Kinetics of liquid phase alkylation of benzene with dodecene over mordenite

This paper presents the kinetics investigation of liquid phase alkylation of benzene with dodecene using mordenite having Si/Al=20. The models are developed based on physicochemical characterization of the catalyst and a laboratory scale fixed bed reactor data. The FTIR analysis shows that approximately 90% of the acidic sites are Brønsted acid type while the remaining 10% are Lewis acid type. The kinetic experiments are conducted with 6:1 molar ratio of benzene to dodecene at four different temperature levels between 80 to 140°C. The product analysis shows that the main alkylation product is 2-phenyldodecane. At lower temperature, the concentration of dodecene isomers is significant. On the other hand at higher temperature linear alkylbenzene isomers are the dominating products. The kinetic models are formulated considering simultaneous dodecene isomerization and benzene alkylation. The reaction rate parameters are estimated by fitting of the experimental data implemented in MATLAB. The adequacy of the estimated model parameters are verified by thermodynamic consistency and statistical fitting indicators. The activation energy for protonation of 1-dodecene to 2-dodecene found to be significantly lower (34kJ/mol) than that of the 2-dodecene to 3-dodecene reaction (51kJ/mol). The activation energies of surface alkylations of benzene to 2-phenyldodecane and 3-phenyldodecane are 49kJ/mol and 66kJ/mol, respectively.