Systems, apparatuses, and methods include predicting a sulfur exposure of one or more copper-zeolite catalysts deployed in an exhaust aftertreatment system; comparing the predicted sulfur exposure to a predefined sulfur exposure threshold; and responsive to the determination, heating the exhaust aftertreatment catalyst to a predefined heat treatment temperature for a predefined time period to desulfate the one or more copper-zeolite catalysts.

Various embodiments of the teachings herein include methods for determining the sulfur content in an exhaust tract of a motor vehicle. The method may include: determining a change in the nitrogen oxide abatement efficiency of a coated particulate filter arranged in the exhaust tract and/or a determined ammonia storage capacity change of a coated particulate filter arranged in the exhaust tract; comparing the determined change to a threshold value; identifying an excessive sulfur content if the comparison shows that the determined change exceeds the threshold value; and undertaking one or more corrective actions in response to identifying an excessive sulfur content.

A method for controlling an exhaust gas purification system that can effectively implement desulfation of a selective catalytic reduction (SCR) device. The method for controlling an exhaust gas purification system, in which a diesel particulate filter (DPF) and an SCR device are combined, may include calculating a sulfur poisoning amount of the SCR device and an amount of soot loading in the DPF; and increasing a temperature of the SCR device to a desulfation temperature when the sulfur poisoning amount is greater than a first predetermined value and the amount of soot loading is less than a second predetermined value.

The subject matter of the disclosure relates to a method of diagnosing NOx storage catalyst during the operation of a motor vehicle. The method uses two diagnosis sub-methods having various sensitivities with respect to sulfur contamination of the NOx storage catalyst. The results of the two sub-methods are used to ascertain proportions of aging of the NOx storage catalyst resulting from thermal aging and sulfur contamination.

An exhaust purification system includes: an NOx reduction type catalyst, which is provided in an exhaust system; a temperature acquisition unit, which acquires a catalyst temperature of the NOx reduction type catalyst; and a regeneration treatment unit, which executes a catalyst regeneration to recover an NOx purification capacity, wherein the regeneration treatment unit alternately executes a rich control, in which an exhaust air fuel ratio is set to a rich state to raise a temperature of the NOx reduction type catalyst to a predetermined target temperature, and a lean control, in which the exhaust air fuel ratio is set to a lean state to lower the temperature of the NOx reduction type catalyst, and sets an execution period of the lean control based on a deviation between the catalyst temperature acquired by the temperature acquisition unit during the previous rich control and the target temperature.

A catalyst regeneration processing apparatus for an internal-combustion engine includes an electronic control unit. The electronic control unit is configured to determine whether a gap is equal to a predetermined degree or less, the gap being a difference between (a) a progress degree of heat deterioration of a NOx catalyst in a predetermined time in a case of assuming that a regeneration process is executed for the predetermined time and (b) a progress degree of heat deterioration of the NOx catalyst in the predetermined time in a case of assuming that the regeneration process is not executed. The electronic control unit is configured to execute the regeneration process in a case of determining that the gap is equal to the predetermined degree or less, even when a sulfur poisoning quantity does not exceed a permissible upper limit quantity.

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.

The sulfur poisoning of a three-way catalyst is intended to be detected with a high degree of accuracy. It is determined whether the sulfur poisoning of the three-way catalyst is made to be recovered, or a determination is made that the degree of sulfur poisoning of the three-way catalyst is higher when the concentration of NOx detected by an NOx sensor is high than when it is low, based on the concentration of NOx downstream of the three-way catalyst after the air fuel ratio of the exhaust gas flowing into the three-way catalyst has been made to change from a rich air fuel ratio to a lean air fuel ratio and before the air fuel ratio of the exhaust gas flowing out of the three-way catalyst changes to a lean air fuel ratio.

A control apparatus for an internal combustion engine is provided. The control apparatus includes a temperature sensor and an electronic control unit. The temperature sensor is configured to detect the temperature of an exhaust gas control apparatus. The electronic control unit is configured to: estimate a sulfuric compound accumulation amount on the exhaust gas control apparatus; and when a specific condition in which the sulfuric compound accumulation amount is equal to or larger than a predetermined accumulation amount and the temperature of the exhaust gas control apparatus is equal to or higher than a predetermined temperature or more is satisfied, control an intake air amount adjuster such that an intake air amount when the specific condition is satisfied is increased as compared to the intake air amount when the specific condition is not satisfied in the same operation state.