The BlueTec system was created because the processes that give diesel engines efficient fuel economy also creates extra emissions of certain pollutants. High compression ratios and lean air-fuel mixtures make high combustion temperatures, which results in more nitrogen oxides and Diesel Particulate Matter (also known as soot) being released into the atmosphere. While the particulate matter can be controlled with higher injection pressures and particulate filters, the big challenge is limiting NOx.
Consisting of many different elements, BlueTec most notably relies upon particulate traps to eliminate soot/smoke throughout the engine's operating range, and upon urea injection from a stored canister (Mercedes calls this AdBlue) into the exhaust stream. AdBlue injection begins a chemical chain reaction which, in conjunction with an additional catalytic converter, converts nearly all remaining NOx into water vapor and nitrogen.
Process:
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).
Exhaust system explained:
Diesel oxidation catalyst reduces the amounts of carbon monoxide (CO) and hydrocarbons (HC) released from the exhaust.
A DeNOx catalytic converter begins a preliminary removal of oxides of nitrogen.
A particulate filter traps and stores soot particles, burning them off when the filter gets full.
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 is injected into the exhaust gas stream to enable the conversion
Trunk Capacity - 16 cubic feet
Wheelbase – 112.4 in
Length - 191 in
Width - 71.7 in
Height - 58.4 in |
