Abstract: Process and device for controlling the regeneration of an element filtering oxidable particles carried along by a gaseous stream, by periodic combustion of these particles, such as, for example, the carbon-containing particles carried along in the exhaust gas of a thermal engine (3), retained in an exhaust silencer (1).

Abstract: Process and device for controlling the regeneration of an element filtering oxidable particles carried along by a gaseous stream, by periodic combustion of these particles, such as, for example, the carbon-containing particles carried along in the exhaust gas of a thermal engine (3), retained in an exhaust silencer (1).

Abstract: The present invention provides a process for reducing oxides of nitrogen to molecular nitrogen in a medium which is superstoichiometric in oxidizing agent using reducing agents in the presence of a catalyst comprising:at least one refractory inorganic oxide at least in part constituted by a zeolite from the group formed by NU-86, NU-87 and EU-1;optionally, at least one element (A) from groups VIB, VIIB, VIII and IB, the transition metals;optionally, at least one element (B) from group VIII, the noble metals comprising platinum, rhodium, ruthenium, iridium and palladium;and optionally at least one element (C) from group IIA, the alkaline-earths and/or group IIIB, the rare earths.

Abstract: A process and an assembly for eliminating nitrogen oxides (NO.sub.x) present in the exhaust gas of a lean-burn diesel or spark-ignition engine, is part of the exhaust line coming from the engine. At least one nitrogen oxides conversion catalyst is placed in the main exhaust line the catalysts having non-coinciding temperature ranges for which the NO.sub.x conversion is below a certain conversion coefficient (C.sub.min). At least one NO.sub.x trap placed upstream is the conversion catalyst(s) and intended to trap, then to release the nitrogen oxides. At least one line bypassing the main exhaust line contains at least one of the NO.sub.x trap(s); and at least one valve intended to modulate the flow of gas between the bypass line and the main exhaust line is provided so that the NO.sub.x trap(s) can trap the nitrogen oxides, notably when conversion catalyst(s) have a conversion coefficient below a predetermined value (C.sub.min) and so that said the NO.sub.

Abstract: The present invention relates to a process and to an assembly for eliminating nitrogen oxides present in the exhaust gas of an internal-combustion engine (1), said assembly being part of the exhaust line (2) coming from the engine and comprising:a nitrogen oxides conversion means,a heat exchanger (4) placed in a bypass line (5) situated upstream from conversion means (3), intended to cool said exhaust gas.According to the invention, the conversion means comprises several catalysts (3) placed in main exhaust line (2), said catalyst(s) having non-coinciding temperature ranges for which conversion of the nitrogen oxides is below a certain threshold (C.sub.min). Furthermore, at least one valve (6) is placed at the inlet of bypass line (5) and intended to modulate the flow of gas between said bypass line (5) and main line (2) so that said exhaust gas reaches catalysts (3) at a temperature where at least one of said catalysts is active.