(378i) Development of Acoustic-Driven Packing Material a Novel Uky-Caer Technology for CO2 Capture

Acoustic devices have shown to be beneficial in providing unique enhancements in the field of process engineering such as agitation, crystallization, cracking, de-caking, and de-foaming. A few of these devices take advantage of the acoustic streaming effect produced from traveling sound waves in an aqueous solution. A propagating surface wave in a liquid film will increase the film’s surface area as it stretches and compresses the liquid, and promote internal mixing. In a gas-liquid absorption process an increase in solvent surface area and gas liquid mixing will increase absorption rate. A novel device is in development at UKy-CAER, acoustic-driven packing material, to scale this concept for use in a counter current CO₂ absorption process. Transmitting high frequency acoustic energy, at resonance, into an absorber column’s packing material will cause that material to vibrate and become a transmitter of the incident acoustic energy. Solvent in contact with the vibrating packing material will oscillate at similar wave parameters to the source of acoustic energy, depending on the solvents physical properties.

This presentation will cover the development of acoustic-driven packing material starting from proof of concept, bench scale testing with random packing material, and ending on the first prototype structured packing test. Lessons learned for future development will also be discussed such as the importance of impedance matching and variable frequency emitters. At 20 and 28 kHz, acoustic-driven packing material has been shown to provide up to a 20% relative increase in solvent absorption rate with 30 wt% monoethanolamine. Additionally, adding 1 wt% fine solids, ≈ 40 µm, to the absorption solvent in combination with acoustic-driven packing material has been shown to further increase absorption rate by up to 40% over baseline testing. Acoustic amplitude was observed to be positively correlated with a minor increase in solvent absorption rate. This suggests that the smallest amount of power required to generate acoustic streaming in the solvent would be the most efficient choice in terms of power consumption optimization. Lastly, no decrease in performance has been observed when scaling from proof concept to prototype testing.