The hemicellulose of each plant material differs, with
xylan being the main component of soft grasses while soft
woods contain mostly glucomannans [17]. In this study it was
found that microwave irradiation as sufficient to break down
the bonds glucomannan bonds, but not the xylan bonds as no
xylose, arabinose or acid by-products were was observed in
the final sugar mixtures. This was confirmed by the FT-IR
analysis of the solid residue as discussed in the next section.
It could be postulated that if longer treatment times were
possible (higher power inputs) the xylose sugars would also be
liberated from the plant structure as the 5-carbon sugars were
shown to increase with increase power input (see Fig. 3).
A total hexose sugar yield of 366 g kg1 and a pentose sugar
yield of 214 g kg1 at 43.2 kJ g1 relates to a conversion efficiency
of 100% for cellulose and 58.5% for hemicellulose. If the
residual sugars present are also taken into account, a total
sugar yield of 830 g kg1 is obtained