Non-destructive high-resolution X-ray micro computed tomography for quantifying dry water particles

Abstract

Dry water, a powder containing up to 98%wt. water and 2–6%wt. hydrophobic nanoparticles, is a novel material for novel applications like CO2 capture, transportation and storage in the form of clathrate hydrates. In this study, novel high-resolution X-ray micro computed tomography (HRXMT) was used as an in situ, non-destructive tool to visually and quantitatively examine the inner structure of dry water that has not been accessible previously. Specifically, the HRXMT was used to study the effect of silica/water wt. ratio on the number, surface area and volume distributions of dry water. The results showed that dry water was stable under ambient condition for long time. The technique was also successful in characterizing the structure changes in dry water after exposing to low temperature, high pressure and stirring. Low temperature did not affect the structure significantly, while high pressure and slow stirring broke the structure fairly readily with separation of dry water into the primary solid and liquid phases. These findings are useful to our understanding of the role of dry water in promoting the formation of CO2 and gas hydrates.