Liquid Flow and Mass Transfer Behaviors in a Butterfly-Shaped Microreactor.

Haicheng Lv,Gang Qian,Zhirong Yang,Xuezhi Duan,Xinggui Zhou,Zhongming Shu,Jing Zhang

doi:10.3390/mi12080883

Abstract

Based on the split-and-recombine principle, a millimeter-scale butterfly-shaped microreactor was designed and fabricated through femtosecond laser micromachining. The velocity fields, streamlines and pressure fields of the single-phase flow in the microreactor were obtained by a computational fluid dynamics simulation, and the influence of flow rates on the homogeneous mixing efficiency was quantified by the mixing index. The flow behaviors in the microreactor were investigated using water and n-butanol, from which schematic diagrams of various flow patterns were given and a flow pattern map was established for regulating the flow behavior via controlling the flow rates of the two-phase flow. Furthermore, effects of the two-phase flow rates on the droplet flow behavior (droplet number, droplet size and standard deviation) in the microreactor were investigated. In addition, the interfacial mass transfer behaviors of liquid–liquid flow were evaluated using the standard low interfacial tension system of “n-butanol/succinic acid/water”, where the dependence between the flow pattern and mass transfer was discussed. The empirical relationship between the volumetric mass transfer coefficient and Reynold number was established with prediction error less than 20%.

Highlights

IntroductionSince the 1990s, microreactor technology has been widely used in the fields of pharmaceuticals, emulsion preparation, and chemical process enhancement [1,2,3]
With the increase in the continuous phase flow rate, the ratio of continuous phase shear force to interfacial tension increases, which leads to the formation of the droplet flow and Taylor flow
The mass transfer behavior of two-phase flow in the microreactor was analyzed by using the standard low surface tension system “n-butanol/succinic acid/water”

Summary

Introduction

Since the 1990s, microreactor technology has been widely used in the fields of pharmaceuticals, emulsion preparation, and chemical process enhancement [1,2,3]. Compared with conventional industrial reactors, microreactors have smaller feature sizes and larger specific surface areas, thereby enabling efficient mass and heat transfer and highly controlled and continuous operation of the process [4]. Excellent mixing performance is one of the major advantages of microreactors [5]. Many studies have been carried out to control or improve the mixing performance by employing external sources of energy such as electric fields [6], magnetic fields [7], ultrasonic fields [8], etc., which are often costly and difficult to integrate. Most of the current research is based on changing the structure of microchannels to achieve effective fluid contact and mixing

Methods

Results

Conclusion