摘要:
Disclosed is a method for producing catalytically active multielement oxide materials containing at least one of the elements Nb and W as well as elements Mo, V, and Cu. According to the inventive method, an intimate dry mixture containing ammonium ions is produced and is thermally treated at a raised temperature in an atmosphere that is low in molecular oxygen. A partial quantity of the ammonium ions contained in the intimate dry mixture is decomposed so as to release ammonia while the oxygen concentration of the thermal treatment atmosphere is increased in the course of the thermal treatment.
摘要:
A method is disclosed for transferring heat to a liquid F containing dissolved monomeric acrylic acid, acrylic acid oligomers obtained by Michael addition, and acrylic acid polymer with the help of an indirect heat exchanger to which the liquid F is fed at a temperature T F ≥ 150°C and a heat transfer fluid W is fed at a temperature T w > T F . In said method, gas bubbles or thin layers of liquid F bordering a gas phase are generated in the liquid F while said liquid F flows through the heat exchanger.
摘要:
The invention relates to a method for producing acrylic acid by the heterogeneously catalysed gas-phase oxidation of propane on a multi-metal oxide mass, said mass containing the elements Mo, V, Te and/or Sb and having a specific X-ray diffractogram.
摘要:
The invention relates to a method for the heterogeneously catalysed partial gas phase oxidation of propene to form acrolein, whereby the initial mixture of reaction gas is oxidised on a fixed-bed catalyst bed arranged in two successive reaction zones A and B, with a propene load
摘要:
A process for preparing acrolein or acrylic acid or a mixture thereof as a target product from propane, in which propane is dehydrogenated partially under heterogeneous catalysis in a reaction zone A, molecular hydrogen formed is combusted at least partly to water, any water present in the product gas A thus formed in reaction zone A is removed therefrom and product gas A is otherwise used to charge a reaction zone B in which propylene formed in reaction zone A is partially oxidized to the target product in the presence of remaining propane. The target product is removed from the product gas B formed in reaction zone B and propane present in the remaining residual gas is absorbed therefrom into a solvent and, after release from the absorbate, recycled into reaction zone A.
摘要:
Disclosed is a method for the heterogeneously catalyzed partial gas phase oxidation of propene into acrolein, according to which the initial reaction gas mixture is oxidized on a fixed catalyst bed that comprises at least two fixed catalyst bed zones and is accommodated in two successive temperature zones A, B, the transition of temperature zone A to temperature zone B not coinciding with a transition from one fixed catalyst bed zone to another.
摘要:
The invention relates to a method for producing acrylic acid by means of two-stage heterogeneously catalyzed partial gas phase oxidation of propylene. According to said method, previously dehydrogenated propane is used as a propylene source while the first partial oxidation stage is operated so as to limit propylene reaction. Furthermore, unreacted propane and propylene contained in the product gas mixture of the second partial oxidation stage are largely redirected into the propane dehydrogenation process taking place upstream.