Deactivation models by fitting the progression of temperature profiles – Coking model for the MTG process in adiabatic reactors

• A deactivation model for the methanol-to-gasoline (MTG) process is developed based on pilot plant data.
• Special efforts have been taken to ensure that the fixed-bed pilot reactor operates adiabatically at industrial conditions.
• The progression of the axial adiabatic temperature profile is used to develop a deactivation model for the process.
• Model equations and method of solution are provided. Unknown parameters are estimated by means of a non-linear least square method.
• The presented methodology is useful for estimating deactivation models for industrial application to be used for design and analysis.

A methodology for estimating deactivation models for catalysts in industrial application is proposed. The method applies the movement of the measured axial temperature profile to gain information of the deactivating phenomena. For adiabatic reactors the conditions must be obtained by controlled heat compensation in a reactor furnace. As an example a deactivation model for the industrial methanol-to-gasoline (MTG) process is developed. The deactivation model together with suitable reactor models is a system of coupled partial differential equations with time and spatial coordinate as the independent variables. The unknown model parameters are estimated via a non-linear least square method, by matching predicted axial temperature profiles with measured profiles obtained in a pilot reactor containing a gasoline synthesis test catalyst.