Patent US6203770B1 successfully refreshed from Google Patents.
US6203770B1
Expired / Lapsed
US
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Urea pyrolysis chamber and process for reducing lean-burn engine NOx emissions by selective catalytic reduction
Assignee: Clean Diesel Technologies Inc
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Filing: 1999-08-20
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Granted: 2001-03-20
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Expires: 2019-08-20
Abstract
Abstract Urea is pyrolyzed in a chamber designed to facilitate gasification of the urea by pyrolysis with conversion of urea to ammonia and isocyanic acid (HNCO) with water vapor and carbon dioxide. The product gases are introduced into exhaust gases from a lean-burn engine, preferably upstream of a turbocharger. The exhaust gases are then contacted with an SCR catalyst.
Inventors
- 👤 Jeremy D. Peter-Hoblyn
- 👤 Eric N. Balles
- 👤 Theodore J. Tarabulski
- 👤 John E. Hofmann
- 👤 James M. Valentine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:04
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N3/2066; B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/90; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9431; F01N2610/00; F01N2610/02; F01N2610/06; F01N2610/14; F01N2610/1453; F01N2610/1473; Y; Y02; Y02C; Y02C20/00; Y02C20/10; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
An apparatus for reducing the emissions of No x from a lean-burn engine having associated therewith an exhaust system having an exhaust passage leading to a SCR reactor effective for selective catalytic No x reduction, comprising: a pyrolysis chamber for pyrolizing urea fed as an aqueous solution including heated internal surfaces and having openings therein to permit discharge of gases generated by pyrolysis of urea and vaporization of water; means for passing the gases generated by pyrolysis into the exhaust passage containing exhaust gases; means for passing the exhaust gases containing the gases generated by pyrolysis to a SCR reactor; spray means capable of spraying the urea solution into the pyrolysis chamber; and said spray means comprising an injector nozzle having associated lines for feeding the solution to the nozzle and returning solution not discharged from the nozzle.
Claim 2
Independent Claim
138 words
An apparatus for reducing the emissions of No x from a lean-burn engine having associated therewith an exhaust system having an exhaust passage leading to a SCR reactor effective for selective catalytic No x reduction, comprising: a pyrolysis chamber for pyrolizing urea fed as an aqueous solution including heated internal surfaces and having openings therein to permit discharge of gases generated by pyrolysis of urea and vaporization of water; means for passing the gases generated by pyrolysis into the exhaust passage containing exhaust gases; means for passing the exhaust gases containing the gases generated by pyrolysis to a SCR reactor; spray means capable of spraying the urea solution into the pyrolysis chamber; and said spray means comprising an injector nozzle having associated lines for feeding the solution to the nozzle and returning solution not discharged from the nozzle.
Claim 3
Dependent Claim
24 words
An apparatus according to claim 1 , which further comprises: a heat exchanger to transfer heat from the exhaust gases to the pyrolysis chamber.
Claim 4
Dependent Claim
18 words
An apparatus according to claim 1 , which further comprises: an auxiliary heater to heat the pyrolysis chamber.
References Cited (Backward Citations)
US4107272A
Cited
CA1100292A
Cited
US4138469A
Cited
US4393031A
Cited
US4268488A
Cited
US4892562A
Cited
US5215652A
Cited
EP0210392A2
Cited
US4891050A
Cited
US4842834A
Cited
WO1990007561A1
Cited
US5034020A
Cited
US5266083A
Cited
EP0487886A1
Cited
US5431893A
Cited
EP0615777B1
Cited
WO1997001387A1
Cited
US5809775A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-19 | 2004-09-18 | 2005-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-19 | 2008-09-18 | 2009-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-19 | 2012-09-18 | 2013-03-20 | $7700.00 | Window Closed / Lapsed |