3 December 2001

Non-thermal plasma (NTP) technology may be closer to commercialization as PSA Peugeot Citroën unveils its Peugeot 206 diesel demonstration car equipped with a plasma assisted NOx reduction catalyst. The NTP catalyst, as well as a number of other technologies incorporated in three recent demonstration models, have been jointly developed by PSA Peugeot Citroën and Delphi Automotive Systems under the innovation plan signed between the two groups in September 1999.

The innovation plan signed with Delphi relates in particular to six technologies: (1) electric power steering, (2) electromechanical braking systems, (3) the E-Start function using a reversible alternator Energen™, (4) NTP exhaust aftertreatment, (5) variable compressors, and (6) oil quality control. The Peugeot 206 environmental demonstration model contains all of these technologies. Other demonstration models include Citroën Xsara Picasso fitted with two different types of brakes - conventional brakes at the front and electromechanical brakes at the back, and the gasoline fueled Citroën Saxo, equipped with the E-Start function using a reversible alternator Energen™ which can operate as an electric motor and is used as the engine starter.

The Peugeot 206 is fitted with a new DV4TED4 diesel engine with the Common Rail Delphi Multec™ DCR1400. The reactor producing non-thermal plasma is located within the exhaust line under the car body. The reactor is connected to a DeNOx catalyst and a diesel particulate filter manufactured by PSA. The technology is designed to reduce NOx emissions, as well as to assist the regeneration process of the particulate filter by utilizing the plasma-generated nitrogen dioxide (NO2). The Peugeot 206 E-Start function using the reversible alternator is the world’s first on a diesel engine.

In the NTP reactor, energetic electrons and free radicals are created that collide with stable molecules in the exhaust gas stream. Because the gas contains excess oxygen, the subsequent chemical reactions result in the oxidation of NO into NO2, which is subsequently reduced to nitrogen in the DeNOx catalyst. A portion of the NO2 which is not reduced in the catalyst can enhance the regeneration of the particulate filter. The potential advantages of NTP technology include tolerance to sulfur and wide operating temperature window.

Peugeot said the NTP technology is in the “advanced development stage”. In 2000, particulate filters have been commercially introduced by PSA on the Peugeot 607 HDi 2.2, which came equipped with an active particulate filter system regenerated through the use of fuel additive and common-rail post injection of fuel. In 2001, this filter system was also introduced on the Peugeot model 406 HDi 2.2.

Source: PSA Peugeot Citroën