FIELD: chemistry.
SUBSTANCE: method of decomposing nitrogen dioxide (NO2) to nitrogen monoxide (NO) in the exhaust gas of an internal combustion engine working on a rare fuel mixture involves a stage for bringing into contact with an acidic metal oxide selected from a group consisting of zeolites, titanium dioxide doped with tungsten, silica-titanium dioxide, zirconium dioxide-titanium dioxide, gamma-alumina, amorphous silica-alumina and a mixture of any two or more of these oxides, which optionally serve as a carrier for metal or metal compound, where the metal is selected from a group consisting of rhodium, palladium, iron, copper and mixtures of any two or more metals, with a gaseous mixture containing exhaust gas, control of composition of the gaseous mixture, injection of hydrocarbons into the gaseous mixture at a rate which varies during the operation cycle such that on average, the ratio Cl hydrocarbon: nitrogen oxides (CI HC:NOx) of the gaseous mixture in contact with the acidic metal oxide ranges from 0.1 to 1.5 and release of the exhaust gas directly into the atmosphere, optionally after the gaseous mixture comes into contact with a hydrocarbon oxidation catalyst, where the hydrocarbons are selected from a group consisting of diesel fuel, petrol, fuel based on liquefied gas and liquefied petroleum gas. The exhaust system for the internal combustion engine working on a rare fuel mixture, which contains a catalyst for decomposition of nitrogen dioxide (NO2) to nitrogen monoxide (NO) with a hydrocarbon as a reducing agent, and apparatus for controlling composition of the exhaust gas by injecting a hydrocarbon at a rate which varies during the operation cycle such that on average, the ratio Cl hydrocarbon: nitrogen oxides (CI HC:NOx) in the exhaust gas in contact with the catalyst ranges from 0.1 to 1.5, in which the catalyst consists of an acidic metal oxide selected from a group consisting of zeolites, titanium dioxide doped with tungsten, silica-titanium dioxide, zirconium dioxide-titanium dioxide, gamma-alumina, amorphous silica-alumina and a mixture of any two or more oxides, which optionally serve as a carrier for the metal or metal compound. The metal is selected from a group consisting of rhodium, palladium, iron, copper and mixtures of any two or more metals, in which gas released from the catalyst is directly released into the atmosphere optionally through a hydrocarbon oxidation catalyst. Hydrocarbons are selected from a group consisting diesel fuel, petrol, fuel based on liquefied gas and liquid petroleum gas. The device has a diesel engine and the above described exhaust system features. A carriage vehicle, such as one used in mines, has the above described device.
EFFECT: invention reduces exhaust gas emissions into the atmosphere in confined spaces in order to improve health and safety of miners.
41 cl, 1 dwg
