Abstract:
A system and method are disclosed for desulfating an oxidation catalyst in an aftertreatment system of a multifuel internal combustion engine. The oxidation catalyst can be desulfated in response to one or more desulfation triggering events. The desulfation process includes providing hydrocarbons from one or all of the multiple fuel sources to an upstream oxidation catalyst. The hydrocarbons react with the exhaust gas within the upstream oxidation catalyst to deplete oxygen in the exhaust flow to thereby reduce the desulfation temperature of the oxidation catalyst while elevating a temperature of the exhaust gas to a desulfation temperature range.
Abstract:
System, apparatus, and methods are disclosed for treating a reduction catalyst that has been exposed to an amount of sulfur. The treating of the reduction catalyst includes providing a fluid stream at a position upstream of the reduction catalyst. The fluid stream includes a temperature and a reductant amount, and the reductant amount includes an amount of urea, ammonia, or hydrocarbons.
Abstract:
An apparatus includes a dosing module structured to suspend dosing in an exhaust aftertreatment system; a selective catalytic reduction (SCR) inlet NOx module structured to interpret SCR inlet NOx data and an SCR inlet temperature; a SCR outlet NOx module structured to interpret SCR outlet NOx data; and a system diagnostic module structured to determine an efficiency of a SCR system based on the SCR inlet and outlet NOx data over a range of SCR temperatures, wherein the system diagnostic module is further structured to determine a state of at least one of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and the SCR system based on the SCR efficiency at an elevated SCR temperature range and the SCR efficiency at a relatively lower SCR temperature range relative to a high SCR efficiency threshold and a low SCR efficiency threshold.
Abstract:
Unique SCR catalyst including multiple washcoat formulations with differing performance characteristics are disclosed. One exemplary embodiment is an apparatus including a catalyst substrate defining a plurality of flow channels leading from an inlet to an outlet, a first washcoat composition distributed over a first portion of the flow channels, and a second washcoat composition distributed over a second portion of the flow channels. The first washcoat composition has a lower ammonia storage density than the second washcoat composition.
Abstract:
An apparatus includes a dosing module structured to suspend dosing in an exhaust aftertreatment system; a selective catalytic reduction (SCR) inlet NOx module structured to interpret SCR inlet NOx data and an SCR inlet temperature; a SCR outlet NOx module structured to interpret SCR outlet NOx data; and a system diagnostic module structured to determine an efficiency of a SCR system based on the SCR inlet and outlet NOx data over a range of SCR temperatures, wherein the system diagnostic module is further structured to determine a state of at least one of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and the SCR system based on the SCR efficiency at an elevated SCR temperature range and the SCR efficiency at a relatively lower SCR temperature range relative to a high SCR efficiency threshold and a low SCR efficiency threshold.
Abstract:
An exhaust aftertreatment system configured to reduce nitrous oxide (N2O) formation includes a first selective catalytic reduction (SCR) catalyst. The first SCR catalyst is configured for low N2O formation and low ammonia (NH3) storage capacity. A second SCR catalyst is positioned downstream of the first SCR catalyst. The second SCR catalyst is configured for high NH3 storage capacity.
Abstract:
Systems, methods and apparatus are disclosed for targeted regeneration of a catalyst device in an exhaust aftertreatment system of an internal combustion engine. The targeted regeneration can include interpreting, initiating, and/or completing a regeneration event for an SCR catalyst or other type of catalyst in response to a catalyst deactivation condition. A catalyst regeneration event includes at least one of exposing the catalyst to a sufficiently high temperature over a time period that removes contaminants from the catalyst and manipulation of the exhaust gas composition to initiate and/or accelerate removal of contaminants from the catalyst.
Abstract:
An exhaust aftertreatment system configured to reduce nitrous oxide (N2O) formation includes a first selective catalytic reduction (SCR) catalyst. The first SCR catalyst is configured for low N2O formation and low ammonia (NH3) storage capacity. A second SCR catalyst is positioned downstream of the first SCR catalyst. The second SCR catalyst is configured for high NH3 storage capacity.
Abstract:
Systems, methods, and apparatuses are provided for determining an SCR component sulfur value, determining whether the SCR component sulfur value exceeds a sulfur regeneration threshold and increasing an engine NO amount incident to an SCR catalyst in response to the SCR component sulfur value exceeding the sulfur regeneration threshold.
Abstract:
An apparatus includes a dosing module structured to suspend dosing in an exhaust aftertreatment system; a selective catalytic reduction (SCR) inlet NOx module structured to interpret SCR inlet NOx data and an SCR inlet temperature; a SCR outlet NOx module structured to interpret SCR outlet NOx data; and a system diagnostic module structured to determine an efficiency of a SCR system based on the SCR inlet and outlet NOx data over a range of SCR temperatures, wherein the system diagnostic module is further structured to determine a state of at least one of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and the SCR system based on the SCR efficiency at an elevated SCR temperature range and the SCR efficiency at a relatively lower SCR temperature range relative to a high SCR efficiency threshold and a low SCR efficiency threshold.