Influência do método de preparação sobre catalisadores à base de Fe203/Mo03 e comparação com catalisador FK-2 (TOPSOE) para obtenção do formaldeído a partir do metanol.

Abstract

In the present work, we present the laboratory preparations of iron oxide and molybdenum catalysts to obtain formaldehyde from methanol, the evaluations and comparisons with the industrial catalyst FK-2 manufactured by Haldor TOPSOE A / S through tests. catalytic These tests were performed on a tubular reactor. The unconverted reagent and the formaldehyde reaction product were analyzed by gas chromatography. Three preparation methods were used for the catalysts: Solvent Evaporation, Heterogeneous Mixing and Mechanical Mixing, the latter presenting the best yield catalyst, referred to as 3.1.1. Stability studies have been performed where it was realized that at the reaction temperature of 330 ° C for 5h of continuous use, catalyst 3.1.1 showed selectivity greater than catalyst FK-2. However, the catalyst industrial production has better performance because of its high activity. It was investigated where the external diffusive effect controls the overall speed of the process and the apparent activation energy (Ea) through the equation of Arrhenius. For catalyst 3.1.1 two "Eaw values ​​equal to 4 Kcal / mol and 24 Kcal / mol at low (250-270 ° C) and high (270-320 ° C) temperature ranges. At the However for the industrial catalyst only the 23 Kcal / mol.