Kinetic Study on Dodecylbenzene Sulfonation in a Mixed Batch Reactor

Abstract

A mixed batch autoclave reactor was used to investigate the sulfonation reaction kinetics of pure samples of DodecylBenzene (DB). The effect of temperature in the range between 20 and 50 °C, and the effect of the concentrations of Sulfur Trioxde and DodecylBenzene upon the sulfonation reaction rate were studied. Two sets of experiments were performed .The first is applying high SO 3 /DB molar ratio C SO3 /C DB >>1, the second is with high DB/SO 3 molar ratio (C DB /C SO3 >> 1). It was shown that the sulfonation reaction is a 0.74 order with respect to DB and a 1.59 order with respect to SO 3 . The reaction rate constant k was determined for both sets. The values determined for the frequency factor and activation energy were as per the following equation: k = 2.2172x10 3 exp{-5207/R g T} (1). The kinetic model for the sulfonation reaction is R D.B = k* í µí° í µí° í µí±†í µí±†í µí±†í µí±†3 1.59 * í µí° í µí° í µí°·í µí°·.í µí°µí µí°µ 0.74 " (2). The progress of the reaction was determined from SO 3 concentration vs. time data conducted at different time intervals. Evaluations of SO 3 , DB concentrations and reaction rates were based on titrations of the inorganic phase with caustic soda standard solutions.