US5433071A
Expired / Lapsed
US
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Apparatus and method for controlling noxious components in automotive emissions using a conditioning catalyst for removing hydrogen
Assignee: Ford Global Technologies LLC
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Filing: 1993-12-27
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Granted: 1995-07-18
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Expires: 2013-12-27
Abstract
Abstract The invention relates to an improved emission control system. The system has particular applicability for use in an internal combustion engine (10) utilizing alternative fuels such as natural gas. More particularly, the invention provides an apparatus and method wherein hydrogen is removed by a conditioning catalyst (16) from the exhaust gas stream (21) to produce a conditioned exhaust gas (22). An exhaust gas oxygen (EGO) sensor (18) is in communication with the conditioned exhaust gas (22) and generates a signal in response to the sensed oxygen concentration of the conditioned exhaust gas (22). The A/F mixture entering engine (10) is adjusted by closed loop control means (14) in response to the signal generated by EGO sensor (18). The removal of hydrogen from the exhaust gas stream (21) eliminates lean shifts and allows oxygen sensor (18) and closed loop control means (14) to more accurately control the A/F ratio. As a result of improved control over the A/F mixture entering engine (10), main three-way catalyst (20) optimally converts noxious components present in the conditioned exhaust gas (22) to produce a purified exhaust stream (23).
Inventors
- 👤 Raymond L. Willey
- 👤 Robert W. McCabe
- 👤 Jeffrey S. Hepburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:57
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/0027; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/9495; F01; F01N; F01N13/00; F01N13/009; F01N13/011; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N2570/00; F02D19/00; F02D19/02; F02D19/021; F02D19/023; F02M; F02M21/00; F02M21/02; F02M21/0203; F02M21/0215; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
183 words
An emission control system for controlling noxious components from an exhaust stream produced by the combustion of an air/fuel mixture in an internal combustion engine, the system comprising: a conditioning catalyst, in communication with the exhaust stream, the catalyst being sized to preferentially oxidize hydrogen from the exhaust stream, the catalyst being capable of removing hydrogen from the exhaust stream to provide a conditioned exhaust stream; an exhaust gas oxygen sensor, in communication with the conditioned exhaust stream, capable of sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; a three-way catalyst, in communication with the conditioned exhaust stream, capable of eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream; and control means for adjusting the air/fuel mixture entering the engine, the control means operating in response to the signal generated by the oxygen sensor, wherein the removal of the hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and reduces deviations in the actual air/fuel mixture entering the engine from a desired ratio.
Claim 2
Dependent Claim
183 words
An emission control system for controlling noxious components from an exhaust stream produced by the combustion of an air/fuel mixture in an internal combustion engine, the system comprising: a conditioning catalyst, in communication with the exhaust stream, the catalyst being sized to preferentially oxidize hydrogen from the exhaust stream, the catalyst being capable of removing hydrogen from the exhaust stream to provide a conditioned exhaust stream; an exhaust gas oxygen sensor, in communication with the conditioned exhaust stream, capable of sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; a three-way catalyst, in communication with the conditioned exhaust stream, capable of eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream; and control means for adjusting the air/fuel mixture entering the engine, the control means operating in response to the signal generated by the oxygen sensor, wherein the removal of the hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and reduces deviations in the actual air/fuel mixture entering the engine from a desired ratio.
Claim 3
Dependent Claim
21 words
The system of claim 1 where the conditioning catalyst removes at least 75% of the hydrogen present in the exhaust stream.
Claim 4
Dependent Claim
22 words
The system of claim 2 where the conditioning catalyst removes at least 80% of the hydrogen present in the exhaust gas stream.
Claim 5
Dependent Claim
21 words
The system of claim 3 where the conditioning catalyst removes more than 90% of the hydrogen in the exhaust gas stream.
Claim 6
Dependent Claim
22 words
The system of claim 1 where the conditioning catalyst has a space velocity which results in negligible damping upon the oxygen sensor.
Claim 7
Dependent Claim
23 words
The system of claim 5 where the conditioning catalyst has a space velocity of from 500,000 h -1 to 1,000,000 h -1 .
Claim 8
Dependent Claim
18 words
The system of claim 1 which has the capacity to store less than 1000 micro-moles of oxygen atoms.
Claim 9
Dependent Claim
18 words
The system of claim 7 where the conditioning catalyst stores between 500 and 1000 micro-moles of oxygen atoms.
Claim 10
Dependent Claim
30 words
The system of claim 1 where the conditioning catalyst has between 100 to 400 cpi, a diameter of less than 4.0 inches, and a length of less than 5.0 inches.
Claim 11
Dependent Claim
44 words
The system of claim 1 where the exhaust gas stream is produced by the combustion of an air/fuel mixture in an internal combustion engine, the fuel being selected from the group consisting of gasoline, natural gas, propane (LPG), methane, methanol, ethanol, and mixtures thereof.
Claim 12
Independent Claim
185 words
A method for controlling noxious components in an exhaust stream produced by the combustion of an air/fuel mixture in an internal combustion engine, the process comprising: positioning a low volume conditioning catalyst in communication with the exhaust stream, the low volume conditioning catalyst being sized to eliminate at least 75% of the hydrogen present in the exhaust gas stream exiting the internal combustion engine; sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; adjusting the air/fuel mixture entering the engine, in response to the signal generated by the oxygen sensor, in order to maintain the oxygen concentration of the exhaust stream between a first and a second value; and eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream, optimum elimination occurring when the oxygen concentration of the exhaust stream is between the first and second value, wherein removal of hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and hence the maintenance of the oxygen concentration of the exhaust stream between the first and second value.
Claim 13
Independent Claim
185 words
A method for controlling noxious components in an exhaust stream produced by the combustion of an air/fuel mixture in an internal combustion engine, the process comprising: positioning a low volume conditioning catalyst in communication with the exhaust stream, the low volume conditioning catalyst being sized to eliminate at least 75% of the hydrogen present in the exhaust gas stream exiting the internal combustion engine; sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; adjusting the air/fuel mixture entering the engine, in response to the signal generated by the oxygen sensor, in order to maintain the oxygen concentration of the exhaust stream between a first and a second value; and eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream, optimum elimination occurring when the oxygen concentration of the exhaust stream is between the first and second value, wherein removal of hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and hence the maintenance of the oxygen concentration of the exhaust stream between the first and second value.
Claim 14
Dependent Claim
29 words
The method of claim 11 where the low volume conditioning catalyst removes at least 80% of the hydrogen present in the exhaust gas stream exiting the internal combustion engine.
Claim 15
Dependent Claim
28 words
The method of claim 12 where the low volume conditioning catalyst removes more-than 90% of the hydrogen present in the exhaust gas stream exiting the internal combustion engine.
Claim 16
Dependent Claim
97 words
The method of claim 11 further comprising: providing an exhaust gas oxygen sensor, in communication with the conditioned exhaust stream, capable of sensing an oxygen concentration of the conditioned exhaust stream and generating a signal proportional to the sensed oxygen concentration; providing a three-way catalyst, in communication with the conditioned exhaust stream, capable of eliminating noxious components from the conditioned exhaust stream; and positioning a control means for adjusting the air/fuel mixture entering the engine to be in communication with the oxygen sensor, the control means operating in response to the signal generated by the oxygen sensor.
Claim 17
Dependent Claim
37 words
The method of claim 11 wherein adjusting the air/fuel mixture further comprises adjusting the air/fuel mixture entering the engine so as to maintain the oxygen concentration of the exhaust gas exiting the engine between λ=0.993 and λ=1.007.
Claim 18
Dependent Claim
48 words
The method of claim 11 for improving the control of noxious components in an exhaust stream produced by the combustion of an air/fuel mixture in an internal combustion engine, the fuel being selected from the group consisting of natural gas, gasoline, methane, propane, methanol, ethanol, and mixtures thereof.
Claim 19
Dependent Claim
239 words
An emission control system for removing noxious components from an exhaust stream produced by the combustion of an air/natural gas mixture in an internal combustion engine, the system comprising: a low volume conditioning catalyst, in communication with the exhaust stream, the catalyst being sized to preferentially oxidize hydrogen from the exhaust stream to provide a conditioned exhaust stream, the catalyst being capable of removing at least 75% of the hydrogen present in the exhaust gas stream; an exhaust gas oxygen sensor, in communication with the conditioned exhaust stream, capable of sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; a three-way catalyst, in communication with the conditioned exhaust stream, capable of eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream and optimally eliminating noxious components when the oxygen concentration of the conditioned exhaust stream is between a first and second value; and control means for adjusting the air/natural gas mixture entering the engine in order to provide an engine exhaust gas stream having an oxygen concentration between the first and second value, the control means operating in response to the signal generated by the oxygen sensor, wherein the removal of hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and reduces deviations in the actual air/natural gas mixture entering the engine from a value between the first and second values.
Claim 20
Dependent Claim
239 words
An emission control system for removing noxious components from an exhaust stream produced by the combustion of an air/natural gas mixture in an internal combustion engine, the system comprising: a low volume conditioning catalyst, in communication with the exhaust stream, the catalyst being sized to preferentially oxidize hydrogen from the exhaust stream to provide a conditioned exhaust stream, the catalyst being capable of removing at least 75% of the hydrogen present in the exhaust gas stream; an exhaust gas oxygen sensor, in communication with the conditioned exhaust stream, capable of sensing an oxygen concentration of the conditioned exhaust stream and generating a signal in response to the sensed oxygen concentration; a three-way catalyst, in communication with the conditioned exhaust stream, capable of eliminating noxious components from the conditioned exhaust stream to produce a purified exhaust stream and optimally eliminating noxious components when the oxygen concentration of the conditioned exhaust stream is between a first and second value; and control means for adjusting the air/natural gas mixture entering the engine in order to provide an engine exhaust gas stream having an oxygen concentration between the first and second value, the control means operating in response to the signal generated by the oxygen sensor, wherein the removal of hydrogen from the exhaust stream improves the accuracy of the oxygen sensor and reduces deviations in the actual air/natural gas mixture entering the engine from a value between the first and second values.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-17 | 1999-01-16 | 1999-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-17 | 2003-01-16 | 2003-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-17 | 2007-01-16 | 2007-07-18 | $7700.00 | Window Closed / Lapsed |