Bionic Packings Enhance the Absorption of SO₂ in a Bubble Column

The development of compact reactors has attracted wide interest from chemical engineering society. Inspired by the special shape of "sea urchin", we propose that bionic packings with this type of shape are superior in breaking bubbles in a bubble column, and therefore, the mass transfer rate of gases in liquids may be greatly enhanced. In this study, different structures and quantities of bionic packings were added to a bubble column to enhance SO2 absorption into water. The absorption rates of SO2 into water with different bionic packings were compared with these systems with commercial packings of Pall rings and Dixon rings. The mass transfer coefficients and gas-liquid specific interfacial areas of different packings with the same volume of packings' addition were measured. Based on the comparison of SO2 removal efficiency for systems with different packings, the system with the addition of 24 "3.5 mm + 5 mm" packings presented the optimum promotion effect. The liquid volumetric mass transfer coefficient (k(L)a) of adding 24 "3.5 mm + 5 mm" packings was 1.5 times of the baseline, indicating that the process was mainly controlled by liquid-phase mass transfer. The increase of the liquid volumetric mass transfer coefficient (k(L)a) was the combined effect of the increased liquid-phase mass transfer coefficient (k(L)) and the specific interfacial area (a).