The Preparation Of Mordenite Zeolite Membranes For The Dehydration Of Organic Solution Under Harsh Condition

In recent years, pervaporation (PV) as a new type membrane separation has gained wide acceptance. This technology has great application on solving resource shortage, energetic and environmental problems. Mordenite membranes prepared with fluoride without fluoride for the acid-resistance test were pervaporation due to its excellent thermal stability, acid-resistance and hydrophilicity.In this thesis, high performance mordenite zeolite membrane on macro-porous supports was prepared by secondary method under fluoride route. The effects of seeding layer and fluoride optimization on orientation, morphology and pervaporation of mordenite zeolite membranes were researched. The membrane in fluoride media showed an excellent acid resistance with1mol/L AcOH in water/ethanol system compared with non-fluoride synthesis system and different synthesis conditions under fluorid media for improving the performance of separation and acid resistance. The main conclusions obtained in this thesis were as follows:(1) The effects of three seeding methods, seeding concentration and crytal morphology on the seeding layer were researched. And the seeded supports with water diping was mainly discussed for the effects of mirostructure and performance of membranes under fluoride route Pervaporation (PV) experiments were carried out at70℃and400Pa using91wt.%ethanol/water mixtures to test the performance of as-synthesized membranes. The results showed that separation factor could reach to4164and the water flux was0.46kg·m-2·h-1.(2) High performance of mordenite zeolite membrane was prepared by optimizing fluoride which can paly a role of template and optimizing the structure and Si/Al (parent solution). Pervaporation experiments were carried out at70℃and400Pa using co.91wt.%for the performance of as-synthesized membranes and the separation factor is between1091and8162, and the total flux is0.31～1.08kg·m-2·h-1. And the as-synthesized membranes with NaF/SiO20.05and parent solution Si/Al12.5for separation factor could reach to6872and the water flux was0.51kg·m-2·h-1.(3) The membranes prepared in fluoride media and non-fluoride synthesis system were tested for acid resistance with1mol/L AcOH in water/ethanol system(70℃), and The membrane in fluoride media showed an excellent acid resistance. The membranes prepared in fluoride media also had a high performance for i-propanol/H2O and AcOH/H2O systems. The water of permeation sides for pervaporation of90wt.%i-propanol/H2O(t=70℃),85wt.%AcOH/H2O(t=70℃)system can reach to100%concentration(limit in GC detection).