Water vapor corrosion behavior of porous silicon carbide membrane support

High-temperature water vapor corrosion of porous silicon carbide with and without additive alumina and its microstructural feature were investigated to examine the corrosion resistance of porous membrane supports for hydrogen production by steam modification of methane. Corrosion test was performed under similar condition as hydrogen production reaction occurred at 600 and 1000 °C, 4 atm (0.4 MPa) and 3/1 = H2O/N2 where nitrogen gas was substituted for methane. In the corrosion at 600 °C, the alumina-doped support showed weight gain of 1.3 mg/cm2, while the undoped support showed weight gain of 0.7 mg/cm2. In the alumina-doped support, pore growth was observed because of the coalescence among oxidized fine particles. In contrast, the pore size of the supports without alumina was slightly reduced, due to thin silica layer formed on the SiC particle. In the corrosion at 1000 °C, the almost complete conversion to silica and the densification of silica were found. The densification of silica was due to the viscous flow sintering of silica under water vapor.