Design Guideline for Passive Microextractors: From Cocurrent Flow to Countercurrent Flow

Abstract

Passive countercurrent microextractors with high throughputs have potentially broad applications in industrialscale solvent extraction and hazardous waste disposal. To date, no design guideline has been available for developing such microextractors based on passive cocurrent microextractors. In this study, an oscillating feedback microextractor was chosen as an example system to provide a clear roadmap for bridging the gap between passive co-and countercurrent microextractors and achieving high-throughput countercurrent microextraction. Four steps were necessary, namely, (1) determination of the countercurrent flow arrangement strategy, (2) selection and modification of a primary passive cocurrent microextractor, (3) establishment of a passive single-unit countercurrent microextractor, and (4) parallelization of the passive single-unit countercurrent microextractor with the aim of achieving high throughput. The development from a passive cocurrent microextractor to a passive and high-throughput countercurrent microextractor was demonstrated using the oscillating feedback microextractor.

Continuous Flow Synthesis of Methyl Oximino Acetoacetate: Accessing Greener Purification Methods with Inline Liquid–Liquid Extraction and Membrane Separation Technology

“…If extractions are operated in a countercurrent mode, higher efficiencies than with cocurrent or crosscurrent arrangements are usually achieved, thereby making the process more economical by reducing solvent consumption and waste. Some examples have demonstrated the high potential of multistage countercurrent extraction systems on the microfluidic scale, in which separation can be driven by gravity, − by wetting properties, ,, or a combination of both . However, existing extraction strategies constantly need to be adapted to fit for specific separation and extraction problems, and the collection of data on a lab-scale is substantial for any process development.…”