Abstract

Micro-encapsulation of Carbon Dioxide Capture Solvents Through Microfluidic Processing

Congwang Ye, Research Staff, Lawrence Livermore National Laboratory

Microfluidics have been developed for many applications such as life science research and lab-on-a-chip. At LLNL, our work focuses on using microfluidics to produce microcapsules for energy application, particularly the capture of CO₂. Recently, new designer solvents have been developed to reduce energy cost for carbon capture. However, they suffer from many drawbacks such as high viscosity, solid precipitates and corrosivity. Separating the capture solvent with a gas permeable shell provides a practical pathway to use these solvents. In our lab, double emulsion drops were generated within a micro capillary device and are composed of liquid capture solvents as the core and different polymer precursor solutions as the shell layer. After crosslinking the polymer shell, the resulting microcapsules are mechanically robust and can be handled in fixed-bed, moving-bed or fluidized-bed reactors for different applications. While the mass transfer of gas through the capsule shell is slightly lower when compared to neat liquid sorbents, the increase in surface area enhances the overall CO₂ absorption rate by 3.5-10x based on experimental data. The absorbed CO₂ can then be released by heat or diffusion for reuse applications or underground storage.