Method and apparatus for reducing oxides of nitrogen in the exhaust gas of an internal combustion engine
AssigneeHonda Giken Kogyo Kabushiki Kaisha
InventorArthur J. Jacobsen
Life of this patent
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Abstract
A method and apparatus for reducing oxides of nitrogen in the exhaust of an internal combustion engine. The apparatus includes a pressurizing unit for providing compressed air to a pressure swing adsorption unit. The pressure swing adsorption removes nitrogen from the air to produce nitrogen-reduced air, which is then supplied to the engine. The pressurizing unit may be a compressor, a turbocharger, or a supercharger. The engine may utilize exhaust gas recirculation and fuel injection with air assist.
Claims27
An engine system comprising:
- an internal combustion engine having a plurality of cylinders, each of which has an intake port and an exhaust port;
- an air intake system through which air is directed to the cylinders of the engine;
- an exhaust system for directing exhaust gas generated by combustion in the cylinders to the outside atmosphere;
- a pressurizing unit operable to compress air;
- and
- a pressure swing adsorption unit having an inlet connected to the pressurizing unit to receive compressed air therefrom, and an outlet connected to the air intake system of the engine, said pressure swing adsorption unit including an adsorbent bed cyclable between a production mode, wherein nitrogen in the air is adsorbed by the adsorbent bed at an elevated pressure to produce nitrogen-reduced air, and a regeneration mode, wherein nitrogen is desorbed from the adsorbent bed at a reduced pressure to produce nitrogen gas, said nitrogen-reduced air from the production mode of the adsorbent bed being supplied to the air intake system of the engine.
An air supply system for an internal combustion engine, said air supply system comprising:
- a pressurizing unit operable to compress air;
- an air filter through which air may be directed to the pressurizing unit, said air filter being operable to filter the air to remove particulates therein;
- an air dryer connected between the air filter and the pressurizing unit, said air dryer containing a desiccant for removing water from the filtered air;
- and
- a pressure swing adsorption unit having an inlet connected to the pressurizing unit to receive compressed air therefrom, and an outlet for connection to an air intake system of the engine, said pressure swing adsorption unit including an adsorbent bed cyclable between a production mode, wherein nitrogen in the air is adsorbed by the adsorbent bed at an elevated pressure to produce nitrogen-reduced air, and a regeneration mode, wherein nitrogen is desorbed from the adsorbent bed at a reduced pressure to produce nitrogen gas, said nitrogen-reduced air from the production mode of the adsorbent bed exiting the pressure swing adsorption unit through the outlet.
A method of reducing NOx in the exhaust of an internal combustion engine, said method comprising the steps of:
- (a) providing an adsorbent bed;
- (b) pressurizing air;
- (c) passing the pressurized air through the adsorbent bed, thereby raising the pressure of the adsorbent bed and causing the adsorbent bed to adsorb nitrogen from the air to produce nitrogen-reduced air;
- (d) directing the nitrogen-reduced air into an air intake system of the engine;
- (e) reducing the pressure in the adsorbent bed such that nitrogen desorbs from the adsorbent bed;
- and
- (f) directing the nitrogen out of the adsorbent bed.
Dependencies are inferred from the claim text.