Process to Prepare a Base Oil From a Fischer-Tropsch Synthesis Product

Abstract

Process to prepare base oils from a Fischer-Tropsch synthesis product by (a) separating the Fischer-Tropsch synthesis product into a fraction (i) boiling in the middle distillate range and below, a heavy ends fraction (iii) and an intermediate base oil precursor fraction (ii) boiling between fraction (i) and fraction (iii), (b) subjecting the base oil precursor fraction (ii) to a catalytic hydroisomerisation step in the presence of a catalyst comprising a binder, zeolite Beta and a Group VIII metal and a catalytic dewaxing step in the presence of a catalyst comprising a binder, a medium pore size zeolite having and a Group VIII hydrogenation component to yield one or more base oil grades, (c) subjecting the heavy ends fraction (iii) to a conversion step to yield a fraction (iv) boiling below the heavy ends fraction (iii) and (d) subjecting the high boiling fraction (v) of fraction (iv) to a catalytic hydroisomerisation and catalytic dewaxing process to yield one or more base oil grades .

1 . A process to prepare base oils from a Fischer-Tropsch synthesis product comprising
 (a) separating a Fischer-Tropsch synthesis product into a fraction (i) boiling in the middle distillate range and below, a heavy ends fraction (iii) and an intermediate base oil precursor fraction (ii) boiling between fraction (i) and fraction (iii); (b) subjecting the base oil precursor fraction (ii) to a catalytic hydroisomerisation step in the presence of a catalyst comprising a binder, zeolite Beta and a Group VIII metal and a catalytic dewaxing step in the presence of a catalyst comprising a binder, a medium pore size zeolite and a Group VIII hydrogenation component to yield one or more base oil grades;   (c) subjecting the heavy ends fraction (iii) to a conversion step to yield a fraction (iv) boiling below the heavy ends fraction (iii); and   (d) subjecting a high boiling fraction (v) of fraction (iv) to a catalytic hydroisomerisation and catalytic dewaxing process to yield one or more base oil grades.   
     
     
         2 . The process according to  claim 1 , wherein the heavy ends fraction (iii) has an initial boiling point of between 500 and 600° C. 
     
     
         3 . The process according to  claim 1 , wherein the medium pore size zeolite in step (b) is selected from the group consisting of mordenite, ZSM-5, ZSM-12, ZSM-22, ZSM-23, SSZ-32, ZSM-35 or ZSM-48 and combinations of said zeolites. 
     
     
         4 . The process according to  claim 3 , wherein the medium pore size zeolite in step (b) is ZSM-48. 
     
     
         5 . The process according to  claim 1 , wherein the hydroisomerisation in step (b) is performed in the presence of a catalyst comprising a binder, zeolite Beta and platinum and a catalytic dewaxing step in the presence of a catalyst comprising a binder, a medium pore size zeolite and platinum. 
     
     
         6 . The process according to  claim 1 , wherein step (c) is performed as a hydrocracking/hydroisomerisation process making use of an amorphous catalyst comprising an acidic functionality and a hydrogenation/dehydrogenation functionality. 
     
     
         7 . The process according to  claim 1 , wherein the effluent of step (c) is provided to step (a), such that in effect steps (b) and (d) take place simultaneously. 
     
     
         8 . A process to prepare base oils from a Fischer-Tropsch synthesis product by comprising
 (a) separating a Fischer-Tropsch synthesis product into a fraction (i) boiling in the middle distillate range and below, a heavy ends fraction (iii) and an intermediate base oil precursor fraction (ii) boiling between fraction (i) and fraction (iii);   (b) subjecting the base oil precursor fraction (ii) to a catalytic hydroisomerisation step in the presence of a catalyst comprising a binder, zeolite Beta and a Group VIII metal and a catalytic dewaxing step in the presence of a catalyst comprising a binder, a medium pore size zeolite and a Group VIII hydrogenation component to yield one or more base oil grades; and   (c) subjecting the heavy ends fraction (iii) to a conversion step to yield a fraction (iv) boiling below the heavy ends fraction (iii) and recycling the high boiling fraction (v) of fraction (iv) boiling in the base oil range to step (b).   
     
     
         9 . The process according to  claim 8 , wherein the fraction boiling above fraction (v) of fraction (iv) is recycled to step (c).