Research Article

Nonisothermal Thermogravimetric Analysis of Thai Lignite with High CaO Content

Table 1

Analysis results of Thai lignite samples.

CharacterizationLow CaO ligniteHigh CaO lignite

Proximate analysis (% w/w, as-received basis)
 Moisture content 35.1 39.6
 Volatile matter 28.2 27.6
 Fixed carbon 25.8 20.9
 Ash 10.9 11.8
Ultimate analysis (% w/w, dry basis)
 C 58.5 58.4
 H 3.0 2.4
 N 1.9 1.8
 O 12.9 12.6
 S 5.5 3.3
Heating value (MJ/kg, dry basis)
 HHV 23.7 22.6
 LHV 23.1 22.0
Ash compositions
 Na2O 1.9 0.7
 MgO 4.2 3.4
 Al2O3 13.4 1.4
 SiO2 21.1 16.6
 P2O5 0.1 0.2
 SO3 17.4 33.4
 K2O 1.3 0.2
 TiO2 0.3 0.1
 Fe2O3 28.9 15.9
 MnO2 0.1 0.1
 CaO 11.4 28.2
 CaO (SO3-free basis) 13.8 42.3
 Base-to-acid ratio 1.37 2.68