سال انتشار: ۱۳۸۷

محل انتشار: همایش بین المللی ژئولیت ایران

تعداد صفحات: ۱۲

نویسنده(ها):

S.N. Ashrafizadeh – Research Lab for Advanced Separation Processes, Department of Chemical Engineering,
f.h Saboor – Research Lab for Advanced Separation Processes, Department of Chemical Engineering,
m Manuchehri Nezhad – Research Lab for Advanced Separation Processes, Department of Chemical Engineering,

چکیده:

In the view of wide applications and high capability of zeolite materials in separation processes,
membrane and micro reactors, gas sensors, zeolitic catalysis, hollow fibers, etc., a large number of studies
during the past 25 years have been focused on the preparation of zeolite type films and membranes. Zeolite
membranes have high potentials to be used in many separation processes, mostly due to the differences in the
diffusivity of various molecules (even of similar kinetic diameters) in the uniform and molecular-size zeolitic
pores. The latter property results in the selective adsorption and separation of molecules.
MFI type zeolite membranes grown on the porous supports, including silicalite and ZSM-5, have been the
most studied zeolitic materials for separation processes. The average pore size of MFI which is similar to the
kinetic diameter of many organic molecules is one of the desirable characteristics of this type of zeolite.
Moreover, MFI type zeolite possesses higher thermal and chemical stability, and adsorption property based
on the hydrophilic/hydrophobic interactions.
Fractionation of xylene isomers is one of the important separation processes in petrochemical industries,
due to the various industrial applications of these isomers. The recovery of xylenes in the industrial scale is
currently achieved either by crystallization or adsorption processes. However, these techniques are very
complex and energy intensive. Thus membrane-based separation processes have been considered as an
alternative for such separations. MFI type zeolite membrane has been synthesized in the laboratory scale by a
number of research groups to separate xylene isomers.
In this study, various synthesis methods of zeolite membranes and their effective parameters have been
reviewed. Results reported by different research groups represent the effective factors on membrane
preparation as well as the optimum operating conditions viable for xylenes separation. The discussions
provided here can assist improving and optimizing membrane separation techniques for xylene recovery.