Phase Equilibrium and Crystallization Process of the Ternary System KCl-(NH2)2CO-H2O at Different Temperatures
Table 3
Phase equilibrium data of the system KCl-(NH2)2CO-H2O at 303.15 K, 323.15 K, 333.15 K, and 343.15 Ka.
Number
Equilibrium solid phasec
Experimental value/(/%)b
Calculated value/(w/%)
Composition of liquid phase
Composition of wet solid phase
Wilson model
NRTL model
KCl
(NH2)2CO
KCl
(NH2)2CO
KCl
(NH2)2CO
KCl
(NH2)2CO
303.15 K
1, M1
P c
27.32
0.00
NDd
ND
27.17
—e
27.32
—
2
P
26.59
4.42
63.08
1.21
26.06
26.28
3, A1
P
25.10
7.06
68.04
2.25
25.33
25.50
4
P
23.73
13.67
71.61
3.93
23.65
23.65
5
P
20.67
23.87
64.25
9.63
21.02
20.71
6
P
18.30
32.47
66.06
12.78
18.81
18.42
7
P
16.67
41.19
59.15
19.88
16.54
16.37
8
P
15.50
45.61
61.96
21.80
15.40
15.40
9
P
15.41
47.41
63.79
20.36
14.90
15.04
10
P
14.23
49.68
65.62
19.25
14.36
14.54
11, E1
P+U
13.96
51.14
59.90
24.64
13.97
49.61
14.26
51.24
12
U
13.35
52.40
9.40
68.54
—
50.11
—
52.02
13
U
7.59
53.75
6.46
66.27
52.95
53.96
14, B1
U
4.15
55.67
2.39
65.33
54.86
55.59
15
U
1.88
56.51
0.90
76.21
56.02
56.50
16, N1
U
0.00
57.01
ND
ND
56.91
57.15
RAD
1.58 × 10−2
0.93 × 10−2
RMSD
0.80
0.24
323.15 K
1, M2
P
29.94
0.00
ND
ND
30.06
—
30.00
—
2, A2
P
28.56
5.89
63.49
3.72
28.36
28.32
3
P
26.32
12.77
73.22
4.41
26.33
26.36
4
P
23.47
22.53
69.23
9.03
23.46
23.62
5
P
21.61
29.23
62.75
15.08
21.49
21.73
6
P
19.15
38.94
53.02
22.51
18.60
18.92
7
P
18.00
41.20
62.41
19.45
17.96
18.32
8
P
15.61
50.51
56.42
25.85
15.18
15.49
9
P
14.54
53.59
44.12
34.35
14.28
14.56
10
P
13.70
56.76
67.18
18.96
13.33
13.54
11
P
13.10
58.11
55.06
30.58
12.95
13.15
12, E2
P+U
12.49
60.15
51.52
32.39
12.35
59.14
12.49
60.68
13
U
11.97
61.55
9.48
67.73
—
59.65
—
61.42
14
U
10.37
62.78
7.65
69.74
60.80
62.39
15
U
8.36
63.21
5.49
75.15
61.92
63.13
16, B2
U
5.85
64.56
4.28
69.42
63.53
64.41
17
U
2.32
65.53
1.43
77.99
65.47
65.78
18, N2
U
0.00
67.35
ND
ND
67.14
67.26
RAD
1.59 × 10−2
0.69 × 10−2
RMSD
0.83
0.21
333.15 K
1, M3
P
31.43
0.00
ND
ND
31.40
—
31.08
—
2, A3
P
28.65
7.93
72.15
2.40
28.94
28.62
3
P
26.32
13.50
72.11
5.05
27.21
26.92
4
P
24.12
23.43
66.08
11.02
24.20
23.98
5
P
22.32
29.07
72.95
9.46
22.48
22.32
6
P
20.23
35.82
70.12
14.32
20.40
20.32
7
P
18.60
42.35
68.7
15.46
18.37
18.32
8
P
16.60
47.05
67.93
16.79
16.97
16.97
9
P
15.19
52.38
62.95
24.05
15.31
15.27
10
P
13.97
56.81
63.73
23.94
13.92
13.81
11, E3
P+U
11.85
63.39
62.59
27.48
11.90
63.24
11.63
63.98
12
U
9.78
65.35
9.60
69.28
—
64.87
—
65.32
13
U
7.09
67.12
5.92
75.54
66.75
67.00
14, B3
U
4.86
69.31
3.08
77.49
68.58
68.70
15
U
2.70
70.19
2.35
81.85
69.90
69.84
16, N3
U
0.00
71.25
ND
ND
71.49
71.23
RAD
0.92 × 10−2
0.90 × 10−2
RMSD
0.37
0.32
343.15 K
1, M4
P
32.62
0.00
ND
ND
32.62
—
31.95
—
2, A4
P
30.17
6.37
77.77
2.44
30.57
29.87
3
P
27.71
11.80
78.88
4.39
28.81
28.16
4
P
25.13
20.74
68.8
7.53
26.01
25.44
5
P
22.49
28.58
60.61
13.01
23.54
23.10
6
P
21.43
33.20
65.39
13.76
22.08
21.69
7
P
19.57
40.22
64.37
18.43
19.83
19.53
8
P
18.58
43.87
68.11
18.06
18.65
18.38
9
P
15.25
52.84
62.61
22.95
15.84
15.62
10
P
14.26
55.97
59.75
26.42
14.84
14.60
11
P
12.99
60.02
69.57
21.44
13.55
13.25
12
P
12.6
61.88
62.16
28.27
12.92
12.55
3
P
11.59
65.31
61.61
27.16
11.81
11.33
14
P
11.18
68.15
69.86
23.92
10.79
10.13
15, E4
P+U
10.29
69.27
60.27
31.25
10.53
68.42
9.91
69.79
16
U
9.19
70.34
6.80
78.69
—
69.53
—
70.26
17
U
7.75
71.34
3.31
82.21
70.60
71.21
18
U
5.91
72.56
3.94
88.77
71.95
72.41
19, B4
U
3.97
73.41
1.85
91.26
73.18
73.54
20
U
2.19
74.78
0.87
84.91
74.55
74.74
21, N4
U
0.00
75.76
ND
ND
75.92
75.94
RAD
2.18 × 10−2
1.69 × 10−2
RMSD
0.60
0.40
aStandard uncertainties u are u(T) = 0.1 K and ur(x) = 0.5%. b: mass fraction. cP: KCl; U: (NH2)2CO. dND: not determined. e—: the calculated value same as the experimental value.
