Silicon carbide-based catalytic sponge production for elimination of soot particles from exhaust gas of diesel engine

摘要

The production of a filtering medium of a beta -SiC sponge with a specific surface of at least 5 m 2/g and incorporating two zones with a different porosity distribution comprises: preparing a polyurethane sponge, incorporating two zones with different porosity foaming the polymer pyrolyzing the sponge to form a carbon sponge, activating the carbon sponge and exposing the activated carbon sponge to a SiO 2vapor to form a silicon carbide sponge. The production of a filtering medium of a beta -SiC sponge with a specific surface of at least 5 m 2/g and incorporating two zones with a different porosity distribution comprises: (a) preparing a medium precursor of carbonizable sponge with an open honeycomb porosity, such as a polyurethane sponge, incorporating two zones with different porosity, that is impregnated with a hardenable resin; (b) reticulating the resin; (c) pyrolyzing the sponge to form a carbon sponge; (d) activating the carbon sponge by heating it under a sweeping of carbon dioxide at 700-1000 [deg] C; and (e) exposing the activated carbon sponge to a SiO 2vapor to form a silicon carbide sponge. Independent claims are also included for the following: (1) a component of beta -SiC sponge produced by the above process; and (2) a device with a catalytic filtering cartridge incorporating this filtering medium.