Low emissions fuel emulsion

Abstract

Emulsions of a hydrocarbon and water in which the hydrocarbon preferably is a Fischer-Tropsch derived hydrocarbon fuel and in which emulsion a major portion of the hydrocarbon has particle sizes of 1 micron or less produce reduced particulate matter emissions upon combustion.

What is claimed is:  
     
         1 . A method for reducing particulate emissions during combustion of a hydrocarbon fuel which comprises combusting an emulsion of a hydrocarbon fuel and water wherein the fuel is a Fischer-Tropsch (FT) derived hydrocarbon as a mixture of a FT fuel and a conventional fuel, and in which emulsion, a major portion of the hydrocarbon has particle sizes of 1 micron or less.  
     
     
         2 . The method of  claim 1  wherein the emulsion is a hydrocarbon-in-water emulsion.  
     
     
         3 . The method of  claim 2  wherein the fuel is a FT derived fuel.  
     
     
         4 . The method of  claim 3  wherein greater than 50% of the hydrocarbon particles are in the range of about 0.1 to about 1.0 microns in size.  
     
     
         5 . The method of  claim 4  wherein the volume ratio of hydrocarbon to water is in the range of 95:5 to 60:40.  
     
     
         6 . The method of  claim 5  wherein greater than 80% of the hydrocarbon particles are in the range of about 0.1 to about 1.0 microns in size.  
     
     
         7 . The method of  claim 6  wherein the Fischer-Tropsch derived hydrocarbon boils in the diesel fuel range.  
     
     
         8 . The method of  claim 7  wherein the emulsion has a viscosity in the range of about 50 to 200 mm 2 /sec.  
     
     
         9 . A method for forming a fuel in water emulsion which when combusted has reduced particulate matter emissions compared with Swedish Class I Diesel Fuel comprising shearing a Fischer-Tropsch derived hydrocarbon boiling in the diesel fuel range and water in the volume ratio of hydrocarbon to water of 95:5 to 40:60 and about 0.05 to about 5.0 wt % based on the weight of hydrocarbon and water with a non-ionic surfactant or mixtures thereof having a HLB of about 5 to about 30 under shearing conditions sufficient to produce a liquid emulsion in which a major portion of the hydrocarbon has particle sizes of 1 micron or less.  
     
     
         10 . A liquid fuel composition comprising an emulsion of FT derived fuel in water wherein the fuel in the emulsion has fuel particle sizes predominately of 1 micron or less and the emulsion has a viscosity of above about 50 mm 2 /sec at 20° C.  
     
     
         11 . The composition of  claim 10  wherein greater than 50% of the fuel particles has particle sizes in the range of about 0.1 to about 1.0 microns.  
     
     
         12 . The composition of  claim 11  wherein the Fischer-Tropsch derived fuel boils in the diesel fuel range.