Pre-atomized fuels and process for producing same

Abstract

Methods and compositions are provided to facilitate the transportation and combustion of highly viscous hydrocarbons by forming reduced viscosity hydrocarbon-in-water emulsions, and in particular, bioemulsifier-stabilized hydrocarbon-in-water emulsions.

We claim: 
     
       1. A pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package, comprising about 15% by weight α-emulsan, about 42.5% by weight ethoxylated monononylphenol with about 40 ethoxy groups, and about 42.5% by weight of an ammonium salt of poly(3)ethoxy C 12  -C 14  linear primary alcohol sulfate, in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume. 
     
     
       2. A combustible pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package, comprising about 15% by weight α-emulsan, about 85% by weight of an ethoxylated alkyl phenol selected from the group consisting of ethoxylated monononyl phenol with about 40 ethoxy groups and ethoxylated monooctyl phenol with about 40 ethoxy groups, in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume. 
     
     
       3. A combustible pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package, comprising about 15% by weight α-emulsan, about 42.5% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and about 42.5% by weight of ethoxylated monooctylphenol with about 40 ethoxy groups, in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon-water ratio from about 60:40 to about 90:10 by volume. 
     
     
       4. A combustible pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package, comprising about 17% by weight of whole broth α-emulsan, about 50% by weight of an ethoxylated monooctylphenol with about 70 ethoxy groups, and about 33% by weight of an ethoxylated monononylphenol with about 70 ethoxy groups, in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon-water ratio from about 60:40 to about 90:10 by volume. 
     
     
       5. A combustible pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package, comprising about 14% by weight of whole broth α-emulsan, about 43% by weight of an ethoxylated monooctylphenol with about 40 ethoxy groups, about 29% by weight of an ethoxylated monononylphenol with about 40 ethoxy groups and about 14% by weight of a salt of a lignosulfonate, in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon-water ratio from about 60:40 to about 90:10 by volume. 
     
     
       6. The pre-atomized fuel of claim 1, 2, 3, 4 or 5 wherein the hydrocarbon:water ratio is about 70:30. 
     
     
       7. The pre-atomized fuel of claim 1 or 2 wherein the hydrocarbon is Number 6 residual fuel oil. 
     
     
       8. The pre-atomized fuel of claim 1, 2, 3, 4 or 5 wherein the aqueous phase is a methanol/water mixture containing a methanol:water ratio of about 45:55 or less. 
     
     
       9. The pre-atomized fuel of claim 1 or 2 wherein the hydrocarbon is Bunker C oil. 
     
     
       10. The pre-atomized of claim 1 or 2 wherein the hydrocarbon is California Kern County crude oil. 
     
     
       11. A method of reducing fuel emissions comprising fueling a burner with the combustible pre-atomized fuel of claim 1, 2, 3, 4 or 5. 
     
     
       12. The method of claim 11 wherein the fuel emissions are NOX emissions. 
     
     
       13. The method of claim 11 wherein the fuel emissions are SO 2  emissions. 
     
     
       14. The method of claim 12 wherein the NOX emissions are reduced by at least about 15%. 
     
     
       15. The method of claim 13 wherein the SO 2  emissions are reduced by at least about 9%. 
     
     
       16. A process for producing a pre-atomized fuel from a hydrocarbon with a viscosity of about 1000 centipoise or greater at 212° F. comprising the steps of: (a) heating the hydrocarbon to a fluid state at a temperature greater than about 212° F.;   (b) contacting the heated hydrocarbon with an aqueous phase comprising a surfactant package capable of promoting emulsification of the heated hydrocarbon;   (c) mixing the hydrocarbon and aqueous phase to form an emulsion while maintaining a pressure sufficient to prevent water in the aqueous phase from vaporizing at the elevated temperature of step (a); and   (d) rapidly cooling the emulsion in a heat exchanger to a temperature below about 212° F.   
     
     
       17. The process of claim 16 wherein the hydrocarbon is a vacuum resid. 
     
     
       18. The process of claim 16 wherein the hydrocarbon is California vacuum resid, the surfactant package comprises about 90% of a linear alkyl benzene sulfonate and about 10% α-emulsan, the heating temperature is about 300° F. and the pressure is maintained at about 70 psi. 
     
     
       19. A process for producing a pre-atomized fuel from a thermally-cracked hydrocarbon discharge comprising the steps of: (a) heating the hydrocarbon discharge to a fluid state;   (b) contacting the hydrocarbon discharge with an aqueous phase comprising a surfactant package capable of promoting emulsification of the heated hydrocarbon discharge to form an emulsion; and   (c) immediately quenching the heated emulsion to a temperature at least about 100° F., less than the softening point of the hydrocarbon.   
     
     
       20. The process of claim 19 wherein the hydrocarbon discharge is a visbreaker resid characterized by incipient phase separation. 
     
     
       21. The process of claim 19 wherein the hydrocarbon discharge is German visbreaker resid and the surfactant package comprises about 50% by weight of nonionic monooctylphenol with about 70 ethoxy groups, about 33% by weight of nonionic monononylphenol with about 70 ethoxy groups and about 17% by weight of α-emulsan. 
     
     
       22. A process for producing a reduced viscosity pre-atomized fuel comprising the steps of: (a) forming a slurry in which particles of a high temperature softening point hydrocarbonaceous material are dispersed in an aqueous phase comprising a surfactant package capable of promoting dispersion of the particles in the aqueous phase;   (b) forming a pre-atomized fuel with a hydrocarbon of lower temperature softening point than the hydrocarbonaceous material of step (a); and   (c) mixing the slurry of step (a) with the pre-atomized fuel of step (b).   
     
     
       23. The process of claim 22 wherein the high temperature softening point hydrocarbonaceous material is selected from the group consisting of coal, coke and ROSE resid. 
     
     
       24. The process of claim 22 wherein the slurry and the pre-atomized fuel are mixed in about a 1:1 ratio. 
     
     
       25. The process of claim 22 wherein the particles of high temperature softening point hydrocarbonaceous material are individually about 30 μm in diameter or less. 
     
     
       26. The process of claim 22 wherein the high temperature softening point hydrocarbonaceous material is ROSE resid, the lower temperature softening point hydrocarbon is California vacuum resid and the surfactant package used to form the slurry and the pre-atomized fuel comprises about 43% by weight of nonionic monooctylphenol with about 40 ethoxy groups, about 29% by weight of nonionic monononylphenol with about 40 ethoxy groups, about 14% by weight of a salt of a lignosulfonate and about 14% by weight of α-emulsan. 
     
     
       27. A combustible pre-atomized fuel comprising a bioemulsifier-stabilized hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume, said surfactant package comprising (a) at least one water-soluble surfactant, an effective amount of which surfactant promotes emulsification of a hydrocarbon with API gravity of about 20°API or less, viscosity of about 100 centipose or greater at 150° F., paraffin content of about 50% by weight or greater into an aqueous phase to form a hydrocarbon-in-water emulsion wherein the proportion of hydrocarbon to aqueous phase is about 90:10 by volume or less, the viscosity of which emulsion is reduced by at least a factor of about 10 compared to the viscosity of the hydrocarbon; and   (b) at least one water-soluble bioemulsifier, being a microbially-derived substance which predominantly resides at hydrocarbon/water interfaces to substantially surround hydrocarbon droplets in hydrocarbon-in-water emulsions, an effective amount of which bioemulsifier stabilizes a hydrocarbon-in-water emulsion formed with a hydrocarbon as in (a) by maintaining viscosity reduced by at least a factor of about 10 for a period of at least about a day under static conditions.   
     
     
       28. The pre-atomized fuel of claim 27 wherein the bioemulsifier of the surfactant package is produced by Acinetobacter calcoaceticus. 
     
     
       29. The pre-atomized fuel of claim 27 wherein the bioemulsifier of the surfactant package is produced by Acinetobacter calcoaceticus ATCC 31012. 
     
     
       30. The pre-atomized fuel of claim 27 wherein the bioemulsifier of the surfactant package is produced by Acinetobacter calcoaceticus NRRL B-15847. 
     
     
       31. The pre-atomized fuel of claim 27 wherein the surfactant package comprises (a) from about 1% to about 50% by weight of α-emulsan; and   (b) from about 50% to about 99% by weight of a water-soluble nonionic surfactant selected from the group consisting of (i) an ethoxylated alkyl phenol represented by the formula R x  C 6  H 4  (OC 2  H 4 ) n  OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms, x represents the number of alkyl groups ranging from about 1 to about 2, and wherein n represents the number of ethoxy groups ranging from about 1 to about 100; (ii) an ethoxylated alcohol represented by the formula R(OC 2  H 4 ) n  OH wherein R represents a branched or linear aliphatic group containing from about 6 to about 18 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 2 to about 100; and (iii) a polyoxyalkylated amine represented by the formula R x  N y  (CH 2 ) 2  wherein R represents an oxyalkyl group containing from 2 to 3 carbon atoms, x represents the number of oxyalkyl groups ranging in number from about 4 to about 500 and y represents the number of nitrogen atoms ranging from about 1 to about 2.   
     
     
       32. The pre-atomized fuel of claim 27 wherein the surfactant package comprises (a) from about 10% to about 20% by weight of α-emulsan; and   (b) from about 90% to about 80% by weight of a water-soluble anionic surfactant selected from the group consisting of (i) a sulfated ethoxylated alkylphenol represented by the formula RC 6  H 4  (OC 2  H 4 ) n  OSO 3  M wherein R represents an aliphatic group containing at least about 8 or 9 carbon atoms, n represents the number of ethoxy groups ranging from about 1 to about 100, and M is ammonium, sodium, potassium, calcium or triethanolamine; (ii) an ethoxylated alcohol sulfate represented by the formula R(OC 2  H 4 ) n  OSO 3  M wherein R represents an aliphatic group containing from about 6 to about 16 carbon atoms, n represents the number of ethoxy groups ranging from 0 to about 4, and M is ammonium, sodium, potassium, calcium or triethanolamine; and (iii) an alkylarylsulfonate represented by the formula R n  A m  (SO 3 ) x  M wherein Ar is an aromatic group which is benzyl, naphthyl, phenyl, tolyl, xylyl or ethylphenyl, R is a linear or branced chain alkyl group containing about 2 to about 16 carbon atoms, n is 1 or 2, m is 1 or greater, x is at least about 1, and M is ammonium, sodium, calcium, potassium or triethanolamine.   
     
     
       33. The pre-atomized fuel of claim 21 wherein the surfactant package comprises (a) from about 1% to about 50% by weight of α-emulsan; and   (b) from about 50% to about 99% by weight of a combination of (i) a water-soluble nonionic ethoxylated alkyl phenol represented by the formula R x  C 6  H 4  (OC 2  H 4 ) n  OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms, x represents the number of alkyl groups ranging from about 1 to about 2, and wherein n represents the number of ethoxy groups ranging from about 1 to about 100 and (ii) a water-soluble anionic ethoxylated or nonethoxylated alcohol sulfate represented by the formula R(OC 2  H 4 ) n  OSO 3  M wherein R represents an aliphatic group containing from about 6 to about 16 carbon atoms, n represents the number of ethoxy groups ranging ffom about 0 to about 4, and M is ammonium, sodium, potassium, calcium or triethanolamine, said combination being in a proportion of about 1:1 by weight.   
     
     
       34. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 27, 28, 29, 30, 31, 32 or 33 wherein the hydrocarbon is a residual oil. 
     
     
       35. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 21, 28, 29, 30, 31, 32 or 33 wherein the hydrocarbon is a residual oil selected from the group consisting of Number 6 residual fuel oil, California vacuum residual oil, Oklahoma vacuum residual oil, German visbreaker residual oil, Texas visbreaker residual oil, catalytic hydrogenated residual oil, ROSE residual oil, cutback tar and Bunker C oil. 
     
     
       36. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 27, 28, 29, 30, 31, 32 or 33 wherein the hydrocarbon is a crude oil. 
     
     
       37. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 27, 28, 29, 30, 31, 32, or 33 wherein the hydrocarbon is selected from the group consisting of Boscan crude oil, Texas fireflood crude oil, Jibaro crude oil, El Jobo crude oil, California Kern County crude oil and Kansas crude oil. 
     
     
       38. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 27, 28, 29, 30, 31, 32 or 33 wherein the aqueous phase is a methanol/water mixture containing a methanol:water ratio of about 45:55 or less. 
     
     
       39. The pre-atomized fuel of claim 1, 2, 3, 4, 5, 27, 28, 29, 30, 31, 32 or 33 wherein the hydrocarbon is a blend of (a) a first hydrocarbon unemulsifiable with said surfactant package and (b) at least a second hydrocarbon capable of adjusting the first hydrocarbon to a form emulsifiable with said surfactant package. .Iadd. 
     
     
       40.  A pre-atomized fuel comprising a hydrocarbon-in-water emulsion comprising: (a) hydrocarbon characterized by a viscosity of about 82,000 centipoise or greater at 80° F.;   (b) water; and   (c) a surfactant package comprising at least one water-soluble surfactant, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio of from about 60:40 to about 90:10 by volume. .Iaddend..Iadd.   
     
     
       41.  The pre-atomized fuel of claim 40 wherein said hydrocarbon is further characterized by an API gravity of about 20° API or less. .Iaddend..Iadd.42. The pre-atomized fuel of claim 40 wherein said hydrocarbon is further characterized by a paraffin content of about 50% by 
     
     
        weight or less. .Iaddend..Iadd.43.  The pre-atomized fuel of claim 40 wherein the viscosity of said oil-in-water emulsion is no greater than about one-tenth of the viscosity of said hydrocarbon. .Iaddend..Iadd.44. The pre-atomized fuel of claim 40 wherein the water soluble surfactant comprises a nonionic surfactant. .Iaddend..Iadd.45. The pre-atomized fuel of claim 44 wherein said n onionic surfactant comprises ethoxylated alkyl phenol. .Iaddend..Iadd.46. The pre-atomized fuel of claim 45 wherein said ethoxylated alkyl phenol comprises ethoxylated monoalkyl or dialkyl phenol. .Iaddend..Iadd.47. The pre-atomized fuel of claim 40 wherein said hydrocarbon:water ratio is from about 70:30 to about 90:10 by volume. .Iaddend..Iadd.48. The pre-atomized fuel of claim 47 wherein said hydrocarbon:water ratio is about 70:30 by volume. .Iaddend..Iadd.49. The pre-atomized fuel of claim 40 wherein said hydrocarbon-in-water emulsion has a surfactant, package:hydrocarbon weight ratio of from about 1:100 to about 1:20000. .Iaddend..Iadd.50. The pre-atomized fuel of claim 40 wherein (a) said hydrocarbon is further characterized by an API gravity of about 20° API or less and a paraffin content of about 50% by weight or less;   (b) said water soluble surfactant comprises ethoxylated alkyl phenol; and,   (c) said hydrocarbon:water ratio is from about 70:30 to about 90:10 by   
     
     
        volume. .Iaddend..Iadd.51.  The pre-atomized fuel according to claim 50 wherein said hydrocarbon-in-water emulsion has a surfactant package:hydrocarbon weight ratio of from 1:100 to about 1:20000 and the viscosity of said oil-in-water emulsion is no greater than about one-tenth of the viscosity of said hydrocarbon. .Iaddend..Iadd.52. The pre-atomized fuel according to claim 44 wherein said nonionic surfactant comprises an ethoxylated alkyl phenol represent by the formula R x  C 6  H 4  (OC 2  H 4 ) n  OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms, x represents the number of alkyl groups ranging from about 1 to about 100. .Iaddend.