Patent ID: 7326802

Claim:
A process for preparing at least one partial oxidation product of propylene selected from the group consisting of acrolein, acrylic acid and propylene oxide, said process comprising: a) subjecting crude propane to at least one reaction selected from the group consisting of a homogeneous dehydrogenation, a heterogeneously catalyzed dehydrogenation, a homogeneous oxydehydrogenation, wherein the reaction(s) is/are carried out under at least one condition selected from the group consisting of 1) in the presence of oxygen and 2) with the exclusion of oxygen, and a heterogeneously catalyzed oxydehydrogenation, to obtain a gas mixture 1 comprising propane and propylene, b) optionally removing, converting to by-products, or both removing and converting to by-products, a portion of the constituents other than propane and propylene from all of or a part of the gas mixture 1 to obtain a gas mixture 1′ comprising propane, propylene and compounds other than oxygen, propane and propylene, and c) subjecting a gas mixture 2 comprising the gas mixture 1, the gas mixture 1′, or the gas mixture 1′ and the remainder of gas mixture 1, to a heterogeneously catalyzed gas phase partial oxidation of the propylene contained in the gas mixture 1, the gas mixture 1′, or the gas mixture 1′ and the remainder of gas mixture 1, wherein the total content of C 4 -hydrocarbons of the gas mixture 2 is ≦3% by volume.