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. (c) 2018 American Institute of Chemical Engineers AIChE J, 65: 409-420, 2019