This video explains SCR or Selective Catalytic Reduction. This catalyctic converter is very specialised in the tasks it performs. It's main job is convert nitrogen oxide from the exhaust gas into nitrogen and water without any harmul side effects. This technology is being showcased at Geneva and will appear in vehicles in the future.
The convertion is done by a new synthetic wwater based urea solution which will be stored in a seperate tank. The fluid is constantly injected into the exhaust pipe before the catalytic converter and is flow adjusted based on the flow of the exhaust fumes, finelly controlled by the engine management system
The additive is non-toxic, odourless and bio-degradable, it is transfored during the flow with the hot gases and as it hits the catalytic converter the reaction takes place and spites off the NOx (nitrogen oxide)
The additive is used up at a rate of about 0.1lt / 100km, making maintenance easy at is can be left for each service.
