Combustion modifiers for water-blended fuels

Abstract

A combustion modifier for an aqueous hydrocarbon fuel emulsion that reduces nitrogen oxides (NOx), hydrocarbons, carbon monoxide (CO) and particulate matter from the emissions of internal combustion engines. A class of combustion modifiers used in this invention contain nitrogen. The nitrogen-containing combustion modifiers are nitro compounds, hydroxylamines or salts thereof, nitrogen compounds having at least one strained ring group containing from 3 to 5 ring atoms, nitrites, nitramines and mixtures thereof. The non nitrogen-containing combustion modifier comprises compounds containing at least one strained ring compound.

What is claimed is:  
     
         1 . An aqueous hydrocarbon fuel emulsion comprising, a liquid hydrocarbon fuel, water, at least one emulsifier and a nitrogen containing combustion modifier, wherein the nitrogen containing combustion modifier comprises: 
 (a) a nitro compound;    (b) a hydroxylamine or a salt thereof wherein each hydroxylamino group of the hydroxylamine or salt thereof contains no more than one tertiary substituent;    (c) a compound having at least one strained ring group containing from 3 to 5 ring atoms;    (d) organic nitrites;    (e) nitramines; and    (f) mixtures thereof.    
     
     
         2 . The fuel composition of  claim 1  comprising a hydroxylamine wherein the hydroxylamine has the general formula  
       
         
           
           
               
               
           
         
       
       wherein each R a  and R b  is, independently, a member selected from the group consisting of H, a primary hydrocarbyl group and a secondary hydrocarbyl group containing from 1 to about 25 carbon atoms, and n ranges from 1 to about 30.  
     
     
         3 . The fuel composition of  claim 1  comprising a hydroxylamine wherein the hydroxylamine has the general formula  
       
         
           
           
               
               
           
         
       
       wherein each R c  is, independently, H or a hydrocarbyl group, each R d  is, independently, a lower alkylene group and x ranges from 1 to about 29.  
     
     
         4 . The fuel composition of  claim 1  comprising a hydroxylamine salt and wherein the salt is at least one member of the group consisting of nitrates, sulfates, sulfonates, carbonates and carboxylates.  
     
     
         5 . The fuel composition of  claim 1  wherein the nitro compounds are selected from the group consisting of aliphatic and aromatic nitro compounds.  
     
     
         6 . The fuel composition of  claim 1  wherein the nitro compound comprises at least one member of the group consisting of nitromethane, dinitrobutyl phenol, dinitropropane, nitromethane, nitropropane, trinitrotoluene, dinitrotoluene, 1,2-dinitropropanol and hydroxymethyl nitropropane.  
     
     
         7 . The fuel composition of  claim 1  wherein the ring group is a hydrocarbyl group substantially free of heteroatoms.  
     
     
         8 . The fuel composition of  claim 1  wherein the ring contains both carbon atoms and heteroatoms, said heteroatoms being selected from the group consisting of O, S and N.  
     
     
         9 . The fuel composition of  claim 7  wherein the ring contains at least two carbon atoms.  
     
     
         10 . The fuel composition of  claim 9  wherein the ring contains no more than 2 heteroatoms.  
     
     
         11 . The fuel composition of  claim 7  wherein the hydrocarbyl group is a cyclopropyl group, a cyclobutyl group or a cyclopentyl group.  
     
     
         12 . The composition of  claim 10  wherein the ring is an epoxy group, an oxetane group or a furan group.  
     
     
         13 . The fuel composition of  claim 1  wherein the compound comprises at least two strained ring groups.  
     
     
         14 . The fuel composition of  claim 11  wherein the compound comprises cyclopropyl methanol, cyclobutyl amine and cyclobutyl hydroxylamine.  
     
     
         15 . The fuel composition of  claim 12  wherein the compound is selected from the group consisting of 3,3-dimethyloxetane, 1-methoxy-2-methylpropylene oxide and 2,5-dimethoxytetrahydrofuran.  
     
     
         16 . The fuel composition of  claim 1  further comprising at least one component selected from the group consisting of (a) dispersants, (b) lubricity agents, (c) cold flow improvers, (d) fluidizers, (e) surfactants, (f) corrosion inhibitors and (g) mixtures thereof.  
     
     
         17 . The fuel composition of  claim 1  comprising a nitramine selected from the group consisting of benzyl nitramine, phenyl nitramine, methyl nitramine 2-propyl nitramine, ammonium dinitramine, ethylene dinitramine and combinations thereof.  
     
     
         18 . A method from improving the combustion characteristics of an aqueous hydrocarbon fuel emulsion comprising incorporating therein a combustion improving amount of a nitrogen containing combustion improver selected from the group comprising: 
 (a) a nitro compound;    (b) a hydroxylamine or a salt thereof wherein each hydroxylamino group of the hydroxylamine or salt thereof contains no more than one tertiary substituent;    (c) a compound having at least one strained ring group containing from 3 to 5 ring atoms;    (d) organic nitrites;    (e) nitramines; and    (f) mixtures thereof.    
     
     
         19 . The method of  claim 18  wherein the improved combustion characteristics comprise at least one of reduced particulate emissions, reduced NO x  emissions, reduce carbon monoxide emissions reduced hydrocarbon emissions or combinations thereof.  
     
     
         20 . A method for operating an internal combustion engine comprising providing to the combustion chamber of said engine during operation thereof, the fuel composition of  claim 1 .  
     
     
         21 . An aqueous hydrocarbon fuel emulsion comprising, a liquid hydrocarbon fuel, water, at least one emulsifier and a non-nitrogen containing combustion modifier containing at least one strained ring compound.