用于乙醇—水分离不锈钢网支撑的Silicalite-1分子筛膜的制备

发布时间：2018-05-13 10:48

  本文选题：Silicalite-1分子筛膜 + 不锈钢网　； 参考：《大连理工大学》2015年硕士论文

【摘要】：Silicalite-1分子筛膜,作为无机膜的一种,具有很好的耐热性和耐酸性,无穷大的硅铝比赋予了其良好的疏水性,使得其在水中脱有机物有很好的应用前景,尤其是在原位法脱除发酵液中低浓度的乙醇,从而实现燃料乙醇连续化生产的应用中。目前,Silicalite-1分子筛膜的制备大多采用含铝的管状载体,但制备得到的膜通量较低,且装载在膜组件中的空间利用率低。而不锈钢网不仅具有高的孔隙率,且其柔软的质地可加工成卷轴式膜组件,从而极大的提高膜组件的空间利用率。本文采用廉价的不锈钢网作载体,制备得到了致密性较好、具有一定分离性能和高于传统管状载体膜通量的Silicalite-1分子筛膜。本论文的主要结论如下：(1)系统地考察了晶化温度、晶化时间、水量、合成液液位、模板剂量等条件对膜形态的影响,晶化温度175℃,配方为1TEOS:0.17-0.34 TPAOH:80-160 H2O,晶化时间2-5 d,反应釜中合成液液位0.05 m左右时能制得致密性较好的Silicalite-1分子筛膜。(2)由于普通热浸渍法很难将晶种引入到不锈钢网载体上,所以考察了二次晶化对膜形态的影响,晶化一段时间后取出直接进行第二次晶化,在一定程度上能缩短晶化时间。(3)考察了水量、晶化时间和不锈钢网目数对Silicalite-1分子筛膜渗透蒸发性能的影响,水量在一定范围内时,晶化时间越长,不锈钢网目数越大,分离因子越大,但通量越低。为了达到较好的综合性能,按1 TEOS:0.17 TPAOH:100-120 H2O配置合成液,晶化时间控制在2-3 d为宜。经优化后,通量能达到7.28kg·m-2h-1,同时分离因子为15.47,高于传统管状载体上制备得到的Silicalite-1分子筛膜的通量。(4)考察了F-含量对Silicalite-1分子筛膜渗透蒸发性能的影响,适量的F-能改善膜的分离性能,当合成液配比为1TEOS:0.17 TPAOH:100 H2O:x NaF,F-应控制在0.12以下。当F-含量在0.12时,通量可达6.76 kg·m-2·h-1,分离因子为20.49。(5)考察了原料液浓度和温度对Silicalite-1分子筛膜渗透蒸发性能的影响,在低浓度范围内(5-25wt.% EtOH),随着乙醇浓度增加,分离因子逐渐降低,但通量变化不大；随着原料液温度从30℃上升到75℃,膜通量逐渐上升,而分离因子逐渐下降。
[Abstract]:As a kind of inorganic membrane, Silicalite-1 molecular sieve membrane has good heat resistance and acid resistance, and the infinite ratio of Si / Al gives it a good hydrophobicity, which makes it have a good application prospect in the removal of organic matter in water. Especially in the application of in situ removal of low concentration ethanol from fermentation broth so as to realize the continuous production of fuel ethanol. At present, the preparation of Silicalite-1 molecular sieve membrane is mostly made of tube carrier containing aluminum, but the membrane flux is low, and the space utilization rate of membrane module is low. The stainless steel mesh not only has high porosity, but also its soft texture can be processed into a reel membrane assembly, thus greatly improving the space utilization ratio of the membrane assembly. In this paper, Silicalite-1 molecular sieve membranes with better densification, better separation performance and higher flux than traditional tubular carrier membranes were prepared by using cheap stainless steel mesh as carrier. The main conclusions of this paper are as follows: (1) the effects of crystallization temperature, crystallization time, water content, liquid level and template dosage on the morphology of the films were investigated systematically, and the crystallization temperature was 175 鈩，

本文编号：1882838