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以无模板剂二氧化硅溶胶为前驱体,用二次生长法在已浸渍分子筛种子层的α-氧化铝支撑体上制备MFI型分子筛膜,采用X射线衍射法、扫描电子显微镜和气体渗透实验表征分子筛膜的性能,研究了单组分和双组分二甲苯异构体在氧化铝支撑分子筛膜的渗透汽化分离性能.结果表明:在50℃和10 h下,二甲苯异构体单组分的渗透汽化通量按对二甲苯、间二甲苯、邻二甲苯的顺序依次减小;单组分的对二甲苯/邻二甲苯和对二甲苯/间二甲苯的分离因子可分别达到67和46,双组分的分别可达到29和42;单组分的对二甲苯和邻二甲苯的通量分别为7.41×10-4和0.11×10-4mol/(m2.s);双组分混合物中对二甲苯和邻二甲苯的通量分别为3.58×10-4和0.086×10-4mol/(m2.s).说明此分子筛膜适于渗透汽化分离二甲苯异构体.
The MFI zeolite membrane was prepared on the α-alumina support impregnated with molecular sieve seed layer by the secondary growth method using silica-sol without template as precursor. X-ray diffractometry, scanning electron microscopy and gas permeation experiments The performance of the molecular sieve membrane was characterized and the pervaporation performance of the zeolites supported on the alumina support zeolites was investigated. The results showed that the xylene isomers at the temperatures of 50 ℃ and 10 h were single group The pervaporation fluxes of p-xylene, m-xylene and ortho-xylene decrease in turn, and the separation factors of p-xylene / o-xylene and p-xylene / m-xylene can reach 67 And 46, the two components can reach 29 and 42, respectively; the fluxes of one-component p-xylene and o-xylene are 7.41 × 10-4 and 0.11 × 10-4mol / (m2.s) The flux of p-xylene and o-xylene in the mixture was 3.58 × 10-4 and 0.086 × 10-4 mol / (m2.s), respectively, indicating that this zeolite membrane is suitable for pervaporation to separate xylene isomers.