Fuel additives with low NOx emissions

Patent metadata

Field	Value
Publication number	US-11046903-B2
Application number	US-202016993850-A
Country	US
Kind code	B2
Filing date	Aug 14, 2020
Priority date	Aug 22, 2019
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

This disclosure relates to compositions and methods of making an additized fuel composition comprising a base fuel composition and a randomly branched nitrate composition. The randomly branched nitrate composition includes a plurality of primary nitrate molecules, each molecule therein having an empirical chemical formula of CnNO3, wherein Cn is a branched aliphatic moiety which may be the same or different for each molecule, n is an integer selected from the group consisting of 8, 9, 10, 11 and 12, at least one carbon atom in the branched aliphatic moiety being bound to three or more carbon atoms, a branching index ranging from 1.8 to 2.2, and greater than 80% of the branches in the aliphatic moiety being in other than the alpha position. The additized fuel composition may be diesel fuel composition or a gasoline fuel composition.

First claim

The invention claimed is:

1. An additized fuel composition comprising:
a base fuel composition, and
a randomly branched nitrate composition comprising a plurality of primary nitrate molecules, each molecule therein having an empirical chemical formula of C n NO 3 , wherein C n is a branched aliphatic moiety which may be the same or different for each molecule, n is an integer selected from the group consisting of 8, 9, 10, 11 and 12, at least one carbon atom in the branched aliphatic moiety being bound to three or more carbon atoms, a branching index ranging from 1.8 to 2.2, and greater than 80% of the branches in the aliphatic moiety being in other than the alpha position; and
wherein the additized fuel composition is a diesel fuel composition or a gasoline fuel composition.

2. The fuel composition as in claim 1 , wherein the additized fuel composition is a diesel fuel composition further comprising a biofuel.

3. The fuel composition as in claim 2 , wherein the biofuel comprises a fatty acid methyl ester, a fatty acid ethyl ester, hydrotreated vegetable oil, or a blend thereof.

4. The fuel composition as in claim 1 , wherein n is 9, 10, or 11.

5. The fuel composition as in claim 1 , wherein the concentration of C n NO 3 molecules in the randomly branched nitrate composition is at least about 60 wt. %.

6. The fuel composition as in claim 1 , wherein the concentration of C n NO 3 molecules in the randomly branched nitrate composition is at least about 60 wt. % and less than about 98 wt. %.

7. The fuel composition as in claim 1 , wherein one of the carbon atoms bound to the at least one carbon atom in the branched aliphatic moiety is part of a methyl group.

8. The fuel composition as in claim 1 , wherein the randomly branched nitrate composition is present at a concentration of about 500 ppmv to about 4000 ppmv.

9. The fuel composition as in claim 1 , wherein when said additized fuel composition is combusted in the presence of oxygen, a lower mass of nitrogen oxide and nitrogen dioxide is produced than the mass of nitrogen oxide and nitrogen dioxide produced from the combustion of a fuel composition comprising the base fuel composition and a concentration of 2-ethylhexyl nitrate equal to the concentration of the randomly branched nitrate composition in the fuel composition.

10. The fuel composition as in claim 1 , wherein the additized fuel composition is a diesel fuel composition and wherein after storage of the diesel fuel composition comprising about 1000 ppmv of the randomly branched nitrate composition for about six weeks at about 43° C., the diesel fuel composition comprises less than about 1.0 mg/100 mL of insoluble material as measured according to ASTM D4625-16e1.

11. The fuel composition as in claim 1 , wherein the additized fuel composition is a gasoline fuel composition further comprising at least one oxygenate selected from the group consisting of di-isopropyl ether, C5 ether, C6 ether, ethanol, methanol, propanol, 2-propanol, butanol, 2-butanol, iso-butanol, tert-butanol, and mixtures thereof.

12. A method for making an additized fuel composition comprising:
providing a base fuel composition; and
adding a randomly branched nitrate composition to the base fuel composition to form an additized fuel composition, the randomly branched nitrate composition comprising a plurality of primary nitrate molecules, each primary nitrate molecule having an empirical chemical formula of C n NO 3 , wherein C n is a branched aliphatic moiety which may be the same or different for each molecule, n is an integer selected from the group consisting of 8, 9, 10, 11 and 12, at least one carbon atom in the branched aliphatic moiety being bound to three or more carbon atoms, a branching index ranging from 1.8 to 2.2, and greater than 80% of the branches in the aliphatic moiety being in other than the alpha position; and
wherein the additized fuel composition is a diesel fuel composition or a gasoline fuel composition.

13. The method of claim 12 further comprising providing the additized fuel composition to a gas station.

14. The method as in claim 12 , wherein the additized fuel composition is a diesel fuel composition further comprising a biofuel.

15. The method as claim 14 , wherein the biofuel comprises a fatty acid methyl ester, a fatty acid ethyl ester, hydrotreated vegetable oil, or a blend thereof.

16. The method as in claim 12 , wherein n is 9, 10, or 11.

17. The method as in claim 12 , wherein the concentration of C n NO 3 molecules in the randomly branched nitrate composition is at least about 60 wt. %.

18. The method as in claim 12 , wherein the concentration of C n NO 3 molecules in the randomly branched nitrate composition is at least about 60 wt. % and less than about 98 wt. %.

19. The method as in claim 12 , wherein substantially all the randomly branched nitrate molecules in the randomly branched nitrate composition have at least one carbon atom bound to three or more carbon atoms.

20. The method as in claim 12 , wherein one of the carbon atoms bound to the at least one carbon atom in the branched is part of a methyl group.

21. The method as in claim 12 , wherein the randomly branched nitrate composition is present in the fuel compositions at a concentration of about 100 ppmv to about 4000 ppmv.

22. The method as in claim 12 , wherein the randomly branched nitrate composition is characterized by a flash point of about 80° C. or greater.

23. The method as in claim 12 , wherein the additized fuel composition is a diesel fuel composition having a higher derived cetane number than the base diesel fuel composition.

24. The method as in claim 12 , wherein the additized fuel composition is a diesel fuel composition having a derived cetane number greater than the derived cetane number of the base diesel fuel composition by at least about 4.

25. The method as in claim 12 , wherein the additized fuel composition is a diesel fuel composition and wherein the diesel fuel composition has a higher derived cetane number than the base diesel fuel composition.

26. The method as in claim 12 , wherein the additized fuel composition is a gasoline fuel composition having a lower anti-knock index than the base gasoline fuel composition.

27. The method as in claim 12 , wherein the additized fuel composition is a gasoline fuel composition having an anti-knock index lower than the anti-knock index of the base gasoline fuel composition by at least about 3.

28. A randomly branched nitrate composition comprising:
a plurality of primary branched nitrate molecules having an empirical chemical formula of C n NO 3 , wherein C n is a branched aliphatic moiety which may be the same or different for each molecule, n is an integer selected from the group consisting of 8, 9, 10, 11 and 12, at least one carbon atom in the branched aliphatic moiety being bound to three or more carbon atoms, a branching index ranging from 1.8 to 2.2, and greater than 80% of the branches in the aliphatic moiety being in other than the alpha position.

29. The composition as in claim 28 , wherein the composition is characterized by a flash point of about 80° C. or greater.

30. The composition as in claim 28 , wherein the composition has a thermal decomposition temperature as measured by thermogravimetric analysis of greater than about 130° C.

31. The co

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Renninger Logan P
• Berkhous Scott K
• Mattran Donald J
• Steenbeke Geert W
• Kang Dongil
• Kar Kenneth C H

Classifications

• C10L2270/026

  for diesel engines, e.g. automobiles, stationary, marine · CPC title

• C10L2270/023

  for gasoline engines · CPC title

• C10L2200/0484

  Vegetable or animal oils · CPC title

• C10L2200/0476

  Biodiesel, i.e. defined lower alkyl esters of fatty acids first generation biodiesel · CPC title

• C10L2200/0469

  Renewables or materials of biological origin · CPC title