Investigation On Gas Separation Performance Of Coal-base Tubular C/C Composite Membrane Prepared By Template Method

The Mingsheng lean coal from Shanxi was used as a row material,A substrate tubular carbon membrane was prepared by a series processes of crushing,screening,adding adhesive,mixing and molding,the tubular carbon supporting membrane was prepared form substrate tubular carbon membrane by drying and carbonization.An Inorganic-organic sol-gel composite was prepared from TEOS and FAR,which was used as template and carbon source.C/C compound separation membrane was prepared by the processes of carbonization and etching after dipping the carbon support membrane in Inorganic-organic sol-gel composite;the effect of catalyst,water,cosolvent and the dosage of FAR on the sol and C/C compound membrane performance was studied;the performance of C/C compound membrane by dipping carbon supporting membrane in Inorganic-organic sol-gel composite,which adding DMF and surfactant was also investigated.Effects of coal particle size,components of synthesis sol on C/C compound membrane performance were investigated and dipping,synthesis membrane,the time of synthesis sol,aging and etc on gas infiltration separation of the C/C compound membrane were also investigated.It indicated that under the better conditions C/C compound membrane with better composite effect,homogeneity of thickness layer and homogenous pore-size distribution could be made.The better conditions of making C/C compound membrane were Synthesis of sol-gel composite on H₂O/EtOH/HCl/TEOS=1.5:4:0.01:1; volumic ratio of FAR and TEOS is 1:1;lean coal particle size is less than 200 mesh; dipping into the inorganic and organic composite sol for 12h,which is prepared by TEOS hydrolysis and polycondensation by HCl;drying at 30℃.The separation coefficient of H₂/N₂ and H₂/CO₂ were 10.5 and 14.5 respectively.The gas separation could be significantly improved by dipping two times in vacuum atmospheric,the separation coefficient of H₂/N₂ and H₂/CO₂ were 15.9 and 19.8 respectively.But the permeation rate decreased significantly.The separation coefficient of H₂/N₂ and H₂/CO₂ were 16.3 and 19.8 respectively,under the Preparation conditions of reaction temperature 40℃and stirring 2h,drying the gel at 40℃and etching 40min by 40%HF solution.Sol aging for 36h at room temperature before digging carbon supporting membrane could significantly improve the separation coefficient of H₂/N₂ and H₂/CO₂ to 18 and 22.5 respectively.Adding dispersant could improve sol stability during synthesis,the performance C/C compound membrane was also improved.When the amounts of added DMF is 4%,the separation coefficient of H₂/N₂ and H₂/CO₂ were 19.5 and 24.After adding cationic surfactant 1631,the separation coefficient of H₂/N₂ and H₂/CO₂ were 19.2 and 23.3.the permeability coefficients are increased slightly After adding 40ml 3%PVA and 1631,the separation coefficient of H₂/N₂ and H₂/CO₂ were 19.6 and 24 respectively.The physical and chemical performance and microscopic structure of compound membrane were characterized using FT-IR,SEM,XRD,TG and other analysis instruments.