(42t) Tuning Al Spatial Distribution in ZSM-5 Membranes: A New Strategy to Improve Separation Performance and Stability of Zeolite Membranes for Dehydration of Acetic Acid

Tuning Al spatial
distribution in ZSM-5 membranes: a new strategy to improve separation
performance and stability of zeolite membranes for dehydration of acetic acid

Liangqing Li ^a, Zan Chen^a, Jianhua Yang ^a,b*,
Wanze Li ^a, Jinqu Wang ^a,Jinming Lu ^a
,Yan Zhang^a, Hongchen Guo^a

a:State Key
Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University
of Technology, Dalian, Liaoning,

116024, China.

 b: Department of Chemical Engineering and
Materials Science, University of Minnesota, MN 55455;   

 *corresponding authors: Prof. Jianhua
Yang, E-mail add.: yjianhua@dlut.edu.cn;

                             
Abstract

Dehydration of acetic acid (AcOH) by the conventional
distillation is particularly energy-intensive process. Membrane
pervaporation is attracting great interest for this
purpose because of the greatly reduced energy requirement. However,
the dehydration of AcOH is very challenging because of the demanded high acid
resistance and the membrane materials are very limited.  So far the water flux, selectivity and acid
resistance of the both of polymer and
zeolite membranes for the dehydration of AcOH are low.

   The fabrication of
a high performance zeolite membrane significantly
relies on the control of essential membrane microstructures including the membrane thickness¹, preferential grain orientation² and grain boundary
defects³. In the present work, a new strategy through tuning the Al spatial
distribution of ZSM-5 membrane
was proposed to improve the acid resistance of zeolite membrane. The organic
template-free synthesis route was designed to tune the spatial distribution of
ZSM-5 membrane. A novel ZSM-5 membrane with a low Si/Al ratio and
homogeneous aluminum spatial distribution was achieved from the designed
synthesis route and the obtained ZSM-5 membrane high selectivity and flux and
improved stability for dehydration of acetic acid in a wide AcOH content range.
The work firstly
demonstrates that the Al spatial
distribution is a key factor for tuning the separation performance of the zeolite membranes⁴.

      Fig. 1 Schematic
illustration of preparation of the ZSM-5 membrane preparation with uniform
spatial distribution

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