The method developed has been shown to be a useful
tool for the simultaneous determination of the moisture
and the VOC emitted during oven drying of biomass
materials. For all materials, acceptable results for the
moisture content were obtained in comparison with the
reference method.
The determinations of VOC imply that for soft wood
(or other materials with predominantly terpenoid compounds
as VOC) the method gives reliable results for the
amount of organic compounds released in the drying
process, since the recovery of the model substance a-pinene
was 98%.
Despite the emitted levels of VOC were generally quite
low, between 0.1% and 2%. This means, when taking the
calorific heat value into account, that the biofuel supplier
will systematically loose some percent of income. Takingthe volumes generally delivered into account this might not
be considered unsubstantial. The extreme case found 11%
for pitchy wood chips is of course a financial disaster for
the supplier if the price is based on standard dry-matter
measurements. Future control of true moisture content on
more materials is, therefore, strongly recommended as a
complement to the standard moisture content determination
method.