Aristotle University Thessaloniki Research Committee

Aristotle University Thessaloniki

Aristotle University of Thessaloniki-research Committee

Koltsakis, Grigorios

Samaras, Zissis

Grigorios Koltsakis

Zissis Samaras

Exhaust gas treatment is based on metal foams using catalytic coatings. A catalytic converter for diesel and gasoline engines includes oxidation catalysts, 3-way catalysts, de-NOx catalysts, NH3 slip catalysts. Foam high surface areas and high mixing rates enhance catalytic performance. Particulate filtration in both diesel and direct injection gasoline engines uses deep bed filtration. A multiple-pass radial flow uses more than one foam segments, separated by a diaphragm. Filtration, pressure drop and catalytic performance are enhanced using variable foam porosities in axial and radial flow directions and non-uniform catalyst coatings. More than one catalytic functionalities may be incorporated in a single shell. Secondary foam segments are placed within main foam segments. Diaphragms at the entrance and exit of the external shell allow the flow to be divided between the main and the secondary foam segments according to the respective flow resistances.

Gas treatment device

A filtering device for diesel engines is based on metal foams. In order to achieve high filtration efficiency with low pressure drop using deep bed filtration metal foams, a radial flow concept is used based on a 'porosity gradient'. The foams can also be coated with catalytically active material to enhance soot oxidation (regeneration), as well as reduction of other exhaust gas pollutants (CO, hydrocarbons, nitrogen oxides). This may be accomplished by using non-uniform amounts of catalytic materials within the filter depending on the targeted application. An additional secondary filter segment may be placed within the metal support of the main filter segment. The metallic diaphragms at the entrance and exit of the external shell are designed in such a way as to allow the flow to be divided between the main and the secondary filter segments according to the respective flow resistances.

Growing community of inventors

Thessaloniki, Greece

Grigorios Koltsakis