# US 2015/0143799 A1 · SYSTEM AND METHOD OF DEFULFURIZING LEAN NOx TRAP

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

- Number: US 2015/0143799 A1
- Document ID: US20150143799A1
- Status: Published application
- Kind: A1
- Application number: 14/313,974
- Filed: 2014-06-24
- Published: 2015-05-28
- Earliest claimed: 2013-11-22
- Assignees: Hyundai Motor Company
- Applicants: Hyundai Motor Company
- Inventors: Jin Ha Lee
- Web page: https://patentgrep.com/patent/US20150143799A1

## CPC

- F01N 9/002: {of filter regeneration}
- B01D 53/50: Sulfur oxides (B01D53/60 takes precedence)
- B01D 53/54: Nitrogen compounds
- B01D 53/60: Simultaneously removing sulfur oxides and nitrogen oxides
- B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas}
- B01D 53/9477: {with catalysts positioned on separate bricks, e.g. exhaust systems}
- B01D 53/9481: {Catalyst preceded by an adsorption device without catalytic function for temporary storage of contaminants, e.g. during cold start}
- B01D 53/9495: {Controlling the catalytic process}
- F01N 3/023: using means for regenerating the filters, e.g. by burning trapped particles
- F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts}
- F01N 3/0821: {combined with particulate filter}
- F01N 3/0842: {Nitrogen oxides}
- F01N 3/0885: {Regeneration of deteriorated absorbents or adsorbents, e.g. desulfurization of NOx traps}
- F01N 3/208: {Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent}
- 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 53/944: {Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445)}
- F01N 2260/04: for regeneration or reactivation, e.g. of catalyst
- F01N 2900/1404: Exhaust gas temperature
- F01N 2900/1602: Temperature of exhaust gas apparatus
- F01N 2900/1606: Particle filter loading or soot amount
- F01N 2900/1612: SOx amount trapped in catalyst
- Y02T 10/12: Improving ICE efficiencies
- Y02T 10/40: Engine management systems
- 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)
- 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)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A system of dusulfurizing an LNT may control desulfurization of the LNT provided in an apparatus of purifying exhaust gas, in which the LNT may be adapted to absorb nitrogen oxide (NOx) contained in the exhaust gas at a lean air/fuel ratio and to release the absorbed nitrogen oxide and reduce the nitrogen oxide contained in the exhaust gas or the released nitrogen oxide at a rich air/fuel ratio and the apparatus of purifying exhaust gas may further include a particulate filter trapping particulate matter contained in the exhaust gas as soot and regenerated by burning the trapped soot when a regeneration condition is satisfied, and a controller controlling desulfurization of the LNT and regeneration of the particulate filter.

## Claims

### Claim 1

A system of desulfurizing a lean NOx trap (LNT) provided in an apparatus of purifying exhaust gas, the system comprising:
the LNT adapted to absorb nitrogen oxide (NOx) contained in the exhaust gas at a lean air/fuel ratio and to release the absorbed nitrogen oxide and reduce the nitrogen oxide contained in the exhaust gas or the released nitrogen oxide at a rich air/fuel ratio; and
the apparatus of purifying exhaust gas comprising:
a particulate filter trapping particulate matter contained in the exhaust gas as soot and regenerated by burning the trapped soot when a regeneration condition is satisfied; and
a controller controlling desulfurization of the LNT and regeneration of the particulate filter,
wherein the controller proceeds to desulfurize the LNT when a regeneration amount of the soot is greater than or equal to a predetermined regeneration amount during the regeneration of the particulate filter, stops the desulfurization of the LNT when a desulfurization stop condition is satisfied during the desulfurization of the LNT, and prepares to regenerate the particulate filter again when desulfurization stop numbers from previous completion of the desulfurization up to the present are greater than or equal to a predetermined value and a sulfur poisoning amount is less than a predetermined sulfur poisoning amount.

### Claim 2 (depends on 1)

The system of claim 1, wherein the controller proceeds to regenerate the particulate filter again when the desulfurization of the LNT is possible after preparing to regenerate the particulate filter again.

### Claim 3 (depends on 2)

The system of claim 2, wherein the controller issues a first warning which suggests desulfurization driving before proceeding to regenerate the particulate filter again.

### Claim 4 (depends on 1)

The system of claim 1, wherein the controller completely stops the desulfurization and the regeneration of the particulate filter and enters a normal driving mode when the desulfurization stop numbers from the previous completion of the desulfurization up to the present are smaller than the predetermined value.

### Claim 5 (depends on 1)

The system of claim 1, wherein the controller prepares to regenerate the particulate filter again when the desulfurization stop numbers from the previous completion of the desulfurization up to the present are greater than or equal to the predetermined value, the sulfur poisoning amount is larger than or equal to the predetermined sulfur poisoning amount, and a NOx purification rate is greater than a predetermined NOx purification rate.

### Claim 6 (depends on 5)

The system of claim 5, wherein the controller proceeds to regenerate the particulate filter again when the desulfurization of the LNT is possible after preparing to regenerate the particulate filter again.

### Claim 7 (depends on 6)

The system of claim 6, wherein the controller issues a first warning which suggests desulfurization driving before proceeding to regenerate the particulate filter again.

### Claim 8 (depends on 1)

The system of claim 1, wherein the controller issues a second warning which suggests visiting a service center when the desulfurization stop numbers from the previous completion of the desulfurization up to the present are greater than or equal to the predetermined value, the sulfur poisoning amount is larger than or equal to the predetermined sulfur poisoning amount, and a NOx purification rate is smaller than or equal to a predetermined NOx purification rate.

### Claim 9

A method of desulfurizing a lean NOx trap (LNT) which absorbs or releases/reduces nitrogen oxide contained in exhaust gas according to air/fuel ratio, wherein the LNT is provided in an apparatus of purifying the exhaust gas, and the apparatus of purifying exhaust gas further comprises a particulate filter trapping particulate matter contained in the exhaust gas, the method comprises:
regenerating the particulate filter;
determining whether a soot regeneration amount of the particulate filter is greater than or equal to a predetermined regeneration amount;
performing desulfurization of the LNT when the soot regeneration amount of the particulate filter is greater than or equal to the predetermined regeneration amount;
determining whether a desulfurization stop condition of the LNT is satisfied;
stopping the desulfurization of the LNT when the desulfurization stop condition of the LNT is satisfied;
determining whether desulfurization stop numbers from previous completion of the desulfurization up to the present are greater than or equal to a predetermined value;
determining whether a sulfur poisoning amount is less than a predetermined sulfur poisoning amount when the desulfurization stop numbers are greater than or equal to the predetermined value; and
preparing to regenerate the particulate filter again when the sulfur poisoning amount is less than the predetermined sulfur poisoning amount.

### Claim 10 (depends on 9)

The method of claim 9, wherein the regeneration of the particulate filter is performed again when the desulfurization of the LNT is possible after preparing to regenerate the particulate filter again.

### Claim 11 (depends on 10)

The method of claim 10, before performing the regeneration of the particulate filter again, further comprising issuing a first warning which suggests desulfurization driving.

### Claim 12 (depends on 9)

The method of claim 9, when the desulfurization stop number are smaller than the predetermined value, further comprising entering a normal driving mode.

### Claim 13 (depends on 9)

The method of claim 9, further comprising:
determining whether a NOx purification rate is greater than a predetermined NOx purification rate when the sulfur poisoning amount is larger than the predetermined sulfur poisoning amount; and
issuing a second warning which suggests visiting a service center when the NOx purification rate is smaller than or equal to the predetermined NOx purification rate.

### Claim 14 (depends on 13)

The method of claim 13, further comprising preparing to regenerate the particulate filter again when the NOx purification rate is greater than the predetermined NOx purification rate.

### Claim 15 (depends on 14)

The method of claim 14, wherein the regeneration of the particulate filter is performed again when the desulfurization of the LNT is possible after preparing to regenerate the particulate filter again.

### Claim 16 (depends on 15)

The method of claim 15, before performing the regeneration of the particulate filter again, further comprising issuing a first warning which suggests desulfurization driving.