Optimization of microstructure and geometry of hydrophobic ceramic membrane for SO₂ absorption from ship exhaust

Membrane gas absorption (MGA) is of great interest for SO₂ capture from ship exhaust, as it has high separation efficiency and, more importantly, is comprised of a separator that can be flexibly installed and operated on ships. Here, we report a class of hydrophobic tubular asymmetric ceramic membranes for SO₂ absorption. To find the membranes with reasonable microstructure and geometry, we used a numerical 2D model to simulate SO₂ absorption process and verified the model by comparing its results with experimental data. Simulations showed that most of the SO₂ mass transfer resistance existed in membrane phase, indicating that the optimization of membrane parameters, rather than operational conditions, should be the primary consideration to enhance the overall SO₂ mass transfer performance. Furthermore, simulations indicated that the SO₂ separation performance depended negligibly on membrane pore sizes, but can be significantly improved by optimizing the thickness and inner diameter of membrane tubes.