An exhaust gas post treatment system for an internal combustion engine, in particular a heavy fuel oil-powered engine, including an SCR catalyst, using ammonia as a reducing agent for the denitration of the exhaust gas, and a device positioned upstream of the SCR catalyst by which ammonia or an ammonia precursor substance, which is converted to ammonia, introduced upstream of the SCR catalyst. Downstream of the SCR catalyst an exhaust gas scrubber is positioned, by which excess ammonia, contained in the exhaust gas leaving the SCR catalyst, together with sulfur oxides, can be scrubbed out of the exhaust gas forming ammonium salts while maintaining a pH value of approximately 6. For the control thereof, a bypass around the SCR catalyst can be provided as a westgate, or comprising an additional SCR catalyst.

An exhaust gas post treatment system for an internal combustion engine, in particular a heavy fuel oil-powered engine, including an SCR catalyst, using ammonia as a reducing agent for the denitration of the exhaust gas, and a device positioned upstream of the SCR catalyst by which ammonia or an ammonia precursor substance, which is converted to ammonia, introduced upstream of the SCR catalyst. Downstream of the SCR catalyst an exhaust gas scrubber is positioned, by which excess ammonia, contained in the exhaust gas leaving the SCR catalyst, together with sulfur oxides, can be scrubbed out of the exhaust gas forming ammonium salts while maintaining a pH value of approximately 6. For the control thereof, a bypass around the SCR catalyst can be provided as a westgate, or comprising an additional SCR catalyst.

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 25 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m.sup.3/h)/(m.sup.3/h).

A method for removing ammonia from a gas stream divides the gas steam into a plurality of separate gas streams and sprays a dilute acid solution into the streams. The acid solution is aqueous sulfuric acid and ammonium sulfate is produced. A device is used to divide the gas stream, the device having a plurality of conduits in fluid communication with a plenum. Spray nozzles are located in each conduit to spray the acid solution into the gas streams. The device creates less than 10 Pa back pressure to the gas stream.

A method for removing ammonia from a gas stream divides the gas steam into a plurality of separate gas streams and sprays a dilute acid solution into the streams. The acid solution is aqueous sulfuric acid and ammonium sulfate is produced. A device is used to divide the gas stream, the device having a plurality of conduits in fluid communication with a plenum. Spray nozzles are located in each conduit to spray the acid solution into the gas streams. The device creates less than 10 Pa back pressure to the gas stream.

A rechargeable battery assembly for a vehicle has a metal-air rechargeable battery and a filter device to condition inlet air supplied to the metal-air rechargeable battery such that the inlet air exhibits predetermined inlet air values. The filter device has one or more filter elements, one or more sensor devices that determine at least one inlet air parameter, and one or more valve devices. A control system is coupled to the sensor devices so as to receive sensor signals for the at least one inlet air parameter and is coupled to the valve devices. The control system adjusts, depending on the received sensor signals, the valve devices in order to control the predetermined inlet air value in that the inlet air is guided through the filter elements; is guided past the filter elements; or is guided to an air outlet for regenerating the filter elements.

A rechargeable battery assembly for a vehicle has a metal-air rechargeable battery and a filter device to condition inlet air supplied to the metal-air rechargeable battery such that the inlet air exhibits predetermined inlet air values. The filter device has one or more filter elements, one or more sensor devices that determine at least one inlet air parameter, and one or more valve devices. A control system is coupled to the sensor devices so as to receive sensor signals for the at least one inlet air parameter and is coupled to the valve devices. The control system adjusts, depending on the received sensor signals, the valve devices in order to control the predetermined inlet air value in that the inlet air is guided through the filter elements; is guided past the filter elements; or is guided to an air outlet for regenerating the filter elements.

An ammonia-containing tail gas absorption system, comprising at least two sets of absorption devices, wherein at least two transport pipelines are provided at inlets of some of the absorption devices, and the transport pipelines are used to communicate the absorption devices with an ammonia-containing tail gas outlet of a reactor or other absorption devices. Valves are provided on the transport pipelines, and the valves are used to control the connection and disconnection of the transport pipelines so as to switch the series-parallel relationship between the sets of absorption devices.

An ammonia-containing tail gas absorption system, comprising at least two sets of absorption devices, wherein at least two transport pipelines are provided at inlets of some of the absorption devices, and the transport pipelines are used to communicate the absorption devices with an ammonia-containing tail gas outlet of a reactor or other absorption devices. Valves are provided on the transport pipelines, and the valves are used to control the connection and disconnection of the transport pipelines so as to switch the series-parallel relationship between the sets of absorption devices.

A gas combustion treatment device that subjects an ammonia-containing gas, a hydrogen cyanide-containing gas, and a hydrogen sulfide-containing gas to combustion treatment includes: a first combustion unit configured to introduce therein fuel, the ammonia-containing gas, the hydrogen cyanide-containing gas, and air and burn and reduce the fuel and the gases at an air ratio lower than 1; a second combustion unit provided downstream of the first combustion unit and configured to burn and reduce, in a reducing atmosphere, nitrogen oxide in a first combustion gas sent from the first combustion unit; and a third combustion unit provided downstream of the second combustion unit and configured to introduce therein hydrogen sulfide-containing gas with air in addition to a second combustion gas sent from the second combustion unit.