Toward Sustainable Energy and Materials: CO₂Capture Using Microencapsulated Sorbents

Microencapsulated carbon sorbents (MECS) are considered as promising materials for enhanced CO2 capture owing to their drastically increased gas-liquid contacting area. By reviewing the mass transfer mechanisms of CO2 absorption in terms of materials and reacting systems, this paper establishes the fundamental principles for designing MECS to lead the selection of solvents and shell materials for enhanced CO2 capture. Current commonly used microfluidic techniques for MECS synthesis are briefly described, and other promising methods are discussed for future studies. CO2 capture using MECS is substantially affected by the solvents, shell materials, and capsule geometry. The effects of shell mass transfer resistance are highlighted in this paper. Detailed process design is fundamental to the scale-up of CO2 capture using MECS, and the CO2 capture behaviors in various reactors can be revealed by modeling methods. Finally, the challenges existing in the current research are assessed, and future directions are given.