US4090923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Butadiene purification with simultaneous prefractionation and vinylacetylene rejection
Assignee: Phillips Petroleum Co
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Filing: 1977-04-06
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Granted: 1978-05-23
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Expires: 1997-04-06
Abstract
Abstract A C 4 -hydrocarbon feedstream containing butenes, butadiene, and vinylacetylene is subjected to a first extractive distillation with a selective solvent to remove butenes and a first portion of vinylacetylene as the extract; by the extraction with a minor quantity of methylethyl ketone in the selective solvent in this step, it has been found that a major portion of the vinylacetylene can be rejected, together with the butenes in the rich extract and that simultaneously the quantity of butadiene extracted could be considerably reduced; in a second extractive distillation the butadiene-rich raffinate of the first extractive distillation is further purified by extractive distillation using a mixture of sulfolane and methylethyl ketone as the solvent; after solvent stripping, the butadiene stream is finally purified in a fractionation step, wherein further vinylacetylene is removed.
Inventors
- 👤 Donald M. Haskell
- 👤 Cecil O. Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:39
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/005; C07C7/04; C07C7/05; C07C7/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
295 words
A process for producing a purified butadiene stream comprising a. extractively distilling in a first extractive distillation zone a feed stream consisting essentially of butadiene, butene-1, butene-2's, and vinylacetylene with a selective solvent selected from the group consisting of a methylethyl ketone and methylethyl ketone/sulfolane mixtures to form a first raffinate stream consisting essentially of butadiene, butene-1, a smaller concentration of butene-2's and a smaller concentration of vinylacetylene than the feed stream and being essentially free of said solvent, the weight ratio of the butene-2's to the vinylacetylene being at least 10:1, and a first rich solvent extract stream, b. stripping said first rich solvent extract stream in a first stripping zone to form a first solvent stream and a vinylacetylene stream, c. reintroducing at least a portion of said first solvent stream into said first extractive distillation zone as selective solvent, d. extractively distilling said first raffinate stream in a second extractive distillation zone using as the selective solvent a mixture of methylethyl ketone and sulfolane, the methylethyl ketone concentration in the mixture being about 10 to about 40 wt. % methylethyl ketone, to form a second raffinate stream, and a second rich solvent extract stream consisting essentially of the selective solvent, butadiene, butenes, and vinylacetylene, e. stripping said second rich solvent extract stream in a second stripping zone to form a second solvent stream consisting essentially of sulfolane and methylethyl ketone and a butadiene stream consisting essentially of butadiene, butenes and vinylacetylene, f. recycling at least a portion of said second solvent stream to said second extractive distillation zone as selective solvent, g. fractionally distilling said butadiene stream to form a purified butadiene stream and a butenes and vinylacetylene-comprising stream, and h. recovering said purified butadiene stream as the product of the process.
Claim 2
Dependent Claim
295 words
A process for producing a purified butadiene stream comprising a. extractively distilling in a first extractive distillation zone a feed stream consisting essentially of butadiene, butene-1, butene-2's, and vinylacetylene with a selective solvent selected from the group consisting of a methylethyl ketone and methylethyl ketone/sulfolane mixtures to form a first raffinate stream consisting essentially of butadiene, butene-1, a smaller concentration of butene-2's and a smaller concentration of vinylacetylene than the feed stream and being essentially free of said solvent, the weight ratio of the butene-2's to the vinylacetylene being at least 10:1, and a first rich solvent extract stream, b. stripping said first rich solvent extract stream in a first stripping zone to form a first solvent stream and a vinylacetylene stream, c. reintroducing at least a portion of said first solvent stream into said first extractive distillation zone as selective solvent, d. extractively distilling said first raffinate stream in a second extractive distillation zone using as the selective solvent a mixture of methylethyl ketone and sulfolane, the methylethyl ketone concentration in the mixture being about 10 to about 40 wt. % methylethyl ketone, to form a second raffinate stream, and a second rich solvent extract stream consisting essentially of the selective solvent, butadiene, butenes, and vinylacetylene, e. stripping said second rich solvent extract stream in a second stripping zone to form a second solvent stream consisting essentially of sulfolane and methylethyl ketone and a butadiene stream consisting essentially of butadiene, butenes and vinylacetylene, f. recycling at least a portion of said second solvent stream to said second extractive distillation zone as selective solvent, g. fractionally distilling said butadiene stream to form a purified butadiene stream and a butenes and vinylacetylene-comprising stream, and h. recovering said purified butadiene stream as the product of the process.
Claim 3
Dependent Claim
36 words
A process in accordance with claim 1 wherein said feed stream has the following composition in parts by weight: ______________________________________
1,3-Butadiene 30-60
Butene-1 20-40
trans Butene-2 15-30
cis Butene-2 5-15
Total butenes 40-70
Vinylacetylene 0.5-3.0
______________________________________
Claim 4
Dependent Claim
21 words
A process in accordance with claim 1 wherein said feed stream is a C 4 -concentrate from a naphtha cracking process.
Claim 5
Dependent Claim
31 words
A process in accordance with claim 1 wherein said selective solvent of step (a) is methylethyl ketone and the solvent/feed ratio in the extractive distillation of step (a) is about 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |