US3843643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery of formaldehyde and phenol contained in waste waters
Assignee: Societa Italiana Resine SpA SIR
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Filing: 1972-12-21
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Granted: 1974-10-22
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Expires: 1992-12-21
Abstract
Abstract Formaldehyde and phenol are recovered from waste liquors, with purification of the liquors, by addition of ammonia to the formaldehyde liquor to form hexamethylene tetramine, evaporation of water, addition of the concentrate to the phenol liquor, and recovery of the hexamethylene tetramine/phenol adduct formed.
Inventors
- 👤 J Ackerman
- 👤 P Radici
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:12
CPC Classifications
C; C07; C07D; C07D487/00; C07D487/12; C07D487/18; C07C; C07C37/00; C07C37/005; C07C37/009; C02; C02F; C02F2101/00; C02F2101/30; C02F2101/34; C02F2101/345
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
PROCESS FOR THE RECOVERY OF FORMALDEHYDE AND PHENOL FROM AQUEOUS WASTE SOLUTIONS, AND FOR THE PURIFICATION OF SUCH AQUEOUS WASTE SOLUTIONS, COMPRISING: A. ADDING AMMONIA OR AQUEOUS AMMONIA TO AN AQUEOUS WASTE SOLUTION CONTAINING FORMALDEHYDE AT AN AMBIENT TEMPERATURE OF 20* TO 25*C TO FORM HEXAMETHYLENE TETRAMINE, THE MOLAR RATIO OF FORMALDEHYDE TO AMMONIA BEING APPROXIMATELY 1.5:1, B. EVAPORATING THE WATER FROM THE RESULTING AQUEOUS SOLUTION OF HEXAMETHYLENE TETRAMINE TO FORM AN AQUEOUS SOLUTION WITH A CONCENTRATION OF HEXAMETHYLENE TETRAMINE OF AT LEAST 64 PERCENT BY WEIGHT OR TO FORM SOLID HEXAMETHYLENE TETRAMINE; C. ADDIING SAID SOLID HEXAMETHYLENE TETRAMINE OR SAID CONCENTRATED AQUEOUS SOLUTION OF HEXAMETHYLENE TETRAMINE TO AN AQUEOUS WASTE SOLUTION CONTAINING PHENOL TO FORM AN ADDUCT BETWEEN THE HEXAMETHYLENE TETRAMINE AND THE PHENOL, THE TEMPERATURE BEING BETWEEN THE SETTING TEMPERATURE OF THE MEDIUM AND APPROXIMATELY 60*C AND THE MOLAR RATIO OF HEXAMETHYLENE TETRAMINE TO PHENOL BEING 0.5:1 TO 3:1; AND D. RECOVERING SAID HEXAMETHYLENE TETRAMINE-PHENOL ADDUCT.
Claim 2
Dependent Claim
158 words
PROCESS FOR THE RECOVERY OF FORMALDEHYDE AND PHENOL FROM AQUEOUS WASTE SOLUTIONS, AND FOR THE PURIFICATION OF SUCH AQUEOUS WASTE SOLUTIONS, COMPRISING: A. ADDING AMMONIA OR AQUEOUS AMMONIA TO AN AQUEOUS WASTE SOLUTION CONTAINING FORMALDEHYDE AT AN AMBIENT TEMPERATURE OF 20* TO 25*C TO FORM HEXAMETHYLENE TETRAMINE, THE MOLAR RATIO OF FORMALDEHYDE TO AMMONIA BEING APPROXIMATELY 1.5:1, B. EVAPORATING THE WATER FROM THE RESULTING AQUEOUS SOLUTION OF HEXAMETHYLENE TETRAMINE TO FORM AN AQUEOUS SOLUTION WITH A CONCENTRATION OF HEXAMETHYLENE TETRAMINE OF AT LEAST 64 PERCENT BY WEIGHT OR TO FORM SOLID HEXAMETHYLENE TETRAMINE; C. ADDIING SAID SOLID HEXAMETHYLENE TETRAMINE OR SAID CONCENTRATED AQUEOUS SOLUTION OF HEXAMETHYLENE TETRAMINE TO AN AQUEOUS WASTE SOLUTION CONTAINING PHENOL TO FORM AN ADDUCT BETWEEN THE HEXAMETHYLENE TETRAMINE AND THE PHENOL, THE TEMPERATURE BEING BETWEEN THE SETTING TEMPERATURE OF THE MEDIUM AND APPROXIMATELY 60*C AND THE MOLAR RATIO OF HEXAMETHYLENE TETRAMINE TO PHENOL BEING 0.5:1 TO 3:1; AND D. RECOVERING SAID HEXAMETHYLENE TETRAMINE-PHENOL ADDUCT.
Claim 3
Dependent Claim
24 words
The process according to claim 1, wherein evaporation of the aqueous solution of hexamethylene tetramine is carried out at a pressure below ambient pressure.
Claim 4
Dependent Claim
20 words
The process according to claim 2, wherein the evaporation is carried out at a pressure of 30 to 150 torr.
Claim 5
Dependent Claim
26 words
The process according to claim 1, wherein the concentration of phenol and formaldehyde in said aqueous waste solution is less than approximately 10 percent by weight.
Claim 6
Dependent Claim
28 words
The process according to claim 4, wherein the phenol concentration is 0.01 to 5.0 percent by weight, and the formaldehyde concentration is 0.5 to 10 percent by weight.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |