The inorganic content
of biomass impairs size reduction tool life
and the conversion process. Conventional ash extraction relies on
furnace combustion that inevitably alters the inorganic compounds
due to oxidation and decomposition. This study developed composition-preserving
methods for extracting and analyzing extrinsic and intrinsic inorganic
compounds. Comprehensive characterization was carried out on selected
biomass feedstocks, including corn stover, pine residue, and pine
anatomical fractions, to reveal their inorganic species and morphology.
The extrinsic inorganic compounds were found to be dominated by quartz,
along with other minor minerals, such as albite, microcline, and gehlenite,
and have particle sizes ranging from tens to hundreds of micrometers.
Among the pine anatomical fractions, the needles contain the highest
intrinsic silicon content while the bark trapped the most extrinsic
minerals. By correlation of the total ash and extrinsic inorganic
contents to the wear behavior, both the extrinsic and intrinsic inorganic
compounds were concluded to have made significant contributions to
the wear process. The results here validated a new approach to characterize
inorganic compounds in biomass and provided fundamental insights for
their potential impact on preprocessing tool wear.