A method for monitoring a nitrogen oxide storage catalyst in an exhaust system of an internal combustion engine, in which a reduction of nitrogen oxides is carried out by means of a reducing agent is disclosed. During a regeneration of the nitrogen oxide storage catalyst, the following steps are carried out: A measurement is carried out, from which a slip rate of the reducing agent not absorbed in the nitrogen oxide storage catalyst is ascertained. In addition, at least one expected value for the slip rate of the reducing agent is ascertained from at least one model. Subsequently, a computation of a monitoring variable is carried out by means of the slip rate of the reducing agent ascertained from the measurement and the at least one expected value for the slip rate of the reducing agent. Finally, a diagnosis of the storage capacity of the nitrogen oxide storage catalyst is carried out on the basis of the monitoring variable.

A compression ignition internal combustion engine system includes an engine and an exhaust system with an upstream exhaust conduit, and an oxidation catalyst device (DOC). Systems and methods of desulfating the oxidation catalyst by the injection of a lightoff fluid to promote ignition of uncombusted fuel in the exhaust stream are disclosed.

An automotive catalytic converter includes a three-way catalyst having Rh as the only precious metal configured as a front zone and a three-way catalyst having a mixture of Rh and Pd, Pt, or both configured as a rear zone, such that an exhaust gas from an internal combustion engine passes through the front zone before passing through the rear zone to minimize sulfur poisoning of the catalytic converter.

A controller for an internal combustion engine includes processing circuitry that performs a dither control process on condition that a temperature increase request of a catalyst is made. The processing circuitry operates fuel injection valves so that during the dither control process, one or more cylinders are lean combustion cylinders in a first period and another one or more cylinders are rich combustion cylinders and so that the average value of an exhaust gas-fuel ratio is a target air-fuel ratio in a second period including the first period. The dither control process is restricted in a manner that, on condition that the rich process is performed, the degree of richening of the richest exhaust gas-fuel ratio of exhaust gas-fuel ratios in the cylinders is reduced.

Various embodiments may include a method for regenerating a particle filter comprising: increasing a measured exhaust-gas temperature from a normal operation level to above a desorption start temperature defined by initiating release of sulfur compounds accumulated in the particle filter; monitoring a particle mass in the exhaust-gas flow downstream of the particle filter; comparing the particle mass to a predefined threshold value above which the formation of white smoke can be expected; if the threshold value is exceeded, setting the exhaust-gas temperature to a desorption temperature for release of sulfur compounds until the particle mass falls below the threshold; if the particle mass threshold value is not exceeded, setting the exhaust-gas temperature to a regeneration temperature for burning-off of the particle loading of the particle filter for a predetermined time period; and after the time period has elapsed, ending the regeneration by lowering the temperature to the normal operation level.

A scrubber for cleaning of a gas comprises a casing enclosing a scrubbing chamber. The casing comprises a gas inlet into and a gas outlet out from the scrubbing chamber. A gas flow of the gas flows through the scrubbing chamber in a flow direction from the gas inlet to the gas outlet. A deflector device is provided in the scrubbing chamber between the gas inlet and the gas outlet and forms a passage between the deflector device and the casing. A spraying nozzle is arranged between the gas outlet and the deflector device for spraying a scrubbing liquid into the scrubbing chamber and the gas flow. An inner shield extends between the casing and the deflector device, surrounds the deflector device at least partly, and forms a gap with the casing. Scrubbing liquid may flow through the gap.

The present application relates to a system and method to determine a total flow rate Q.sub.tot of a washing liquid at a washing liquid inlet of an exhaust gas cleaning unit installed in a marine vessel, the exhaust gas cleaning unit comprising a scrubber pipe and two or more spraying nozzles mounted at different height levels in the scrubber pipe, being adapted to spray washing liquid into the exhaust gas present in the scrubber pipe and being operated by a valve adapted to open and to close the respective spraying nozzle. The system comprises at least one pressure sensor arranged to measure the pressure P outside the scrubber pipe before the valve operating the uppermost active spraying nozzle, and a process controller calculating the total flow rate Q.sub.tot of the washing liquid at the exhaust gas inlet of the exhaust gas cleaning unit by summing up the flow rate Q.sub.ind of the washing liquid flowing through each of the individual active spraying nozzles.

A controlling method of exhaust gas purification system to which a lean combustion engine is applied and an LNT device, a DPF or an SDPF, and an SCR device are provided includes detecting vehicle information and determining whether the vehicle information satisfies nitrogen oxide desorption condition of the LNT device; desorbing the nitrogen oxide until the nitrogen oxide of the LNT reaches predetermined reference amount through engine rich combustion when vehicle information satisfies the nitrogen oxide desorption condition of the LNT device; injecting urea to purify the nitrogen oxide after a first period after ending of desorption of the nitrogen oxide of the LNT; desorbing sulfide of the LNT through the engine rich combustion; and injecting urea to purify the nitrogen oxide after a second period after ending of desorption of the sulfide rich combustion of the LNT.

A fluid cleaning and filtering system includes a pre-treatment system before a force generation turbine to condense and pretreat gases and particulate matter; a flow rectifier before a tangential inlet; diffuser pipes for compressing the gases and particulate matter therein and project same into the deflector disks, diffuser pipes at an outlet of the so-called condenser, a purger, a diffuser and a deflector; a force generation turbine; an energy generator using torque from the turbine rotor; an internal energy generator; a flow rectifier in a first tangential inlet and a flow rectifier in a second tangential inlet; a new full-cone atomizer nozzle to wet particles and clean gases; a diffuser in the condensers and a deflector disk for the condensers.

Presented is a process for the off-line regeneration of a deactivated nitrogen oxide decomposition catalyst of a selective catalytic reduction system that is a component of a flue gas treating system. The selective catalytic reduction system is isolated to allow for removal and replacement of deactivated SCR catalyst. The removed SCR catalyst may be regenerated off-line from the flue gas treating system. The off-line regenerated SCR catalyst can be used as a replacement SCR catalyst.