Factors which affect volatile compound emissions from drying loblolly pine lumber.

摘要

Southern yellow pine (SYP) wood contains many non-structural components which are relatively volatile such as monoterpenes. These volatile organic compounds (VOC) are given off by living pine trees and during drying of wood products such as lumber, veneer, strands, particles, and fibers. This research focused on two aspects of the VOC emissions from drying SYP wood.; The first aspect of this study was to continue research on quantification of hydrocarbon VOC emitted from SYP lumber during drying. Initial research had been conducted in this area with respect to age, species, heartwood/sapwood ratio, density, and season of processing. There were, however, many fundamental questions which still needed to be answered. This research addressed some of these questions, and also generated future research questions.; In the first part of this study the effect of end grain and the wood's surface area to volume ratio with respect to VOC emissions were investigated. In these experiments, neither end effect nor size effect were found to be statistically significant. The results from these two investigations increased our knowledge base of the inherent hydrocarbon VOC emission characteristics of SYP lumber.; The second aspect of this research was to investigate potential methods of reducing the total VOC emissions from SYP lumber drying. One such method was subjecting lumber to pre-treatments before it was dried. The two types of pre-treatments studied were steaming and radio frequency energy. It had been demonstrated that steam-heating small wood particles prior to drying caused a reduction in the amount of VOC emitted during drying. In this research, both live steam and radio frequency energy were used as pre-treatments on pine dimension lumber, before drying. A high humidity kiln schedule (120 dry bulb, 96 wet bulb temperature, degrees Celsius) significantly increased the total VOC emissions level with respect to the controls. Neither the radio frequency nor the live steam pre-treatments were statistically different from the controls.