Bionic Packings Enhance the Absorption of SO₂ in a Bubble Column

Abstract

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 SO 2 absorption into water. The absorption rates of SO 2 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 SO 2 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).

Computational Fluid Dynamics Based Modeling of Gas Absorption Process: A State-of-the-Art Review

“…As a result, the liquid mass transfer coefficient as well as the specific surface area are increased. The promotional effect of the novel packings on SO 2 removal efficiency is more significant than Pall or Dixon rings …”

“…105 In the bubble reactor with novel packings with a special shape, such as "sea urchin", Pall and Dixon rings can be added into the bulk phase to break bubbles and increase the turbulence of the flow field. 106 Inside a bubble, the internal circulation is favorable for the gas absorption process, as the internal flow has a positive impact on the gas−liquid interfacial mass transfer. 107 In terms of a preferred flow in a packed bed, liquid exists on the packings as thin films.…”

“…The promotional effect of the novel packings on SO 2 removal efficiency is more significant than Pall or Dixon rings. 106 The difficult part facing the simulation of the packed bed column is the simplification of the packing sections. Due to the irregular structure of packings, the estimation of mass transfer conditions is normally achieved by obtaining the formulas of MTCs for both gas and liquid through experimental data optimization.…”

An Overview of Flue Gas SO2 Capture Technology Based on Absorbent Evaluation and Process Intensification

“…Cai et al proposed a biomimetic packing material with a "sea urchin" shape to enhance the mass transfer rate of gas in liquid. 127 The "sea urchin" shaped packing material punctures large bubbles into small bubbles in the bubble column, thereby enhancing the mass transfer rate of gas in liquid. The "3.5 mm +5 mm" "sea urchin" packing material exhibits the best desulfurization effect, with a liquid volume mass transfer coefficient (k L a) 1.5 times that of Pall rings.…”

“…The smaller the volume and the greater the quantity of bubbles, the better the mass transfer efficiency. Cai et al proposed a biomimetic packing material with a “sea urchin” shape to enhance the mass transfer rate of gas in liquid . The “sea urchin” shaped packing material punctures large bubbles into small bubbles in the bubble column, thereby enhancing the mass transfer rate of gas in liquid.…”