Open AccessLow VOC drying of lumber and wood panel products. Progress report No. 4, annual summary
Author(s) -
James R. Boerner,
Wei Su,
Hui Yan
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/542020
Subject(s) - softwood , pulp and paper industry , volatile organic compound , veneer , environmental science , waste management , chemistry , materials science , composite material , engineering , organic chemistry
Heating softwood in a low-headspace environment draws out the VOCs from the wood, without removing the water. The VOCs can be collected from the headspace, and represent a valuable product. The VOC-depleted wood can then be dried conventionally with much reduced emissions. Heating can be accomplished through radiofrequency (RF) or steam. For lumber, steam is inefficient, but brief RF treatment under low-headspace conditions draws out 80% of the VOCs. The power used is quite low, since the RF energy is not used to remove water, but only to maintain the wood at a set temperature. The technology is now at the pre-pilot stage. Either steam or RF can be used for particle, OSB, and veneer, again under low-headspace conditions. Increasing steam temperature facilitates VOC removal. In order to understand the mechanism of VOC release in lumber, the transport of water and VOCs to the surface is being studied as a function of sample size and orientation. Characterization of the terpenes and resin/fatty acids from a control set of trees is underway in order to define the seasonal influence on VOCs