采用二次生长水热合成法,在廉价的大孔α-Al2O3载体上(长度为800 mm,外径为12 mm,平均孔尺寸为2~5μm)成功制备高分离性能NaA沸石膜。通过XRD和SEM等表征方法对制备的NaA沸石膜的分子筛晶体与表面形貌进行表征,并对其渗透汽化性能进行测试,在操作温度为75℃、真空度为500~700 Pa的条件下,对乙醇含量为90%(wt)的乙醇/水体系进行分离,渗透通量大于2.0 kg·m-2·h-1且分离系数在8 000以上。表征和测试结果表明,制备的NaA沸石膜表面晶体结晶度高、连续致密且重复性高。
High separation performance NaA zeolite membrane was successfully prepared by secondary growth hydrothermal synthesis on an inexpensive macroporous α-Al2O3 support(length 800 mm, outer diameter 12 mm, average pore size 2~5 μm). The molecular sieve crystals of the prepared NaA zeolite membrane were characterized by X-ray diffraction(XRD) and the surface morphology of the prepared NaA zeolite membrane were characterized by scanning electron microscopy(SEM), the pervaporation performance was tested. Under the conditions of the operating temperature of 75 ℃ and the vacuum of 500~700 Pa, the ethanol/water system with ethanol content of 90%(wt) was separated, the permeate flux was greater than 2.0 kg·m-2·h-1 and the separation factor was above 8 000. The characterization and test results showed that the prepared NaA zeolite membrane had high crystal crystallinity, continuous dense and high repeatability.
Contemporary Chemical Industry