EXHAUST SYSTEM FOR AN AMMONIA-BURNING COMBUSTION ENGINE

Abstract

The present invention relates to a system for ammonia combustion and exhaust gas treatment, the system comprising: an internal combustion engine for combusting ammonia; and an exhaust system comprising an intake for receiving an exhaust gas from the combustion engine, an upstream injector for adding hydrogen gas to the exhaust gas and a downstream catalyst article, wherein the downstream catalyst article comprises a three-way catalyst (TWC) composition. The invention further relates to a method for the treatment of an exhaust gas from an ammonia internal combustion engine.

Claims

1. A system for ammonia combustion and exhaust gas treatment, the system comprising: an internal combustion engine for combusting ammonia; and an exhaust system comprising an intake for receiving an exhaust gas from the combustion engine, an upstream injector for adding hydrogen gas to the exhaust gas and a downstream catalyst article, wherein the downstream catalyst article comprises a three-way catalyst (TWC) composition.

2. The system according to claim 1, wherein the internal combustion engine further comprises a controller for maintaining stoichiometric engine conditions.

3. The system according to claim 1, wherein the system further comprises an ammonia storage vessel and/or a hydrogen storage vessel.

4. The system according to claim 1, wherein the TWC composition is provided on a flow-through substrate or a wall-flow filter substrate.

5. The system according to claim 4, wherein the TWC composition is provided on from 25 to 75% of an axial length of the substrate, extending from an upstream end of the substrate.

6. The system according to claim 1, wherein the TWC composition comprises: (i) a platinum group metal component comprising one or more of Pt, Pd and Rh; (ii) a support material, preferably alumina; and (iii) an oxygen storage component (OSC).

7. The system according to claim 1, wherein the TWC composition comprises ruthenium.

8. The system according to claim 1, the system further comprising a NOx sensor arranged upstream or downstream of the downstream catalyst article, wherein the system is configured to adjust the addition of hydrogen based on measurements obtained from the NOx sensor.

9. The system according to claim 1, wherein the system further comprises a PGM-containing slip catalyst arranged downstream of the downstream catalyst article for converting slipped hydrogen to water and/or for converting slipped ammonia to nitrogen and water.

10. The system according to claim 1, wherein the downstream catalyst article further comprises a PGM-containing slip catalyst composition arranged extending from an outlet end of the downstream catalyst article for converting slipped hydrogen to water and/or for converting slipped ammonia to nitrogen and water.

11. A method for the treatment of an exhaust gas from an ammonia internal combustion engine, the method comprising: injecting hydrogen gas into the exhaust gas upstream of a TWC catalyst.

Description

FIGURES

[0058] The invention will now be described further in relation to the following non-limiting figures, in which:

[0059] FIG. 1 shows a system in accordance with the present invention.

[0060] FIG. 1 shows an ammonia-combustion and exhaust gas treatment system 32. The system 32 comprises an ammonia-combustion engine 30 having a manifold 40 for passing exhaust gas from the ammonia-combustion engine 30 into an exhaust gas duct 34.

[0061] The exhaust gas duct 34 conveys the exhaust gas to a TWC catalyst article 50 as described herein, and then the treated exhaust gas is released to the atmosphere 36. Before the exhaust gas enters the TWC catalyst article 50 it is dosed with hydrogen 46 from a hydrogen dosing spray 48.

[0062] The TWC catalyst article 50 may be a washcoated catalyst article as described herein. This can be provided with an integrated downstream ASC composition to handle any slipped H.sub.2 or NH.sub.3.

[0063] The term “comprising” as used herein can be exchanged for the definitions “consisting essentially of” or “consisting of”. The term “comprising” is intended to mean that the named elements are essential, but other elements may be added and still form a construct within the scope of the claim. The term “consisting essentially of” limits the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s) of the claimed invention. The term “consisting of” closes the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith.

[0064] The foregoing detailed description has been provided by way of explanation and illustration, and is not intended to limit the scope of the appended claims. Many variations in the presently preferred embodiments illustrated herein will be apparent to one of ordinary skill in the art, and remain within the scope of the appended claims and their equivalents.

[0065] For the avoidance of doubt, the entire contents of all documents acknowledged herein are incorporated herein by reference.