Supporting Information
Conversion of potassium chloride into
potassium sulfate by four-compartment
electrodialysis: Batch operation process
Xu Zhang1, Xiaoyao Wang1, Xianchao Liu1, Xiaozhao Han1*, Chenxiao Jiang2,
Qiuhua Li2, Tongwen Xu2**
1
School of Chemistry and Chemical Engineering, Hefei University of Technology,
Hefei 230009, People’s Republic of China
2
Laboratory of Functional Membranes, School of Chemistry and Materials Science,
University of Science and Technology of China, Hefei Anhui 230026, People’s
Republic of China
∗
Corresponding author.
Tel.: +86-551-6290-5769. E-mail address: [email protected] (X.Z. Han).
∗∗
Corresponding author.
Tel.: +86-551-6360-1587. E-mail address: [email protected] (T.W. Xu).
The supporting information provides additional details as follows:
(1) Table S1. Properties of Cation Exchange Membrane and Anion Exchange
Membrane.
(2) Table S2. Effect of current density on KCl conversion ratio, final K2SO4
concentration and energy consumption when the molar ratio of (NH4)2SO4 to KCl
is 1:2.
S1
(3) Table S3. Effect of molar ratio of (NH4)2SO4 to KCl on KCl conversion ratio,
final K2SO4 concentration and energy consumption.
(4) Table S4. Effect of the K2SO4 tank initial volume on KCl conversion ratio, final
K2SO4 concentration and energy consumption.
(5) Table S5. Effect of the solution temperature of K2SO4 tank on KCl conversion
ratio, final K2SO4 concentration and energy consumption.
S2
Table S1. Properties of Cation Exchange Membrane and Anion Exchange Membrane.
Membrane name
LabC
LabA
Membrane type
Thickness (µm)
IEC (meq/g)
Water uptake (%)
Burst strength (Mpa)
Area resistance (Ωcm2)
Transport number (%)
CEM
~145
0.8-1.0
35-40
>0.35
0.5-1.5
>98%
AEM
~200
0.8-1.0
35-40
>0.35
0.5-1.5
>98%
S3
Table S2. Effect of current density on KCl conversion ratio, final K2SO4
concentration and energy consumption when the molar ratio of (NH4)2SO4 to KCl is
1:2.
Item
i=10 mA/cm2
i=15 mA/cm2
i=20 mA/cm2
i=25 mA/cm2
KCl conversion
ratio (%)
99.73
95.06
98.55
83.09
Final K2SO4
Energy consumption
concentration (g/L)
(kw.h/kg K2SO4)
86.96
0.26
89.07
0.37
91.99
0.43
83.99
0.50
S4
Table S3. Effect of molar ratio of (NH4)2SO4 to KCl on KCl conversion ratio, final
K2SO4 concentration and energy consumption.
Item
1.0:2
1.2:2
1.4:2
1.6:2
1.8:2
2.0:2
KCl conversion
ratio (%)
95.06
99.65
98.12
98.35
99.58
99.98
Final K2SO4
Energy consumption
concentration (g/L)
(kw.h/kg K2SO4)
89.07
0.37
89.75
0.38
90.48
0.35
92.14
0.36
92.47
0.38
93.69
0.34
S5
Table S4. Effect of the initial K2SO4 tank volume on KCl conversion ratio, final
K2SO4 concentration and energy consumption.
Item
VK2SO4=400 mL
VK2SO4=500 mL
VK2SO4=600 mL
VK2SO4=700 mL
KCl conversion
ratio (%)
99.07
98.74
98.97
99.98
Final K2SO4
Energy consumption
concentration (g/L)
(kw.h/kg K2SO4)
123.50
0.37
123.04
0.38
105.49
0.37
93.69
0.34
S6
Table S5. Effect of the solution temperature in K2SO4 tank on KCl conversion ratio,
final K2SO4 concentration and energy consumption.
Item
T=RT
T=40oC
T=50oC
KCl conversion
ratio (%)
99.07
99.53
99.85
Final K2SO4
concentration (g/L)
123.50
133.41
135.29
S7
Energy consumption
(kw.h/kg K2SO4)
0.37
0.35
0.31