US5149511A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of selectively reducing NOx
Assignee: Ford Global Technologies LLC
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Filing: 1991-10-07
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Granted: 1992-09-22
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Expires: 2011-10-07
Abstract
Abstract A catalyst system for the selective reduction of gaseous NO x in the presence of excess oxygen, having a copper-containing ZSM5 zeolite to which a NO x -containing gas is exposed, and means for introducing a metered volume of comminuted water-soluble, oxygen-containing organic compound (alcohol, aldehyde, ketone, ether) into the NO x -containing gas prior to exposure to the Cu-ZSM5 zeolite. Also, a method of treating automotive exhaust gas emissions, having an excess of oxygen, by the steps of: (a) introducing a water-soluble, oxygenated organic compound (steam/oxygenate mixture) into the exhaust gas emissions as a reductant and at a location closely adjacent the source of the exhaust gas generation (in an appropriate amount with respect to the NO x ); (b) substantially immediately exposing the reductant/emission mixture to a transition metal-exchanged high silica ZSM5 zeolite (SiO 2 /Al 2 O 3 of between 10-50) catalyst at a space velocity in the range of 20-80 K hr -1 ; and (c) sequentially exposing the effluent of such zeolite catalyst to an oxidation catalyst.
Inventors
- 👤 Clifford N. Montreuil
- 👤 Mordecai Shelef
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:45
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; B01J29/42; B01J29/46; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01D53/944; B01D53/9459; B01D2251/00; B01D2251/20; B01D2251/208; B01D2251/21; B01D2255/00; B01D2255/10; B01D2255/102; B01D2255/1021; B01D2255/1023; B01D2255/20; B01D2255/207; B01D2255/20761; B01D2255/50; B01D2255/504; B01D2258/00; B01D2258/01; B01D2258/012
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A method of treating automotive exhaust gas emissions from a lean-burn engine carrying excess oxygen, comprising the steps of: (a) distributing a liquified, oxygenated organic compound into said emissions as a reductant and at a location adjacent the source of emission generation, said compound being a partially oxygenated, low molecular weight compound selected from within the group consisting of alcohols, aldehydes, ketones, and ethers; (b) substantially immediately exposing said reductant/emission mixture to a transition metal-exchanged high silica ZSM5 zeolite {(SiO 2 /Al 2 O 3 of between 10-50)} catalyst at a compatible space velocity; and (c) sequentially exposing the effluent from said zeolite catalyst to an oxidation catalyst.
Claim 2
Independent Claim
108 words
A method of treating automotive exhaust gas emissions from a lean-burn engine carrying excess oxygen, comprising the steps of: (a) distributing a liquified, oxygenated organic compound into said emissions as a reductant and at a location adjacent the source of emission generation, said compound being a partially oxygenated, low molecular weight compound selected from within the group consisting of alcohols, aldehydes, ketones, and ethers; (b) substantially immediately exposing said reductant/emission mixture to a transition metal-exchanged high silica ZSM5 zeolite {(SiO 2 /Al 2 O 3 of between 10-50)} catalyst at a compatible space velocity; and (c) sequentially exposing the effluent from said zeolite catalyst to an oxidation catalyst.
Claim 3
Dependent Claim
24 words
The method as in claim 1, in which said reductant is distributed in a ratio to NO x in said emission of about 3-5.
Claim 4
Dependent Claim
31 words
The method as in claim 1, in which said compound is water soluble and is introduced at a predetermined metered volume proportionate to the variance of NO x in said emissions.
Claim 5
Dependent Claim
13 words
The method as in claim 3, in which said liquified compound is sprayed.
Claim 6
Dependent Claim
23 words
The method as in claim 1, in which step (c) is carried out at a space velocity of 20-80 K hr -1 .
Claim 7
Dependent Claim
30 words
The method as in claim 1, in which the method results in a conversion efficiency of NO x in said emissions of at least 42% when O 2 is 0.1-0.5%.
Claim 8
Dependent Claim
13 words
The method as in claim 1, in which said water-soluble compound is propanol.
Claim 9
Dependent Claim
18 words
The method as in claim 1, in which step (a) introduces the reductant as a steam/organic oxygenate mixture.
Claim 10
Independent Claim
117 words
A method of treating automotive exhaust gas emissions from a lean-burn engine carrying excess oxygen, the treatment providing for the staged conversion of HC, CO, and NO x , comprising the steps of: (a) distributing a liquified, oxygenated organic compound into said emissions as a reductant and at a location adjacent the source of emission generation, said compound being a partially oxygenated, low molecular weight compound selected from the group consisting of alcohols, aldehydes, ketones, and ethers; (b) substantially immediately exposing said reductant/emission mixture to a copper-exchanged high silica ZSM5 zeolite catalyst at a compatible space velocity; and (c) sequentially exposing the effluent from said zeolite catalyst to an oxidation catalyst comprised of noble or base metals.
Claim 11
Independent Claim
117 words
A method of treating automotive exhaust gas emissions from a lean-burn engine carrying excess oxygen, the treatment providing for the staged conversion of HC, CO, and NO x , comprising the steps of: (a) distributing a liquified, oxygenated organic compound into said emissions as a reductant and at a location adjacent the source of emission generation, said compound being a partially oxygenated, low molecular weight compound selected from the group consisting of alcohols, aldehydes, ketones, and ethers; (b) substantially immediately exposing said reductant/emission mixture to a copper-exchanged high silica ZSM5 zeolite catalyst at a compatible space velocity; and (c) sequentially exposing the effluent from said zeolite catalyst to an oxidation catalyst comprised of noble or base metals.
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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) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-22 | 2004-03-23 | 2004-09-22 | $7700.00 | Window Closed / Lapsed |