Hydro-Solvothermal Synthesis of NaX Zeolite Membranes for the Separation of MeOH/Methyl tert-Butyl Ether Mixtures

Zeolite membranes are emerging asattractive candidatesfor theseparation of methanol/methyl tert-butyl ether (MTBE)mixtures, while the random deposition of silicon aluminum componentson the surface of the support can lead to the poor quality of zeolitemembranes, restricting the use of zeolite membranes in separationand purification applications. In this study, the deposition processof the silicon aluminum components was controlled, and compact NaXzeolite membranes with great pervaporation performance for methanol/MTBEmixtures were synthesized using water-organic solvent synthesissolutions. Systematic research showed the existence of a stable liquidfilm on the surface of the support controlling the formationenvironment of zeolite membranes during their synthesis; organic solventsthat partly replaced water in the synthesis solution improved thequality of the zeolite membranes. The water-organic solventsystem could not only decrease the nucleation and crystallizationrate of zeolite particles in the main body of the synthesis solutionand reduce the consumption of silicon aluminum components in the mainbody of the synthesis solution but also promote the migration of siliconaluminum components to the liquid film on the surfaceof the support from the main body of the synthesis solution, thuspromoting the growth of zeolite membranes. The zeolite membrane synthesizedin the 20(v) % 1,3-propanediol synthesis solution exhibited a MeOH/MTBEseparation factor greater than 10,000 with a permeation flux of 1.6kg & BULL;m(-2)& BULL;h(-1), indicatingthat a compact zeolite membrane was grown on the support. In thiswork, the formation of zeolite membranes was controlled by addingan organic solvent to the synthesis solution to adjust the depositionprocess of silicon aluminum components to the support and a new methodfor the preparation of compact membranes was developed.

Automated summary

In this study, compact NaX zeolite membranes with excellent pervaporation performance for methanol/MTBE mixtures were synthesized by controlling the deposition process of the silicon aluminum components using water-organic solvent synthesis solutions. This new method provides a new approach for the preparation of compact membranes.