Optimization of ethylene dimerization in a bubble column reactor based on coupling kinetic and equilibrium models

Abstract

The main object of this research is modeling, sensitivity analysis, and multi-objective optimization of the ethylene dimerization process at the presence of a homogenous catalyst. Industrially, the ethylene dimerization occurs in a bubble column reactor equipped with an external cooler to prevent temperature runaway. In the first step, the considered bubble column reactor is heterogeneously simulated considering a two-phase flow regime by coupling the kinetic and equilibrium based models. To validate the accuracy of developed model, the simulation results are compared with the plant data. The simulation results show that the mass transfer from gas to liquid phase controls the ethylene dimerization rate in the considered plant. In the second step, the effects of operating pressure and temperature on the ethylene conversion and butene selectivity are investigated by the developed model. The simulation results show that pressure has an insignificant effect on the conversion and selectivity due to the high contact time of gas and liquid medium, low gas to liquid flow rate, and high mass transfer area. In the third step, a multi-objective optimization problem is programmed and the optimal temperature of reactor is calculated by the TOPSIS decision-making method.