CO₂ Capture With Absorbents of Tertiary Amine Functionalized Nano-SiO₂

To improve CO₂ adsorption performance of nanoparticle absorbents, a novel tertiary amine functionalized nano-SiO₂ (NS-NR₂) was synthesized based on the 3-aminopropyltrimethoxysilane (KH540) modified nano-SiO₂ (NS-NH₂) via methylation. The chemical structure and performances of the NS-NR₂ were characterized through a series of experiments, which revealed that NS-NR₂ can react with CO₂ in water and nanofluid with low viscosity revealed better CO₂ capture. The CO₂ capture mechanism of NS-NR₂ was studied by kinetic models. From the correlation coefficient, the pseudo second order model was found to fit well with the experiment data. The influencing factors were investigated, including temperature, dispersants, and cycling numbers. Results has shown the additional surfactant to greatly promote the CO₂ adsorption performance of NS-NR₂ because of the better dispersity of nanoparticles. This work proved that NS-NR₂ yields low viscosity, high capacity for CO₂ capture, and good regenerability in water. NS-NR₂ with high CO₂ capture will play a role in storing CO₂ to enhanced oil recovery in CO₂ flooding.