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Table 5 Elemental compositions of ash and char collected from various locations of the reactor

From: Characterisation of the Contaminants Generated from a Large-Scale Ex-Situ Underground Coal Gasification Study Using High-Rank Coal from the South Wales Coalfield

  Raw coal Atmosphere 30 bar
Element   Char 1 m Char 2 m Char 3 m Ash Char 1 m Char 2 m Char 3 m Ash
mg/kg (ppm) mg/kg (ppm)
As 10 ± 2 26 ± 5 17 ± 3 11 ± 2 < 2 10 ± 3 3 ± 1 7 ± 3 98 ± 20
B 14 ± 3 25 ± 5 9 ± 2 15 ± 3 103 ± 20 19 ± 4 11 ± 2 16 ± 3 123 ± 25
Cd < 1 1 ± 0.4 < 1 < 1 10 ± 3.5 < 1 < 1 < 1 < 2
Co 10 ± 3 33 ± 2 13 ± 3 11 ± 2 130 ± 26 21 ± 4 18 ± 4 11 ± 2 456 ± 90
Cr 73 ± 15 32 ± 7 12 ± 2 5 ± 1 330 ± 66 13 ± 3 8 ± 2 75 ± 15 166 ± 33
Cu 25 ± 5 96 ± 19 34 ± 7 15 ± 3 299 ± 60 22 ± 4 16 ± 3 16 ± 3 646 ± 130
Hg 0.22 ± 0.07 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01
Mn 218 ± 44 59 ± 12 13 ± 3 5 ± 1 366 ± 73 19 ± 4 11 ± 2 80 ± 16 535 ± 107
Mo 4 ± 1 9 ± 3 4 ± 1 1 ± 0.35 24 ± 5 22 ± 4 13 ± 3 8 ± 3 4 ± 1
Ni 52 ± 10 89 ± 18 36 ± 7 21 ± 4 467 ± 93 38 ± 8 24 ± 5 57 ± 11 558 ± 111
Pb 27 ± 5 15 ± 3 3 ± 1 9 ± 2 570 ± 114 38 ± 8 9 ± 3 7 ± 2 207 ± 41
Sb 17 ± 3 10 ± 3 2 ± 0.7 3 ± 1 141 ± 28 25 ± 5 1 ± 0.35 3 ± 1 2500 ± 500
Se < 2 3 ± 1 < 2 < 2 11 ± 2 < 2 < 2 < 2 13 ± 3
Zn 14 ± 3 21 ± 4 16 ± 3 7 ± 1 225 ± 45 60 ± 12 36 ± 7 17 ± 3 285 ± 57
   % mass.     % mass.    
Al 1.05 ± 0.23 2.75 ± 0.33 1.29 ± 0.19 0.93 ± 0.14 16.24 ± 1.95 1.06 ± 0.16 0.41 ± 0.06 0.56 ± 0.08 17.19 ± 2.1
Fe 1.04 ± 0.08 5.41 ± 0.44 2.08 ± 0.17 0.90 ± 0.09 18.11 ± 1.45 1.04 ± 0.10 0.55 ± 0.06 0.41 ± 0.04 8.53 ± 0.68
K 0.09 ± 0.005 0.066 ± 0.004 0.025 ± 0.002 0.017 ± 0.003 0.28 ± 0.02 0.033 ± 0.003 0.033 ± 0.003 0.042 ± 0.004 0.85 ± 0.05
Ti 0.04 ± 0.005 0.11 ± 0.013 0.066 ± 0.008 0.018 ± 0.02 0.46 ± 0.06 0.024 ± 0.003 0.006 ± 0.001 0.012 ± 0.001 0.40 ± 0.005