TITLE:
Spectroscopic Elucidation of the Links between Char Morphology and Chemical Structure of Coals of Different Ranks
AUTHORS:
Andrew O. Odeh
KEYWORDS:
Coal Char, Char Morphology, Chemical Structure, XRD, SAXS
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.6 No.4,
September
30,
2016
ABSTRACT: In this investigation, SAXS and XRD were used to investigate both the physical and chemical changes in six coals of different ranks subjected to heat treatment. The specific surface area which gives an indication of the reactivity of the coal (measures surface area available for reaction) was determined to be in the range of 70.04 - 260.40 m2/cm3 particle volume for lignite from 450°C - 700°C. The specific surface area was determined to be in the range of 51.58 - 239.00 m2/cm3 particle volume for sub-bituminous; 440.60 - 241.70 m2/cm3 particle volume for light volatile bituminous; 452.71 - 247.73 m2/cm3 particle volume for high volatile bituminous; 349.11 - 347.52 m2/cm3 particle volume for semi-anthracite and 333.60 - 125.34 m2/cm3 particle volume for anthracite respectively. On the other hand, the aromaticity was determined in the range of 0.66 - 0.76 for lignite; 0.67 to 0.80 for sub-bituminous; 0.91 - 0.97 for light volatile bituminous; 0.93 - 0.99 for high volatile bituminous; 0.96 - 1.00 for semi-anthracite and 0.96 to 0.99 for anthracite respectively. The porosity, pore size distribution associated with SAXS and the other crystallite parameters identified with XRD were also determined. Links between the physical and chemical parameters were established.