Performance and purification mechanism of the mullite/SiC composite filter tube membrane

Asymmetric composite tubular membranes were prepared with SiC as the support body and mullite as the membrane layer. The asymmetric mullite/SiC composite filter tube membranes were characterized by different analytic techniques. The mullite membrane was prepared as a layer on the SiC support with a thickness of about 175 μm, pore size of about 1-10 μm and porosity of 9.9%. The SiC support tube had a pore size of about 20-150 μm and porosity of 19.0%. After 360 days of high-temperature flue gas filtration, the most available pore size of the mullite/SiC composite filter tube membrane reduces from 45.2 to 36.4 μm (the reduction rate of about 19.4%). Analysis of the dust collected by back-blowing revealed that the dust particle size range was between 0.1-100 μm and about 50%of the dust particles were below 2.5 μm in size. The average capture rate of dust can reach 98.4%, indicating that the asymmetric mullite/SiC composite filter tube membrane has excellent filtration performance for the dust below PM2.5 in the high-temperature complex flue gas.