Kalashnykov Y. Kalashnykov Y.V. Preparation of an oxide catalyst for the conversion of methanol to formaldehyde based on ammonium molybdoferates(II)

The thesis deals with the issues of scientific foundation of technology for the production of oxide iron-molybdenum catalyst for the conversion of methanol to formaldehyde based on ammonium molybdoferates(II). Composition of various ammonium molibdoferates(II) depending on the solution pH and given ratio of iron and molybdenum have been studied. Was shown that deposition of ammonium molibdoferates(II) from the reaction mixture can be carried out by salting-out from the solution using acetone. Acetone also tends to minimize the amount of ammonium sulfate impurity salting-out with ammonium molibdoferates(II) which has been compared to other salting-out agents. Kinetic studies of ammonium molibdoferates(II) heat treatment have been conducted and mathematical model of chemical transformations in a pre-catalyst mass was developed. It was shown that titanium stearate solution in n-hexane can be used for the forming of the pre-catalyst mass. It was experimentally proved that the addition of titanium oxide prolongs the lifetime of oxide iron-molybdenum catalyst by transforming low selective iron(III) oxide impurity, which is obtained in the catalyst aging process, into the more selective to formaldehyde iron(III) titanate phase. The main technological parameters for obtaining the oxide iron-molybdenum catalyst promoted by titania have been established and the corresponding technological scheme for its production has been developed.