关联外扩散影响的合成直链烷基苯催化反应动力学

Kinetics of Catalytic Reaction for Linear Alkylbenzenes Synthesis Associated with External Diffusion

在固定床反应器内进行固体酸催化苯与直链烯烃烷基化反应实验,并将外扩散传质过程与烷基化反应相结合,确定了烯烃转化反应动力学模型方程,以及直链烷基苯、小分子烯烃和小分子烷基苯收率动力学模型方程。利用实验数据进行模型参数估值,建立了关联外扩散影响的烷基化反应动力学模型。研究结果表明,反应温度越高,各反应速率常数和外扩散传质速率常数均越大,而烷基化反应选择性越低。利用烷基化动力学模型对烯烃转化率进行预测的结果表明,随着流体空塔流速提高,烯烃转化率先增大后趋于不变,外扩散阻力对反应的影响趋于忽略不计;并且随着反应温度升高,化学反应速率增大,消除外扩散影响所要求的流体空塔流速更大。

The solid acid catalyzed alkylation reaction of benzene with linear olefins was carried out in a fixed-bed reactor and the external diffusion mass transfer process was combined with the alkylation reaction to determine the kinetic model equation for the olefin conversion and yield model equations of products for linear alkylbenzene（LAB）, short chain olefin（D） and short chain alkylbenzene（DB）. The kinetic model of the alkylation associated with the external diffusion was established based on the experimental data and the estimation of model parameters. The results of the study showed that the higher the reaction temperature, the higher the rate constant of each reaction and the mass transfer as well as the lower the selectivity of LAB. The prediction of the olefin conversion rate using the kinetic model of alkylation showed that with the increase of linear velocity of the fluid, the olefin conversion rate increased, and then tended to be constant and the influence of the external diffusion resistance on the reaction tended to be neglected. As the reaction temperature increased, the rate of the chemical reaction increased and the linear velocity of the fluid required for eliminating the external diffusion was greater.