Fuel oils

Abstract

A fuel oil composition comprises a fuel oil blend, at least one ethylene-vinyl ester polymer and at least one polyalkylmethacrylate polymer. The fuel oil blend comprises a middle-distillate fuel oil and a hydrotreated vegetable, animal or fish oil, wherein the amount of hydrotreated vegetable oil in the fuel oil blend is sufficient to provide the blend with an increase in the C 15 to C 20 n-alkane distribution of at least 3% by weight over the C 15 to C 20 n-alkane distribution of the middle-distillate alone.

1 . A fuel oil composition comprising a fuel oil blend, at least one ethylene-vinyl ester polymer and at least one polyalkylmethacrylate polymer, wherein the fuel oil blend comprises a middle-distillate fuel oil and a hydrotreated vegetable, animal or fish oil, and wherein the amount of hydrotreated vegetable oil in the fuel oil blend is sufficient to provide the blend with an increase in the C 15  to C 20  n-alkane distribution of at least 3% by weight over the C 15  to C 20  n-alkane distribution of the middle-distillate alone. 
     
     
         2 . A fuel oil composition according to  claim 1 , wherein the polyalkylmethacrylate polymer is formed or obtainable from monomers corresponding to formula (II) 
       
         
           
           
               
               
           
         
       
       wherein R 1  is a C 4  to C 16  alkyl group. 
     
     
         3 . A fuel oil composition according to  claim 2 , wherein R 1  is a C 8  to C 16  alkyl group. 
     
     
         4 . A fuel oil composition according to  claim 3 , wherein R 1  is a C 14  alkyl group (tetradecyl), or R 1  is a C 12  alkyl group (dodecyl). 
     
     
         5 . A fuel oil composition according to  claim 1 , wherein the number average molecular weight of the at least one polyalkylmethacrylate polymer is in the range from 1,500 to 6,000 as measured by GPC with reference to polystyrene standards. 
     
     
         6 . A fuel oil composition according to  claim 1 , wherein the at least one ethylene-vinyl ester polymer comprises a copolymer of ethylene and a vinyl ester, wherein the copolymer has a vinyl ester content of between 5 and 25 mole %. 
     
     
         7 . A fuel oil composition according to  claim 1 , wherein the at least one ethylene-vinyl ester polymer comprises a terpolymer of ethylene, vinyl acetate and a branched-chain ester chosen from the group containing vinyl 2-ethylhexanoate, vinyl neononanoate, vinyl neodecanoate and vinyl neoundecanoate. 
     
     
         8 . A fuel oil composition according to  claim 1 , wherein the combined total amount of ethylene-vinyl ester polymer and polyalkylmethacrylate polymer in the fuel oil composition is in the range from 100 to 5,000 ppm by weight, based on the weight of the fuel oil blend. 
     
     
         9 . A fuel oil composition according to  claim 1 , wherein the weight ratio of ethylene-vinyl ester to polyalkylmethacrylate polymer in the fuel oil composition is in the range from 1:8 to 8:1. 
     
     
         10 . A fuel oil composition according to  claim 1  further comprising an additional cold-flow additive. 
     
     
         11 . A fuel oil composition according to  claim 10  further comprising an oil-soluble, hydrogenated block diene polymer. 
     
     
         12 . A fuel oil composition according to  claim 10  further comprising one or more of the following: lubricity additives, anti-oxidants, electrical conductivity improving additives, metal deactivators and/or demulsifiers. 
     
     
         13 . A method of improving the low temperature properties of a blend of a middle-distillate fuel oil and a hydrotreated vegetable, animal or fish oil comprising adding to the blend at least one ethylene-vinyl ester polymer and at least one polyalkylmethacrylate polymer, wherein the amount of hydrotreated vegetable oil in the blend is sufficient to provide the blend with an increase in the C15 to C20 n-alkane distribution of at least 3% by weight over the C15 to C20 n-alkane distribution of the middle-distillate alone. 
     
     
         14 . The method of  claim 13  wherein the improvement in low temperature properties of the blend of a middle-distillate fuel oil and a hydrotreated vegetable, animal or fish oil is as determined by CFPP measurement.