(722c) Preparation of Porous SiC Ceramic Supports with Enhanced Air Purification Performance By Recycling of Naa Zeolite Residue

NaA zeolite membrane which exhibits remarkable selectivity for pervaporative dehydration of organic compounds has been widely applied in industrial scale. Typical preparation of NaA zeolite membrane involves the hydrothermal synthesis of the NaA zeolite and the formation of a zeolite membrane layer on a ceramic substrate. However, the preparation of NaA membrane generates large quantity of zeolite residues in the synthesis solution. In this paper, the NaA residues from the preparation of the NaA zeolite membrane was recovered and reused as additives for the fabrication of porous SiC support (PSCS). The effect of loading of NaA and sintering temperature on the porosity, pore size, gas permeability and bending strength of PSCS were investigated. The results showed that the addition of 8% of NaA zeolite lead to the decrease in sintering temperature of SiC ceramic from1550 to 1200 °C, a 22.6 % decrease as compared to sintering pure SiC powder. Also, the gas permeability and the bending strength were significantly increased to 1200 m³ / (m²·h·kPa) and 25 MPa, respectively compared to 600 m³ / (m²·h·kPa) and 2 MPa of the pristine PSCS without NaA. The prepared PSCS with NaA sieve also showed enhanced acid corrosion resistance and thermal shock resistance property. By modifying the sintering condition to N₂ environment and 1100 °C (sintering conditions based on our previous results), the alkali corrosion resistance property of the new NaA/PSCS membrane can also be greatly enhanced. The new membrane produced from recycling NaA residues shows promising results in high temperature gas-solid separation.