Stabilizer blends for alcohol in hydrocarbon fuel

Abstract

The present invention relates to compositions to stabilize hydrocarbon fuel, over a range of alcohol and water concentrations, against phase separation, containing a blend of two or more wide or one or more wide and one or more tall gaint hydrophobe nonionic surfactants. It also relates to fuel compositions stable toward such phase separation, which include (a) a major portion of a hydrocarbon fuel; (b) a minor amount of a low-alkyl (C1-C3) alcohol; (c) a minor portion of water; and (d) a minor portion of a stabilizer comprising a blend of wide or wide and tall giant hydrphobe nonionic surfactants. Optionally, the fuel compositions also include (e) a minor amount of a combustion aid, such as a cetane improver and (f) a minor amount of a solvent, such as a water solubilizing higher (C4 to C16) alcohol.

We claim:  
     
         1 . A surfactant combination suitable for emulsification of C 1-3  alkyl alcohol in a hydrocarbon liquid comprising a blend of at least two nonionic surfactants selected from the group consisting of: 
 (i) a nonionic surfactant having less than about 25% by weight non-hydric hydrophile groups;    (ii) a nonionic surfactant having greater than about 25% by weight non-hydric hydrophile groups; and    (iii) a nonionic surfactant comprising the condensation product of a) a hydrophobe having greater than 24 carbons in a row and b) polyhydric hydrophiles having a molecular weight less than about 400 and more than 1 hydrogen bonding hydrogens 11 or less atoms apart.    
     
     
         2 . The surfactant combination of  claim 1  wherein said non-ionic surfactant having greater than about 25% non-hydric hydrophile groups comprises the condensation product of: 
 c) a copolymer of the formula  
 R—CO—[O—CR 3 H—R 2 ) x —CO] y —OH  
  wherein R is hydrogen or C 1 -C 24  hydrocarbon; 
 R 3  is hydrogen or a monovalent C 1 -C 24    
 hydrocarbon group; R 2  is a divalent C 2 -C 24    
 hydrocarbon group; x is 0 or 1; and y is an integer from 0 to 200 and  
 
 d) a water soluble polyalkylene glycol moiety represented by the formula:  
 H—[O—CR 4 H—CH 2 ] z —R 5    
  wherein R4 is hydrogen or C 1 -C 4  alkyl; and z is an integer from about 10 to 400 and R 5  is —OH or a C 1 -C 23  acyl group.  
 
     
     
         3 . The surfactant combination of  claim 1  wherein said non-ionic surfactant having greater then about 25% non-hydric hydrophile groups comprises the condensation product of: 
 d) fatty amine of the general formula  
 R 5 —NH—[CH 2 —CHOH—CH 2 —NR 5 ] q —H  
  wherein R 5  is a C 1 -C 24  hydrocarbon group and q is an integer from about 5 to 50; and  
 f) epichlorohydrin.  
 
     
     
         4 . The surfactant combination of  claim 1  wherein said non-ionic surfactant having less than about 25% non-hydric hydrophile groups comprises the condensation product of: 
 c) a copolymer of the formula  
 R—CO—[O—CR 3 H—(R 2 ) x —CO] y —OH  
  wherein R is hydrogen or C 1 -C 24  hydrocarbon; 
 R 3  is hydrogen or a monovalent C 1 -C 24    
 hydrocarbon group; R 2  is a divalent C 2 -C 24    
 hydrocarbon group; x is 0 or 1; and y is an integer from 0 to 200 and  
 
 d) a water soluble polyalkylene glycol moiety represented by the formula:  
 H—[O—CR 4 H—CH 2 ] z —R 5    
  wherein R 4  is hydrogen or C 1 -C 4  alkyl; and z is an integer from about 10 to 400 and R 5  is —OH or a C 1 -C 23  acyl group.  
 
     
     
         5 . The surfactant combination of  claim 1  wherein the ratio of said at least two nonionic surfactants ranges from 99:1 to 1:99 by weight.  
     
     
         6 . The surfactant combination of  claim 1  wherein when said at least two nonionic surfactants comprises (i) and (iii), nonionic surfactant (iii) comprises a nonionic surfactant having more than 14% by weight hydric hydrophilic groups.  
     
     
         7 . The surfactant combination of  claim 1  wherein when said at least two nonionic surfactants comprises (ii) and (iii), nonionic surfactant (iii), comprises a nonionic surfactant having less than 14% by weight hydric hydrophilic groups.  
     
     
         8 . The surfactant combination of  claim 1  wherein said at least two nonionic surfactants comprise (I) and (ii) and (iii) wherein nonionic surfactant (iii) comprises a nonionic surfactant having about 14% by weight hydric hydrophilic groups.  
     
     
         9 . The surfactant combination of  claim 1  diluted to from about 1% to about 40% by weight in a low polarity organic solvent.  
     
     
         10 . The surfactant combination of  claim 9  wherein said low polarity solvent is selected from the group consisting of saturated hydrocarbons, unsaturated hydrocarbons, ethers, esters, N-alkylated amides, C 8  or higher alcohols or mixture thereof.  
     
     
         11 . The surfactant combination of  claim 9  wherein said low polarity organic solvent comprises a combination aid selected from the group consisting of alkyl nitrates, organic peroxides, aromatic naphthas, and bio-diesels.  
     
     
         12 . The surfactant combination of  claim 11  wherein said bio-diesel comprises a methyl ether of naturally occurring fatty acids.  
     
     
         13 . The surfactant combination of  claim 11  wherein said bio-diesel comprises methyl soyate.  
     
     
         14 . The surfactant combination of  claim 1  wherein said nonionic surfactant component (i) has a molecular weight ranging from about 1,000 to 1,000,000.  
     
     
         15 . The surfactant combination of  claim 1  wherein said nonionic surfactant component (ii) has a molecular weight ranging from about 1,000 to 1,000,000.  
     
     
         16 . The surfactant combination of  claim 1  wherein said nonionic surfactant component (i) comprises hydrophobes comprising heteroatom, punctuated hydrocarbon polymers comprising hydrophiles spread out over more than 5 individual polar groups.  
     
     
         17 . The surfactant combination of  claim 16  wherein nonionic surfactant component (i) comprises C 5-30  alkyl, or alkenyl hydrocarbon groups punctuated by non-C and non-H heteroatom groups.  
     
     
         18 . The surfactant combination of  claim 17  wherein said heteroatom groups are selected from the group consisting of ethers, esters, amides, amines and mixtures thereof.  
     
     
         19 . The surfactant combination of  claim 1  wherein said nonionic surfactant component (ii) comprises hydrophobes comprising heteroatom, punctuated hydrocarbon polymers comprising hydrophiles spread out over more than 5 individual polar groups.  
     
     
         20 . The surfactant combination of  claim 19  wherein nonionic surfactant component (i) comprises C 5-30  alkyl, or alkenyl hydrocarbon groups punctuated by non-C and non-H heteroatom groups.  
     
     
         21 . The surfactant combination of  claim 20  wherein said heteroatom groups are selected from the group consisting of ethers, esters, amides, amines and mixtures thereof.  
     
     
         22 . The surfactant combination of  claim 1  wherein said nonionic surfactant (iii) comprises the condensation product of a hydrophile having a molecular weight less than 400 selected from the group consisting of polyols and polyamines and said polyhydric hydrophile comprises polybutylene.  
     
     
         23 . An emulsion of C 1-3  alkyl alcohol in a liquid hydrocarbon, the emulsion containing 1% to 50% by weight of C 1-3  alkyl alcohol as the disperse phase and from 50% to 99% by weight of the hydrocarbon fuel as the continuous phase, from about 0.004% to about 25% by weight water and in addition as emulsifying agent, a surfactant composition as claimed in  claim 1.