摘要:
A process for the long-term operation of a heterogeneously catalyzed gas phase partial oxidation of acrolein to acrylic acid, in which the temperature of the fixed catalyst bed is increased over time and partial oxidation is interrupted and an oxygen-containing gas is conducted through the fixed catalyst bed before the temperature increase is 8° C.
摘要:
In a process for partially oxidizing propene to acrylic acid in the gas phase under heterogeneous catalysis, a starting reaction gas mixture comprising propene and oxygen and having a specific composition is oxidized in a first reaction stage over a first fixed catalyst bed having a volume-specific activity which is constant or increases in the flow direction and the acrolein-containing product gas mixture of the first reaction stage is subsequently oxidized in a second reaction stage over a second fixed catalyst bed having a volume-specific activity increasing in the flow direction, and the shaped catalyst bodies of both fixed catalyst beds are annular and each have a specific multimetal oxide composition.
摘要:
The present invention relates to a process for charging a reactor with a catalyst, to the resulting charged reactors, and to the use thereof for carrying out catalytic gas phase reactions.
摘要:
Catalytically active multielement oxide materials which contain at least one of the elements Nb and W and the elements Mo, V and Cu are prepared by a process in which an intimate dry blend containing ammonium ions is prepared and said dry blend is subjected to a thermal treatment in an atmosphere having a low molecular oxygen content at elevated temperatures, a portion of the ammonium ions contained in the intimate dry blend being decomposed with liberation of ammonia and the oxygen content of the thermal treatment atmosphere being increased in the course of the thermal treatment.
摘要:
A process for preparing an organic target compound by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound with molecular oxygen in two oxidation reactor lines operated in parallel and removal of the target compound from the mixture of the product gas streams in a workup line, wherein the catalysts charge of one of the oxidation lines comprises a portion of catalyst over which the heterogeneously catalyzed gas phase partial oxidation has already been carried out for longer than over the portions of catalyst of the catalyst charge of the other oxidation reactor line.
摘要:
A process for operating an exothermic heterogeneously catalyzed partial gas phase oxidation of an organic starting compound in a tube bundle reactor cooled with a fluid heat carrier, in which an increase in the loading of the fixed catalyst bed disposed in the reaction tubes with the organic starting compound is preceded by an increase in the inlet temperature of the fluid heat carrier into the space surrounding the reaction tubes.
摘要:
A process for the long-term operation of a heterogeneously catalyzed gas phase partial oxidation of propene to acrolein, in which the temperature of the fixed catalyst bed is increased over the time and the gas phase partial oxidation is interrupted at least once per calendar year and the gas mixture G consisting of molecular oxygen, inert gas and optionally steam is conducted through the fixed catalyst bed at a temperature of the fixed catalyst bed of from 250 to 550° C.
摘要:
A shell which encloses an interior and has at least one first orifice for feeding at least one gas stream into the interior and at least one second orifice for withdrawing a gas stream fed to the interior beforehand via the at least one first orifice from the interior, the surface of the shell, on its side in contact with the interior, being manufactured at least partly, in a layer thickness of at least 1 mm, from a steel which has a specific elemental composition, and in the interior, a process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated is carried out in a reactor which is manufactured from the steel on its side in contact with the reaction gas.
摘要:
Emissions treatment systems and methods for treating an engine exhaust gas stream containing NOx and particulate matter are disclosed including a particulate filter comprising a first SCR catalyst for NOx conversion a second SCR catalyst for NOx conversion on a substrate disposed downstream of the particulate filter. The system NOx conversion and the system back pressure increase lie within a targeted operational window.
摘要:
Disclosed are processes for the preparation of copper containing molecular sieves with the CHA structure having a silica to alumina mole ratio greater than about 10, wherein the copper exchange step is conducted via wet state exchanged and prior to the coating step and wherein in the copper exchange step a liquid copper solution is used wherein the concentration of copper is in the range of about 0.001 to about 0.25 molar using copper acetate and/or an ammoniacal solution of copper ions as copper source. Catalysts made by the processes, catalyst systems and methods of treating exhaust gas with the molecular sieves and catalysts are also disclosed.