US4158047A
Expired / Lapsed
US
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Process for the preparation of a hydroxylamine salt
Assignee: Stamicarbon BV
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Filing: 1977-08-30
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Granted: 1979-06-12
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Expires: 1997-08-30
Abstract
Abstract A process for pre-treating platinum/palladium catalysts, used in the preparation of hydroxylamine, comprising contacting the same with an aqueous salt solution, inhibits (a) the decomposition of hydroxylamine and (b) the consequent formation of explosive mixtures of N 2 O with hydrogen or hydrocarbons.
Inventors
- 👤 Cornelis G. M. van de Moesdijk
- 👤 Maria J. F. Smeets-Mertens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:10
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/082; C01B21/14; C01B21/1409; C01B21/1418
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A process for the inhibition of decomposition of hydroxylamine salts during the preparation of hydroxylamine, which preparation includes the reduction in an aqueous acid medium of nitrate ions or of nitrogen monoxide in the presence of a catalyst composition containing platinum or palladium or a combination of said metals, which comprises subjecting, in the absence of hydroxylammonium salt, said catalyst to a pre-treatment of contacting the same with an aqueous salt solution having pH between about 1 and 3.5, and at a temperature between about 60° to 190° C., and with agitation, for a period of time requiring between about 5 to 80 hours, in the substantial absence of molecular oxygen.
Claim 2
Dependent Claim
111 words
A process for the inhibition of decomposition of hydroxylamine salts during the preparation of hydroxylamine, which preparation includes the reduction in an aqueous acid medium of nitrate ions or of nitrogen monoxide in the presence of a catalyst composition containing platinum or palladium or a combination of said metals, which comprises subjecting, in the absence of hydroxylammonium salt, said catalyst to a pre-treatment of contacting the same with an aqueous salt solution having pH between about 1 and 3.5, and at a temperature between about 60° to 190° C., and with agitation, for a period of time requiring between about 5 to 80 hours, in the substantial absence of molecular oxygen.
Claim 3
Dependent Claim
15 words
The process of claim 1, wherein said temperature is between about 75° to 100° C.
Claim 4
Dependent Claim
14 words
The process of claim 1, wherein said pH is between about 1.5 to 2.5.
Claim 5
Dependent Claim
33 words
The process of claim 1, wherein said aqueous salt solution is composed of aliphatic organic salts or of water soluble alkali metal salts or ammonium salts of mineral acids other than hydrochloric acid.
Claim 6
Dependent Claim
26 words
The process of claim 4, wherein said salt is present at a concentration of between about 2 to 50% by weight of said aqueous salt solution.
Claim 7
Dependent Claim
12 words
The process of claim 4, wherein said salt solution contains a nitrate.
Claim 8
Dependent Claim
22 words
The process of claim 1, wherein an inert gas is introduced into said solution during said agitation to exclude molecular oxygen therefrom.
Claim 9
Dependent Claim
15 words
The process of claim 7, wherein said inert gas is nitrogen, carbon dioxide or helium.
References Cited (Backward Citations)
CA811651A
Cited
US3996165A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-11 | 1982-12-11 | 1983-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-11 | 1986-12-11 | 1987-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-11 | 1990-12-11 | 1991-06-12 | $7700.00 | Window Closed / Lapsed |