# US 11,078,139 B1 · Cyclopentadiene fuels

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- Number: US 11,078,139 B1
- Document ID: US11078139B1
- Status: Granted
- Kind: B1
- Application number: 16/559,778
- Filed: 2019-09-04
- Granted: 2021-08-03
- Earliest claimed: 2019-09-04
- Assignees: The United States of America as represented by the Secretary of the Navy
- Applicants: The United States of America as Represented by the Secretary of the Navy
- Inventors: Benjamin G. Harvey
- Web page: https://patentgrep.com/patent/US11078139B1

## CPC

- C07C 29/145: with hydrogen or hydrogen-containing gases
- C07C 1/24: by elimination of water
- C07C 2/50: Diels-Alder conversion
- C07C 2/52: Catalytic processes
- C07C 5/03: of non-aromatic carbon-to-carbon double bonds
- C07C 5/2206: {Catalytic processes not covered by C07C5/23 - C07C5/31}
- C07C 5/27: Rearrangement of carbon atoms in the hydrocarbon skeleton
- C07C 7/04: by distillation
- C07C 29/143: of ketones
- C07C 45/41: by hydrogenolysis or reduction of carboxylic groups or functional derivatives thereof
- C07C 45/45: by condensation
- C07C 45/51: by pyrolysis, rearrangement or decomposition
- C07C 45/59: in five-membered rings (from ozonides C07C45/40)
- C07C 45/61: by reactions not involving the formation of >C = O groups
- C07C 45/66: by dehydration
- C07C 51/36: by hydrogenation of carbon-to-carbon unsaturated bonds
- C07C 51/42: Separation; Purification; Stabilisation; Use of additives
- C07C 67/08: by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
- C07C 2521/02: Boron or aluminium; Oxides or hydroxides thereof
- C07C 2527/167: Phosphates or other compounds comprising the anion (PnO3n+1)(n+2)-
- C07C 2527/18: with metals
- C07C 2531/08: Ion-exchange resins
- C07C 2601/08: the ring being saturated
- Y02P 20/10: Process efficiency
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A method for making cyclopentadiene fuels comprising producing cyclopent-2-en-1-one or a mixture of cyclopent-2-en-1-one from a bio-based source. The cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one is hydrogenated, thereby forming cyclopent-2-en-1-ol or a mixture of cyclopent-2-en-1-ol. The cyclopent-2-en-1-ol or the mixture of cyclopent-2-en-1-ol is dehydrated with a dehydrating agent, thereby forming cyclopentadiene or a mixture of cyclopentadiene. The cyclopentadiene or mixture of cyclopentadiene is converted to dicyclopentadiene or dihydrodicyclopentadiene. The dicyclopentadiene or dihydrodicyclopentadiene is hydrogenated, thereby forming tetrahydrodicyclopentadiene. The tetrahydrodicyclopentadiene is isomerized, thereby forming exo-tetrahydrodicyclopentadiene.

## Claims

### Claim 1

A method for making cyclopentadiene fuel, comprising:
producing cyclopent-2-en-1-one or a mixture of cyclopent-2-en-1-one from a bio-based sources;
hydrogenating the cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one, thereby forming cyclopent-2-en-1-ol or a mixture of cyclopent-2-en-1-ol;
dehydrating the cyclopent-2-en-1-ol or the mixture of cyclopent-2-en-1-ol with a dehydrating agent, thereby forming cyclopentadiene or a mixture of cyclopentadiene;
converting the cyclopentadiene or the mixture of cyclopentadiene to dicyclopentadiene or dihydrodicyclopentadiene;
hydrogenating the dicyclopentadiene or dihydrodicyclopentadiene, thereby forming tetrahydrodicyclopentadiene; and
isomerizing the tetrahydrodicyclopentadiene, thereby forming a stream comprising exo-tetrahydrodicyclopentadiene.

### Claim 2 (depends on 1)

The method of claim 1, wherein the producing the cyclopent-2-en-1-one from the bio-based sources includes:
i. obtaining furfural or furfuryl alcohol and converting the furfural or furfuryl alcohol to 4-hydroxy-2-cyclopentenone, or obtaining a combination of furfuryl alcohol and 4-hydroxy-2-cyclopentenone from the bio-based sources; and
ii. reacting the 4-hydroxy-2-cyclopentenone or the combination of furfuryl alcohol and 4-hydroxy-2-cyclopentenone in the presence of a catalyst and hydrogen, water, or a combination thereof, wherein the catalyst is selected from the group consisting of Ni, Cu/Ni, Zn, and combinations thereof, thereby forming the cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one.

### Claim 3 (depends on 1)

The method of claim 1, wherein the mixture of cyclopent-2-en-1-one comprises cyclopent-2-en-1-one and cyclopentanone.

### Claim 4 (depends on 1)

The method of claim 1, wherein the producing the cyclopent-2-en-1-one from the bio-based sources includes:
i. obtaining muconic acid from the bio-based sources;
ii. converting the muconic acid to hex-3-enedioic acid;
iii. converting the hex-3-enedioic acid to dimethyl-hex-3-en-dioate through transesterification with methanol; and
iv. converting the dimethyl-hex-3-en-dioate to the cyclopent-2-en-1-one using a basic catalyst.

### Claim 5 (depends on 1)

The method of claim 1, wherein the producing the cyclopent-2-en-1-one from the bio-based sources includes:
i. obtaining penta-1,4-diene-3-one from a bio-based source containing mevalonic acid; and
ii. cyclizing the penta-1,4-diene-3-one, thereby forming the cyclopent-2-en-1-one.

### Claim 6 (depends on 1)

The method of claim 1, wherein the producing the cyclopent-2-en-1-one from the bio-based sources includes:
i. obtaining gamma-valerolactone from the bio-based sources and converting the gamma-valerolactone to methyl-pent-3-enoate; and
ii. cyclizing the methyl-pent-3-enoate, thereby forming the cyclopent-2-en-1-one.

### Claim 7 (depends on 1)

The method of claim 1, wherein the hydrogenating the cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one occurs in the presence of (i) borohydride and a lanthanide (III) catalyst, (ii) an aluminum hydride, or combinations thereof.

### Claim 8 (depends on 1)

The method of claim 1, wherein the hydrogenating the cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one occurs in the presence of a ruthenium-based catalyst under a hydrogen atmosphere, wherein the ruthenium based catalyst is bound to one or more ligands.

### Claim 9 (depends on 1)

The method of claim 1, wherein the dehydrating agent is selected from the group consisting of a molecular sieve, an acid catalyst a metal salt, and combinations thereof.

### Claim 10 (depends on 1)

The method of claim 1, wherein the cyclopentadiene or the mixture of cyclopentadiene is collected by reactive distillation as the cyclopentadiene or the mixture of cyclopentadiene is formed.

### Claim 11 (depends on 1)

The method of claim 1, wherein the cyclopentadiene or the mixture of cyclopentadiene includes cyclopentadiene trimers, cyclopentadiene tetramers, cyclopentene, or a combination thereof in a reaction vessel.

### Claim 12 (depends on 11)

The method of claim 11, wherein the cyclopentadiene trimers and the cyclopentadiene tetramers, the cyclopentene, or the combination thereof are isolated using filtration or washing with water.

### Claim 13 (depends on 1)

The method of claim 1, wherein the converting the cyclopentadiene or the mixture of cyclopentadiene to dicyclopentadiene occurs using heat, a Lewis acid catalyst, or a combination thereof.

### Claim 14 (depends on 1)

The method of claim 1, wherein the hydrogenating the dicyclopentadiene is performed using a transition metal catalyst based on a metal selected from the group consisting of Ni, Pd, Pt, Ru, Rh, Cu, and combinations thereof.

### Claim 15 (depends on 1)

The method of claim 1, wherein the hydrogenating the dicyclopentadiene is performed at a temperature ranging from about 20° C. to about 250° C. and a pressure ranging from about 1 psi to about 3000 psi.

### Claim 16 (depends on 1)

The method of claim 1, wherein the isomerizing the tetrahydrodicyclopentadiene occurs by a reaction with a Lewis acid catalyst selected from the group consisting of BF3, P2O5, AlCl3, AlBr3, FeCl3, ZnCl2, and combinations thereof.

### Claim 17 (depends on 1)

The method of claim 1, wherein the exo-tetrahydrodicyclopentadiene is isomerized to adamantane.

### Claim 18 (depends on 1)

The method of claim 1, wherein the exo-tetrahydrodicyclopentadiene is isolated by separating and distilling the stream comprising exo-tetrahydrodicyclopentadiene.