Kinetics of the irreversible deactivation of the HZSM-5 catalyst in the MTO process

The kinetics of the reversible and irreversible deactivation of the catalyst (based on a HZSM-5 zeolite) in the methanol to olefins process, in the 673-773 K range, has been obtained from experimental results in fixed-bed reactor operating under reaction-regeneration cycles. The total activity remaining in the catalyst is quantified as the product of a function for recoverable activity due to coke deposition (which depends on the composition of the lumps of the kinetic scheme and includes the attenuating effect of water on coke deposition) and a function for the non-recoverable activity due to dealumination (caused by water at high temperature). (C) 2003 Elsevier Ltd. All rights reserved.