Patent US3903187A successfully refreshed from Google Patents.
US3903187A
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US
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High temperature gradient elution liquid chromatography
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1973-08-09
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Granted: 1975-09-02
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Expires: 1993-08-09
Abstract
Abstract In a liquid chromatography commercial process for the separation of two or more components contained in admixture in a feedstream including the steps of (a) contacting the feedstream mixture containing the components to be separated with a bed of crystalline aluminosilicate adsorbent at conditions to effect the selective retention of two or more of the components by said adsorbent, (b) passing through said bed an eluent selected from the group consisting of aromatics and substituted aromatics, (c) increasing the strength of the eluting agent in the liquid carrier during the operation of the steps (a) and (b) above, (d) recovering from said bed a stream or streams containing at least a portion of the less selectively adsorbed components, and (e) recovering a stream substantially enhanced in concentration of said selectively adsorbed components relative to other components of feedstream wherein the improvement comprises operating the process at temperatures of from 160*C to about 200*C to thereby effect the desired separation under conditions that cause low elution volume to feed ratios. The improved liquid chromatography process is particularly applicable to the separation of paraxylene and ethylbenzene from a C8 aromatic isomer mixture containing ethylbenzene. The above process when operated at temperatures of about 160*C or higher, and using larger feed slug sizes to provide lower elution volume to feed ratios thereby produces paraxylene more economically.
Inventors
- 👤 Paul R Geissler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:53
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/28; G01N30/34; C; C07; C07C; C07C7/00; C07C7/12; C07C7/13
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
198 words
IN A LIQUID CHROMATOGRAPHIC SEPARATION PROCESS OF UP TO TWO COMPONENTS CONTAINED IN ADMIXTURE IN A FEEDSTREAM IN CLUDING THE STEPS OF: A. CONTACTING THE FEEDSTREAM MIXTURE, WHEREIN SAID FEEDSTREAM MIXTURE IS A C8 AROMATIC FEEDSTREAM CONTAINING ETHYLBENZENE WITH A BED OF CRYSTALLINE ALUMINOSILICATE ADSORBENT AT CONDITIONS TO EFFECT THE SELECTIVE RETENTION OF B. PASSING THROUGH SAID BED AN ELUENT SELECTED FROM THE GROUP CONSISTING OF AROMATICS AND SUBSTITUTED AROMATICS, C. INCREASING THE STRENGTH OF THE ELUENT DURING THE OPERATION OF STEPS (B) ABOVE TO THEREBY EFFECT DESIRED SEPARATION UNDER CONDITION THAT CAUSE LOW ELUTION VOLUME TO FEED RATIOS, D. RECOVERING FROM SAID BED STREAM OR STREAMS CONTAINING A PORTION OF THE LESS PERFERENTIALLY ADSORBED COMPONENTS AND E. RECOVERING A STREEAM OR STREAMS SUBSTANTIALLY ENHANCED IN UP TO TWO OF THE COMPONENTS BY ADSORBENT, CONCENTRATION OF PARAXYLENE AND ETHYLBENZENE RELATIVE TO OTHER FEEDSTREAM COMPONENTS WHEREIN THE IMPROVEMENT COMPRISES OPERATING THE PROCESS AT TEMPERATURE OF FROM ABOUT 160*C TO ABOUT 200*C TO THEREBY EFFECT THE DESIRED SEPERATION OF ONE SAID PERFERENTIALLY ADSORBED COMPONETS UNDER CONDITIONS RESULTING IN LOWE ELUTION VOLUME TO FEED RATIOS WITHOUT A CORRESPONDING SUBSTANTIAL DECREASE IN THE SEPERATION OF THE OTHER OF SAID PERFERENTIALLY ADSORBED COMPONENTS.
Claim 2
Dependent Claim
198 words
IN A LIQUID CHROMATOGRAPHIC SEPARATION PROCESS OF UP TO TWO COMPONENTS CONTAINED IN ADMIXTURE IN A FEEDSTREAM IN CLUDING THE STEPS OF: A. CONTACTING THE FEEDSTREAM MIXTURE, WHEREIN SAID FEEDSTREAM MIXTURE IS A C8 AROMATIC FEEDSTREAM CONTAINING ETHYLBENZENE WITH A BED OF CRYSTALLINE ALUMINOSILICATE ADSORBENT AT CONDITIONS TO EFFECT THE SELECTIVE RETENTION OF B. PASSING THROUGH SAID BED AN ELUENT SELECTED FROM THE GROUP CONSISTING OF AROMATICS AND SUBSTITUTED AROMATICS, C. INCREASING THE STRENGTH OF THE ELUENT DURING THE OPERATION OF STEPS (B) ABOVE TO THEREBY EFFECT DESIRED SEPARATION UNDER CONDITION THAT CAUSE LOW ELUTION VOLUME TO FEED RATIOS, D. RECOVERING FROM SAID BED STREAM OR STREAMS CONTAINING A PORTION OF THE LESS PERFERENTIALLY ADSORBED COMPONENTS AND E. RECOVERING A STREEAM OR STREAMS SUBSTANTIALLY ENHANCED IN UP TO TWO OF THE COMPONENTS BY ADSORBENT, CONCENTRATION OF PARAXYLENE AND ETHYLBENZENE RELATIVE TO OTHER FEEDSTREAM COMPONENTS WHEREIN THE IMPROVEMENT COMPRISES OPERATING THE PROCESS AT TEMPERATURE OF FROM ABOUT 160*C TO ABOUT 200*C TO THEREBY EFFECT THE DESIRED SEPERATION OF ONE SAID PERFERENTIALLY ADSORBED COMPONETS UNDER CONDITIONS RESULTING IN LOWE ELUTION VOLUME TO FEED RATIOS WITHOUT A CORRESPONDING SUBSTANTIAL DECREASE IN THE SEPERATION OF THE OTHER OF SAID PERFERENTIALLY ADSORBED COMPONENTS.
Claim 3
Dependent Claim
40 words
The process of claim 1 wherein the initial concentration of said eluent is about 25% and is increased to a final concentration in the range of from about 50 to about 100% during the operation of steps (b) and (c).
Claim 4
Dependent Claim
160 words
In a liquid chromatographic process for the separation of paraxylene from a feedstream containing a C8 aromatic isomer mixture and ethylbenzene including the steps of: a. contacting said feedstream with a bed of crystalline aluminosilicate adsorbent at conditions to effect the selective retention of paraxylene by said adsorbent; b. passing through said bed an eluent selected from the group consisting of aromatics and substituted aromatics; c. increasing the strength of the eluent in a liquid carrier containing said eluent during operation of step (b) above; d. recovering from said bed a stream or streams containing a portion of the less preferentially adsorbed feedstream components; and e. recovering a stream or streams substantially enhanced in concentration of paraxylene wherein the improvement comprises operating the process at temperatures of from 160*C to about 200*C to thereby effect the desired separation of paraxylene under conditions resulting in low elution volume to feed ratios without a corresponding substantial decrease in the separation of ethylbenzene.
Claim 5
Dependent Claim
160 words
In a liquid chromatographic process for the separation of paraxylene from a feedstream containing a C8 aromatic isomer mixture and ethylbenzene including the steps of: a. contacting said feedstream with a bed of crystalline aluminosilicate adsorbent at conditions to effect the selective retention of paraxylene by said adsorbent; b. passing through said bed an eluent selected from the group consisting of aromatics and substituted aromatics; c. increasing the strength of the eluent in a liquid carrier containing said eluent during operation of step (b) above; d. recovering from said bed a stream or streams containing a portion of the less preferentially adsorbed feedstream components; and e. recovering a stream or streams substantially enhanced in concentration of paraxylene wherein the improvement comprises operating the process at temperatures of from 160*C to about 200*C to thereby effect the desired separation of paraxylene under conditions resulting in low elution volume to feed ratios without a corresponding substantial decrease in the separation of ethylbenzene.
Claim 6
Dependent Claim
185 words
In a liquid chromatographic separation process for the separation of paraxylene contained in a C8 aromatic isomer mixture containing ethylbenzene including the steps of: a. contacting a C8 aromatic isomer mixture with a bed containing a type Y molecular sieve selected from the group consisting of potassium Y, ammonium/potassium Y and barium potassium Y at conditions to effect the selective retention of paraxylene by said sieve; b. passing through said sieve an eluent selected from the group consIsting of metadiisopropylbenzene, paradiisopropylbenzene and toluene; c. increasing the strength of the eluent in the liquid carrier containing said eluent during the operation of step (b) above; d. recovering from said bed a stream or streams containing a portion of the feedstream components less preferentially adsorbed by said sieve; e. recovering a stream or streams substantially enhanced in concentration of paraxylene wherein the improvement comprises operating the process at a temperature in the range of from 160*C to about 200*C to thereby effect the desired separation of paraxylene under conditions resulting in low elution volume to feed ratios without a corresponding substantial decrease in the separation of ethylbenzene.
Claim 7
Dependent Claim
185 words
In a liquid chromatographic separation process for the separation of paraxylene contained in a C8 aromatic isomer mixture containing ethylbenzene including the steps of: a. contacting a C8 aromatic isomer mixture with a bed containing a type Y molecular sieve selected from the group consisting of potassium Y, ammonium/potassium Y and barium potassium Y at conditions to effect the selective retention of paraxylene by said sieve; b. passing through said sieve an eluent selected from the group consIsting of metadiisopropylbenzene, paradiisopropylbenzene and toluene; c. increasing the strength of the eluent in the liquid carrier containing said eluent during the operation of step (b) above; d. recovering from said bed a stream or streams containing a portion of the feedstream components less preferentially adsorbed by said sieve; e. recovering a stream or streams substantially enhanced in concentration of paraxylene wherein the improvement comprises operating the process at a temperature in the range of from 160*C to about 200*C to thereby effect the desired separation of paraxylene under conditions resulting in low elution volume to feed ratios without a corresponding substantial decrease in the separation of ethylbenzene.
Claim 8
Dependent Claim
22 words
The process of claim 4 wherein said less preferentially adsorbed components are selected from the group consisting of metaxylene, orthoxylene and ethylbenzene.
Claim 9
Dependent Claim
11 words
The process of claim 4 wherein the eluent employed is metadiisopropylbenzene.
Claim 10
Dependent Claim
25 words
The process of claim 6 wherein the eluent strength is increased from a beginning 25% concentration to a final concentration of up to about 95%.
Claim 11
Dependent Claim
21 words
The process of claim 4 wherein the carrier is selected from the group consisting of hexane, heptane, isooctane, cetane and eicosane.
References Cited (Backward Citations)
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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) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |