US4349418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of methylnaphthalenes and tar bases including indole
Assignee: Honeywell International Inc
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Filing: 1981-07-28
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Granted: 1982-09-14
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Expires: 2001-07-28
Abstract
Abstract Methylnaphthalenes, indole and other tar bases are recovered from a base-extracted coal tar distillation fraction. In one form, an aqueous salt solution of pH 0.5-3 extracts other tar bases from the starting material, and thereafter both products are recovered from the raffinate by several alternate methods including ethylene glycol extraction and extractive distillation. In other forms, the starting material is extracted with ethylene glycol and the extract is distilled to recover several products including indole. The raffinate of ethylene glycol extraction contains methylnaphthalenes and other hydrocarbons and can be purified to solvent-grade material.
Inventors
- 👤 Stephen E. Belsky
- 👤 Chempolil T. Mathew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:20
CPC Classifications
C; C10; C10C; C10C1/00; C10C1/18
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
107 words
A process for the recovery of tar bases from a base-extracted tar distillation fraction which comprises the steps: (a) extracting a base-extracted tar distillation fraction having a boiling point range not exceeding about 300° C.; containing methylphthalenes, indole and a member selected from the group consisting quinoline, isoquinoline and mixtures thereof with a buffered aqueous salt solution having a pH between about 0.5 and about 3.0 to produce an aqueous extract containing quinoline, isoquinoline or both and raffinate containing methylnaphthalenes and indole and substantially free of quinoline and isoquinoline, (b) recovering indole from said raffinate, and (c) recovering quinoline, isoquinoline or mixtures thereof from said aqueous extract.
Claim 2
Dependent Claim
107 words
A process for the recovery of tar bases from a base-extracted tar distillation fraction which comprises the steps: (a) extracting a base-extracted tar distillation fraction having a boiling point range not exceeding about 300° C.; containing methylphthalenes, indole and a member selected from the group consisting quinoline, isoquinoline and mixtures thereof with a buffered aqueous salt solution having a pH between about 0.5 and about 3.0 to produce an aqueous extract containing quinoline, isoquinoline or both and raffinate containing methylnaphthalenes and indole and substantially free of quinoline and isoquinoline, (b) recovering indole from said raffinate, and (c) recovering quinoline, isoquinoline or mixtures thereof from said aqueous extract.
Claim 3
Dependent Claim
41 words
The process of claim 1 wherein said buffered aqueous salt solution is a solution of a bisulfate of ammonium or an alkali metal, or a mixture thereof with the corresponding sulfate or sulfuric acid having a pH in the above range.
Claim 4
Dependent Claim
20 words
The process of claim 2 wherein said bisulfate is ammonium bisulfate, or mixtures thereof with ammonium sulfate or sulfuric acid.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein step (c) includes neutralizing said aqueous extract with ammonia to recover said quinoline, isoquinoline or mixtures thereof as an organic layer.
Claim 6
Dependent Claim
20 words
The process of claim 2 wherein said bisulfate is sodium bisulfate, or mixtures thereof with sodium sulfate or sulfuric acid.
Claim 7
Dependent Claim
28 words
The process of claim 5 wherein step (c) includes neutralizing said aqueous extract with sodium hydroxide to recover said quinoline, isoquinoline or mixtures thereof as an organic layer.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein indole is recovered from said raffinate by extraction with phosphoric acid and subsequent neutralization of the extract with a base.
Claim 9
Dependent Claim
28 words
The process of claim 1 wherein indole is recovered from said raffinate by extraction with a polyhydric alcohol and separation of the extract into indole and polyhydric alcohol.
Claim 10
Dependent Claim
12 words
The process of claim 8 wherein said polyhydric alcohol is ethylene glycol.
Claim 11
Dependent Claim
17 words
The process of claim 8 or 9 wherein indole is separated from said polyhydric alcohol by distillation.
Claim 12
Dependent Claim
17 words
The process of claim 8 or 9 wherein indole is separated from said polyhydric alcohol by crystallization.
Claim 13
Dependent Claim
45 words
The process of claim 1 wherein indole is recovered from said extract by extractive distillation in the presence of ethylene glycol to produce a first overhead comprising methylnaphthalenes and a second overhead comprising indole and ethylene glycol, and indole is crystallized from said second overhead.
Claim 14
Dependent Claim
50 words
The process of claim 12 wherein said base-extracted tar distillation fraction further comprises additional components selected from the group consisting of biphenyl, acenaphthene, dibenzofuran and mixtures thereof, and wherein said additional components are recovered during extractive distillation with ethylene glycol as overheads between said first overhead and said second overhead.
Claim 15
Dependent Claim
47 words
The process of claim 12 wherein said base-extracted tar distillation fraction contains 1-methylnaphthalene and 2-methylnaphthalene in a first proportion, and wherein said first overhead includes an initially recovered portion richer in 2-methylnaphthalene than said first proportion and a subsequently recovered fraction richer in 1-methylnaphthalene than said proportion.
Claim 16
Independent Claim
48 words
A method of separating a mixture comprising methylnaphthalenes and indole which comprises extracting said mixture having a boiling point range not exceeding about 300° C.; with ethylene glycol and recovering a raffinate comprising methylnaphthalenes and an extract comprising indole and ethylene glycol, and recovering indole from said extract.
Claim 17
Independent Claim
48 words
A method of separating a mixture comprising methylnaphthalenes and indole which comprises extracting said mixture having a boiling point range not exceeding about 300° C.; with ethylene glycol and recovering a raffinate comprising methylnaphthalenes and an extract comprising indole and ethylene glycol, and recovering indole from said extract.
Claim 18
Dependent Claim
35 words
The method of claim 15 wherein said mixture further comprises quinoline, isoquinoline, biphenyl and acenaphthene; wherein biphenyl and acenaphthene are present predominantly in said raffinate; and wherein quinoline and isoquinoline are present in said extract.
Claim 19
Dependent Claim
12 words
The method of claim 16 wherein methylnaphthalene is distilled from said raffinate.
Claim 20
Dependent Claim
50 words
The method of claim 16 or 17 wherein the extract is distilled to produce a quinoline, isoquinoline, ethylene glycol mixture as a first overhead, ethylene glycol as a second overhead and indole with minor amounts of ethylene glycol as a third overhead, and indole is crystallized from said third overhead.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-13 | 1986-03-15 | 1986-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-13 | 1990-03-15 | 1990-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-13 | 1994-03-15 | 1994-09-14 | $7700.00 | Window Closed / Lapsed |