STUDY OF PARAMETERS AFFECTING THE COALESCENCE OF DIMETHYL DISULFIDE DROPS IN A MEROX UNIT

Abstract This study focuses on the coalescence of dimethyl disulfide drops with the mother phase at a flat aqueous-organic interface between dimethyl disulfide and different sodium hydroxide solutions. Drop coalescence is an important part of the Merox process for regenerating the solvent. A digital high-frame rate camera was used for recording drops coalescence and duration time. Drops of dimethyl disulfide were directed in different sodium hydroxide solutions as the continuous phase. Applying the experimental design method, the influences of independent variables of drop size and physical properties on coalescence time were investigated. Computational fluid dynamics (CFD) was employed to simulate the drops released from a nozzle, moving toward the interface, and the CFD results were validated by experimental data. The maximum deviation between the predicted and experimental coalescence times was 18.7%. It was found that, among the physical properties, interfacial tension plays the most important role on the coalescence time. Based on the results, a correlation for coalescence time was proposed.

摘要 本研究聚焦于二甲基二硫醚（dimethyl disulfide）液滴在二甲基二硫醚与不同氢氧化钠溶液构成的平坦水-有机界面处，与母相的聚并过程。液滴聚并是溶剂再生工艺Merox过程的核心环节。本研究采用高帧率数码摄像机记录液滴聚并行为与聚并持续时长。实验中将二甲基二硫醚液滴注入以不同氢氧化钠溶液为连续相的体系中，通过实验设计方法，探究了液滴尺寸与物理性质等自变量对聚并时间的影响。本研究采用计算流体动力学（Computational Fluid Dynamics，CFD）模拟了液滴从喷嘴喷出、向界面运动的全过程，并通过实验数据对CFD模拟结果进行了验证。预测聚并时间与实验测得值的最大偏差为18.7%。研究发现，在各项物理性质中，界面张力对聚并时间的影响最为显著。基于上述实验结果，本研究提出了一则聚并时间的关联式。