Most advanced exhaust gas management: SCR catalyst with AdBlue injection

BMW Advanced Diesel with BluePerformance optimizes emission management by incorporating an oxidation catalyst placed close to the engine, a diesel particulate filter housed in the same unit, and an SCR catalyst with urea injection. Apart from filtering out even the smallest particles from the flow of exhaust gases, this combination ensures effective reduction of nitric oxides (NOX) by way of a chemical reaction within the exhaust system initiated by the injection of a small dose of urea referred to as AdBlue. The ammonia (NH3) generated in this process within the SCR catalyst subsequently converts the nitric oxides (NO and, respectively, NO2) in the exhaust gas into environ¬mentally compatible nitrogen (N2) and vapor (H2O).

BMW has developed a two-tank system for AdBlue ensuring convenient use of this new technology with all the benefits and ease required by the customer: The amount of AdBlue required in each case is drawn from the active tank comprising approximately 1.6 gallons by means of a dosage pump. And since the urea solution would freeze at a temperature of −11oC, this active tank, as well as the dosage pipes are heated.