In order to remain compliant with EPA protocols and to reduce harmful emissions, fleets utilize exhaust aftertreatment devices like Diesel Particulate Filters, Selective Catalytic Reduction filters, and Diesel Oxidation Catalysts (DPF, SCR, and DOC). These technologies work in tandem to make fleets cleaner and more fuel-efficient.
Selective Catalytic Reduction filter systems are a critical piece of the puzzle, designed to reduce NOx emissions from diesel vehicles. Learn more about SCR filter systems and the importance of carefully maintaining them.
How Does SCR Work?
NOx refers to the nitrogen oxides NO and NO2, which are created through the combustion process in diesel engines. These gasses contribute to smog and other harmful air pollution. The SCR filters this gas and turns it into harmless N2 and H2O gasses through the following steps:
- A urea-water solution is injected into the exhaust gas.
- The exhaust gas and urea-water solution pass through the SCR catalyst.
- The SCR catalyst and the reaction with the urea-water convert NOx into diatomic nitrogen (N2) and water (H2O).
This process can significantly reduce the environmental harm caused by emissions — but only if all of the pieces are in proper working order.
How Do DPFs and SCRs Work Together?
DPF, SCR, and DOC are all commonly used in an effort to make trucking less harmful to the environment. DPF and SCR are a perfect match because DPF technology targets particulate emissions such as ash and soot, while SCR aims to remove gaseous emissions (NOx). Together, they help prevent particle pollution and harmful gasses from entering the air.
The Importance of Maintaining SCR Filter Systems
Properly maintaining, cleaning, and, when necessary, replacing the SCR system is imperative for several reasons:
- EPA Compliance: To reduce air pollution and protect public health, the EPA requires fleets to take measures to reduce their emissions. Regular SCR maintenance ensures the system remains effective and compliant with these legal standards.
- Longevity of DPF/SCR: Regular maintenance and cleaning prevent premature wear and tear of SCR components, such as the catalyst and injectors, thereby extending their lifespan. This, in turn, reduces the need for frequent replacements and associated costs.
- Social Responsibility: By ensuring the SCR system operates efficiently, businesses and vehicle owners prevent unnecessary NOx from entering the atmosphere. This actively contributes to environmental preservation and sustainable practices.