Bio-based lubricant base stock and distillate range products and production methods

Abstract

Biolubricant base stocks and distillate range products and methods for producing them from triglyceride-containing seed oils by converting the triglyceride feedstocks into mono-unsaturated free fatty acids or fatty acid esters, dimerizing the fatty acids or fatty acid esters and converting such dimers to fully saturated acyclic hydrocarbon basestocks by a multistep process.

1 . A method for producing primarily acyclic lubricants or fuels from triglyceride-containing, biologically-derived oils, either comprising the steps of:
 a. providing a >75% monounsaturated triglyceride feedstock;   b. converting such triglyceride feedstock into free fatty acids by hydrolysis and/or free fatty esters by transesterification;   c. optionally converting both said fatty acids and/or fatty acid esters to dimers having less than a 20% cyclic structure by heating both such fatty acids and/or fatty acid esters in the presence of an acidic clay catalyst at temperatures between 200-250° C.;   d. selectively hydrogenating said dimers from step c or fatty acids and/or fatty acid esters from step b to the degree necessary to fully saturate them and remove residual double bonds;   e. hydro-deoxygenating the product of step d to the extent necessary to remove the oxygen therefrom by forming H2 O or CO2:   f. selectively hydro-isomerizing the product of step e to the degree necessary to reduce the pour point of the produced product to a desired level;   g. mildly hydrogenating the product of step f to remove residual double bonds; and   h. separating the deoxygenated dimers from the distillate range hydrocarbons formed in step g.,   
       or comprising the steps of:
 a. providing a >75% monounsaturated triglyceride feedstock; 
 b. converting such triglyceride feedstock into free fatty acids by hydrolysis and/or free fatty esters by transesterification; 
 c. optionally converting both said fatty acids and/or fatty acids esters to dimers having less than a 20% cyclic structure by heating both such fatty acids and/or fatty acid esters in the presence of an acidic clay catalyst at temperatures between 200-250° C.; 
 d. separating the remaining monomer fatty acids and/or fatty acid esters from the dimers formed in the previous step; 
 e. selectively hydrogenating said dimers to the degree necessary to fully saturate them and remove residual double bonds; 
 f. hydro-deoxygenating said saturated dimers to the extent necessary to remove the oxygen therefrom by forming H2 O or CO2; 
 g. selectively hydro-isomerizing the deoxygenated dimers to the degree necessary to reduce the pour point of the produced product to a desired level; and 
 h. mildly hydrogenating the deoxygenated dimers to remove residual double bonds. 
 
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1 , wherein step c. includes converting such fatty acids and/or fatty acid esters to dimers, and step h produces primarily acyclic lubricant basestocks. 
     
     
         4 . The method of  claim 1 , wherein such fatty acids and/or fatty acid esters are not converted to dimers in step c, and step h produces primarily distillate range hydrocarbon products. 
     
     
         5 . The method of  claim 1 , wherein the clay catalyst in step c. Includes a bentonite clay catalyst. 
     
     
         6 . The method of  claim 1 , wherein step b. includes subjecting the triglyceride containing feedstock to an HCU process for reducing the content of metals and other contaminants therein and simultaneously converting the triglycerides to free fatty acids by hydrolysis. 
     
     
         7 . The method of  claim 1 , further including fractionating the resulting isomerized dimers by distillation to obtain hydrocarbon isomers of a desired carbon chain length range. 
     
     
         8 . The method of  claim 1 , wherein step a includes partially hydrogenating a triglyceride-containing, biologically derived oil eliminate double or triple unsaturation content to the extent necessary to raise the monounsaturated content of the triglycerides to at least 80% while minimizing the formation of fully saturated content. 
     
     
         9 . The method of  claim 3 , wherein the carbon chain length of said saturated dimers is reduced by controlling the conditions under which said hydro-deoxygenating step is performed so that primarily CO2 is formed. 
     
     
         10 . The method of  claim 9 , wherein said biologically derived oils comprise soy, canola or sunflower, or other non-food seed oils such as castor, camelina or jatropha and said partial hydrogenation step is controlled to yield a lubricant basestock having a C18:1 free fatty acid content of at least 90%. 
     
     
         11 . The method of  claim 9 , wherein after fractionation the isomerized dimers have a carbon chain length in the range of C28 to C34 and the lubricant basestock has a KV100 of >3 cSt. 
     
     
         12 . The method of  claim 8 , wherein said biologically-derived oils comprise Camelina oil. 
     
     
         13 . The method of  claim 10 , wherein after fractionation the isomerized dimers have a carbon chain length in the range of C38 to C42 and the lubricant basestock has a KV100 of >4 cSt. 
     
     
         14 . The method of  claim 1 , wherein a >75% monounsaturated fatty acid or fatty acid alkyl ester is used in place of or in combination with the >75% monounsaturated triglyceride feedstock. 
     
     
         15 . A fully saturated biomass derived hydrocarbon composition in which at least 80% of the hydrocarbon molecules have carbon numbers between C 28 and C 32, at least at least 30% of the molecules have an odd carbon number according to FIMS, which the biobased carbon content is >98% by ASTM-D6866-12; and the composition has a KV100 in the range of 3.0-15.0 cSt, a pour point in the range of −20 to −55.degree. C., a Noack and CCS @−35.degree. C. relationship such that Noack is less than or equal to 0.9×2750 (CCS @−35.degree. C.).sup.(−0.8).+2; with a BP/BI in the range of gtoreq.0.58 per molecule' and, on average from 0.2 to 1.6 5+ methyl branches per molecule. 
     
     
         16 . A fully saturated biomass derived hydrocarbon composition in which at least 80% of the hydrocarbon molecules have carbon numbers between C 28 and C 36, at least at least 33% of the molecules have an odd carbon number according to FIMS which the biobased carbon content is >98% by ASTM-D6866-12; and the composition has a KV100 in the range of 3.0-15.0 cSt, a pour point of less than-18 degrees C., a Noack and CCS @-35.degree. C. relationship such that Noack is less than or equal to 0.9×2750 (CCS @−35.degree. C.).sup.(−0.8).+2; with a BP/BI in the range of .gtoreq.0.58 per molecule and, on average from 0.2 to 1.6 5+ methyl branches per molecule. 
     
     
         17 . The hydrocarbon mixture of  claim 16 , wherein the carbon numbers of the hydrocarbon mixture predominantly fall within the range of 30 to 32 and the hydrocarbon mixture further exhibits the following characteristics: a. KV100 is less than 10.0 cSt; b. VI in the range of +120 to +150, and an overall carbon intensity as calculated by the CA GREET-3.0 is less than 80% of that for a petroleum based analogs. 
     
     
         18 . The hydrocarbon mixture of  claim 16  derived from a genetically modified crop that generates a free fatty acid profile in the triglyceride stream that is predominantly mono-unsaturated. 
     
     
         19 . The hydrocarbon mixture of  claim 18 , wherein triglyceride contains predominantly C14 and C16 hydrocarbon chains in the free fatty acid molecules.