1、 What are the exhaust gases of diesel engines?
Diesel engine tail gas refers to the tail gas emitted by diesel engine after burning diesel. The tail gas contains hundreds of different compounds. This kind of gas emission not only smells strange, but also makes people dizzy and sick, affecting people's health. Who experts believe that diesel engine exhaust, like asbestos, arsenic and other substances, is highly carcinogenic.
On october27,2017, the list of carcinogens published by the international agency for research on cancer of the World Health Organization was preliminarily sorted out for reference. Diesel engine exhaust was included in the list of class I carcinogens.
Diesel exhaust pollutants mainly include carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide, soot particles (some heavy metal compounds, lead compounds, black smoke and oil mist), odor (formaldehyde, etc.). Diesel engine exhaust has complex chemical composition, and the composition of exhaust varies significantly with the change of engine operating conditions. The pollutants emitted by diesel engine include soot particles (PM), hydrocarbons (HC), CO and NOx. " The main emissions of diesel engine are PM (particulate matter) and NOx (nitrogen oxide). The control of diesel engine exhaust emission is mainly to control the generation of particulate matter PM and N0 and reduce the direct emission of PM and NOx.
2、 GRVNES Environmental Protection grvnes' black smoke control scheme for off-road diesel engines
The formation mechanism of particulate matter can be roughly divided into primary and secondary components. Primary particulate matter is directly emitted by motor vehicles, coal and other emission sources, while secondary particulate matter refers to the particulate matter formed by carbon dioxide, nitrogen oxides, volatile organic compounds (VOCs) and other primary pollutants through complex chemical reactions in the atmosphere.
Regeneration method after DPF carbon particle catcher is blocked:
Active regeneration: the DPF unit is not removed, and the carbon combustion is promoted by the high temperature generated by diesel injection combustion or by the specially designed electric heater, so as to clean up the carbon deposit and restore the working capacity;
Passive regeneration: DPF is coated with precious metal catalyst with special formula. Under appropriate temperature, NO2 produced by Doc unit will react with C in DPF;
The chemical equation for the removal of CO and HC in doc unit is as follows (main reaction equation):
4HC+5O2 =4CO2 +2H2O
Among them, water washing regeneration: when the particle trap independently developed by Green Valley is saturated with carbon, loosen the clamp, pull out the unit filter element, and wash it with tap water for 30 seconds to complete the regeneration of a unit.
GRVNES Environmental Protection grvnes: focus on engine and industrial organic waste gas treatment
GRVNES Environmental Protection grvnes diesel engine exhaust dry alloy black smoke purifier (conventional 10L -90l processing capacity, customizable)
2、GRVNES Environmental Protection on the treatment scheme of nitrogen oxides in off-road diesel engine exhaust
The current technical route for the treatment of tail gas ammonia oxide is: SCR denitration (selective catalytic reduction); The working principle of this technical route is as follows: in the temperature range of 180-600 ° C, urea is injected to hydrolyze to NH3 as reducing agent, NOx and NH3 react with catalyst to reduce NO and NO2 to N2 and H20.