Patent ID: 6423875
Filing Date: 2002-07-23
Classification: C07C

Abstract:
A process for the preparation of acrolein and/or acrylic acid from propane, in which, in a first reaction zone, the propane is subjected to a partial oxydehydrogenation with molecular oxygen under homogeneous and/or heterogeneous catalysis to give propene, and the propene-containing product gas mixture formed in the first reaction zone is fed, without separating off a component of the product gas mixture, into at least one further reaction zone and, in this at least one further reaction zone, the propene contained in the product gas mixture of the first reaction zone, together with all components of the product gas mixture of the first reaction zone, is subjected to a gas-phase catalytic oxidation to acrolein and/or acrylic acid, acrolein and/or acrylic acid and water contained in the product gas mixture of the gas-phase catalytic oxidation are separated from said mixture, and the unconverted propane contained in the remaining residual gas stream is recycled as a component of the residual gas stream to the first reaction zone, wherein the molecular oxygen required in the first reaction zone and differing from recycled oxygen is added in the form of air to the reaction gas starting mixture fed to the first reaction zone and, before the recycling of the residual gas stream to the first reaction zone, at least a part of the atmospheric nitrogen contained in the residual gas stream is separated from the residual gas stream.