Advanced filters for less emissions
In line with European directives for further reductions in emissions levels, the COMET project focused on a new technological filter concept. The new improved particulate filter system has been specifically designed to cover the needs of heavy duty applications. It may also be employed in combination with exhaust gas recirculation (EGR), a NOx reduction technique employed in the majority of gasoline and diesel engines. PUREM provided a wide range of new material variants to be tested for the new design concept. These materials feature appropriate filtration capabilities meeting requirements of mechanical properties including weight, size, coating ability and thermal resistance to soot combustion. At the second stage, another set of new material variants was further developed aiming at a better porosity/pore diameter/permeability according to the catalytic coating requirements. In combination with a favourable permeability characteristic, ferrierite coatings with higher wash-coat loading levels were found to be a very promising solution. A new filter design technology, highly suitable for catalytic coated filter units was also developed. This new design displays size advantages in respect to construction volume and has undergone extensive testing including bench tests and ash cleaning investigations. PUREM will release such filter systems into the market for various applications meeting future emission levels such as those set by the Environmental Protection Agency (EPA) 2010 requirements for heavy duty engines.