US5476975A
Expired / Lapsed
US
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Extraction of toxic organic contaminants from wood and photodegradation of toxic organic contaminants
Assignee: Bell Canada Inc
•
Filing: 1994-07-08
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Granted: 1995-12-19
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Expires: 2014-07-08
Abstract
Abstract A process is provided herein for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood, e.g., utility poles, fence posts, or railway ties. The process comprises extracting the wood with a supercritical fluid in conjunction with an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures. The process is further improved by exposing, either in a slurry of the wood phase, or in a liquid phase resulting from such extraction, the contaminants to UV, e.g., sunlight, in the presence of a photosensitizer. The present invention also provides for the photodegradation of a solution of organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, by exposing such solution to UV, e.g., sunlight, in the presence of a photosensitizer.
Inventors
- 👤 John N. R. Ruddick
- 👤 Futong Cui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:36
CPC Classifications
A; A62; A62D; A62D3/00; A62D3/10; A62D3/17; A62D3/176; A62D2101/00; A62D2101/20; A62D2101/22; A62D2101/28
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
64 words
A process for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood which process comprises: extracting said wood with a supercritical fluid, an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures, thereby to extract said contaminants from said wood.
Claim 2
Dependent Claim
64 words
A process for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood which process comprises: extracting said wood with a supercritical fluid, an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures, thereby to extract said contaminants from said wood.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said supercritical fluid is carbon dioxide.
Claim 4
Dependent Claim
28 words
The process of claim 1 wherein said entrainer is an agent selected from the group consisting of water, methanol, ethanol, propanol, isopropanol, toluene, acetone, tetrahydrofuran, dimethylfurmamide and dimethylsulfoxide.
Claim 5
Dependent Claim
10 words
The process of claim 3 wherein said entrainer is water.
Claim 6
Dependent Claim
10 words
The process of claim 3 wherein said entrainer is methanol.
Claim 7
Dependent Claim
10 words
The process of claim 2 wherein said entrainer is water.
Claim 8
Dependent Claim
10 words
The process of claim 2 wherein said entrainer is methanol.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein said hydrogen-bond-breaking agent is an alkali metal fluoride.
Claim 10
Dependent Claim
24 words
The process of claim 8 wherein said alkali metal fluoride is selected from the group consisting of lithium fluoride, potassium fluoride and sodium fluoride.
Claim 11
Dependent Claim
27 words
The process of claim 2 wherein said hydrogen-bond-breaking agent is an alkali metal fluoride selected from the group consisting of lithium fluoride, potassium fluoride and sodium fluoride.
Claim 12
Dependent Claim
13 words
The process of claim 10 wherein said alkali methal fluoride is sodium fluoride.
Claim 13
Dependent Claim
12 words
The process of claim 6 wherein said hydrogen-bond-breaking agent is sodium fluoride.
Claim 14
Dependent Claim
12 words
The process of claim 7 wherein said hydrogen-bond-breaking agent is sodium fluoride.
Claim 15
Dependent Claim
23 words
The process of claim 1 including the step of reducing the size of said wood by comminuting said wood before said extraction step.
Claim 16
Dependent Claim
23 words
The process of claim 1 including the step of reducing the size of said wood by chipping said wood before said extraction step.
Claim 17
Dependent Claim
25 words
The process of claim 1 including the step of reducing the size of said wood by forming flakes from said wood before said extraction step.
Claim 18
Dependent Claim
28 words
The process of claim 1 including the step of producing segments from outer sapwood of treated utility poles and reducing said segments to flakes before said extraction step.
Claim 19
Dependent Claim
25 words
The process of claim 1 including the step of producing thin sheets of wood from outer sapwood of treated utility poles before said extraction step.
Claim 20
Dependent Claim
101 words
A process for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood and the subsequent photodegradation of the reaction products which process comprises: extracting said wood with a supercritical fluid, an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures; and exposing, in a slurry of said extracted wood, or in a liquid solvent resulting from said extractions, said contaminants to radiation including UV or sunlight, in the presence of a photosensitizing amount of a suitable photosensitizer.
Claim 21
Dependent Claim
101 words
A process for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood and the subsequent photodegradation of the reaction products which process comprises: extracting said wood with a supercritical fluid, an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures; and exposing, in a slurry of said extracted wood, or in a liquid solvent resulting from said extractions, said contaminants to radiation including UV or sunlight, in the presence of a photosensitizing amount of a suitable photosensitizer.
Claim 22
Dependent Claim
11 words
The process of claim 19 wherein said radiation comprises direct sunlight.
Claim 23
Dependent Claim
12 words
The process of claim 19 wherein said suitable photosensitizer is methylene blue.
Claim 24
Dependent Claim
11 words
The process of claim 19 wherein said photosensitizer is a porphyrin.
Claim 25
Dependent Claim
11 words
The process of claim 22 wherein said porphyrin is protoporphyrin IX.
Claim 26
Dependent Claim
12 words
The process of claim 19 wherein said suitable photosensitizer is a phthalocyanine.
Claim 27
Dependent Claim
16 words
The process of claim 19 wherein the irradiation takes place in the presence of an amine.
Claim 28
Dependent Claim
10 words
The process of claim 25 wherein said amine is triethanolamine.
Claim 29
Dependent Claim
12 words
The process of claim 19 wherein said solvent is a water-miscible solvent.
Claim 30
Dependent Claim
24 words
The process of claim 19 wherein said water-miscible solvent for said solvent phase is selected from the group consisting of acetonitrile, methanol and ethanol.
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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) | 1998-12-18 | 1999-06-19 | 1999-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-18 | 2003-06-19 | 2003-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-18 | 2007-06-19 | 2007-12-19 | $7700.00 | Window Closed / Lapsed |