Process Improvements in Methanol Oxidation to Formaldehyde: Application and Catalyst Development

摘要

Compared with oxide catalysts for many other selective oxidation and ammoxidation processes, the commercial iron molybdate type catalyst for the oxidation of methanol to formaldehyde has an outstanding performance giving a selectivity in the range 92-95 % to formaldehyde at almost complete methanol conversion. In this presentation an overview is given describing the historical and present developments that have made possible a fourfold increase of the productivity per reactor tube and day since the late 1950s, which has been achieved without any change of the basic chemical composition of the catalyst. The effects on steam production and power consumption are described as well. Moreover, some results on novel Fe-(V)-Mo-O catalysts with spinel-type structures are described, showing good stability in methanol oxidation. Compared with conventional catalysts, the spinel-type catalysts have a larger number of reoxidation sites (Fe) per active Mo atom and allow the metals to change valence retaining the structure type.