BlueTec is Daimler AG's name for its two nitrogen oxide (NOx) reducing systems, for use in their Diesel automobile engines. One is a urea-based reductant called AdBlue, the other is called DeNOx and uses an oxidizing catalytic converter and particulate filter combined with other NOx reducing systems. Both systems are designed to reduce pollutant emissions.
Mercedes-Benz introduced the systems in the E-Class (using the 'DeNOx' system) and GL-Class (using 'AdBlue') at the 2006 North American International Auto Show as the E320 and GL320 Bluetec vehicles. This system makes these vehicles 45-state and 50-state legal, respectively in the United States, and is expected to meet all emissions regulations through 2009.
A Jeep Grand Cherokee with the same BlueTec engine is also expected, and Mercedes announced tentative plans for a BLUETEC/electric hybrid S-Class.
Daimler AG has entered into an agreement with Volkswagen and Audi to share BlueTec technology with them in order to increase the Diesel passenger-vehicle market in the US.
Volkswagen introduced the Jetta Clean TDI, the Tiguan concept, and the VW Touareg BlueTDI as part of the BlueTec licensing program. All are expected to be introduced in the American market in 2008. The Jetta and the Tiguan use NOx Adsorbers, while the Touareg uses a Selective Catalytic Reduction catalytic converter.
In August 2007 VW Group announced that cooperation on BlueTec with Daimler AG would end. The reasoning for this change is due to the recognition of the VW TDI branding. VW did not want to use a competitor's branding for a product they would introduce into the market.
The BlueTec system will use two catalytic converters specifically targeting NOx. The first converter traps the NOx, and later releases it to the second converter which then converts it to nitrogen (N2) and water (H2O). This will make a diesel car legal in 45 states. But to make it pass the more stringent regulations of California, Maine, Massachusetts, New York and Vermont, AdBlue (NH4) will have to be introduced into the system, making the conversion more complete.
NH_3 + NO_x \rightarrow \; N_2 + H_2O
The whole exhaust system would work like so:
1. A Diesel oxidation catalyst reduces the amounts of carbon monoxide (CO) and hydrocarbons (HC) released from the exhaust.
2. A DeNOx catalytic converter begins a preliminary removal of oxides of nitrogen.
3. A particulate filter traps and stores soot particles, burning them off when the filter gets full.
4. If the above are not sufficient to meet the exhaust specifications, a Selective Catalytic Reduction (SCR) catalytic converter will take the remaining nitrogen oxides and convert them to nitrogen and water. AdBlue will be injected into the exhaust gas stream to enable the conversion.
BlueTec
