Preparation And Performance Of Mordenite Zeolite Membranes For Dehydration Of Acetic Acid Solution

Technology of pervaporation has advantages such as high efficiency, low energy consumption, easy to enlarge,operation simply. The high cost of zeolite membrane limits its application in industrial pervaporation process. Therefore,lowering the cost of the preparation of zeolite membrane is one of the key point to the technology. This experiment proposes two aspects to reduce the preparation cost of zeolite membrane. The first method is to use cheap commercial macroporous alumina tubes as the supporter.The second one is tring to decrease the crystallization temperature so that we can reduce the energy consumption in the process of synthesis.The pervaporation process research shows that the pervaporation process conditions (such as temperature, feed concentration and operation time) dramaticly impact on the performance of the membrane. The main points can be summarized as follows:(1) In this thesis, we purchase the commercialised macroporous α-Al2O3tube as supporter. In order to make the tube surface mooth,we adopted the secondry crystal method which has two advantages that not only can modify the defects on the surface of the supporter but aslo can take the effect of inducing the crystal to grow.Post-processing (rubbing) of the seed layer plays an important role on the morphology and performance of zeolite membrane. The perfomance of synthesised mordenite membranes become better which the flux was incresed up to20%.In addition, the crystallization temperature and time also plays a key role on the formation rate, morphology, separation flux and membrane permeability. When dehydration of the90wt.%IP A solution at75℃, the total flux of the membrane reached0.74kg m-2h-1.(2) The Acid-resistance and PV operating conditions were investigated.Research shows that after about150hours pervaporation experiments in acetic acid solution,the separation factor did not change significantly, water concentration of permeate side has been less than0.1wt.%which explain that the membrane shows perfect property of Acid resistance.When dehydration of the50wt.%acetic acid solution at90℃, the total flux of the membrane reached nearly1kg m-2h-1and2.5kg m-2h-1when dehydration of the5wt.%5at75℃.