Numerical investigation on the structural optimization of a counter flow contact-cyclone reactor for epoxidation of fatty acid methyl ester

Abstract

In this paper, a counter flow contact-cyclone reactor was designed for the epoxidation of fatty acid methyl ester (FAME). The impinging stream was applied to enhance the mixing and reaction of FAME and peroxyformic acid. And the optimization of structural parameter of counter flow contact chamber (height, H, impinging length, L_i, accelerating tube length, L_a) was conducted using Eulerian model and RSM model. A parameter named mixing non-uniformity parameter, β, was used to evaluate the mixing performance between two liquids. Based on the variation of β along the radial and axial directions, the mixing between two liquids tends to be stable with the axial cross section approaching the guided vane. The structural parameters considered show influence on the mixing time evolution and the initial conditions for enhancing mixing using impinging stream, respectively. Eventually, the data shows the β after optimization (H of 120 mm, L_i of 30 mm, L_a of 40 mm) is approximately 0.09×10⁻² in the stable flow area, a decrease of 62.5 % compared to that before optimization. Moreover, the results also indicate that the vortices induced by impinging stream experience the evolution in both size and number, which is closely related to the gradual improvement of mixing efficiency between two liquids.