling range product, the first lubricant boiling range product having an aromatics content of 2.0 wt % or less; and   exposing at least a portion of the second dewaxed effluent to the aromatic saturation catalyst in the third reactor under second aromatic saturation conditions to form a second saturated product comprising the second lubricant boiling range product, the second lubricant boiling range product having an aromatics content of 2.0 wt % or less.   
     
     
         17 . The method of  claim 16 , wherein the first aromatic saturation conditions are substantially similar to the second aromatic saturation conditions 
     
     
         18 . The method of  claim 16 , wherein the second reactor further comprises a second aromatic saturation catalyst, the at least a portion of the first hydrocracked effluent contacting at least a portion of the second aromatic saturation catalyst prior to being exposed to the dewaxing catalyst. 
     
     
         19 . A method for producing lubricant boiling range product using blocked operation, comprising:
 fractionating a feedstock to form at least a first lubricant boiling range fraction comprising a 343° C.+ portion and a second lubricant boiling range fraction having a T10 distillation point of at least 343° C. and a kinematic viscosity at 100° C. of 6.0 cSt or more, the 343° C.+ portion having a kinematic viscosity at 100° C. of 1.5 cSt to 6.0 cSt;   hydroprocessing at least a portion of the first lubricant boiling range fraction under first hydroprocessing conditions to form a first hydroprocessed effluent;   hydrocracking at least a portion of the first hydroprocessed effluent in the presence of hydrocracking catalyst under first hydrocracking conditions comprising a in a first reactor to form a first hydrocracked effluent, the first hydroprocessing conditions and the first hydrocracking conditions comprising a combined conversion of the first lubricant boiling range fraction of 40 wt % to 80 wt % relative to 370° C.;   dewaxing at least a portion of the first hydrocracked effluent under first catalytic dewaxing conditions in a second reactor to form a first dewaxed effluent;   hydroprocessing at least a portion of the second lubricant boiling range fraction under second hydroprocessing conditions to form a second hydroprocessed effluent;   hydrocracking at least a portion of the second hydroprocessed effluent in the presence of the hydrocracking catalyst under second hydrocracking conditions in the first reactor to form a second hydrocracked effluent, the second hydroprocessing conditions and the second hydrocracking conditions comprising a combined conversion of the second lubricant boiling range fraction of 20 wt % to 60 wt % relative to 370° C.;   dewaxing at least a portion of the second hydrocracked effluent under second catalytic dewaxing conditions in the second reactor to form a second dewaxed effluent;   fractionating at least a portion of the first dewaxed effluent to form at least a first fuels boiling range product and a first lubricant boiling range product; and   fractionating at least a portion of the second dewaxed effluent to form at least a second fuels boiling range product and a second lubricant boiling range product, a viscosity index of the second lubricant boiling range product being lower than a viscosity index of the first lubricant boiling range product by at least 5.   
     
     
         20 . A multi-reactor reaction system, comprising:
 a first reactor comprising a first gas inlet, hydrocracking reactor inlet, a hydrocracking reactor outlet, and a hydrocracking catalyst comprising 0.1 wt % to 5.0 wt % of a Group 8-10 noble metal supported on the hydrocracking catalyst;   a second reactor comprising a second gas inlet, a dewaxing reactor inlet, a dewaxing reactor outlet, and a dewaxing catalyst, the dewaxing reactor inlet being in fluid communication with the hydrocracking reactor outlet;   a third reactor comprising an aromatic saturation inlet, an aromatic saturation outlet, and a first aromatic saturation catalyst, the aromatic saturation inlet being in fluid communication with the dewaxing reactor outlet;   a heater comprising a feed heater flow path and a hydrogen heater flow path, the feed heater flow path being in fluid communication with the hydrocracking reactor inlet, the hydrogen heater flow path being in fluid communication with the first gas inlet and the second gas inlet.   
     
     
         21 . The system of  claim 20 , wherein the third reactor further comprises a third gas inlet in fluid communication with the hydrogen heater flow path. 
     
     
         22 . The system of  claim 20 , wherein at least a portion of a second aromatic saturation catalyst is located upstream from the dewaxing catalyst relative to a direction of flow in the second reactor. 
     
     
         23 . The system of  claim 20 , wherein the hydrocracking reactor inlet comprises the first gas inlet. 
     
     
         24 . The system of  claim 20 , the system further comprising a first storage tank and a second storage tank, the first storage tank and the second storage tank being in selective fluid communication with the feed heater flow path, the first storage tank comprising a first lubricant boiling range feed comprising a 343° C.+ portion, the 343° C.+ portion of the first lubricant boiling range feed having a kinematic viscosity at 100° C. of 1.5 cSt to 6.0 cSt, the second storage tank comprising a second lubricant boiling range feed having a T10 distillation point of at least 343° C. and a kinematic viscosity at 100° C. of 6.0 cSt or more. 
     
     
         25 . The system of  claim 20 , wherein the second gas inlet is in selective fluid communication with the heated hydrogen flow path. 
     
     
         26 . A method for producing a lubricant boiling range product, comprising:
 hydrocracking a lubricant boiling range fraction in the presence of hydrocracking catalyst under first hydrocracking conditions comprising a first hydrocracking inlet temperature and a first hydrocracking outlet temperature in a first reactor to form a first hydrocracked effluent, the first hydrocracking conditions comprising a first amount of conversion relative to 370° C. of the at least a portion of the lubricant boiling range fraction;   dewaxing at least a portion of the first hydrocracked effluent under first catalytic dewaxing conditions comprising a first dewaxing inlet temperature in a second reactor to form a first dewaxed effluent, the first dewaxing inlet temperature being greater than the first hydrocracking outlet temperature by at least 3° C.;   modifying the conditions for hydrocracking while performing hydrocracking of the lubricant boiling range fraction;   hydrocracking the lubricant boiling range fraction in the presence of the hydrocracking catalyst under modified hydrocracking conditions comprising a modified hydrocracking inlet temperature and a modified hydrocracking outlet temperature in the first reactor to form a second hydrocracked effluent, the modified hydrocracking conditions comprising a second amount of conversion relative to 370° C. of the at least a portion of the lubricant boiling range fraction, the second amount of conversion relative to 370° C. being different from the first amount of conversion relative to 370° C. by 5 wt % or less;   dewaxing at least a portion of the second hydrocracked effluent under second catalytic dewaxing conditions comprising a second dewaxing inlet temperature in the second reactor to form a second dewaxed effluent, the second dewaxing inlet temperature being less than the modified hydrocracking outlet temperature by at least 3° C.;   fractionating at least a portion of the first dewaxed effluent to form at least a first fuels boiling range product and a first lubricant boiling range product; and   fractionating at least a portion of the second dewaxed effluent to form at least a second fuels boiling range product and a second lubricant boiling range product, a viscosity index of the second lubricant boiling range product being different than a viscosity index of the first lubricant boiling range product by 5 or less.   
     
     
         27 . The method of  claim 26 , wherein the lubricant boiling range fraction has a T10 distillation point of at least 343° C. and a kinematic viscosity at 100° C. of 6.0 cSt or more. 
     
     
         28 . The method of  claim 26 , wherein the lubricant boiling range fraction has a T10 distillation point of at least 371° C. and a kinematic viscosity at 100° C. of 15 cSt or more. 
     
     
         29 . The method of  claim 26 , wherein the lubricant boiling range fraction comprises a 343° C.+ portion, the 343° C.+ portion having a kinematic viscosity at 100° C. of 1.5 cSt to 6.0 cSt. 
     
     
         30 . The method of  claim 26 , wherein the first catalytic dewaxing conditions comprise introducing a heated hydrogen-containing stream into the second reactor. 
     
     
         31 . The method of  claim 26 , further comprising hydrofinishing the at least a portion of the first dewaxed effluent prior to fractionation, after fractionation, or a combination thereof. 
     
     
         32 . The method of  claim 26 , further comprising modifying the conditions for dewaxing while performing dewaxing of hydrocracked effluent produced during the modification of the conditions for hydrocracking. 
     
     
         33 . The method of  claim 32 , wherein the second dewaxing conditions comprise modified dewaxing conditions, the second dewaxing inlet temperature comprising a modified dewaxing inlet temperature. 
     
     
         34 . The method of  claim 32 , further comprising modifying the conditions for dewaxing i) while performing dewaxing of the at least a portion of the first hydrocracked effluent, ii) while performing dewaxing of the at least a portion of the second hydrocracked effluent, or iii) a combination of i) and ii).