Falling liquid-film on hydrophilic porous ceramic membrane for boosting CO₂ absorption

Membrane absorption has received considerable attention for CO₂ capture owning to a membrane contactor enables to provide high mass transfer area. However, a key challenge with hydrophobic membrane-based gas absorption is the issue of membrane wetting. Here, a falling liquid-film absorption process using hydrophilic porous ceramic membrane was proposed for CO₂ capture. This approach not only keeps the advantage of high contact area, but also avoids the problem of membrane wetting. The mass transfer performance of falling liquid-film membrane contactor under different operating cases were experimentally investigated, considering the flow domains for the gas and liquid fluids, co– and counter-current flows and the specific surface area of the membrane. The results of the falling liquid-film membrane contactor were compared with a random packed column. It can be inferred from the experimental results that the falling liquid-film membrane contactor can be a competitive alternative for CO₂ absorption.