摘要 |
A process for the preparation of olefinically unsaturated compounds by catalytic oxidation, ie oxidative dehydrogenation by transferring oxygen from a previously oxidized oxygen carrier acting as catalyst, in the absence of molecular oxygen, the catalyst being regenerated after exhaustion, wherein, during the operating phase of the catalyst (oxidation/dehydration partial step), the residence time, space velocity and/or temperature of the reactants in the reactor is/are adjusted, ie, controlled, continuously or in discrete steps, in a manner appropiate to the momentary state of activity of the redox catalyst by adjusting-continuously or stepwise-the residence time of the reactants in the freshly regenerated catalyst (ie at the commencement of the reaction) to a shorter time, and/or the temperature to a lower value, than the corresponding parameter(s) in the partially reduced catalyst. |