(194s) Crystal Morphology Modifid and Solution Recovery Improved Membrane Crystallization
AIChE Annual Meeting
2017
2017 Annual Meeting
Food, Pharmaceutical & Bioengineering Division
Poster Session: Food and Bioprocess Engineering
Monday, October 30, 2017 - 3:15pm to 4:45pm
Crystal morphology
modifid and solution recovery improved membrane crystallization
Xiaobin Jiang, Dapeng Lu, Guannan
Li, Gaohong He*
State Key Laboratory of Fine
Chemicals, School of Chemical Engineering, Petrochemical Energy-efficient
Separation Technology Engineering Lab of Liaoning Province, Dalian University
of Technology, Dalian, P. R. China
*Corresponding author: Email: hgaohong@dlut.edu.cn
Abstract
For the multiple
requirements of environmental protection and biochemical resource reuse, the treatment
of industrial wastewater and recovery of the high value-added products in the food
and bioprocess with high efficiency is a pivotal topic.1,2
Traditional treatment approach of multi-component wastewater with high salinity
and organic solvent (which is commonly found in petrochemical, biochemical,
food and pharmaceutical engineering) include vacuum evaporation crystallization
(VEC), membrane based-hybrid separation technology, etc.3-5
Among these approaches, membrane distillation crystallization (MDC) that combined
membrane distrillation with traditional crystallization process was attractive
and significant by simultaneously recycling valuable salt crystals with high
purity and specified molecular structural properties, pure volatile solvents
with with high recovery.6-8
In this work, the comprehensive
investigation is focused on the crystal nucleation and growth kinetics by
considering both the membrane property and operational conditions of MDC. One
of typical multi-component high sality wastewater, ethylene glycol (EG)-NaCl aqueous
solution system, is introduced for the evaluation. The nucleation barrier, diffusion controlled crystal grwoth and
interface reaction processes present a significant difference under various
feed conditions and operation temperatures, which have profound effect on the
crystal morphology (Fig. 1) and size distribution (Fig. 2). As a consequence, the
resulting crystal with specified morphology can furtherly improve the
separation efficiency. The advantage operating range of MDC for crystal
morphology modification and solution recovery improvement on the researched
system can be then outlined and optimized.
Acknowledgment
We acknowledge fnancial
contribution from from National Natural Science Foundation of China (Grant No.
21527812, 21676043, U1663223), Changjiang Scholars Program (T2012049), the
Fundamental Research Funds for the Central Universities (DUT16TD19) and
Education Department of the Liaoning Province of China (No. LT2015007).
Fig. 1. NaCl
crystal morphologies under different feed solution composition MEG/(MEG
+MH2O): (a), 0 %; (b), 20 %;
(c), 40 %; (d), 60%; (e), 80% (Pv=7
kPa£¬T=70 ¡æ).
Fig. 2. Crystal particle
properties comparison between with various feed composition and operation temperature.
(Pv=7 kPa, MNaCl: MH2O=6.6:
40; Number in the figure: average crystal size and C.V. (underlined).
References