摘要:
The invention relates to a method for carrying out the heterogeneously catalyzed gas phase oxidation of propane into acrolein and/or acrylic acid in which the initial mixture of reaction gas is fed over a fixed-bed catalyst which is comprised of catalyst charges A, B arranged in two reaction zones A, B that are placed in a spatially successive manner, whereby the temperature of reaction zones A, B are kept at different temperatures.
摘要:
A method for producing acrolein and/or acrylic acid from propane, whereby the propane undergoes partial homogeneous and/or heterogeneous catalysed oxydehydrogenation with molecular oxygen in a first reaction step to form propane. The product gas mixture formed in the first reaction step is subsequently used to produce acrolein and/or acrylic acid by means of gas-phase catalytic propane oxidation. The method is characterised in that the molecular oxygen which is required in the first reaction step and is different from the recycled oxygen gas is added to the initial reaction gas mixture of the first reaction step as modified air containing nitrogen with the proviso that the nitrogen content of the modified air is lower than and the oxygen content of the modified air is greater than the corresponding air contents. The invention is also characterised in that at least one part of the molecular nitrogen contained in the product gas mixture is separated from the product gas mixture before the product gas mixture containing propane formed in the first reaction step is further processed to produce acrolein and/or acrylic acid in at least one additional reaction step.
摘要:
The invention concerns titanium dioxide pigments obtained by complete hydrolysis of a hydrolizable titanium compound at between 0 and 100 °C with intensive stirring, a pH set between 3 and 8 and maintenance of this pH within a range of 0.3 units. The titanium dioxide pigments can be used to produce cosmetic preparations and medicaments.
摘要:
A method for producing acrolein and/or acrylic acid from propane, whereby the propane undergoes homogenous and/or heterogeneous catalysed oxide hydrogenation in a first reaction step with molecular oxygen to form propane and the product-gas mixture thus formed in the first reaction step is used to produce acrolein and/or acrylic acid by gas-phase catalytic oxidation of propane.
摘要:
A method for producing acrolein and/or acrylic acid from propane, whereby the propane undergoes partial homogeneous and/or heterogeneous catalysed oxydehydrogenation in a first reaction step with molecular oxygen to form propane. The product gas mixture formed in the first reaction step is used to produce acrolein and/or acrylic acid by means of gas-phase catalytic propane oxidation. The method is characterised in that the molecular oxygen which is required in the first reaction area and is different from the recycled oxygen gas is added to the initial reaction gas mixture of the first reaction area as modified air containing nitrogen with the proviso that the nitrogen content of the modified air is lower than and the oxygen content of the modified air is greater than the corresponding air contents. The invention is further characterised in that at least one part of the molecular nitrogen contained in the flow of residual gas is separated from the residual gas flow before the residual gas flow is returned to the first reaction area.
摘要:
The invention relates to polymetallic oxide materials with specific element composition and physical properties, which are suitable as catalysts for oxidative catalytic dehydrogenation of propane to propene.