Low temperature operable fatty acid ester fuel composition and method thereof

Abstract

A fuel composition comprises (A) a major amount of a fatty carboxylic acid ester composition from at least one naturally occurring triglyceride and (B) a minor amount of a low temperature operability composition. A method for improving the low temperature operability of a fuel composition comprises admixing (A) with a low temperature improving amount of (B). The fuel composition is derived from a renewable resource and is especially useful in internal combustion engines such as compression-ignited diesel engines.

1 . A fuel composition for an internal combustion engine, comprising: 
 (A) a major amount of a fatty carboxylic acid ester composition from the transesterification of at least one naturally occurring triglyceride; and    (B) a minor amount of a low temperature operability composition comprising an esterified copolymer of an alpha-olefin or styrene and an alpha, beta-unsaturated monocarboxylic or dicarboxylic acid or anhydride, wherein the copolymer of (B) is esterified with a mixture of two or more alcohols having 5 to 28 carbon atoms wherein the mixture of the two or more alcohols has an average carbon length of 9.2 to 11.8 on a weight % basis.    
   
   
       2 . The fuel composition of  claim 1  wherein the naturally occurring triglyceride is a vegetable oil.  
   
   
       3 . The fuel composition of  claim 2  wherein the vegetable oil is a rapeseed oil, a soybean oil, a palm oil, or a mixture thereof.  
   
   
       4 . The fuel composition of  claim 1  wherein the naturally occurring triglyceride is transesterified with at least one monohydric alcohol having 1 to 22 carbon atoms.  
   
   
       5 . The fuel composition of  claim 3  wherein the rapeseed oil, the soybean oil, the palm oil, or the mixture thereof is transesterified with methanol.  
   
   
       6 . The fuel composition of  claim 1  wherein the alpha, beta-unsaturated monocarboxylic or dicarboxylic acid or anhydride is maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, acrylic acid, or methacrylic acid.  
   
   
       7 . The fuel composition of  claim 6  wherein the copolymer of (B) is formed from styrene and maleic anhydride.  
   
   
       8 . The fuel composition of  claim 7  wherein the copolymer of (B) prior to esterification has a reduced specific viscosity of 0.05 to 2.  
   
   
       9 . The fuel composition of  claim 1  wherein the copolymer of (B) further comprises an additional comonomer selected from the group consisting of a C 1-4  alkyl alpha, beta-unsaturated monocarboxylic acid ester, a di(C 1-4  alkyl) alpha, beta-unsaturated dicarboxylic acid ester, a vinyl monocarboxylic acid ester, an alkyl vinyl ether, and a mixture thereof.  
   
   
       10 . The fuel composition of  claim 9  wherein the additional comonomer is methyl methacrylate.  
   
   
       11 . The fuel composition of  claim 1  wherein the copolymer of (B) is esterified with a mixture of two or more alcohols having 5 to 20 carbon atoms.  
   
   
       12 . The fuel composition of  claim 1  wherein the esterified copolymer of (B) is further reacted with an amine having only one amino group that is a primary or a secondary amino group.  
   
   
       13 . The fuel composition of  claim 1  wherein the ester composition (A) is present in the fuel composition from 30 to 99.99% by weight and the low temperature operability composition (B) is present in the fuel composition from 100 to 10,000 ppm by weight.  
   
   
       14 . The fuel composition of  claim 1 , further comprising: 
 (C) at least one additional fuel additive.    
   
   
       15 . The fuel composition of  claim 1 , further comprising: 
 (D) a normally liquid fuel.    
   
   
       16 . The fuel composition of  claim 15  wherein the normally liquid fuel is a diesel fuel.  
   
   
       17 . A method for improving the low temperature operability of a fuel composition, comprising: 
 admixing the ester composition (A) with a low temperature improving amount of the composition (B) of  claim 1.