(468d) Enhanced Mass Transfer Process Control Via Hollow Fiber Membrane Assisted Antisolvent Crystallization
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Separations Division
Modeling and Control of Crystallization
Wednesday, October 31, 2018 - 9:05am to 9:25am
Enhanced Mass Transfer Process Control via
Hollow Fiber Membrane Assisted Antisolvent Crystallization
Xiaobin Jianga*,
Linghan Tuoa,
Xuehua Ruanb, Wu Xiaoa,
Gaohong Hea,b*
a State Key Laboratory of Fine Chemicals, Engineering
Laboratory for Petrochemical Energy-efficient Separation Technology of Liaoning
Province, School of Chemical Engineering, Dalian University of
Technology, Dalian, Liaoning 116024, China
b School of
Petroleum and Chemical Engineering, State Key Laboratory of Fine Chemicals,
Dalian University of Technology at Panjin, Panjin 124221, China
Corresponding author: xbjiang@dlut.edu.cn; hgaohong@dlut.edu.cn
Abstract
Antisolvent crystallization plays an important role in various fields as
an effective separation1-4 and
crystal manufacture technology5-10. Due to the operation under ambient
temperature and atmospheric pressure, antisolvent crystallization is environment
friendly and low energy consumption 11,12.
In this work, a novel hollow fiber membrane assisted antisolvent
crystallization (MAAC) was proposed to enhance the antisolvent crystallization
process control. PES membrane module was introduced as the key device for
antisolvent mass transfer and solution mixing. An antisolvent liquid film formed
on the membrane surface was renewed by the crystallization solution. The liquid
film can additionally prevent the membrane from contacting with crystallization
solution. By controlling the shell side flow velocity and the antisolvent mass
transfer process, the antisolvent permeate rate can achieve sensitive, stable
and accurate control during long term utilization.
Benefited from the
nano and sub-nano size pores on the membrane surface and high packing density
of the membrane module, MAAC greatly improved the micromixing between
antisolvent and crystallization solution and reducing the local supersaturation
degree. The calculated interfacial mass transfer rate of MAAC was approximately
1/50 of the one of the conventional antisolvent crystallization. On the basis
of this effective and accurate antisolvent mass transfer control, MAAC
provided the erythritol crystal products with better morphology, narrower CSD
and smaller C.V. compared to the products manufactured by conventional
antisolvent crystallization under the same antisolvent adding rate and
operation duration.
Additionally, due to the the intrinsic feature of antifouling of the
proposed MAAC operation, the permeate rate of MAAC could keep a stable value in
a long running and the permeate performance of the membrane module was
repeatable after more than twenty four times utilization. With well-controlled
nucleation and crystal growth in the membrane module reducing the required
retention time and the size of the tank for suspension liquid in MAAC, the
production capacity P.C. (kg
products¡¤m-3¡¤h-1) can be also enhanced via MAAC.
Figure. 1 Comparison of size distributions of aspect
ratio (A), crystal morphology (B) and interfacial mass transfer rate (C) between
erythritol produced by MAAC and conventional antisolvent crystallization after
1 hour operation.
Acknowledgements
We acknowledge financial contribution from National
Natural Science Foundation of China (Grant No. 21527812, 21676043, U1663223,
21606035), Changjiang Scholars Program (T2012049), the Fundamental Research
Funds for the Central Universities (DUT16TD19, DUT17ZD203) and Education
Department of the Liaoning Province of China (No. LT2015007).
References