Catalytic ceramic papers to remove diesel exhaust pollutants: Enhancement of the impregnation method used to incorporate the catalyst

F.E. TULER; DAMIEN DEBECKER; ERIC GAIGNEAUX; E.E. MIRÓ; V.G. MILT

San Sebastián

Congreso; Congreso ICOSCAR 5; 2016

The most adequate technology for the abatement of soot particles coming from diesel enginesis theone that employs catalytic filters.Nowadays, commercialized filters consist of SiC monolithswith active elements on it. As an alternative, in a previous work, it was proposed to use ceramicpapers as suitable materials to conform diesel filters. Indeed, they were flexible, easy to handle andpresented suitable mechanical properties to resist the tests from a test bench in which they wereplaced inside a metal housing, at the exhaust pipe outlet of a Corsa 1.7 vehicle. These optimalmechanical properties were obtained through the incorporation of a suspension of CeO2 nanoparticles (10 or 20 wt. % CeO2) during the papermaking process.The passive regeneration of the filter implies the addition of catalytic components. In thiscontribution, two different methods are used and compared in order to achieve the best distribution of the catalyst throughout the ceramic matrix: drip impregnation and spray deposition. The first oneinvolves the impregnation by dripping a solution containing the desired catalytic componentsprecursors. The second one is carried out in dedicated equipment, which consists of an aerosolgenerating system that possesses a compressed air inlet and a Venturi device to suck up the solution of precursors. The generated aerosol is passed through a tubular oven, heated at 400 °C in order to quickly dry the formed droplets. This dried aerosol is sprayed onto the ceramic paper disc and the excess of particles are retained by an absolute filter.