(567c) Interfacial and Surface Area Characterization of Dense Sprays with Application to Absorption

Despite the wide use of sprays, the fundamentals of spray absorption are poorly understood. There is a particular lack of understanding about the relationship between surface area and interfacial area for dense sprays. The available surface area has a strong impact on the overall efficiency of absorption using sprays. However, not all of the surface area of a spray is available for mass transfer. Reaction of the solute gas with the solvent drops can result in saturation of the solvent mass and a decrease in the available interfacial area for mass transfer. Comparison of sprays with packed columns and other contactors can conveniently be made on an interfacial area basis. Thus, there is a need to ascertain the effective interfacial area for spray absorption along with the surface area availability. This study presents droplet size measurements using a Phase Doppler Interferometer (PDI), surface area quantification, and interfacial area measurements with the CO₂-0.1 N NaOH system inside a laboratory spray column. The effect of L/G ratio and gas-liquid contact height on the surface area availability and interfacial area are elucidated. A methodology is presented to compare the surface area measurements to interfacial area measurements, and this work will ultimately help in providing fundamental insight into spray absorption and spray behavior.