Metal molybdate/iron-molybdate dual catalyst bed system and process using the same for methanol oxidation to formaldehyde

摘要

A process and fixed bed reactor for oxidizing methanol in a reactant gas feed stream to formaldehyde. The process comprises introducing the reactant gas feed stream into an upstream region containing a first metal molybdate catalyst (substantially free of a volatile Mo/MoO3 species) under oxidizing conditions to form a partially oxidized reactant gas feed stream which is then introduced under oxidizing conditions into a downstream region containing a second metal molybdate catalyst to further oxidize any residual methanol contained therein. A fixed bed reactor comprising an upstream region and a downstream region containing the aforementioned first and second metal molybdate catalysts, respectively, is utilized to implement the inventive process to yield a product gas stream containing formaldehyde preferably at a conversion of 85% or more and a selectivity of 90% or more.