Demulsifiers for mixtures of middle distillates with fuel oils of vegetable or animal origin

Abstract

The invention provides fuel oils comprising a major proportion of a mixture of A) a middle distillate fuel oil, and B) a biofuel oil, and also a minor proportion of C) an oil-soluble copolymer of ethylene and at least 0.2 to 35 mol % of a further olefinically unsaturated compound which contains at least one free hydroxyl group, and which has an OH number of from 10 to 300 mg KOH/g.

1 . A fuel oil comprising a major proportion of a mixture of 
 A) a middle distillate fuel oil, and    B) a biofuel oil, and a minor proportion of    C) an oil-soluble copolymer of ethylene and at least 0.2 to 35 mol % of a first comonomer, wherein the first comonomer is an olefinically unsaturated compound containing at least one free hydroxyl group, and having an OH number of from 10 to 300 mg KOH/g.    
     
     
         2 . A fuel oil as claimed in  claim 1 , wherein the A):B) mixing ratio is from 99:1 to 1:99.  
     
     
         3 . A fuel oil as claimed in  claim 1 , wherein the OH number of the oil-soluble copolymer C) is between 20 and 250.  
     
     
         4 . A fuel oil as claimed in  claim 1 , wherein the copolymer C) has an average molecular weight of from 700 to 10,000 g/mol.  
     
     
         5 . A fuel oil as claimed in  claim 1 , wherein the proportion of the olefinically unsaturated compound in the copolymer C) is between 0.5 and 15 mol %.  
     
     
         6 . A fuel oil as claimed in  claim 1 , wherein the copolymer C) further comprises at least one second comonomer selected from the group consisting of vinyl esters, acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, vinyl ethers and olefins.  
     
     
         7 . A fuel oil as claimed in  claim 1 , wherein the content of C) in the fuel oil is from 0.001 to 5% by weight.  
     
     
         8 . A fuel oil as claimed in  claim 1 , further comprises at least one alkylphenol-formaldehyde resin of the formula  
       
         
           
           
               
               
           
         
       
       where R A  is C 6 -C 24 -alkyl or -alkenyl, R B  is OH or O-(A-O) x -H where A=C 2 -C 4 -alkylene and x=1 to 50, and n is a number from 2 to 50.  
     
     
         9 . A method for demulsifing a mixture of at least one middle distillate fuel oil and at least one biofuel oil comprising the step of adding the the mixture an oil-soluble copolymer of ethylene and at least 0.2 to 35 mol % of a further olefinically unsaturated compound having at least one free hydroxyl group and having an OH number of from 10 to 300 mg KOH/g.  
     
     
         10 . A fuel oil as claimed in  claim 8 , wherein n is from 5 to 40.