Exhaust gas purification apparatus for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9970343-B2
Application number	US-201415023032-A
Country	US
Kind code	B2
Filing date	Aug 5, 2014
Priority date	Sep 19, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The production efficiency of ammonia is more raised while avoiding the necessity for a user to supply water for himself/herself in order to produce the ammonia. An exhaust gas purification apparatus comprises a catalyst which purifies an exhaust gas of an internal combustion engine by using ammonia; and an ammonia supplier which supplies the ammonia to the catalyst; wherein the ammonia supplier includes an ammonia producer which produces the ammonia from nitrogen and water; a nitrogen supplier which separates the nitrogen from air and which supplies the nitrogen to the ammonia producer; and a water supplier which separates the water from the exhaust gas of the internal combustion engine and which supplies the water to the ammonia producer.

First claim

The invention claimed is:

1. An exhaust gas purification apparatus for an internal combustion engine, comprising:
a catalyst which is provided at an exhaust gas passage of the internal combustion engine and configured to purify an exhaust gas of the internal combustion engine by using ammonia; and
an ammonia supplier that supplies the ammonia to the catalyst, wherein the ammonia supplier includes:
an ammonia producer that produces the ammonia from nitrogen and water;
a nitrogen supplier that separates the nitrogen from air and supply the nitrogen to the ammonia producer; and
a water supplier that separates the water from the exhaust gas of the internal combustion engine and supply the water to the ammonia producer, wherein the water supplier includes: a condenser configured to condense the water contained in the exhaust gas of the internal combustion engine; and a vaporizer configured to convert the water condensed by the condenser into water vapor.

2. The exhaust gas purification apparatus for the internal combustion engine according to claim 1 , wherein:
the water supplier separates the water from the exhaust gas of the internal combustion engine and the water supplier supplies the water in a state of water vapor to the ammonia producer; and
the ammonia producer electrolytically synthesizes the ammonia.

3. The exhaust gas purification apparatus for the internal combustion engine according to claim 1 , wherein the ammonia producer includes:
a molten salt vessel configured to store a molten salt; and
a pair of electrodes which are provided in the molten salt vessel, wherein:
the nitrogen supplier supplies the nitrogen to the molten salt vessel;
the water supplier supplies the water to the molten salt vessel; and
the ammonia producer electrolytically synthesizes the ammonia by applying electricity to the electrodes.

4. The exhaust gas purification apparatus for the internal combustion engine according to claim 1 , wherein the water supplier includes a water tank configured to store at least one of the water condensed by the condenser and the water obtained by recondensing the water vapor converted from the water by the vaporizer.

5. The exhaust gas purification apparatus for the internal combustion engine according to claim 4 , wherein the water supplier condenses the water by means of the condenser even when the ammonia is not produced by the ammonia producer, and the water condensed by the condenser is stored in the water tank.

6. The exhaust gas purification apparatus for the internal combustion engine according to claim 4 , wherein the water supplier condenses the water by means of the condenser even after the internal combustion engine stops, and the water condensed by the condenser is stored in the water tank, if an amount of water stored in the water tank is less than a predetermined amount of water.

7. The exhaust gas purification apparatus for the internal combustion engine according to claim 4 , further comprising:
a controller comprising at least one processor configured to cause automatic stop of the internal combustion engine, wherein:
the controller prohibits the automatic stop of the internal combustion engine if an amount of water stored in the water tank is less than a predetermined amount of water; and
the water supplier condenses the water by means of the condenser if the amount of water stored in the water tank is less than the predetermined amount of water, and the water condensed by the condenser is stored in the water tank.

8. The exhaust gas purification apparatus for the internal combustion engine according to claim 1 , further comprising:
a controller comprising at least one processor configured to cause automatic stop of the internal combustion engine, wherein:
the controller prohibits the automatic stop of the internal combustion engine if the water is condensed by the condenser.

9. The exhaust gas purification apparatus for the internal combustion engine according to claim 1 , wherein:
the water supplier includes an exhaust gas intake passage which is a passage for intaking the exhaust gas from a portion of the exhaust gas passage disposed on a downstream side from the catalyst; and
the water supplier separates the water from the exhaust gas intake via the exhaust gas intake passage.

10. The exhaust gas purification apparatus for the internal combustion engine according to claim 9 , wherein the water supplier separates the water from the exhaust gas intake via the exhaust gas intake passage when NOx is purified by the catalyst.

11. An exhaust gas purification apparatus for an internal combustion engine, comprising:
a catalyst which is provided at an exhaust gas passage of the internal combustion engine and configured to purify an exhaust gas of the internal combustion engine by using ammonia;
an ammonia supplier that supplies the ammonia to the catalyst, wherein the ammonia supplier includes:
an ammonia producer that produces the ammonia from nitrogen and water;
a nitrogen supplier that separates the nitrogen from air and supply the nitrogen to the ammonia producer;
a water supplier that separates the water from the exhaust gas of the internal combustion engine and supply the water to the ammonia producer, and
an ammonia tank that stores the ammonia produced by the ammonia producer, and

a controller comprising at least one processor configured to cause automatic stop of the internal combustion engine,
wherein the controller prohibits the automatic stop of the internal combustion engine if an amount of ammonia stored in the ammonia tank is less than a predetermined ammonia amount, and
wherein the ammonia producer produces the ammonia and the produced ammonia is stored in the ammonia tank, if the amount of ammonia stored in the ammonia tank is less than the predetermined ammonia amount.

12. The exhaust gas purification apparatus for the internal combustion engine according to claim 11 , wherein the ammonia producer produces the ammonia and the produced ammonia is stored in the ammonia tank, even after the internal combustion engine stops, if an amount of ammonia stored in the ammonia tank is less than a predetermined ammonia amount.

13. An exhaust gas purification apparatus for an internal combustion engine, comprising:
a catalyst which is provided at an exhaust gas passage of the internal combustion engine and configured to purify an exhaust gas of the internal combustion engine by using ammonia;
an ammonia supplier that supplies the ammonia to the catalyst, wherein the ammonia supplier includes:
an ammonia producer that produces the ammonia from nitrogen and water;
a nitrogen supplier that separates the nitrogen from air and supply the nitrogen to the ammonia producer;
a water supplier that separates the water from the exhaust gas of the internal combustion engine and supply the water to the ammonia producer, and

a controller comprising at least one processor configured to cause automatic stop of the internal combustion engine,
wherein the controller prohibits the automatic stop of the internal combustion engine if the ammonia is produced by the ammonia producer.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kato Akira

Classifications

• F02D41/042

  for stopping the engine · CPC title

• F01N2240/25

  an ammonia generator · CPC title

• F01N3/2073 Primary

  Means for generating a reducing substance from the exhaust gases · CPC title

• F01N3/208

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title

• F01N2900/1814

  Tank level · CPC title