本文選題：ZSM-5沸石膜　切入點(diǎn)：異丙醇脫水　出處：《武漢科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：滲透汽化是一種高效率、低能耗、投資少的新型環(huán)保膜分離技術(shù)，其分離過程不受汽-液平衡的限制，特別適合共沸物的分離，廣泛應(yīng)用于有機(jī)物脫水尤其是醇類有機(jī)溶劑脫水的研究。ZSM-5沸石膜具有很高的熱穩(wěn)定性、耐酸性、離子交換性和良好的選擇性，是理想的滲透汽化膜分離材料。通過適宜路線制備高質(zhì)量ZSM-5沸石膜已成為膜研究的熱點(diǎn)。 本文采用二次生長法，無模板劑條件下在α-Al2O3載體上制備ZSM-5沸石膜，用異丙醇/水體系評價(jià)膜的滲透汽化性能。研究了晶種濃度、晶化次數(shù)、晶化時(shí)間、Si/Al摩爾比和F/Si摩爾比對ZSM-5沸石膜滲透汽化性能的影響，確定出兩次預(yù)涂晶種，兩次晶化合成，n(F/Si)=0.9；n(Si/Al)=7的ZSM-5沸石膜制備方法。通過優(yōu)化膜的合成時(shí)間、晶種濃度、涂晶溫度等條件，提高了膜的滲透汽化性能，，可制備出高通量高選擇分離性的ZSM-5沸石膜，其滲透通量高達(dá)1.106kg·m-2·h-1，分離因數(shù)高達(dá)24991。 用優(yōu)化條件下制備的ZSM-5沸石膜進(jìn)行熱穩(wěn)定性和耐酸性測試，結(jié)果表明在不同的溫度條件下ZSM-5沸石膜的分離因數(shù)均在1×104以上，說明其有很高的熱穩(wěn)定性。在pH約為5.8酸性環(huán)境中，考察了操作溫度對沸石膜滲透汽化性能的影響。當(dāng)操作溫度為70℃，進(jìn)料乙酸乙酯濃度約為97wt.%時(shí)，滲透通量可達(dá)0.287kg·m-2·h-1，分離因數(shù)可達(dá)3790。在pH約為5.8的乙酸乙酯溶液中浸泡10d后，其滲透汽化分離因數(shù)為7894，說明ZSM-5沸石膜具有一定的耐酸性。 用制備的ZSM-5沸石膜對異丙醇水溶液進(jìn)行脫水濃縮，在進(jìn)料異丙醇濃度約為80wt.%、操作溫度為70℃條件下，脫水濃縮48h后，異丙醇濃度升高至99.613wt.%，滲透液水含量保持99wt.%以上，表明ZSM-5沸石膜可以高效分離水和異丙醇。
[Abstract]:Pervaporation is a new environmentally friendly membrane separation technology with high efficiency, low energy consumption and low investment. The separation process is not restricted by vapor-liquid equilibrium, and is especially suitable for the separation of azeotrope. ZSM-5 zeolite membrane has high thermal stability, acid resistance, ion exchange and selectivity. It is an ideal material for pervaporation membrane separation, and the preparation of high quality ZSM-5 zeolite membrane by suitable route has become a hot spot of membrane research. In this paper, ZSM-5 zeolite membrane was prepared on 偽 -Al _ 2O _ 3 carrier without template by secondary growth method. The pervaporation performance of the membrane was evaluated by isopropanol / water system. The effect of Si / Al molar ratio and F / Si molar ratio on pervaporation performance of ZSM-5 zeolite membrane was determined. The preparation method of ZSM-5 zeolite membrane was obtained by twice pre-coated seed and twice crystallization. The pervaporation performance of the membrane was improved under the condition of coating temperature, and the high flux and high selectivity ZSM-5 zeolite membrane was prepared. The permeation flux was 1.106 kg 路m-2 路h-1 and the separation factor was 24991. The thermal stability and acid resistance of the ZSM-5 zeolite membrane prepared under the optimized conditions were tested. The results showed that the separation factor of the ZSM-5 zeolite membrane was above 1 脳 10 ~ 4 at different temperatures. The effect of operating temperature on the pervaporation performance of zeolite membrane was investigated in pH 5.8 acid environment. When the operating temperature was 70 鈩

本文編號：1557596