# US 4,398,505 A · Diesel fuel composition

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,398,505 A
- Document ID: US4398505A
- Status: Granted
- Kind: A
- Application number: 06/313,799
- Filed: 1981-10-22
- Granted: 1983-08-16
- Earliest claimed: 1981-10-22
- Assignees: Standard Oil Company (Indiana)
- Inventors: Paul J. Cahill
- Web page: https://patentgrep.com/patent/US4398505A

## CPC

- C10L 1/232: containing nitrogen in a heterocyclic ring {(C10L1/221 takes precedence)}
- F02B 47/00: Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
- F02B 3/06: with compression ignition (compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02)
- Y02T 10/12: Improving ICE efficiencies
- C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

N,N-disubstituted organic nitroxides are highly effective ignition improvers for diesel fuels.

## Claims

### Claim 1

A diesel fuel composition comprising a liquid hydrocarbon fuel of diesel fuel boiling range in combination with an N,N-disubstituted organic nitroxide wherein the amount of said nitroxide is from about 0.3 to about 2 weight percent of said composition.

### Claim 2

A diesel fuel composition comprising a major proportion of a liquid hydrocarbon fuel of diesel fuel boiling range in combination with a minor amount of an N,N-disubstituted organic nitroxide of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of aryl and substituted aryl of from 6 to 10 carbon atoms and CR.sup.3 R.sup.4 R.sup.5 wherein R.sup.3, R.sup.4 and R.sup.5 each contain from 1 to 15 carbon atoms and are independently selected from the group consisting of hydrocarbyl, aminohydrocarbyl, alkoxyhydrocarbyl, carboxyhydrocarbyl, carboalkoxyhydrocarbyl and cyanohydrocarbyl with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring, and wherein the amount of said nitroxide is effective to increase the cetane number of said liquid hydrocarbon fuel.

### Claim 3 (depends on 2)

A composition as set forth in claim 2 wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of tertiary alkyl and tertiary aminoalkyl of from 4 to 10 carbon atoms with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring.

### Claim 4 (depends on 3)

A composition as set forth in claim 3 wherein the amount of said nitroxide is from about 0.01 to about 5 percent by weight of said composition.

### Claim 5 (depends on 4)

A composition as set forth in claim 4 wherein said nitroxide is di-tert-butylnitroxide.

### Claim 6 (depends on 4)

A composition as set forth in claim 4 wherein said nitroxide is 2,2,6,6-tetramethylpiperidine-1-oxyl.

### Claim 7 (depends on 4)

A composition as set forth in claim 4 wherein said nitroxide is 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl.

### Claim 8

A method for increasing the cetane number of a liquid hydrocarbon diesel fuel which comprises mixing said fuel with an N,N-disubstituted organic nitroxide of the formula: ##STR3## wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of aryl and substituted aryl of from 6 to 10 carbon atoms and CR.sup.3 R.sup.4 R.sup.5 wherein R.sup.3, R.sup.4 and R.sup.5 each contain from 1 to 15 carbon atoms and are independently selected from the group consisting of hydrocarbyl, aminohydrocarbyl, alkoxyhydrocarbyl, carboxyhydrocarbyl, carboalkoxyhydrocarbyl and cyanohydrocarbyl with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring, and wherein the amount of said nitroxide is effective to increase said cetane number.

### Claim 9 (depends on 8)

A method as set forth in claim 8 wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of tertiary alkyl and tertiary aminoalkyl of from 4 to 10 carbon atoms with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring.

### Claim 10 (depends on 9)

A method as set forth in claim 9 wherein the amount of said nitroxide is from about 0.01 to about 5 percent by weight of said mixture.

### Claim 11 (depends on 10)

A method as set forth in claim 10 wherein said nitroxide is di-tert-butylnitroxide.

### Claim 12 (depends on 10)

A method as set forth in claim 10 wherein said nitroxide is 2,2,6,6-tetramethylpiperidine-1-oxyl.

### Claim 13 (depends on 10)

A method as set forth in claim 10 wherein said nitroxide is 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl.

### Claim 14

A method of operating a compression ignition engine which comprises combusting in said engine a composition which comprises a liquid hydrocarbon fuel in combination with an N,N-disubstituted organic nitroxide wherein the amount of said nitroxide is from about 0.3 to about 2 weight percent of said composition.

### Claim 15

A method of operating a compression ignition engine which comprises combusting in said engine a composition which comprises a major proportion of a liquid hydrocarbon fuel in combination with a minor amount of an N,N-disubstituted organic nitroxide of the formula: ##STR4## wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of aryl and substituted aryl of from 6 to 10 carbon atoms and CR.sup.3 R.sup.4 R.sup.5 wherein R.sup.3, R.sup.4 and R.sup.5 each contain from 1 to 15 carbon atoms and are independently selected from the group consisting of hydrocarbyl, aminohydrocarbyl, alkoxyhydrocarbyl, carboxyhydrocarbyl, carboalkoxyhydrocarbyl and cyanohydrocarbyl with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring, and wherein the amount of said nitroxide is effective to increase the cetane number of said liquid hydrocarbon fuel.

### Claim 16 (depends on 15)

A method as set forth in claim 15 wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of tertiary alkyl and tertiary aminoalkyl of from 4 to 10 carbon atoms with the proviso that R.sup.1 and R.sup.2 can be joined to form a 5- or 6-membered ring.

### Claim 17 (depends on 16)

A method as set forth in claim 16 wherein the amount of said nitroxide is from about 0.01 to about 5 percent by weight of said composition.

### Claim 18 (depends on 17)

A method as set forth in claim 17 wherein said nitroxide is di-tert-butylnitroxide.

### Claim 19 (depends on 17)

A method as set forth in claim 17 wherein said nitroxide is 2,2,6,6-tetramethylpiperidine-1-oxyl.

### Claim 20 (depends on 17)

A method as set forth in claim 17 wherein said nitroxide is 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl.