Dissertations in Forestry and Natural Sciences

Materials and methods
heat energy from these gases was recycled to maintain the
process conditions.
The vapors were condensed into collectable liquids by
transporting them through cooled pipes. The evaporation of
moisture from the raw material began below 100 °C. As
expected, the liquids formed from these vapors consisted
primarily of water. At 100–300 °C, the formation of condensable
vapors continued, but the composition of liquids changed; as
the temperature increased, the share of water decreased and
that of acetic acid and other organic acids increased. When the
temperature exceeded 300 °C, the formation of tars began and
continued until the final temperature (350 °C) was reached. This
fraction was used for the treatments.
The softwood distillate originated from industrial
ThermoWood ® process conducted by LunaWood Ltd (Iisalmi,
Finland). In the process, primarily Scots pine planks were
thermally treated as described in section 4.1. During the process,
the evaporation of condensable compounds resulted in the
formation of liquids, a part of which was collected into a liquid
container (V = 1 m 3 ) and further processed. Due to the
differences in the compositions and densities, there were two
distinguishable phases in the container; the lighter phase
consisted primarily of water and water-soluble organic
compounds, such as acetic acid, and the heavier phase, which
physically resembled tar, was a mixture of acetic acid, methanol,
phenols, long chain fatty acids and their esters, squalene, cyclic
hydrocarbons and PAHs. This heavier phase was separated,
processed and used for the treatments.
Both distillates, hardwood and softwood, were processed
similarly before they were used for the treatments. First, the
distillates were rinsed three times with water (T 40 °C) to
extract water-soluble compounds, such as simple carbohydrates,
from the distillate. In general, simple carbohydrates have low
melting points (< 200 °C) and therefore, they could start to burn
during injection molding. When the distillates were rinsed,
water was added to the distillates in a ratio of 1:1, and the
resulting blend was carefully mixed for 15 minutes. After the
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