Abstract:
The invention concerns materials for eliminating oxides of nitrogen NO and NO2 present in exhaust gases, in particular from the internal combustion engines of automotive vehicles operating in a medium that is super-stoichiometric in oxidizing agents, which can adsorb oxides of nitrogen then desorb the oxides of nitrogen by elevating the temperature with respect to the adsorption temperature or by passage of a rich mixture, the materials comprising mixed oxides the metals of which are in octahedral co-ordination, with the octahedra connecting together so that the structure generates micropores in the form of channels. The channel width of the materials is such that the sides are composed of 2 and/or 3 octahedra. These materials adsorb oxides of nitrogen by insertion and do not become poisoned in contact with oxides of sulfur and carbon contained in the gases. In the presence of a group VIII metal or another suitable element such as iron, zinc or aluminum, these materials are capable of eliminating oxides of nitrogen adsorbed by reduction during passage of a rich mixture.
Abstract:
The invention concerns a process for producing a ceramic honeycomb filter from a porous ceramic honeycomb material comprising a plurality of channels extending through it from one end face to the other end face. The process of the invention comprises at least the following steps consisting of a) providing each end face of the honeycomb material with a perforated film the perforations of which are such that the channels traversing the material are alternately open at one or the other of their end faces so that, for each channel open at one end face, the adjacent channels are closed; and b) introducing, by suction through the perforations of the film applied to each end face, a sealing material into the channels to obtain a ceramic filter the channels of which are not sealed at one of the end faces and are sealed at the other end face.
Abstract:
The invention concerns materials for eliminating oxides of nitrogen NO and NO2 present in exhaust gases, in particular from the internal combustion engines of automotive vehicles operating in a medium which is super-stoichiometric in oxidising agents, which can adsorb oxides of nitrogen then desorb the oxides of nitrogen by elevating the temperature with respect to the adsorption temperature or by passage of rich mixture, said materials comprising mixed oxides the metals of which are in octahedral coordination, with the octahedra connecting together so that the structure generates micropores in the form of channels. These materials adsorb oxides of nitrogen by insertion and do not become poisoned in contact with oxides of sulphur and carbon contained in the gases. In the presence of a group VIII metal, these materials are capable of eliminating oxides of nitrogen absorded by reduction during passage of a rich mixture.
Abstract:
The present invention relates to a method for impregnating a porous body (14) by a suspension (12) containing at least partly particles, said body comprising a multiplicity of channels (16) delimited by porous walls (22) extending from one (18) of the faces to the other (20) face of said body, part of said channels being obstructed at one face and the other part of the channels being obstructed at the other face.According to the invention, the method consists in: making a suspension whose particle size distribution meets a DV90/Dpores ratio below 0.25 and whose viscosity is such that said suspension is brought inside the walls while depositing part of the particles on the surface of the pores of the walls, communicating one (18, 20) of the faces of body (14) with an enclosure (30) containing the suspension, feeding the suspension into the body, exerting a force on the suspension introduced so that said suspension flows through the walls, passing a fluid through the walls.
Abstract:
The invention relates to materials for removing the nitrogen oxides NO and NO2 present in exhaust gases, particularly from internal combustion engines of automotive vehicles running in a medium containing a superstoichiometric proportion of oxidizing agents, said materials being capable of absorbing the nitrogen oxides and of desorbing the nitrogen oxides when the temperature is raised, relative to the absorption temperature, or when the gas composition is changed to a rich mixture, said materials being mixed oxides in which the metals A and B are all octahedrally coordinated and are arranged to form the ilmenite structure ABO3. These materials absorb the nitrogen oxides and do not become poisoned in contact with the sulfur oxides and carbon oxides containing in the gases. In the presence of a group VIII metal, the material is capable of eliminating the adsorbed nitrogen oxides by reduction when the gas composition is changed to a rich mixture.
Abstract:
The invention concerns materials for adsorbing and desorbing oxides of nitrogen NO and NO2 present in exhaust gases, in particular from the internal combustion engines of automotive vehicles operating in a medium which is super-stoichiometric in oxidizing agents, which can desorb the oxides of nitrogen by elevating the temperature, with respect to an adsorption temperature, the structure of the materials being composed of phosphate tetrahedra and containing at least one element (A) from groups IVB, VB, VIB, VIIB, IVA, optionally at least one element (B) selected from the group formed by alkali elements IA, alkaline-earth elements IIA, rare earths IIIB and transition metals, and optionally at least one metal (C) selected from the group formed by the precious metals of the platinum family (group VIII). These materials are insensitive to the oxides of sulphur and carbon contained in the gas.
Abstract:
The invention concerns materials for eliminating oxides of nitrogen NO and NO2 present in exhaust gases, in particular from the internal combustion engines of automotive vehicles operating in a medium which is super-stoichiometric in oxidising agents, which can adsorb oxides of nitrogen then desorb the oxides of nitrogen by elevating the temperature with respect to the adsorption temperature or by passage of a rich mixture, said materials comprising mixed oxides the metals of which are in octahedral coordination, with the octahedra connecting together so that the structure generates lamellae.Said materials adsorb oxides of nitrogen by insertion and do not become poisoned in contact with oxides of sulphur and carbon contained in the gases.In the presence of a group VIII metal, said materials are capable of eliminating oxides of nitrogen adsorbed by reduction during the passage of a rich mixture.
Abstract:
A redox mass for chemical looping combustion processes includes a redox pair or set of pairs having a material able to be alternatively oxidized and reduced between CuO and Cu, between Cu2O and Cu, between NiO and Ni, between MnO2 and Mn2O3, between Mn2O3 and Mn3O4, between Mn3O4 and MnO, between MnO and Mn, between CO3O4 and CoO or between CoO and Co, and a binder containing at least one mixed cerine-zirconia oxide (Ce/Zr) of the general formula CexZr1-xO2, where 0.05≦x≦0.95.
Abstract translation:用于化学循环燃烧过程的氧化还原物质包括在MnO 2和Mn 2 O 3之间,Mn 2 O 3和Mn 3 O 4之间具有能够在CuO和Cu之间,NiO和Ni之间,NiO和Ni之间,MnO 2和Mn 2 O 3之间在CuO和Cu之间交替氧化和还原的材料的氧化还原对或成对 MnO和Mn之间,CO 3 O 4与CoO之间或CoO和Co之间的粘合剂,以及含有至少一种通式CexZr1-xO2的混合铈 - 氧化锆(Ce / Zr)的粘合剂,其中0.05< x≦̸ 0.95。
Abstract:
The present invention relates to a new type of redox mass that can be used in any chemical looping combustion process, said mass comprising a binder containing at least cerine-zirconia.