【作者】 盛春光；

【导师】 殷德宏； 王金渠；

【作者基本信息】 大连理工大学 ， 化学工程与技术， 2011， 硕士

【摘要】 渗透蒸发作为一种新型的膜分离技术,相对于传统的分离方法而言,具有分离效率高、能耗低、操作简便、设备简单等优点,近年来得到广泛的关注。NaA沸石分子筛膜由于其强的亲水性和介于大多数有机溶剂与水分子之间小的孔径,使其成为渗透蒸发过程脱除有机溶剂中微量水最理想的沸石膜。对于乙醇/水体系,NaA沸石分子筛膜具有非常好的的分离性能,将其与精馏过程耦合用于生物质燃料乙醇的制备,具有广阔的应用前景。本论文利用SEM、XRD以及渗透蒸发等表征手段寻求在大孔载体管上制备出高性能的NaA沸石膜。首先分别采用二次修补法和两步涂晶法在长度为25 cm的载体管上制备出高性能的NaA沸石膜,并在两种制备方法的基础上对NaA沸石膜进行放大制备,通过渗透蒸发性能测试,制备的长度为80 cm的NaA沸石分子筛膜具有较好的分离效果,已达到工业化应用的要求。本论文取得的具体成果如下：(1)采用高浓度合成液配方1Al2O3：2SiO2：2Na2O：120H2O对于低浓度合成液配方1Al2O3：5SiO2：50Na2O：1000H2O合成一次存在小缺陷的膜能够给以很好的修补,对于乙醇含量为90wt.%的乙醇/水体系,在温度为70℃和真空度为200～300 Pa的条件下,其分离系数大于5000,渗透通量最高可达到1.9210 kg·m-2·h-1,而且具有很高重复性。(2)采用合成液摩尔配比1Al2O3：5SiO2：50Na2O：1000H2O,对于采用两步涂晶后的载体管进行动态水热合成一次就可以获得高性能的NaA沸石分子筛膜。通过渗透蒸发性能测试,在温度为70℃和真空度为200～300 Pa的条件下,对90wt.%水/乙醇混合物进行分离,其分离系数大于10000,渗透通量最高可以达到1.8510 kg·m-2·h-1,且具有很高的重复性。(3)在大孔a-Al2O3载体管上成功制备出长度为80 cm的NaA沸石分子筛膜,通过渗透蒸发性能测试,对于乙醇浓度为90 wt.%的乙醇/水体系,保持进料流量为200L·h-1,当料液温度升高到120℃,其渗透通量最高可达到8.6781 kg·m-2·h-1,而且分离系数大于1000,已能够满足工业化应用要求。更多还原

【Abstract】 Pervaporation has received widely attention as a new type membrane separation in recent years, because it is an effective and energy-efficient technology compared with conventional separation process.NaA zeolite membranes have become ideal materials on dehydration of organic by pervaporation due to its high hydrophilicity and small pore size which range between most organic solvents and water molecules.NaA zeolite membrane has good ethanol/water separation performance, which is expected to be utilized in a hybrid distillation/pervaporation system for bio-ethanol dehydration.In this thesis, the characterization methods of SEM、XRD and pervaporation were utilized to seek preparation methods of high performance NaA zeolite membrane on macro-porous support. First of all, high performance NaA zeolite membranes with the length of 25 cm were prepared by second repair method and two-step seeding method. NaA zeolite membranes were enlarged preparation on the basis of the previous two methods, which had good pervaporation performance and met the requirements of industrial application. The main conclusions obtained in this thesis were as follows:(1)NaA zeolite membrane with the defects was repaired well by another high concentration formulation 1Al2O3:2SiO2:2Na2O:120H2O,which was dynamic hydrothermally synthesized one time with the formulation 1Al2O3:5SiO2= 50Na2O: 1000H2O.Pervaporation (PV) experiments were carried out at 70℃and 200～300 Pa using a 90 wt.% water/ethanol mixture with a laboratory scale apparatus to test the performance of as-synthesized membranes. They showed the high performance with the water flux up to 1.9210 kg·m-2·h-1 and the separation factor more than 5000.(2) High performance NaA zeolite membrane was prepared by two-step seeding method, which was dynamic hydrotherrmally synthesized just one time with the formulation 1Al2O3:5SiO2:50Na2O:1000H2O.Pervaporation (PV) experiments were carried out at 70℃and 200～300 Pa using a 90 wt.% water/ethanol mixture with a laboratory scale apparatus to test the performance of as-synthesized membranes.They showed the high performance with the water flux up to 1.8510 kg·m-2·h-1 and the separation factor more than 10000.(3)NaA zeolite membranes with the length of 80 cm were successfully prepared on the macro-porousα-Al2O3 support. Pervaporation (PV) experiments were carried out using a 90 wt. % water/ethanol mixture with a pilot scale apparatus to test the performance of as-synthesized membranes, maintain the feed flow rate was 200 L·h-1,when the feed temperature was increased to 120℃,the permeation flux could reach 8.6781 kg·m-2·h-1 and the separation factor>1000, which had met the requirements of industrial application.更多还原