Effect of wet and dry torrefaction on chemical structure and
pyrolysis behavior of corncobs was investigated. Most of hemicellulose
can be removed from corncobs by torrefaction. However, dry
torrefaction caused severe degradation of cellulose and cross-linking
and charring of corncobs, thus more acid insoluble lignin were
formed. FTIR analysis implied that dry torrefaction causes more
dramatic structural change of corncobs than wet torrefaction.
Py–GC/MS analysis indicated that wet torrefaction significantly
improved levoglucosan yield. Therefore, from a technical point of
view, wet torrefaction can be considered as a more effective pretreatment
method for fast pyrolysis of corncobs.