IMPROVED PROCESS FOR OXIDATION ON FIXED CATALYTIC BED OF METHANOL TO FORMALDEHYDE

摘要

A process for the fixed bed oxidation of methanol to formaldehyde wherein the bed comprises at least two layers having different catalytic activity, wherein the layer of lower activity is comprised in the part of the bed from which the reactant gas mixture enters and its activity is calibrated so that the maximum hot spot temperature in the layer is comprised between 350° C. and 430° C. and is higher than the maximum hot spot temperature of the layer of greater activity formed by pure catalyst, and wherein during the period in which the situation of the maximum hot spot temperature of the layer of lower activity remains at the values cited above, the conversion of methanol is higher than 96% by mols.