(640h) CO2 Capture and Transport Behaviors of Encapsulated Liquid-like Nanoparticle Organic Hybrid Materials (NOHMs)

The development of hybrid CO₂ capture sorbents has provided a transformative solution to novel water-less and water-lean CO₂ capture solvents that have been challenged with their high viscosities. A number of novel CO₂ capture solvents including ionic liquids (ILs) and nanoparticle organic hybrid materials (NOHMs) have been developed to capture CO₂ from various industrial sources. While NOHMs show thermodynamic advantages for stable CO₂ capture such as strong CO₂ binding energy resulting from functionalized amine groups, great oxidative thermal stability due to silica nanoparticles as a support, low regeneration energy, and negligible vapor pressure, the overall CO₂ capture process is often limited by mass transfer as a result of high viscosity. Therefore, the application of NOHMs in large-scale CO₂ capture requires an innovative design of novel solvent carriers. In order to overcome these issues, we have designed and developed a hybrid CO₂ capture sorbent system based on a unique encapsulation technique, Solvent Impregnated Polymers (SIPs). By immobilizing NOHMs solvents as microemulsions inside a gas permeable polymer (PDMS) matrix, the CO₂ capture rate was significantly improved compared to the bulk NOHMs solvent due to the increase in the gas-liquid interfacial areas and the gas permeability. The governing mechanism of CO₂ capture using encapsulated NOHMs was investigated based on kinetic modeling. The experimental findings suggest that the encapsulation of NOHMs can allow for a flexible design of CO₂ capture units ranging from a fixed bed to a fluidized bed as the sorbents can be treated as a particulate system. The effect of moisture on the CO₂ capture behavior was also investigated as well as the recyclability of the encapsulated NOHMs.

Prepared by LLNL under Contract DE-AC52-07NA27344