US3724170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Staged separations of aromatic mixtures with zeolites
Assignee: Mobil Oil AS
•
Filing: 1971-09-13
•
Granted: 1973-04-03
•
Expires: 1991-09-13
Abstract
Abstract An improved method for the separation and isolation of individual components contained in a C8 aromatic mixture such as a p-xylene and ethylbenzene, by contacting the mixture with an aluminosilicate zeolite in stages and recovering the components. It is preferred to use as the zeolite one which has been contacted with an organic-radical substituted silane to modify the characteristics of the zeolite.
Inventors
- 👤 P Allen
- 👤 E Unger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:07
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/12; C07C7/13; C07C7/135
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
22 words
A process according to claim 1 wherein the process is conducted in at least two chromatographic columns with adsorbent in each column.
Claim 2
Dependent Claim
25 words
A process according to claim 1 wherein the process is conducted in a single chromatographic column having at least two distinct stages therein containing adsorbent.
Claim 3
Dependent Claim
29 words
A process according to claim 1 wherein the adsorbent is maintained in the said stages is maintained at an elevated temperature, and said mixture and carriers are passed therethrough.
Claim 4
Dependent Claim
26 words
A process according to claim 4 wherein said carrier is selected from the group consisting of steam, water, nitrogen, air, helium, hydrogen, hydrocarbons and mixtures thereof.
Claim 5
Dependent Claim
17 words
A process according to claim 5 wherein the elevated temperature ranges from about 100* to about 250*C.
Claim 6
Dependent Claim
22 words
A process according to claim 6 wherein the unadsorbed meta-xylene and ortho-xylene mixture is removed from the system after the first stage.
Claim 7
Dependent Claim
86 words
A process according to claim 7 wherein the absorbent is a modified zeolite reaction product of a ZSM-5 or ZSM-8 crystalline aluminosilicate zeolite with an organic radical-substituted silane of the formula: wherein R is an organic radical and each R1 is an organic radical the same as R, hydrogen or a halogen atom, provided that at least one R1 is halogen, by contacting said mixture with said modified zeolite, whereby said components are sorbed at different respective rates by said modified zeolite and recovering the para-xylene.
Claim 8
Dependent Claim
40 words
A process according to claim 7 wherein the zeolite is selected from the group consisting of ZSM-5 type zeolites having the X-ray diffraction pattern of Table 1, ZSM-8 zeolites having the X-ray diffraction pattern of Table 4 and mixtures thereof.
Claim 9
Dependent Claim
35 words
A process according to claim 9 wherein, in prepaRation of the modified zeolite, the zeolite and silane are reacted in weight ratios of about 5:1 to 1:5, respectively, in the presence of an organic solvent.
Claim 10
Dependent Claim
26 words
A process according to claim 10 wherein the organic solvent is pyridine and the reaction is carried out at a temperature of about 75* to 200*C.
Claim 11
Dependent Claim
114 words
A process according to claim 11 wherein the silane compound is of the formula: wherein R is an alkyl group of one to about 40 carbon atoms, an alkyl or aryl acyl group where the organic portion of said alkyl group contains about one to 30 carbon atoms, and of said aryl group contains about six to 24 carbon atoms, aryl groups of about six to 24 carbon atoms, alkaryl and aralkyl groups containing about seven up to about 30 carbon atoms and each R1 is the same as R, hydrogen, or a halogen atom, providing that no more than one R1 is the same as R and at least one R1 is halogen.
Claim 12
Dependent Claim
80 words
A process according to claim 12 wherein the stages are at least two separate chromatographic columns, each containing said adsorbent, said feed and carrier are introduced into the top of the first column, the unadsorbed meta-xylene and ortho-xylene are removed from the bottom of the first column, the adsorbed products are eluted from the first column directly into the second column where they are again adsorbed and the para-xylene is recovered by elution from the bottom of the last column.
Claim 13
Dependent Claim
20 words
A process according to claim 13 wherein two columns are used and the para-xylene is recovered from the second column.
Claim 14
Dependent Claim
85 words
A process according to claim 12 wherein the stages are at least two separate sections in a single chromatographic column, each section containing said adsorbent, said feed and carrier are introduced into the top of the first section, the unadsorbed meta-xylene and ortho-xylene are removed from the bottom of the first section, the adsorbed products are eluted from the first section directly into the second section where they are again adsorbed and the para-xylene is recovered by elution from the bottom of the last section.
Claim 15
Dependent Claim
22 words
A process according to claim 15 wherein two sections are used and the para-xylene is recovered from the second section by elution.
References Cited (Backward Citations)
US3295296A
Cited
US3285701A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |