High performance process oil based on distilled aromatic extracts

Abstract

Naphthenic process oils are made by blending one or more naphthenic vacuum gas oils in one or more viscosity ranges with a high CA content distilled aromatic extract feedstock to provide at least one blended oil, and hydrotreating the at least one blended oil to provide an enhanced CA content naphthenic process oil. The order of the vacuum distillation and blending steps may be reversed.

1 . A method for making naphthenic process oils, the method comprising:
 a1) vacuum distilling residual bottoms from a naphthenic crude atmospheric distillation unit to provide one or more vacuum gas oils in one or more viscosity ranges; or   a2) atmospheric distilling naphthenic crude to provide one or more atmospheric gas oils in one or more viscosity ranges and residual bottoms, and vacuum distilling the residual bottoms to provide one or more vacuum gas oils in one or more viscosity ranges;   b) blending at least one such vacuum gas oil with a high C A  distilled aromatic extract feedstock to provide at least one blended oil; and   c) hydrotreating the at least one blended oil to provide an enhanced C A  content naphthenic process oil;   
       wherein the high C A  distilled aromatic extract feedstock and enhanced C A  content naphthenic process oil each have greater C A  content than that of a comparison oil made by similarly hydrotreating the one or more vacuum gas oils alone. 
     
     
         2 . The method according to  claim 1  wherein vacuum distilled residual bottoms from a naphthenic crude atmospheric distillation unit provide the at least one such vacuum gas oil. 
     
     
         3 . The method according to  claim 1  wherein atmospheric distilled naphthenic crude provides the one or more atmospheric gas oils in one or more viscosity ranges and residual bottoms, and wherein the residual bottoms are vacuum distilled to provide the at least one such vacuum gas oil. 
     
     
         4 . The method according to  claim 1  wherein the at least one such vacuum gas oil contains at least about 10% C A  content. 
     
     
         5 . The method according to  claim 1  wherein the distilled aromatic extract feedstock is fractionated to isolate oils that distill in the same general range as at least one of the vacuum gas oils. 
     
     
         6 . The method according to  claim 1  wherein the blended oil contains about 2 to about 40 wt. % distilled aromatic extract feedstock based on the weight of the blended oil. 
     
     
         7 . The method according to  claim 1  wherein the at least one such vacuum gas oil has a viscosity from about 100 to about 3,500 SUS at 38° C. 
     
     
         8 . The method according to  claim 1  wherein the enhanced C A  content naphthenic process oil has a viscosity of about 100 to about 2000 SUS at 38° C. 
     
     
         9 . The method according to  claim 1  wherein the enhanced C A  content naphthenic process oil has reduced unsaturation and reduced amounts of sulfur-, nitrogen- or oxygen-containing compounds compared to the at least one such vacuum gas oil. 
     
     
         10 . The method according to  claim 1  wherein the enhanced C A  content naphthenic process oil has increased C A  content, reduced aniline point, increased UV absorption and refractive index, and increased VGC value compared to the at least one such vacuum gas oil. 
     
     
         11 . The method according to  claim 1  wherein the enhanced C A  content naphthenic process oil has less than about 10 ppm PAH 8-markers when evaluated according to European standard EN 16143:2013. 
     
     
         12 . The method according to  claim 1  further comprising a step of solvent extraction, catalytic dewaxing, solvent dewaxing, hydrofinishing or hydrocracking. 
     
     
         13 . The method according to  claim 1  wherein steps of deasphalting, solvent extraction, catalytic dewaxing, solvent dewaxing, hydrofinishing and hydrocracking are not employed. 
     
     
         14 . The method according to  claim 1  wherein the enhanced C A  content naphthenic process oil has the following desirable characteristics separately or in combination: a flash point according to Cleveland Open Cup, ASTM D92 of at least about 240° C.; a boiling point (corrected to atmospheric pressure) of about 320° to about 650° C.; a kinematic viscosity of about 15 to about 30 cSt @ 100° C. according to ASTM D445; a viscosity index of about 5 to about 30; a pour point according to ASTM D5949 of about −6° to about 4° C.; an aromatic content according to Clay Gel Analysis ASTM D2007 of about 30 to about 55 weight percent; a saturates content (Clay Gel Analysis ASTM D2007) of about 40 to about 65 weight percent; a polar compounds content according to Clay Gel Analysis ASTM D2007 of about 0.4 to about 1 weight percent; a VGC of about 0.86 to about 0.89; a PCA extract content less than 3 weight percent as determined according to IP 346; and a PAH 8-markers content less than 10 ppm when evaluated according to European standard EN 16143:2013. 
     
     
         15 . The method according to  claim 1  further comprising combining the enhanced C A  content naphthenic process oil with a rubber formulation. 
     
     
         16 . A method for making naphthenic process oils, the method comprising:
 a) blending a naphthenic vacuum gas oil having a viscosity of at least 60 SUS at 38° C. with a high C A  distilled aromatic extract feedstock to provide a blended oil; and   b) hydrotreating the blended oil to provide an enhanced C A  content naphthenic process oil;   wherein the feedstock and enhanced C A  content naphthenic process oil each have greater C A  content than that of a comparison oil made by similarly hydrotreating the naphthenic vacuum gas oil alone.   
     
     
         17 . A naphthenic process oil comprising a hydrotreated blend of a) at least one naphthenic vacuum gas oil having a viscosity of at least 60 SUS at 38° C. and b) a high C A  distilled aromatic extract feedstock having greater C A  content than that of a comparison oil made by similarly hydrotreating the at least one naphthenic vacuum gas oil alone.