Product scorching and air emission problems, particularly with nitrogen oxides (NOx) and
VOCs, are prevalent because the rotary drum operates at up to 1000 oF as it reduces moisture
from 50-60% to 2-4%. Such high temperatures produce VOCs both from extractives
contained in the wood and from thermal degradation of the wood material itself. It is common
practice to dry wood furnish in panel mills to very low moisture levels to ensure that press
“blows” caused by a build up of steam pressure in the panel do not occur in the subsequent
gluing step. VOCs emission increases when wood is almost dry (