Gas Production Strategy of Underground Coal Gasification Based on Multiple Gas Sources

Table 1

Averages and standard deviations of hydrogen concentration in the gas produced in the pure oxygen steam test done on July 4, 2010.

Number	Hydrogen concentration in gas (%)	Standard deviation of hydrogen concentration
1	42.7	0.02
2	42.4	0.02
3	42.4	0.01
4	42.7	0.24
5	42.7	0.42
6	42.7	0.88
7	42.8	0.95
8	43.0	0.76
9	42.6	0.52
10	42.6	0.06
11	42.3	0.05
12	43.0	0.16
13	42.5	0.31
14	42.6	0.30
15	42.7	0.27
16	42.8	0.21
17	42.8	0.21
18	42.8	0.12
19	43.3	0.10
20	43.5	0.14
21	43.3	0.19