Patent US3980755A successfully refreshed from Google Patents.
US3980755A
Expired / Lapsed
US
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System for removing chloromethyl ether and bis-chloromethyl ether from air contaminated therewith
Assignee: Rohm and Haas Co
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Filing: 1975-12-24
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Granted: 1976-09-14
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Expires: 1995-12-24
Abstract
Abstract Chloromethyl methyl ether and di(chloromethyl) ether contaminants are removed from air in laboratories, industrial plants and other locales wherein chloromethyl ether (more accurately called chloromethyl methyl ether) and bis-chloromethyl ether are used for various purposes. Silica gel and/or activated alumina are employed for removing the chloromethyl ethers either with or without other contaminants from the gaseous atmosphere wherein they occur. The absorption of the ethers on the silica gel or activated alumina is carried out under conditions of temperature that have been found to result in the hydrolytic decomposition of these chloromethyl ethers, apparently by virtue of catalytic action occurrng on the surface of the silica gel or activated alumina. The decomposition of these ethers on contact with the silica gel or activated alumina results in the production of hydrogen chloride, as well as methylal, methanol, formaldehyde or mixtures thereof depending on the particular ether (CME, BCME or both) present in the contaminated stream.
Inventors
- 👤 Ronald F. Black
- 👤 Clarence P. Kurtz
- 👤 Robert J. Pasek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:46
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/68; B01D53/70; B01D53/72
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
64 words
A method of removing chloromethyl methyl ether and/or bis-chloromethyl ether from inert gasses, such as air, contaminated with small amounts of such ether which comprises contacting the contaminated gas containing a small amount by volume of water vapor with an adsorbent bed comprising silica gel or activated alumina, or mixtures thereof, at such a temperature that said ether component of the gas is hydrolized.
Claim 2
Independent Claim
64 words
A method of removing chloromethyl methyl ether and/or bis-chloromethyl ether from inert gasses, such as air, contaminated with small amounts of such ether which comprises contacting the contaminated gas containing a small amount by volume of water vapor with an adsorbent bed comprising silica gel or activated alumina, or mixtures thereof, at such a temperature that said ether component of the gas is hydrolized.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein the temperature is in the range of up to about 150°C.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein the temperature is in the range of about 60° to about 80°C.
Claim 5
Dependent Claim
47 words
A method according to claim 1 wherein the contaminated gas is preheated to a temperature sufficiently above 70°C. before it is passed into contact with the adsorbent bed to assure that the temperature of the effluent gas stream discharged from the adsorber is at least about 65°C.
Claim 6
Dependent Claim
43 words
A method according to claim 1 wherein the contaminated gas is passed through silica gel heated to a temperature sufficiently above 70°C. to assure that the temperature of the effluent gas stream discharged from the silica gel adsorber is at least about 65°C.
Claim 7
Dependent Claim
43 words
A method according to claim 1 wherein the contaminated gas is passed through activated alumina heated to a temperature sufficiently above 70°C. to assure that the temperature of the effluent gas stream discharged from the activated alumina adsorber is at least about 65°C.
Claim 8
Dependent Claim
71 words
A method according to claim 4 wherein the preheated contaminated gas is supplied to the upper region of the adsorber above the column or adsorbent bed and is discharged from the bottom thereof, the rate of flow of the gas and the temperature thereof being correlated with the volume of adsorbent in the adsorber to assure substantially complete break-down of said ether component into hydrogen chloride, methylal and/or methanol and formaldehyde.
Claim 9
Dependent Claim
32 words
A method according to claim 6 wherein the gas effluent from the adsorber is subjected to a scrubbing aqueous stream, e.g., by passing countercurrent to a stream of water in a scrubber.
Claim 10
Dependent Claim
45 words
A method according to claim 4 wherein the contaminated gas stream is periodically heated to a temperature level at least 50°C. above the range mentioned in claim 4 for short periods of time to reduce or eliminate any adsorbed organic matter accumulated on the adsorbent.
Claim 11
Dependent Claim
58 words
A method according to claim 5 wherein the silica gel is in particulate form having a mesh size in the range of about 6 to 20, U.S. wire screen scale and the moisture content of the air contaminated with said ether(s) is about 0.1 to 10% by volume of the air as it passes to the silica gel.
References Cited (Backward Citations)
US1614615A
Cited
US3772425A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |