摘要:
The invention concerns a process for reducing emissions of oxides of nitrogen in a medium which is super-stoichiomeitric in oxidising agents, comprising: a) a step for oxidising at least a portion of the oxides of nitrogen in the presence of an oxidation material; b) a step for injecting organic compounds which comprise at least one atom selected from carbon, hydrogen, oxygen and nitrogen; c) a step for adsorbing at least a portion of the organic compounds onto an adsorption material in the form of molecular species and/or carbonaceous residues; d) a step for selective reduction of at least a portion of the oxides of nitrogen to molecular nitrogen by at least a portion of the molecular species and/or carbonaceous residues formed on the adsorption material.
摘要翻译:本发明涉及一种减少氧化剂中超化学计量的介质中氮氧化物排放的方法,包括:a)在氧化物质存在下氧化至少一部分氮氧化物的步骤; b )用于注入包含至少一个选自碳,氢,氧和氮的原子的有机化合物的步骤; c)将至少一部分有机化合物以分子种类和/或形式吸附到吸附材料上的步骤 碳质残渣; d)通过在吸附材料上形成的分子种类和/或碳质残渣的至少一部分,将至少一部分氮氧化物选择还原成分子氮的步骤。
摘要:
The invention relates to a process for synthesis of lamellar solids based on silicates comprising: i) a mixing stage, during which a mixture that comprises an alkaline metal, a silica source, water and an organic structuring agent is prepared, and ii) a crystallization stage during which this mixture is kept under conditions allowing the formation of a crystalline solid. The organic structuring agent that is used in this process comprises an alcohol group and an amine group that are separated by a hydrocarbon chain.
摘要:
A device for eliminating nitrogen oxides in an exhaust line of a lean-burn internal-combustion engine (1) a NOx trap (3) for trapping the nitrogen oxides, a system for regenerating the nitrogen oxides when the NOx trap is saturated, a hydrocarbon treating catalyst (2) placed upstream from the NOx trap (3), a hydrocarbon injector (4) placed upstream from hydrocarbon treating catalyst (2), a probe (7) for measuring the gas mixture strength. The hydrocarbon treating catalyst (2) is a partial (or controlled) hydrocarbon oxidation catalyst that cooperates with the NOx trap (3) for trapping the nitrogen oxides and that allows to obtain, at the outlet thereof, gases with a low oxygen (O2) concentration and with high carbon monoxide (CO) and hydrogen (H2) concentrations. A control unit is furthermore provided for recording and processing data coming from various detectors and/or stored in order to carry out effective regeneration of the NOx trap (3) without disrupting the smooth running of the engine.
摘要:
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.The invention also provides a catalyst comprising at least one refractory inorganic oxide at least in part constituted by at least one zeolite from the group formed by NU-86, NU-87 and EU-1 and at least one element selected from the group formed by elements from groups VIB, VIIB, VIII and IB, the transition metals, and from noble group VIII metals. The invention also concerns the preparation of the catalyst.
摘要:
The invention describes a catalyst comprising at least one material with a hierarchical porosity comprising silicon and at least one hydrodehydrogenating element from group VIB and/or group VIII of the periodic table of the elements. Said material with a hierarchical porosity comprising silicon is constituted by at least two elementary spherical particles, each of said spherical particles comprising zeolitic nanocrystals having a pore size in the range 0.2 to 2 nm and a matrix based on silicon oxide, which is mesostructured, having a pore size in the range 1.5 to 30 nm and having amorphous walls with a thickness in the range 1 to 30 nm, said elementary spherical particles having a maximum diameter of 100 μm. The matrix based on silicon oxide may contain aluminium. The catalyst also optionally comprises at least one doping element in a controlled quantity selected from phosphorus, boron and silicon, optionally at least one element from group VB of the periodic table of the elements, and optionally an element from group VIIA. The invention also concerns hydrocracking/hydroconversion and hydrotreatment processes employing said catalyst.
摘要:
The invention relates to a process for synthesis of lamellar solids based on silicates comprising: i) a mixing stage, during which a mixture that comprises an alkaline metal, a silica source, water and an organic structuring agent is prepared, and ii) a crystallization stage during which this mixture is kept under conditions allowing the formation of a crystalline solid. The organic structuring agent that is used in this process comprises an alcohol group and an amine group that are separated by a hydrocarbon chain.
摘要:
The present invention relates to a process for controlled injection of hydrocarbons into an exhaust line of a lean-burn internal-combustion engine, comprising catalytic elimination of the nitrogen oxides. The process according to the invention consists in injecting a certain amount of hydrocarbons upstream from the catalytic elimination, periodically and for a short time interval, by means of pulsed hydrocarbon injections. The frequency and the amplitude of the hydrocarbon pulses are preferably controlled according to the running conditions of the engine.