US4394299A
Expired / Lapsed
US
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Palladium-rhodium catalyst for purification of crude terephthalic acid
Assignee: BP Corp North America Inc
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Filing: 1981-10-29
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Granted: 1983-07-19
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Expires: 2001-10-29
Abstract
Abstract A process for producing a purified terephthalic acid which comprises reacting in a liquid phase a mixture of hydrogen and crude terephthalic acid, a palladium/rhodium catalyst on a porous carbonaceous support wherein the catalyst compound is prepared by adsorbing palladium on the support from a complex salt formed in the presence of an amine and acetic acid, followed by deposition of rhodium from a solution of sodium hexanitritorhodate.
Inventors
- 👤 Imre Puskas
- 👤 David E. James
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:00
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/46; B01J23/464; C; C07; C07C; C07C51/00; C07C51/42; C07C51/487; F; F01; F01N; F01N2550/00; F01N2550/20; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
165 words
A method of making a catalyst used for purification of terephthalic acid containing up to 10,000 ppm of 4-carboxybenzaldehyde in a standard laboratory test wherein 4-carboxybenzaldehyde content is decreased to less than 100 parts per million and p-toluic acid content increase is minimized wherein catalytically active palladium crystallites and rhodium crystallites are adsorbed on a porous activated carbon support material having a surface area of at least 600 m 2 /g which comprises contacting said support with (a) an aqueous solution of an amine and a palladium salt in the presence of an organic carboxylic acid wherein concentration of said amine is sufficient to solubilize said palladium salt and mole ratio of said acid to said amine is at least 0.75 and with (b) an aqueous solution of a rhodium salt and an alkali metal nitrite wherein penetration of said palladium and rhodium crystallites into said porous support is within the range of from about 70 to 150 micrometers of the surface of said support.
Claim 2
Independent Claim
165 words
A method of making a catalyst used for purification of terephthalic acid containing up to 10,000 ppm of 4-carboxybenzaldehyde in a standard laboratory test wherein 4-carboxybenzaldehyde content is decreased to less than 100 parts per million and p-toluic acid content increase is minimized wherein catalytically active palladium crystallites and rhodium crystallites are adsorbed on a porous activated carbon support material having a surface area of at least 600 m 2 /g which comprises contacting said support with (a) an aqueous solution of an amine and a palladium salt in the presence of an organic carboxylic acid wherein concentration of said amine is sufficient to solubilize said palladium salt and mole ratio of said acid to said amine is at least 0.75 and with (b) an aqueous solution of a rhodium salt and an alkali metal nitrite wherein penetration of said palladium and rhodium crystallites into said porous support is within the range of from about 70 to 150 micrometers of the surface of said support.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein deposition of said palladium and said rhodium crystallites on said support is in two separate sequential steps.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said palladium salt is selected from the group consisting of palladium chloride, palladium bromide, palladium iodide, and palladium acetate.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said palladium salt is palladium chloride.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein said rhodium salt is selected from the group consisting of rhodium chloride, rhodium bromide, rhodium iodide and rhodium acetate.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein said rhodium salt is rhodium chloride.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein said alkali metal nitrite is selected from the group consisting of sodium nitrite and potassium nitrite.
Claim 9
Independent Claim
26 words
The method of caim 1 wherein said support material is selected from the group consisting of plant origin carbon, animal origin carbon, and mineral origin carbon.
Claim 10
Independent Claim
26 words
The method of caim 1 wherein said support material is selected from the group consisting of plant origin carbon, animal origin carbon, and mineral origin carbon.
Claim 11
Dependent Claim
13 words
The method of claim 8 wherein said plant origin carbon is coconut charcoal.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein said alkaline nitrite is sodium nitrite.
Claim 13
Dependent Claim
136 words
A catalyst composition for purification of terephthalic acid which comprises crystallites of palladium and rhodium adsorbed on a porous activated carbon support material, said support material having a surface area of at least 600 m 2 /g wherein said catalyst composition is prepared by contacting said support with (a) an aqueous solution of an amine and a palladium salt in the presence of an organic carboxylic acid wherein concentration of said amine is sufficient to solubilize said palladium salt and mole ratio of said acid to said amine is at least 0.75 and with (b) an aqueous solution of a rhodium compound and an alkali metal nitrite wherein penetration of said palladium and rhodium crystallites into said porous support is within the range of from about 70 to 150 micrometers of the surface of said support.
Claim 14
Dependent Claim
136 words
A catalyst composition for purification of terephthalic acid which comprises crystallites of palladium and rhodium adsorbed on a porous activated carbon support material, said support material having a surface area of at least 600 m 2 /g wherein said catalyst composition is prepared by contacting said support with (a) an aqueous solution of an amine and a palladium salt in the presence of an organic carboxylic acid wherein concentration of said amine is sufficient to solubilize said palladium salt and mole ratio of said acid to said amine is at least 0.75 and with (b) an aqueous solution of a rhodium compound and an alkali metal nitrite wherein penetration of said palladium and rhodium crystallites into said porous support is within the range of from about 70 to 150 micrometers of the surface of said support.
Claim 15
Dependent Claim
22 words
The composition of claim 11 wherein said amine is selected from the group consisting of ammonia, pyridine, the picolines and the lutidines.
Claim 16
Dependent Claim
10 words
The composition of claim 11 wherein said amine is pyridine.
Claim 17
Dependent Claim
36 words
The composition of claim 11 wherein said acid has from 2 to 5 carbon atoms and is selected from the group consisting of acetic acid, propionic acid, butyric acid, isobutyric acid, n-valeric acid and mixtures thereof.
Claim 18
Dependent Claim
11 words
The composition of claim 11 wherein said acid is acetic acid.
Claim 19
Dependent Claim
24 words
The composition of claim 11 wherein said palladium and rhodium compounds are halides individually selected from the group consisting of chlorides, bromides and iodides.
Claim 20
Dependent Claim
13 words
The composition of claim 16 wherein said palladium and rhodium halides are chlorides.
Claim 21
Dependent Claim
21 words
The composition of claim 11 wherein said alkali metal nitrite is selected from the group consisting of sodium and potassium nitrite.
Claim 22
Dependent Claim
11 words
The composition of claim 11 wherein said nitrite is sodium nitrite.
Claim 23
Dependent Claim
25 words
The composition of claim 11 wherein said support is selected from the group consisting of plant origin carbon, animal origin carbon, and mineral origin carbon.
Claim 24
Dependent Claim
11 words
The composition of claim 12 wherein said support is coconut charcoal.
Claim 25
Dependent Claim
40 words
The composition of claim 11 wherein said palladium salt is palladium chloride, said amine is pyridine, said acid is acetic acid, said rhodium salt is rhodium chloride, said alkali metal nitrite is sodium nitrite and said support is coconut charcoal.
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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) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |