Patent ID: 9169188
Filing Date: 2015-10-27
Classification: B01J,C07C

Abstract:
1. A process for preparing an α,β-unsaturated aldehyde and/or an α,β-unsaturated carboxylic acid, the process comprising: reacting an alkene with molecular oxygen by gas phase oxidation in a reactor with an inlet and an outlet over a fixed catalyst bed comprising a bed of hollow cylindrical shaped catalyst bodies comprising a multimetal oxide active composition, wherein the fixed catalyst bed comprises at least three successive reaction zones; the highest local temperature in the fixed catalyst bed does not occur in a reaction zone closest to the reactor outlet; the highest local temperature in the fixed catalyst bed does not occur in a reaction zone closest to the reactor inlet; and a value WT calculated according to the following equation in a reaction zone in which the highest local temperature in the fixed catalyst bed occurs is lower than WT values in the other reaction zones: where ED is an external diameter and ID is an internal diameter of the cylindrical shaped catalyst body.