# US 9,038,372 B2 · Exhaust purification system of internal combustion engine

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,038,372 B2
- Document ID: US9038372B2
- Status: Granted
- Kind: B2
- Application number: 13/264,062
- Filed: 2010-10-04
- Published: 2013-07-18
- Granted: 2015-05-26
- Earliest claimed: 2010-10-04
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Masao Watanabe; Koutarou Hayashi; Kohei Yoshida; Yuki Bisaiji; Kazuhiro Umemoto
- Inventors: Masao Watanabe; Koutarou Hayashi; Kohei Yoshida; Yuki Bisaiji; Kazuhiro Umemoto
- Web page: https://patentgrep.com/patent/US9038372B2

## CPC

- B01D 53/9422: {for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)}
- B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas}
- F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts}
- F01N 3/0871: {using means for controlling, e.g. purging, the absorbents or adsorbents}
- F01N 13/009: {having two or more separate purifying devices arranged in series}
- F02D 41/0275: {the exhaust gas treating apparatus being a NOx trap or adsorbent}
- F02D 41/405: {with post injections}
- B01D 2251/208: Hydrocarbons
- B01D 2255/1021: Platinum
- B01D 2255/1023: Palladium
- B01D 2255/1025: Rhodium
- B01D 2255/2042: Barium
- B01D 2255/2047: Magnesium
- B01D 2255/2092: Aluminium
- F01N 3/0842: {Nitrogen oxides}
- F01N 2240/30: a fuel reformer
- F01N 2510/06: for exhaust purification, e.g. catalytic reaction
- F01N 2560/06: the means being a temperature sensor
- F01N 2610/03: the substance being hydrocarbons, e.g. engine fuel
- F02D 41/1408: {Dithering techniques}
- Y02T 10/12: Improving ICE efficiencies
- Y02T 10/40: Engine management systems
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

In an internal combustion engine, inside an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. The carrier (50) of the exhaust purification catalyst (13) is formed from a crystallized composite oxide of aluminum and an alkali earth metal. On this carrier (50), precious metal catalysts (51, 52) are carried. The concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to vibrate by within a predetermined range of amplitude of a 200 ppm or more and within a predetermined range of period of 5 second or less, whereby the NOx which is contained in exhaust gas is reduced at the exhaust purification catalyst (13).

## Claims

### Claim 1

An exhaust purification system of an internal combustion engine, the exhaust purification system comprising:
an engine exhaust passage;
an exhaust purification catalyst for reacting NOx contained in exhaust gas and reformed hydrocarbons arranged inside of the engine exhaust passage;
a carrier of the exhaust purification catalyst, wherein the carrier formed from a crystallized composite oxide of aluminum and an alkali earth metal;
a precious metal catalyst carried on the carrier; and
an electronic control unit, wherein the electronic control unit is configured to control a vibration of a concentration of hydrocarbons flowing into the exhaust purification catalyst within a predetermined range of amplitude and within a predetermined range of period, and is configured to control the vibration period of the hydrocarbon concentration longer than the predetermined range of period, wherein
when the electronic control unit controls the vibration of the concentration of hydrocarbons flowing into the exhaust purification catalyst within the predetermined range of amplitude and within the predetermined range of period, the exhaust purification catalyst has a property of chemically reducing the NOx that is contained in exhaust gas without storing, or storing a fine amount of nitrates in the exhaust purification catalyst, and
when the electronic control unit controls the vibration period of the hydrocarbon concentration longer than the predetermined range period, the exhaust purification catalyst has a property of being increased in storage amount of NOx that is contained in exhaust gas.

### Claim 2 (depends on 1)

The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the composite oxide is comprised of barium aluminate (BaAl2O4).

### Claim 3 (depends on 1)

The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the precious metal is comprised of at least platinum (Pt) and rhodium (Rh).

### Claim 4 (depends on 1)

The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the exhaust purification catalyst is comprised of a mixture of a first catalyst in which platinum (Pt) is carried on the carrier made of the composite oxide and a second catalyst in which rhodium (Rh) is carried on zirconia.

### Claim 5 (depends on 4)

The exhaust purification system of an internal combustion engine as claimed in claim 4, wherein the composite oxide is comprised of barium aluminate (BaAl2O4).

### Claim 6 (depends on 1)

The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein inside the exhaust purification catalyst, NOx contained in exhaust gas and reformed hydrocarbons react to produce a reducing intermediate containing nitrogen and hydrocarbons and wherein the vibration period of the hydrocarbon concentration is a vibration period required for continued production of the reducing intermediate.

### Claim 7 (depends on 6)

The exhaust purification system of an internal combustion engine as claimed in claim 6, wherein the vibration period of the hydrocarbon concentration is 0.3 second to 5 second.