Compositions, Uses and Methods for Improving The Low Temperature Properties of a Middle Distillate Fuel

Abstract

A method of improving the low temperature properties of a middle distillate fuel composition comprising: (a) a nitrogen-containing dispersant; and (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof; the method comprising adding to the fuel an additive (c) which is a copolymer comprising units of formula (A): and units of formula (B): wherein R is an alkyl group and each of R1 and R2 is an alkyl group.

1 . A method of improving the low temperature properties of a middle distillate fuel composition comprising:
 (a) a nitrogen-containing dispersant; and   (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof;   the method comprising adding to the fuel an additive (c) which is a copolymer comprising units of formula (A):   
       
         
           
           
               
               
           
         
       
       and units of formula (B): 
       
         
           
           
               
               
           
         
       
       wherein R is an alkyl group and each of R 1  and R 2  is an alkyl group. 
     
     
         2 . (canceled) 
     
     
         3 . An additive composition for improving the low temperature properties of a middle distillate fuel composition the additive composition comprising:
 (a) a nitrogen-containing dispersant;   (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives (y) middle distillate flow improvers and mixtures thereof; and   (c) a copolymer comprising units of formula (A):   
       
         
           
           
               
               
           
         
       
       and units of formula (B): 
       
         
           
           
               
               
           
         
       
       wherein R is an alkyl group and each of R 1  and R 2  is an alkyl group. 
     
     
         4 . A middle distillate fuel composition comprising:
 (a) a nitrogen-containing dispersant;   (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof; and   (c) a copolymer comprising units of formula (A):   
       
         
           
           
               
               
           
         
       
       and units of formula (B): 
       
         
           
           
               
               
           
         
       
       wherein R is an alkyl group and each of R 1  and R 2  is an alkyl group. 
     
     
         5 . The method according to  claim 1  wherein additive (c) is prepared by copolymerising vinyl ester monomers and dialkyl fumarate monomers. 
     
     
         6 . The method according to  claim 1  wherein R is methyl. 
     
     
         7 . The method according to  claim 1  wherein each of R 1  and R 2  is an alkyl group having less than 18 carbon atoms. 
     
     
         8 . The method according to  claim 1  wherein component (a) is selected from:
 (i) a quaternary ammonium salt additive; 
 (ii) the product of a Mannich reaction between an aldehyde, an amine and an optionally substituted phenol; 
 (iii) the reaction product of a carboxylic acid-derived acylating agent and an amine; 
 (iv) the reaction product of a carboxylic acid-derived acylating agent and hydrazine; 
 (v) a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine; 
 (vi) the reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride and an amine compound or salt which product comprises at least one amino triazole group; and 
 (vii) a polyalkylene substituted amine. 
 
     
     
         9 . The method according to  claim 1  wherein component (a) is selected from:
 (i) a quaternary ammonium salt additive; 
 (ii) the product of a Mannich reaction between an aldehyde, an amine and an optionally substituted phenol; and 
 (iii) the reaction product of a carboxylic acid-derived acylating agent and an amine. 
 
     
     
         10 . The method according to  claim 1  wherein component (a) is selected from one or more of:
 a quaternary ammonium salt additive formed by reacting methyl salicylate or dimethyl oxalate with the reaction product of a polyisobutylene-substituted succinic anhydride having a PIB number average molecular weight of 700 to 1300 and dimethylaminopropylamine; 
 the Mannich reaction product of dodecylphenol, formaldehyde and either ethylene diamine or tetraethylpentamine; and 
 the reaction product of a polyisobutenyl substituted succinic acid/anhydride having a PIB molecular weight (Mn) of 500 to 1300 and a polyethylene polyamine having 1 to 9 amino groups and 1 to 8 ethylene groups. 
 
     
     
         11 . The method according to  claim 1  wherein component (b) comprises at least one wax antisettling additive (x) and at least one middle distillate flow improver (y). 
     
     
         12 . The method according to  claim 1  wherein component (b) comprises a wax antisettling additive (x) which is the reaction product of (I) a compound containing the segment —NR 3 R 4  where R 3  represents a group containing from 4 to 44 carbon atoms and R 4  represents a hydrogen atom or a group R 3 , and (II) a carboxylic acid having from 1 to 4 carboxylic acid groups or a reactive equivalent thereof. 
     
     
         13 . The method according to  claim 1  wherein component (b) comprises a wax antisettling additive (x) which is the reaction product of di(hydrogenated) tallow amine (I) and phthalic acid or its acid anhydride (II). 
     
     
         14 . The method according to  claim 1  wherein component (b) comprises a middle distillate flow improver (y) which is a copolymer of ethylene and an olefinically unsaturated compound. 
     
     
         15 . The method according to  claim 1  wherein component (b) comprises a middle distillate flow improver (y) which, in addition to ethylene, contains 1 to 23 mol %, of olefinically unsaturated compounds as co-monomers. 
     
     
         16 . (canceled) 
     
     
         17 . The composition according to  claim 3  wherein additive (c) is prepared by copolymerising vinyl ester monomers and dialkyl fumarate monomers. 
     
     
         18 . The composition according to  claim 3  wherein R is methyl. 
     
     
         19 . The composition according to  claim 3  wherein each of R 1  and R 2  is an alkyl group having less than 18 carbon atoms. 
     
     
         20 . The composition according to  claim 4  wherein additive (c) is prepared by copolymerising vinyl ester monomers and dialkyl fumarate monomers. 
     
     
         21 . The composition according to  claim 4  wherein R is methyl. 
     
     
         22 . The composition according to  claim 4  wherein each of R 1  and R 2  is an alkyl group having less than 18 carbon atoms.