Rapid Microfluidic Screening of Solubility and Mass Transfer of CO2 In Solvents

In this talk, we describe a high-throughput method to determine the essential fluid properties of solvent mixtures for CO₂ capture. Capture, and subsequent storage, of CO₂ can be a viable route to reduce emissions of CO₂ into the atmosphere. These emissions are typically dilute, and selective and fast absorbing solvents are needed to achieve commercial process efficiencies and to minimize capital cost. To select solvents and design processes, the intrinsic properties of these solvents such as vapor-liquid equilibrium and kinetics are required. However, this information is often lacking and time- and material-consuming experiments are needed to obtain this information.

Microchannels are attractive to screen solvents because of their large surface area and short distances for mass transfer. In this work, we developed a rapid and flexible screening method for CO₂ absorption in a micro-channel. Gas bubbles were injected via a T-junction into the liquid solvent stream and the absorption process was followed visually. In this way, direct information could be obtained about solubility and mass transfer of CO₂ in different solvents. The presented method is rapid, requires only small quantities of solvents and can be used for the fast screening of (new) fluid mixtures for CO₂ absorption.

Acknowledgment: Partial financial support from the European Community in the FP7- project Decarbit (Grant Agreement Number 211971) is gratefully acknowledged.