More recently, Chen et al. (2013) investigated the effect of the
pyrolysis conditions on the gasification reactivity of lignite chars
in mixtures of H2O + CO2. Two types of char were prepared, by fast
pyrolysis and slow pyrolysis, at a temperature of 1273 K. The
authors found that both the fast-chars and slow-chars were dense.
The shrinking core model was able to predict both fast-char gasification
and slow-char gasification, which indicates that the reaction
occurs mainly in the external surface. The majority of these studies
did not tackle the issue of coal pyrolysis atmosphere effects on
char-CO2 gasification. Additionally, comparatively little investigation
has been conducted on the relationship between microstructure
changes and biomass char gasification. Therefore, further
research is needed to better understand the pyrolysis atmosphere
effects on the gasification behavior of biomass char-CO2