摘要:
In a process for preparing at least one partial oxidation and/or ammoxidation product of propylene, the propylene is obtained from crude propane by dehydrogenating and subjected in the presence of unconverted propane as a constituent of a gas mixture 2 which comprises a total C4-hydrocarbon content of ≦3% by volume to a heterogeneously catalyzed gas phase partial oxidation and/or partial gas phase ammoxidation.
摘要:
Process for preparing at least one partial oxidation and/or ammoxidation product of propylene, in which the propylene is produced from crude propane by dehydrogenation and is subjected to a heterogeneously catalyzed gas-phase partial oxidation and/or partial gas-phase ammoxidation in the presence of unreacted propane as constituent of a gas mixture 2 containing
摘要:
A process for preparing at least one partial oxidation and/or ammoxidation product of a hydrocarbon by partially dehydrogenating at least one saturated hydrocarbon H under heterogeneous catalysis and using the resulting product gas mixture A, which comprises the partially dehydrogenated hydrocarbon H, as such or in modified form for heterogeneously catalyzed partial oxidation and/or ammoxidation of the partially dehydrogenated hydrocarbon present in the product gas mixture A, said process including at least one mechanical separating operation inserted between the product gas mixture A and the heterogeneously catalyzed partial oxidation and/or ammoxidation.
摘要:
A process for long-term operation of a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a reaction gas mixture stream comprising the hydrocarbon to be dehydrogenated in a molar starting amount KW is conducted through an overall catalyst bed comprising the total amount M of dehydrogenation catalyst and the deactivation of the overall catalyst bed is counteracted in such a way that, with increasing operating time, the contribution to the conversion in the first third of the total amount M of dehydrogenation catalyst in flow direction decreases, the contribution to the conversion in the last third of the total amount M of dehydrogenation catalyst in flow direction increases, and the contribution to the conversion in the second third of the total amount M of dehydrogenation catalyst in flow direction passes through a maximum.
摘要:
A process for preparing acrolein or acrylic acid or a mixture thereof from propane, in which the propane is initially dehydrogenated under heterogeneous catalysis to give propene, secondary components are removed and the remaining gas mixture, comprising propane and propene, is subjected to the heterogeneously catalyzed partial oxidation to acrolein or acrylic acid or a mixture thereof as the target product, target product is removed from the product gas mixture and the remaining residual gas, comprising excess oxygen and unconverted propane, is recycled into the propane dehydrogenation in such a way that the other propane fed to the dehydrogenation is at least partly converted under dehydrogenating conditions at the recycle point.
摘要:
A process for preparing acrolein or acrylic acid or a mixture thereof from propane, in which the propane is initially dehydrogenated under heterogeneous catalysis to give propene, secondary components are removed and the remaining gas mixture, comprising propane and propene, is subjected to the heterogeneously catalyzed partial oxidation to acrolein or acrylic acid or a mixture thereof as the target product, target product is removed from the product gas mixture and the remaining residual gas, comprising excess oxygen and unconverted propane, is recycled into the propane dehydrogenation in such a way that the other propane fed to the dehydrogenation is at least partly converted under dehydrogenating conditions at the recycle point.
摘要:
Acrolein and/or acrylic acid are prepared from propane and/or propene by a process comprising the following steps: (a) separation of propane and/or propene from a propane- and/or propene-containing gas mixture by absorption in an absorbent, (b) separation of the propane and/or propene from the absorbent to give a gas B and (c) use of the gas B obtained in stage (b) for an oxidation of propane and/or propene to acrolein and/or acrylic acid, no heterogeneously catalyzed dehydrogenation of propane without supply of oxygen being carried out between steps (b) and (c).
摘要:
A process for the continuous recovery of (meth)acrylic acid from the reaction gas of a catalytic gas-phase oxidation comprising the following process stages is proposed: I quenching of the reaction gas by evaporative cooling using a high-boiling solvent, II separation of the (meth)acrylic acid from the quenched reaction gas by absorption into the high-boiling solvent, III separation of the solvent laden with (meth)acrylic acid by rectification into a first part-stream IIIA), which contains predominantly (meth)acrylic acid, and into a second part-stream IIIB) which contains predominantly the solvent, IV recycling of the stream IIIB) to process stage II and V distillative production of (meth)acrylic acid from stream IIIA), all liquid residual streams obtained in process stage V being recycled to process stage I.
摘要:
A process for removing methacrylic acid from liquid phase P comprising acrylic acid as a main constituent and target product, and methacrylic acid as a secondary component in which the removal is effected by crystallization, the acrylic acid accumulating in the crystals formed and the methacrylic acid in the remaining mother liquor.
摘要:
A process for preparing at least one target product by partial oxidation and/or ammoxidation of propylene, in which the propylene source used is a propane dehydrogenation, the propane used therein being obtained by a rectificative prepurification of crude propane.