Environmental Engineering Reference
In-Depth Information
(a)
(b)
6
300 bar and 600°C
210 bar and 350°C
5
1
4
0.9
CO
2
210 bar and 350°C
0.8
3
CH
4
2
0.7
H
2
0.6
1
CO
0.5
0 0 0 0 0
Dr
y matter content (wt%)
0
0
50
60
70
80
90
5
10
15
20
25
30
Dr
y matter content (wt%)
(d)
(c)
6
12
300 bar and 600°C
10 wt% organic and 350°C
5
10
H
2
4
8
CO
2
3
6
CH
4
CO
2
2
4
CH
4
H
2
1
2
CO
CO
0
0
0
0
50
100
150
200
Pressure (bar)
250
300
350
400
5
10
15
20
25
30
Dry matter content (wt%)
(e)
(f)
12
12
10 wt% organic and 600°C
10 wt% organic and 300 bar
10
10
H
2
H
2
8
8
6
6
CO
2
4
CO
2
4
CH
4
2
2
CH
4
CO
CO
0
200
0
300
400
600
Temperature (°C)
500
700
800
900
1000
0
50
100
150
200
Pressure (bar)
250
300
350
400
FIGURE 10.12
Results of equilibrium calculations
for
low- and high-temperature
gasification of C
6
H
12
O
6
in hot compressed water.
pressure does not influence the product distribution to a large extent (see Figure 10.12d
and e). It is worthwhile to note that, from a thermodynamic point of view, high-
temperature gasification should be carried out at the lowest possible pressure to
achieve maximal hydrogen yields (see Figure 10.12e).
Figure 10.12f shows that, according to thermodynamics, there is strong shift from
methane toward hydrogen and carbon monoxide upon increasing the temperature.
Methane-rich gas can be produced up to temperatures of approximately 500
C, while
higher temperatures favor the production of hydrogen.
Search WWH ::
Custom Search