How to achieve cleaner emissions from diesel engines through advanced exhaust purification technologies?
Publish Time: 2025-04-22
With the improvement of global environmental awareness and increasingly stringent regulations on vehicle emission standards, exhaust treatment of diesel engines has become a key area.Globally, environmental protection has become one of the important issues for governments, especially in reducing automobile exhaust pollution. For diesel engines, the effective elimination of the main pollutants in their exhaust - nitrogen oxides (NOx) and particulate matter (PM) - is the key to achieving higher emission standards. In the National VI emission standards implemented in China, a series of advanced exhaust purification technologies are widely used, such as exhaust gas recirculation (EGR), oxidation catalyst (DOC), diesel particulate filter (DPF), selective catalytic reduction system (SCR) and ammonia slip filter (ASC). These technologies not only help to significantly reduce the emission of harmful substances, but also promote the development of diesel engines in a more environmentally friendly and efficient direction.First of all, exhaust gas recirculation (EGR) technology plays an important role in controlling NOx emissions. By reintroducing a portion of the exhaust gas into the intake system, the oxygen concentration in the combustion chamber can be reduced, thereby reducing the amount of NOx produced under high temperature and high pressure conditions. This method is simple and effective, and can be combined with other post-treatment technologies to further improve the overall emission reduction effect. In addition, the application of EGR technology can also improve the working efficiency of the engine and reduce fuel consumption.Secondly, the oxidation catalyst (DOC) is the first line of defense for exhaust gas purification, mainly used to oxidize unburned hydrocarbons (HC) and carbon monoxide (CO) and convert them into water and carbon dioxide. This step not only reduces the toxic gases directly discharged into the atmosphere, but also lays the foundation for subsequent particulate matter filtration. The design of DOC is usually compact and easy to install, suitable for various types of diesel engine applications.Next, the diesel particulate filter (DPF) is a technology specifically used to capture and remove PM. It intercepts tiny particles by physical filtration to prevent them from entering the atmosphere. DPF is usually made of ceramic materials with high porosity and good thermal stability. Regularly cleaning the particulate matter accumulated inside the filter can keep it running efficiently for a long time. Although DPF requires a certain maintenance cost, its role in improving air quality cannot be ignored.The selective catalytic reduction system (SCR) is another effective NOx emission reduction solution. The system uses urea solution (AdBlue) as a reducing agent to convert NOx into harmless nitrogen and water vapor under the action of a catalyst. The biggest advantage of SCR technology is its high NOx conversion rate without significantly affecting engine performance. However, in order to ensure optimal working conditions, the amount of urea injection must be precisely controlled and the status of related components must be checked regularly.Finally, the ammonia skid filter (ASC) is an additional device designed to solve the problem of excessive ammonia leakage that may occur during the SCR process. When the SCR system fails to completely consume all the added urea, the residual ammonia may be discharged with the exhaust gas, causing secondary pollution. ASC decomposes excess ammonia through an additional catalyst layer to ensure that the final emissions meet the most stringent environmental standards.In summary, by integrating a variety of advanced diesel engine exhaust purification technologies, we can effectively reduce NOx and PM emissions and meet increasingly stringent emission regulations. Whether it is exhaust gas recirculation (EGR), oxidation catalyst (DOC), diesel particulate filter (DPF), selective catalytic reduction system (SCR) or ammonia skid filter (ASC), each technology plays a vital role in its respective areas of expertise. In the future, with the advancement of science and technology, we have reason to believe that more innovative solutions will emerge to jointly promote the diesel engine to develop in a greener and more sustainable direction. For those companies and individuals committed to environmental protection, investing in such advanced technologies is not only a manifestation of fulfilling social responsibility, but also an effective way to win market recognition and support.
