Modeling of the Molybdenum Loss in Iron Molybdate Catalyst Pellets used for Selective Oxidation of Methanol to Formaldehyde

Kristian Viegaard Raun (Guest lecturer)

Activity: Talks and presentationsConference presentations

Description

Formaldehyde (CH2O) may be synthesized industrially by selective oxidation of methanol over an iron-molybdate (Fe-Mo) oxide catalyst, known as the Formox process [1]. The fresh catalyst consists of a mixture of Fe2(MoO4)3 and MoO3. Fe2(MoO4)3 is the active phase and excess MoO3 must be present to form a surface layer of MoOx and make the pellets mechanically stronger. However, under the reaction conditions molybdenum oxide forms volatile species with methanol in the feed gas and migrates through the catalyst bed. The volatile molybdenum species decompose and accumulate downstream in the reactor bed leading to pressure drop build-up and finally plant shutdown. The volatility of the Mo in the catalyst and pressure drop build-up in the industrial reactor is the main reason for the short lifetime of only 1–2 years [2]. In this work the rate of volatilization of Mo from industrial catalyst pellets has been studied as a function of operating conditions and a single pellet model that take the relevant phenomena into account has been developed.
Period28 Aug 2018
Event title18th Nordic Symposium on Catalysis
Event typeConference
Conference number18
LocationCopenhagen, Denmark