Solubility of Na2CO3 and NaHCO3 in Aqueous Sodium Sulfate Solutions
and Application to Separating Na2CO3 and Na2SO4 Salt Mixtures
Wen-Yu Zhu, Lin Zhang, Hui Jing, Bo Liu, Feng-Bao Zhang, Guo-Liang Zhang, Qing Xia*
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, PR China
Supporting Information
Table S1. Mole fraction solubility data of Na2CO3 ( x1 ) at different compositions of in
(Na2SO4−water) solvent mixtures at temperature T exp and pressure 0.1M Pa. w30 represents the
solute-free mass fraction of Na2SO4 in binary solutiona.
Table S2. Mole fraction solubility data of NaHCO3 ( x2 ) at different compositions of in
(Na2SO4−water) solvent mixtures at temperature T exp and pressure 0.1M Pa. w30 represents the
solute-free mass fraction of Na2SO4 in binary solutiona.
Table S3. Parameters of K sm equations for NaHCO3 and Na2CO3 in (Na2SO4−water) solvent
mixtures (Defined by eqs 2).
Table S4. E-NRTL model parameters for Na2CO3−Na2SO4−H2O system (Defined by eqs 4).
Table S5. E-NRTL model parameters for NaHCO3−Na2SO4−H2O system (Defined by eqs 4).
Table S6. Root-mean-square deviations σ from the description by the E-NRTL model.
Figure S1. XRD pattern of Na2CO3·H2O.
Figure S2. XRD pattern of NaHCO3.
AUTHOR INFORMATION
Corresponding Author
*Tel.:
+86-22-27400292. Fax:
+86-22-27408778. E-mail:
[email protected].
Table S1. Mole fraction solubility data of Na2CO3 ( x1 ) at different compositions of in
(Na2SO4−water) solvent mixtures at temperature T exp and pressure 0.1M Pa. w30 represents the
solute-free mass fraction of Na2SO4 in binary solutiona.
x1 103
T exp /K
x1 103
T exp /K
x1 103
T exp /K
w30 =0.00
13.73
276.95
32.24
292.05
77.04
308.75
14.57
278.35
42.81
296.95
76.58
312.45
19.81
284.35
50.72
300.15
74.87
319.65
22.56
286.55
56.98
302.15
73.42
325.75
22.66
286.55
70.25
305.55
72.63
329.95
26.13
288.95
75.28
307.25
71.88
333.95
w30 =0.05
13.34
278.75
47.23
299.65
71.74
321.95
18.23
283.55
55.10
302.45
70.55
328.05
22.21
286.85
64.31
304.35
69.27
332.05
26.36
289.75
73.04
308.65
67.61
334.05
32.31
292.95
74.97
312.45
39.13
296.65
72.99
317.25
w30 =0.10
39.49
296.35
62.93
304.55
68.20
312.55
44.70
298.85
66.89
306.15
66.77
320.45
49.80
301.05
70.16
306.95
64.85
326.35
58.36
302.95
70.14
307.15
62.54
333.75
w30 =0.15
33.94
294.75
59.42
304.25
50.91
327.75
35.70
295.55
61.73
305.85
49.13
332.15
40.67
297.55
57.72
312.95
48.07
333.85
47.95
300.25
55.28
318.35
55.02
302.45
53.04
322.65
w30 =0.20
37.92
297.95
47.13
301.15
37.96
311.95
39.70
298.25
47.46
301.65
35.36
316.15
41.84
298.95
44.36
302.85
32.43
322.95
44.99
299.75
40.43
308.35
29.65
330.55
10.74
331.55
w30 =0.25
31.07
301.25
18.24
315.95
26.31
305.85
15.57
320.35
21.78
311.75
13.58
326.25
a Standard uncertainty u is u(T exp )  0.3K
Table S2. Mole fraction solubility data of NaHCO3 ( x2 ) at different compositions of in
(Na2SO4−water) solvent mixtures at temperature T exp and pressure 0.1M Pa. w30 represents the
solute-free mass fraction of Na2SO4 in binary solutiona.
x2 103
T exp /K
x2 103
T exp /K
x2 103
T exp /K
302.25
308.65
314.55
318.95
30.86
33.07
35.12
324.65
329.35
333.35
w30 =0.00
14.51
16.42
18.51
21.13
276.95
281.25
287.05
296.65
23.04
25.10
27.22
29.14
w30 =0.05
13.57
15.06
16.70
282.05
287.25
292.95
21.61
23.39
25.33
308.65
313.95
320.45
28.44
29.53
30.30
327.35
330.05
331.75
18.03
298.05
26.56
322.35
30.82
333.15
19.90
303.75
27.34
325.45
305.45
310.35
315.35
319.85
24.24
26.95
325.75
332.95
310.45
314.55
319.15
323.05
21.81
23.78
328.25
333.15
311.65
316.85
321.65
17.81
19.32
325.95
330.75
313.45
318.55
14.22
16.29
324.35
329.45
w30 =0.10
12.84
15.05
16.37
16.54
288.85
296.85
301.65
301.85
17.32
18.87
20.53
21.87
w30 =0.15
11.66
12.90
14.02
15.33
294.45
298.35
302.75
307.05
16.02
17.47
18.51
19.92
w30 =0.20
10.39
11.58
12.61
297.05
301.85
306.85
13.80
15.17
16.37
w30 =0.25
7.58
9.84
301.35
306.45
11.84
12.91
a Standard uncertainty u is u(T exp )  0.3K
Table S3. Parameters of K sm equations for NaHCO3 and Na2CO3 in (Na2SO4−water) solvent
mixtures (Defined by eqs 2).
Am
Bm /K
3.16412
-94.6091
-7.58131
-4665.08
25138.5
-7151.45
solute
NaHCO3
a
Na2CO3
1
2a
a 1: Before the transition points, 2: After the transition points
Table S4. E-NRTL model parameters for Na2CO3−Na2SO4−H2O system (Defined by eqs 4).
i
j
Na2CO3
Na2SO4
Na2CO3
H2O
Na2SO4
H2O
1a
2a
1a
2a
1a
2a
aij
bij /K
a ji
b ji /K
64.1573
4277.62
-194.465
-35.0065
-272.862
-309.192
27010.4
1285930
43040.8
4169.95
94112.7
441796
8.43783
77.1704
28.1448
2.28844
-49.5600
31.7360
-3638.05
-1308.11
-8193.13
-4208.86
19322.5
-12279.8
a 1: Before the transition points, 2: After the transition points
Table S5. E-NRTL model parameters for NaHCO3−Na2SO4−H2O system (Defined by eqs 4).
i
j
aij
bij /K
a ji
b ji /K
NaHCO3
NaHCO3
Na2SO4
Na2SO4
H2O
H2O
21.8657
-2.85735
-9.37676
-3989.70
-7315.89
-3536.87
345.793
-17.8114
-8.22360
-94769.4
6387.45
8368.67
Table S6. Root-mean-square deviations σ from the description by the E-NRTL model.
solute Na2CO3
solvent system
Pure water
water +5 wt % Na2SO4
water +10 wt % Na2SO4
water +15 wt % Na2SO4
water +20 wt % Na2SO4
water +25 wt % Na2SO4
average σ value
solute NaHCO3
 1 /Ka
 2 /Ka
 /K
0.35
0.89
0.56
0.41
0.39
0.52
0.53
1.14
1.50
1.08
0.96
1.02
1.04
0.65
0.41
0.73
0.55
0.55
0.69
0.59
a  1 : Before the transition points,  2 : After the transition points
Figure S1. XRD pattern of Na2CO3·H2O.
Figure S2. XRD pattern of NaHCO3.