Water nano-carbonation by CO2 infusion into submersible and pipe-flow nanobubble generators: The rise and fall of dissolved CO2

The CO2-bubble-based carbonation of water using established methods is very energy-intensive with the status quo of mechanical bubble generation, and there is rapid loss of CO2 from the dispersed (bubble) phase in water, due to larger bubbles sizes in the micro-, meso- and macro-range and their associated instability. Instead, the “nano-carbonation” of water, by CO2 fine bubbles (including CO2 nanobubbles) provides for longer-lived levels of dissolved CO2. The present research details how the use of both submersible and continuous-flow nanobubble generators can boost levels of dissolved CO2 far above Henry’s-Law level, and tracks longevity and decay of the dissolved-CO2 levels in the water. In particular, in the case of the submersible fine-bubble generators, both mechanical and novel electrostriction (electric-field) approaches are used, whilst in the case of pipe-based generators, hydrodynamic approaches are used for fine-bubble carbonation, with optional application of electric field to boost longer-time dissolved-CO2 levels. The decay times for the dissolved CO2 were assessed, which were a great deal longer – magnitudes – than without nano-carbonation, owing to the nanoscale CO2 keeping the overall dissolved-CO2 concentration higher with slower Fick’s-Law release.