The Influence of Hydrogen Injection on the Reduction …
153
Table 2 Thermodynamic
conditions for equilibrium
calculation
Thermodynamic Conditions
Value
Temperature
1523.15 K
Thermodynamic data
From HSC
Chemistry 6.0
System pressure
350~400 kPa
Gas partial pressure
25%O 2 + 75%N 2
Result and Discussion
Thermodynamics of the Reduction of Wustite by Carbon
The balance calculation is based on the production of one ton of iron, and the
initial input amount of each substance is determined by the stoichiometric number.
Assuming that the reaction heat required for carbon reduction Wustite is all provided
by the combustion of pulverized coal which includes complete combustion and
incomplete combustion. The degree of progress of the two combustion reactions
is directly related to the initial input of pulverized coal, so determining the distribution ratio of the combustion reaction is a very critical issue. To determine the
combustion ratio distribution, the ratio assumption listed in Table 3 was carried out.
The reaction ratio calculated according to the equilibrium composition is compared
with the assumed ratio, and the appropriate combustion ratio is finally determined.
Figure 2 shows the calculation of the relative deviation of different combustion
ratios under current thermodynamic conditions. It can be seen from Fig. 2 that the
minimum value of the relative deviation is almost at the lowest point K that the
ratio is 0.35:0.65, and the relative deviation is about 3.4% when the pressure is
between 3.5 and 4.0 bar. The r G m −T relationship curve of complete combustion
and incomplete combustion of carbon intersects at 965.50 K. The reason why the
balance calculation result is inconsistent with the thermodynamic calculation result
that incomplete combustion of carbon at high temperature should occupy the main
part is that this is a comprehensive result of being affected by three other reactions
at the same time.
Table 3 The distribution ratio assumption of the carbon combustion reaction
Num
Incomplete combustion
Complete combustion /% Num
Incomplete combustion
Complete combustion /% Num
Incomplete combustion
Complete combustion /%
A
85:15
G
55:45
M
25:75
B
80:20
H
50:50
N
20:80
C
75:25
I
45:55
O
15:85
D
70:30
J
40:60
P
10:90
E
65:35
K
35:65
Q
5:95
F
60:40
L
30:70
–
–
153
Table 2 Thermodynamic
conditions for equilibrium
calculation
Thermodynamic Conditions
Value
Temperature
1523.15 K
Thermodynamic data
From HSC
Chemistry 6.0
System pressure
350~400 kPa
Gas partial pressure
25%O 2 + 75%N 2
Result and Discussion
Thermodynamics of the Reduction of Wustite by Carbon
The balance calculation is based on the production of one ton of iron, and the
initial input amount of each substance is determined by the stoichiometric number.
Assuming that the reaction heat required for carbon reduction Wustite is all provided
by the combustion of pulverized coal which includes complete combustion and
incomplete combustion. The degree of progress of the two combustion reactions
is directly related to the initial input of pulverized coal, so determining the distribution ratio of the combustion reaction is a very critical issue. To determine the
combustion ratio distribution, the ratio assumption listed in Table 3 was carried out.
The reaction ratio calculated according to the equilibrium composition is compared
with the assumed ratio, and the appropriate combustion ratio is finally determined.
Figure 2 shows the calculation of the relative deviation of different combustion
ratios under current thermodynamic conditions. It can be seen from Fig. 2 that the
minimum value of the relative deviation is almost at the lowest point K that the
ratio is 0.35:0.65, and the relative deviation is about 3.4% when the pressure is
between 3.5 and 4.0 bar. The r G m −T relationship curve of complete combustion
and incomplete combustion of carbon intersects at 965.50 K. The reason why the
balance calculation result is inconsistent with the thermodynamic calculation result
that incomplete combustion of carbon at high temperature should occupy the main
part is that this is a comprehensive result of being affected by three other reactions
at the same time.
Table 3 The distribution ratio assumption of the carbon combustion reaction
Num
Incomplete combustion
Complete combustion /% Num
Incomplete combustion
Complete combustion /% Num
Incomplete combustion
Complete combustion /%
A
85:15
G
55:45
M
25:75
B
80:20
H
50:50
N
20:80
C
75:25
I
45:55
O
15:85
D
70:30
J
40:60
P
10:90
E
65:35
K
35:65
Q
5:95
F
60:40
L
30:70
–
–