An exhaust system of an internal combustion engine of a motor vehicle includes a particulate filter where particles are filterable out from the exhaust gas by the particulate filter. A selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine is flowable for denitrifying the exhaust gas from the internal combustion engine is disposed downstream of the particulate filter. The exhaust gas of the internal combustion engine is heatable by a combustor at a point disposed upstream of the SCR catalytic converter and downstream of the particulate filter where the combustor provides an exhaust gas of the combustor. Particles are filterable out from the exhaust gas of the combustor by a filter element.

The invention relates in particular to a method for adjusting the loading (19) of a particulate filter (9) and to an assembly designed to carry out the method, wherein the exhaust gas aftertreatment unit (8) comprises at least two SCR systems (11, 12) and a particulate filter (9), a first operating material amount being introduced in a metered manner before the first SCR system (11), and a second operating material amount being introduced in a metered manner before the second SCR system (12), the operating material being convertible into a reducing agent. The state of loading of the particulate filter (9) is determined using a model, and, if the determined state of loading is below a previously defined loading range (16), the first operating material amount is adjusted in such a way that the amount of reducing agent is greater than or equal to the amount of reducing agent necessary for nitrogen oxide reduction in accordance with the reaction stoichiometry in the first SCR system (11), and/or, if the determined state of loading is above a previously defined loading range (16), the first operating material amount is adjusted in such a way that the amount of reducing agent is less than the amount of reducing agent necessary for nitrogen oxide reduction in accordance with the reaction stoichiometry in the first SCR system (11).

Provided are an exhaust purification device and an exhaust purification method which can achieve improved fuel efficiency. The exhaust purification device (100) is equipped with: a DOC (5) for occluding hydrocarbons in an exhaust gas; a DPF (6) that is provided downstream from the DOC (5) and is for trapping particulate matter in the exhaust gas; and an ECU (10) for determining, in accordance with the amount of occluded hydrocarbons in the DOC (5), a start time for a regeneration process for removing particulate matter accumulated in the DPF (6).

A process is provided for regenerating an exhaust gas after-treatment device in an exhaust line of an internal combustion engine arrangement, the exhaust line including a particle filter. The process includes identifying when soot loading of the particle filter exceeds a predetermined level. After that, temperature of exhaust gases at the particle filter is maintained within a first temperature range until at least one of a predetermined period of time has lapsed or a determination is made that soot loading of the particle filter is below the predetermined level. After that, the temperature of the exhaust gases at the particle filter is increased to within a second temperature range above the first temperature range. An internal combustion engine arrangement is also disclosed.

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s403); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

A catalytic aftertreatment system for a diesel engine exhaust gas is described. The system comprises a diesel oxidation catalyst (DOC) and an aftertreatment device located downstream of the diesel oxidation catalyst (DOC), which aftertreatment device requires periodic heat treatment, and means to generate a temperature increase within the aftertreatment device, said diesel oxidation catalyst (DOC) comprising an upstream zone of length from 0.5 to 2 inches (12.7-50.81 mm) of higher oxidation activity for hydrocarbons (HC) than the remainder of the diesel oxidation catalyst (DOC).

An exhaust gas purification system for an internal combustion engine is provided with a filter including a selective catalytic reduction NOx catalyst carried thereon. Further, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N.sub.2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. A filter regeneration process execution unit is programmed to control the temperature of the post-catalyst to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst.

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s4103); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC) or a passive NOx adsorber (PNA), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst, which may also include an additional PNA.