SiC ceramic membranes for high-efficiency micron-sized bubble aeration

Micron-sized bubbles can enhance gas-liquid contact area and mass transfer efficiency, but the preparation of ceramic membranes with controllable microstructures for gas dispersion remains challenging. This study investigated the performance of symmetric silicon carbide (SiC) ceramic membranes as oxygen dispersers, focusing on the influence of SiC powder particle size (2–10 μm) on membrane microstructure, surface properties, and gas-liquid mass transfer efficiency. By adjusting the SiC powder particle size, it was found that SiC membranes prepared from smaller particles exhibited more uniform pore size distribution, higher porosity, and smoother surfaces, generating smaller and more uniformly distributed micron-sized bubbles, thereby increasing oxygen dissolution rate and saturated dissolved oxygen concentration. However, under long-term aeration, the membranes suffered from insufficient structural stability, leading to increased porosity and deteriorated bubble size. In contrast, SiC membranes prepared from 8 μm SiC powder exhibited high bending strength (50 MPa), low operating pressure (0.097 MPa), and excellent mass transfer efficiency. By optimizing pore size and porosity, efficient mass transfer could be achieved at low energy consumption, with overall performance superior to traditional alumina membranes. This work provides a novel solution for gas dispersion processes.