مدل سازي تشكيل كك و اثر آن بر غير فعال شدن كاتاليزور مونومراستايرن

MODELING OF COKE FORMATION AND ITS EFFECTS ON STYRENE MONOMER CATALYST DEACTIVATION

Styrene is an important industrial unsaturated aromatic monomer. Styrene monomer is used for production of polymers. The most important commercial process for production of styrene is based on catalytic dehydrogenation of ethyl benzene. The major problem in this process is the decrease of catalyst life time and catalyst deactivation. Catalyst deactivation occurs by several mechanisms. Coke formation is considered to be the most important factor in catalyst deactivation. Gasification reaction is used for catalyst regeneration. Modeling and determination of kinetic parameters and optimization of the process can improve the final conversion to styrene and postpone catalyst deactivation. From different coke formation modeling levels, deactivation at particle level was selected in this re-search. In this level, four rival models for the gasification reaction and four deactivation functions for coke formation in the particle level type are developed. The 16 models obtained are the results of the coupling of these cases. Anova one-way was used for the analysis of models with SPSS software.The reference model is the model with the largest F. co-efficient. Kinetic parameters are estimated from a set of experimental data. The reference model de-scribes satisfactorily the experimental results and has the necessary and sufficient validity and reliability. The reference model was compared with the Froment model.The error was less than 0.1% in the range of experimental data. This model is easy to use and has acceptable accuracy. Catalyst coke con-tent, rate of coke formation and gasification and net rate of coke formation are considered under various temperatures and hydrogen, steam and aromatics pressures, with respect to the run length and other variables. The results obtained in this work correspond satisfactorily with the published data.