The direct synthesis of unsaturated aldehydes from alcohol mixtures

摘要

The direct synthesis of unsaturated aldehydes of formula CH2 = C (R) -CHO, in which R represents H or CH3, from a charge containing a mixture of methanol and a second alcohol of formula R-CH2- CH2OH, which comprises introducing into a single set of reaction, comprising a single reactor operated in the gas phase at a temperature between 200 and 400 ° C and a pressure between 1 and 10 bar absolute, which contains a catalyst bed consisting of a only selective oxidation catalyst, solid, selected from catalysts based on molybdenum, or a physical mixture of a catalyst selective solid oxidation, molybdenum-based, with solid condensation catalyst by aldol, a charge containing the mixture of the two alcohols with oxygen and non-reactive diluent gas, such that the alcohol mixture and oxygen are each at most 10% of the total volume of the mez cla reaction, then the reaction set out in collecting the gaseous effluent comprising forming, in the presence of water co-produced by the reaction unsaturated aldehyde.