SCR stands for Selective Catalytic Reduction, a technology that reduces nitrogen oxide (NOx) emissions from diesel engines and equipment. It works by injecting a vaporized reagent, like ammonia or urea, into the exhaust stream, where it reacts with NOx to create nitrogen and water vapor. The SCR system uses a catalytic converter and a urea-based diesel exhaust fluid (DEF) to achieve this. Here’s a quick overview of SCR systems:
- DEFA non-toxic fluid made of 32.5% urea and purified water, also known as AdBlue.
- ProcessVaporized DEF reacts with NOx in the presence of a catalyst to create nitrogen and water vapor.
- MaintenanceRequires periodic DEF replenishment.
- RegulationsA key technology for meeting the EPA’s 2010 emissions reduction regulations for heavy-duty vehicles.
- WarningIf DEF runs out, the SCR system won’t function normally. A warning light will turn on or flash, and a message will appear on the display.
