Analysis and modeling of deactivation of zeolite catalyst for diethanolamine production

The demand for diethanolamine as a raw material for herbicides has been increasing, and a selective production process for diethanolamine is required. We found that pentasil-type zeolite modified with a rare earth element was an excellent catalyst with high activity and diethanolamine selectivity, and commercialized the process using this catalyst. The catalyst is deactivated in several days, so regeneration of the catalyst is necessary. Analysis and modeling of catalyst deactivation are necessary for industrial process design and for determination of operation conditions. We analyzed deactivated catalysts and catalyst-bed temperature profile change in relation to ethylene oxide conversion, and proposed a model in which cumulative reaction amount of ethylene oxide and diethanolamine corresponds to catalyst deactivation. This model can explain the change of temperature profile and product distribution, and is useful for reaction process design.