Systems and methods for desulfation of catalysts included in aftertreatment systems

Patent metadata

Field	Value
Publication number	US-11867106-B2
Application number	US-202318197930-A
Country	US
Kind code	B2
Filing date	May 16, 2023
Priority date	Apr 9, 2019
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured to, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius, cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period, and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.

First claim

What is claimed is:

1. An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content, the aftertreatment system comprising:
an oxidation catalyst;
a filter disposed downstream of the oxidation catalyst; and
a controller configured to, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied:
cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius,
cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period, and
after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius,
wherein the desulfation condition being satisfied comprises a measured exotherm of the oxidation catalyst being smaller than the exothermal efficiency curve of a non-sulfated oxidation catalyst.

2. The aftertreatment system of claim 1 , wherein the controller is configured to, in response to determining that the filter is to be regenerated and the desulfation condition is not satisfied:
cause increase of the temperature of the oxidation catalyst to the second regeneration temperature without maintaining the oxidation catalyst at the first regeneration temperature for the first time period; and
cause insertion of hydrocarbons into the oxidation catalyst.

3. The aftertreatment system of claim 2 , further comprising:
an oxidation catalyst heater that is coupled to the oxidation catalyst and configured to be controlled by the controller to cause the temperature of the oxidation catalyst to increase and be maintained.

4. The aftertreatment system of claim 1 , further comprising:
an oxidation catalyst heater that is coupled to the oxidation catalyst and configured to be controlled by the controller to cause the temperature of the oxidation catalyst to increase and be maintained.

Assignees

• Cummins Emission Solutions Inc

Inventors

• Cunningham Michael
• Yezerets Aleksey
• Li Junhui
• Cramer James A

Classifications

• F01N3/103 Primary

  Oxidation catalysts for HC and CO only · CPC title

• B01D53/9477

  with catalysts positioned on separate bricks, e.g. exhaust systems · CPC title

• B01D53/9495

  Controlling the catalytic process · CPC title

• B01D53/96

  Regeneration, reactivation or recycling of reactants · CPC title

• F01N3/021

  by means of filters · CPC title