Device and method for exhaust gas aftertreatment
4 Assignments
0 Petitions
Accused Products
Abstract
The exhaust gas aftertreatment device according to the invention having a reforming unit for generating hydrogen by steam reforming, partial oxidation of hydrocarbons and/or mixed forms thereof is distinguished by the fact that the reforming unit is arranged directly in the main exhaust gas stream from an internal combustion engine. The steam and residual oxygen which are required for the reforming preferably originate from the exhaust gas. The step of providing the required reducing agents consists in briefly switching the internal combustion engine, which is predominantly operated in lean-burn mode and the exhaust gas from which is undergoing the aftertreatment, to rich-burn mode, allowing reforming by means of the reforming reactor according to the invention using the hydrocarbons that are present in the exhaust gas.
106 Citations
37 Claims
-
1-14. -14. (canceled)
-
15. An exhaust gas aftertreatment device for a motor vehicle, comprising
a reforming unit (1) that is designed to generate hydrogen by at least one of steam reforming and partial oxidation of hydrocarbons, wherein the reforming unit (1) is arranged directly in a main exhaust gas stream (4) of an internal combustion engine, and wherein steam and residual oxygen which are required for reforming are derived from exhaust gas; -
an NOx storage catalytic converter (2) that is arranged in the main exhaust gas stream (4) downstream of the reforming unit (1), wherein the NOx storage catalytic converter (2) is designed to remove NOx from lean exhaust gas by storing the NOx as the lean exhaust gas flows through the NOx storage catalytic converter and to generate N2 by reducing the stored NOx when reducing exhaust gas flows through the NOx storage catalytic converter; and
an SCR catalytic converter (3) that is arranged in the main exhaust gas stream (4) downstream of the NOx storage catalytic converter (2), wherein the SCR catalytic converter (3) is designed to reduce NOx contained in the exhaust gas using NH3 that has been generated by the NOx storage catalytic converter. - View Dependent Claims (16, 17, 18, 19)
-
-
20. An exhaust gas aftertreatment device for a motor vehicle, comprising
a reforming unit (1) that is designed to generate hydrogen by at least one of steam reforming and partial oxidation of hydrocarbons, wherein the reforming unit (1) is arranged directly in a main exhaust gas stream (4) of an internal combustion engine, and wherein steam and residual oxygen which are required for reforming are derived from exhaust gas; -
an NOx storage catalytic converter (2) that is arranged in the main exhaust gas stream (4) downstream of the reforming unit (1), wherein the NOx storage catalytic converter (2) is designed to remove NOx from lean exhaust gas by storing the NOx as the lean exhaust gas flows through the NOx storage catalytic converter and to generate N2 by reducing the stored NOx when reducing exhaust gas flows through the NOx storage catalytic converter; and
an SCR catalytic converter (3) that is arranged in the main exhaust gas stream (4) downstream of the reforming unit (1) but upstream of the NOx storage catalytic converter (2), wherein the SCR catalytic converter (3) is designed to reduce NOx contained in the exhaust gas using NH3 that has been generated by the NOx storage catalytic converter. - View Dependent Claims (21, 22, 23, 24)
-
-
25. An exhaust gas aftertreatment device for a motor vehicle, comprising
a reforming unit (1) that is designed to generate hydrogen by at least one of steam reforming and partial oxidation of hydrocarbons, wherein the reforming unit (1) is arranged directly in a main exhaust gas stream (4) of an internal combustion engine, and wherein steam and residual oxygen which are required for reforming are derived from exhaust gas; - and
an exhaust gas catalytic converter, wherein the exhaust gas catalytic converter is arranged in the main exhaust gas stream (4) downstream of the reforming unit (1), wherein the exhaust gas catalytic converter includes the functions of an NOx storage catalytic converter (2) and an SCR catalytic converter (3). - View Dependent Claims (26, 27, 28, 29)
- and
-
30. An exhaust gas aftertreatment device for a motor vehicle, comprising
a reforming unit (1) that is designed to generate hydrogen by at least one of steam reforming and partial oxidation of hydrocarbons, wherein the reforming unit (1) is arranged directly in a main exhaust gas stream (4) of an internal combustion engine, and wherein steam and residual oxygen which are required for reforming are derived from exhaust gas; - and
a DENOX catalytic converter (8) that is arranged in the main exhaust gas stream (4) downstream of the reforming unit (1). - View Dependent Claims (31)
- and
-
32. A method for operating an exhaust gas aftertreatment device, the method comprising:
-
using hydrogen to reduce NOx in exhaust gas from an internal combustion engine of a motor vehicle by way of a catalytic converter;
generating the hydrogen onboard the motor vehicle by at least one of steam reforming and partial oxidation of hydrocarbons, wherein the steam and residual oxygen which are required for the reforming originates from the exhaust gas; and
carrying out the reforming by a reforming unit arranged directly in a main exhaust gas stream (4) from the internal combustion engine. - View Dependent Claims (33, 34, 35, 36, 37)
-
Specification