Innovative compact multi-fluid absorber for CO₂ capture using advanced absorbents and microbubble technology

Enhancing gas–liquid mass transfer efficiency while reducing operational energy consumption and cost is essential for the industrial application of amine-based CO₂ capture technology. This study proposes a novel compact multi-fluid absorber that integrates spray, bubble and packed to reduce the absorber tower's size. The absorbent is atomized into fine droplets, which then pass through a foaming network to form more bubbles, increasing the gas–liquid contact area and enhancing CO₂ absorption. Four surfactants were evaluated for their foaming performance, viscosity, and surface tension when complexed with monoethanolamine (MEA). CO₂ uptake and equilibrium solubility of these solutions were tested in a bubbling vessel and analyzed using Nuclear Magnetic Resonance (NMR). Based on these experiments, the most effective absorber was applied to the novel compact multi-fluid absorber. The effects of gas and liquid flow rates on CO₂ performance were tested, revealing relationships between flow rates, bubble sizes, and absorption performance. The results show that the novel absorber improves absorption performance by over 30% compared to the unimproved version. It achieves a CO₂ removal efficiency of 80% at gas–liquid ratios up to 160 and a total absorption rate of 3.77 kmol/m³·h.