Just as a whole batch of new fifty state-legal diesel vehicles are about to hit the market in the U.S., chemical company BASF is set to take advantage of the situation. BASF has announced that they will be raising the price of AdBlue by €45 per 1,000 liters. AdBlue is the 1/3 urea, 2/3 water solution used for the NOx after-treatment system in new diesel engines. The urea solution is injected into the exhaust gas stream where the heat of the exhaust causes it turn into ammonia by a hydrolysis reaction. The ammonia reacts with the exhaust in a special catalyst to turn the NOx into nitrogen and water.

The only reason for using the urea solution instead of straight urea is to allow for more precise dosing so that it lasts longer and no excess is used and passed through the exhaust. The Mercedes and BMW vehicles that are coming to market with urea injection systems that hold about 4-5 gallons of AdBlue which needs to be replenished every 15,000 miles or so. BASF claims the price increase is due to tight raw material supplies and the need to ensure product quality.

[Source: BASF]

The key to cleaning up diesel nitrogen oxide emissions on modern engines is the addition of ammonia to the exhaust stream. The most common way of doing that right is the injection of a urea solution into the exhaust as used in the Mercedes-Benz developed BlueTec system. The only problem with that is that the urea supply must be replenished periodically, typically at about 15,000 mile intervals.

In order to help car-makers optimize the use of the urea to maximize service intervals and minimize emissions, Delphi has developed an exhaust ammonia sensor. The sensor will sit in the exhaust stream much like an oxygen sensor to directly measure the ammonia content. This signal can then be used by the power-train control to more precisely meter the injection rate. The Delphi press release is after the jump.

[Source: Delphi]