Kinetic study of propane aromatization over Zn/HZSM-5 zeolite under conditions of catalyst deactivation using genetic algorithm

Abstract

The kinetic studies of propane aromatization reaction over Zn/
/HZSM-5 catalyst at temperature of 500–560 °C and space velocity of 500–
–2500 cm³ g_cat^-1 h^-1, in a plug flow reactor, under catalyst deactivating con­di­tions were performed. A lumped kinetic model consisting of six lumped com­ponents and six reaction steps was proposed to describe the aromatization of propane. The kinetic model involves 18 kinetic parameters and one catalyst deactivation constant. The reaction steps orders were obtained by the power law model. Frequency factors and the apparent activation energies of the react­ion steps were calculated based on the Arrhenius equation. An exponential function depending on the time-on-stream was applied for the catalyst deacti­vation model and the kinetic parameters were calculated via a genetic algo­rithm. The kinetic results indicated that the lumped kinetic model can well estimate the product yields of propane aromatization.