DEF dosing using multiple dosing locations while maintaining high passive soot oxidation
US-11008917-B2 · May 18, 2021 · US
Exhaust system including SCRF catalyst with oxidation zone
US11280240B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11280240-B2 |
| Application number | US-201917043322-A |
| Country | US |
| Kind code | B2 |
| Filing date | Mar 29, 2019 |
| Priority date | Mar 29, 2018 |
| Publication date | Mar 22, 2022 |
| Grant date | Mar 22, 2022 |
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- Title
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Abstract
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Systems and methods of the present invention related to an exhaust gas purification system comprising: (a) a first injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas; (b) a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalyst reduction (SCR) catalyst and an oxidation catalyst; (c) a second injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas, located downstream of the filter; and (d) a downstream catalyst comprising a selective catalytic reduction catalyst, located downstream of the second injector.
First claim
Opening claim text (preview).
The invention claimed is: 1. An exhaust gas purification system comprising: a. a first injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas; b. a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalyst reduction (SCR) catalyst and an oxidation catalyst; c. a second injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas, located downstream of the filter; and d. a downstream catalyst comprising a selective catalytic reduction catalyst, located downstream of the second injector; wherein the oxidation catalyst is coated on the outlet of the filter. 2. The exhaust gas purification system of claim 1 , wherein the oxidation catalyst comprises one or more platinum group metals. 3. The exhaust gas purification system of claim 1 , wherein the oxidation catalyst comprises platinum, palladium, or combinations thereof. 4. The exhaust gas purification system of claim 1 , wherein the selective catalytic reduction catalyst comprises a metal oxide based SCR catalyst formulation, a molecular sieve based SCR catalyst formulation, or mixtures thereof. 5. The exhaust gas purification system of claim 1 , wherein the downstream catalyst further comprises an ammonia oxidation catalyst. 6. The exhaust gas purification system of claim 1 , wherein the exhaust gas entering the downstream catalyst has a NO 2 :NO x ratio of more than 10%. 7. The exhaust gas purification system of claim 1 , further comprising an upstream catalyst located upstream of the filter, the upstream catalyst comprising a diesel oxidation catalyst, a NO x storage catalyst, or combinations thereof. 8. A method of purifying exhaust gas, comprising: a. adding ammonia or a compound decomposable into ammonia into the exhaust gas by a first injector; b. passing the exhaust gas through a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalytic reduction (SCR) catalyst and an oxidation catalyst; c. adding ammonia or a compound decomposable into ammonia into the exhaust gas by a second injector, located downstream of the filter; and d. passing the exhaust gas through a downstream catalyst comprising a selective reduction catalyst, located downstream of the second injector; wherein the oxidation catalyst is coated on the outlet of the filter. 9. The method of claim 8 , wherein the oxidation catalyst comprises one or more platinum group metals. 10. The method of claim 8 , wherein the oxidation catalyst comprises platinum, palladium, or combinations thereof. 11. The method of claim 8 , wherein the selective catalytic reduction catalyst comprises a metal oxide based SCR catalyst formulation, a molecular sieve based SCR catalyst formulation, or mixtures thereof. 12. The method of claim 8 , wherein the downstream catalyst further comprises an ammonia oxidation catalyst. 13. The method of claim 8 , wherein the exhaust gas entering the downstream catalyst has a NO 2 :NO x ratio of more than 10%. 14. The method of claim 8 , further comprising an upstream catalyst located upstream of the filter, the upstream catalyst comprising a diesel oxidation catalyst, a NO x storage catalyst, or combinations thereof. 15. An exhaust gas purification system comprising: a. a first injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas; b. a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalyst reduction (SCR) catalyst and an oxidation catalyst; c. a second injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas, located downstream of the filter; and d. a downstream catalyst comprising a selective catalytic reduction catalyst, located downstream of the second injector; wherein the downstream catalyst further comprises an ammonia oxidation catalyst. 16. A method of purifying exhaust gas, comprising: a. adding ammonia or a compound decomposable into ammonia into the exhaust gas by a first injector; b. passing the exhaust gas through a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalytic reduction (SCR) catalyst and an oxidation catalyst; c. adding ammonia or a compound decomposable into ammonia into the exhaust gas by a second injector, located downstream of the filter; and d. passing the exhaust gas through a downstream catalyst comprising a selective reduction catalyst, located downstream of the second injector; wherein the downstream catalyst further comprises an ammonia oxidation catalyst.
Assignees
Inventors
Classifications
for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas · CPC title
with catalysts positioned on separate bricks, e.g. exhaust systems · CPC title
Oxidation catalysts for HC and CO only · CPC title
the purifying devices are of the same type · CPC title
NOx amount trapped in catalyst · CPC title
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Frequently asked questions
Answers are generated from the same data shown on this page.
- What does patent US11280240B2 cover?
- Systems and methods of the present invention related to an exhaust gas purification system comprising: (a) a first injector for injecting ammonia or a compound decomposable to ammonia into the exhaust gas; (b) a diesel particulate filter including an inlet and an outlet, wherein the filter includes a selective catalyst reduction (SCR) catalyst and an oxidation catalyst; (c) a second injector fo…
- Who is the assignee on this patent?
- Bergeal David, Johnson Matthey Plc
- What technology area does this patent fall under?
- Primary CPC classification F01N3/035. Mapped technology areas include Mechanical Engineering.
- When was this patent published?
- Publication date Tue Mar 22 2022 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 7 related publications on this page (citations in our corpus or others sharing the same primary CPC).