METHOD OF EXHAUST GAS PURIFICATION OF ENGINE WITH COMPRESSION IGNITION Russian patent published in 2019 - IPC F01N3/10 F01N3/20 

FIELD: machine building.

SUBSTANCE: invention relates to method of exhaust gas purification of engine with compression ignition. Method includes injection of an aqueous solution of urea into exhaust gas upstream of a first catalyst, which is a selective catalytic reduction catalyst NOx (SCR) containing vanadium oxide on a titanium oxide substrate. Said first catalyst is located close to the engine and is in close proximity to the second catalyst, which is a diesel oxidation catalyst (DCO) containing platinum on titanium oxide and/or aluminum oxide. First operating mode at exhaust gas temperature between 150 and 220 °C consists in catalytic hydrolysis of aqueous solution of urea to ammonia reducing agent by contact with first catalyst and further removal of part of nitrogen oxides contained in exhaust gas, by contacting exhaust gas mixed with ammonia reducing agent with second catalyst located downstream of first catalyst. Second operating mode at exhaust gas temperature higher than 220 °C consists in decomposition of aqueous solution of urea to ammonia reducing agent and removal of part of nitrogen oxides contained in exhaust gas, by reaction with ammonia reducing agent in presence of first catalyst and subsequent oxidation of hydrocarbons, carbon monoxide and ammonia contained in the exhaust gas from the first catalyst by contacting exhaust gas with the second catalyst.

EFFECT: reduced amount of nitrogen oxide emissions and emissions from an internal combustion engine with compression ignition operated on a lean mixture.

8 cl, 4 dwg