US3884769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying benzene and toluene by extractive azeotropic distillation
Assignee: IFP Energies nouvelles
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Filing: 1973-03-20
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Granted: 1975-05-20
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Expires: 1993-03-20
Abstract
Abstract Process for separating aromatics from hydrocarbon mixtures (containing the same) by combined extractive and azeotropic fractional distillation thereof in the presence of a liquid alkyl aliphatic amide as extraction (solvent) agent, comprising introducing said mixture at a first level of a distillation column, introducing the extraction (solvent) agent at a second level of the distillation column above the first one, introducing steam as an azeotropic agent in the distillation column above said second level, withdrawing the aromatics and the extraction (solvent) agent from the bottom of the column and the nonaromatic hydrocarbons and the steam from the top thereof.
Inventors
- 👤 Paul Mikitenko
- 👤 Georges Cohen
- 👤 Lionel Asselineau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:35
CPC Classifications
C; C10; C10G; C10G21/00; C07; C07C; C07C7/00; C07C7/04; C07C7/05; C07C7/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
153 words
A PROCESS FOR SEPARATING AT LEAST ONE AROMATIC HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF BENZENE AND TOLUENE, FROM MIXTURES CONTAINING THE SAME TOGETHER WITH AT LEAST ONE SATURATED PARAFFINIC OR CYCLOPARAFFINIC HYDROCARBON, IN WHICH SAID MIXTURES ARE SUBJECTED TO AN EXTRACTIVE AZEOTROPIC DISTILLATION IN THE PRESENCE OF AN EXTRACTION SOLVENT IN THE LIQUID STATE, SAID EXTRACTION SOLVENT BEING AN ALKYL ALIPHATIC AMIDE, SAID PROCESS COMPRISING INTRODUCING THE MIXTURE OF HYDROCARBONS TO BE SEPARATED TO AN INTERMEDIATE POINT OF A DISTILLATION ZONE, INTRODUCING SAID EXTRACTION SOLVENT TO A POINT OF THE DISTILLATION ZONE ABOVE SAID INTERMEDIATE POINT, INTRODUCING STEAM AT A POINT OF THE DISTILLATION ZONE ABOVE THE POINT OF INTRODUCTION OF THE EXTRACTION SOLVENT, WITHDRAWING FROM THE BOTTOM OF SAID DISTILLATION ZONE THE AROMATIC HYDROCARBONS AND THE EXTRACTION SOLVENT, AND WITHDRAWING FROM THE TOP OF SAID DISTILLATION ZONE, A DISTILLATE SUBSTANTIALLY FREE OF THE EXTRACTION SOLVENT AND CONTAINING NON-AROMATIC HYDROCARBONS AND STEAM.
Claim 2
Dependent Claim
153 words
A PROCESS FOR SEPARATING AT LEAST ONE AROMATIC HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF BENZENE AND TOLUENE, FROM MIXTURES CONTAINING THE SAME TOGETHER WITH AT LEAST ONE SATURATED PARAFFINIC OR CYCLOPARAFFINIC HYDROCARBON, IN WHICH SAID MIXTURES ARE SUBJECTED TO AN EXTRACTIVE AZEOTROPIC DISTILLATION IN THE PRESENCE OF AN EXTRACTION SOLVENT IN THE LIQUID STATE, SAID EXTRACTION SOLVENT BEING AN ALKYL ALIPHATIC AMIDE, SAID PROCESS COMPRISING INTRODUCING THE MIXTURE OF HYDROCARBONS TO BE SEPARATED TO AN INTERMEDIATE POINT OF A DISTILLATION ZONE, INTRODUCING SAID EXTRACTION SOLVENT TO A POINT OF THE DISTILLATION ZONE ABOVE SAID INTERMEDIATE POINT, INTRODUCING STEAM AT A POINT OF THE DISTILLATION ZONE ABOVE THE POINT OF INTRODUCTION OF THE EXTRACTION SOLVENT, WITHDRAWING FROM THE BOTTOM OF SAID DISTILLATION ZONE THE AROMATIC HYDROCARBONS AND THE EXTRACTION SOLVENT, AND WITHDRAWING FROM THE TOP OF SAID DISTILLATION ZONE, A DISTILLATE SUBSTANTIALLY FREE OF THE EXTRACTION SOLVENT AND CONTAINING NON-AROMATIC HYDROCARBONS AND STEAM.
Claim 3
Dependent Claim
39 words
A process according to claim 1, in which steam is used in an amount of at least 5 percent by weight and at most 50 percent by weight of the non-aromatic hydrocarbons contained in the feed to be treated.
Claim 4
Dependent Claim
40 words
A process according to claim 1, in which steam is used in an amount of at least 10 percent by weight and at most 35 percent by weight of the non-aromatic hydrocarbons contained in the feed subjected to the treatment.
Claim 5
Dependent Claim
31 words
A process according to claim 1, in which the hydrocarbons in admixture with said at least one aromatic hydrocarbon are saturated hydrocarbons having from 5 to 8 carbon atoms per molecule.
Claim 6
Dependent Claim
27 words
A process according to claim 1, in which the ratio by volume of the amount of extraction solvent to the hydrocarbon feed is from 0.4 to 15.
Claim 7
Dependent Claim
26 words
A process according to claim 1, in which said mixtures subjected to extractive azeotropic distillation are gasolines produced by pyrolysis, cracking, steam cracking or catalytic reforming.
Claim 8
Dependent Claim
94 words
A process according to claim 1, in which the distillate withdrawn from the top of the distillation zone, is condensed, the obtained condensate is separated in two liquid phases, a first phase containing the non-aromatic hydrocarbons and a second phase containing the condensed water vapor, in which the first and the second phase are separately withdrawn, at least a portion of the first phase is fed back to the distillation zone, as reflux, and at least a portion of the condensed vapor water is fed back, after revaporization to steam, to the distillation zone.
Claim 9
Dependent Claim
34 words
A process according to claim 7, in which the steam is introduced into the distillation column at a level above the point of introduction of the extraction solvent and below that of said reflux.
Claim 10
Dependent Claim
28 words
A process according to claim 1, in which the ratio by volume of the amount of extraction solvent used to the hydrocarbon feed is from 1 to 6.
Claim 11
Dependent Claim
21 words
A process according to claim 9, comprising a further step of separating the aromatic hydrocarbons from the extraction solvent by distillation.
References Cited (Backward Citations)
US2804427A
Cited
US2859155A
Cited
US2957811A
Cited
US3151046A
Cited
US3114783A
Cited
US3328267A
Cited
US3684665A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |