Variation of terpenes in sapwood and heartwood of loblolly pine: Impact on VOC emissions from drying lumber samples

摘要

A single loblolly pine tree approximately 45 years in age was harvested for use in this study. Increment core samples from throughout the length of the tree bole were analyzed for terpenes. Lumber samples from different locations within the tree weretested for volatile organic compound (VOC) emissions in a pilot-scale kiln. The concentration of terpenes was also determined in samples from lumber before and after drying. Analysis of terpenes in increment cores gave concentrations of terpenes in heartwood, inner sapwood, and outer sapwood of 1.1 (0.068), 0.29 (0.061) and 0.11 (0.11) percent on a dry weight basis, respectively (standard deviations are shown in parentheses). The measured VOC emissions from heartwood and sapwood lumber samples were 6.21and 3.27 pounds per dry ton as carbon, respectively. Approximately 50 to 60 percent of total terpenes remained in the lumber samples after drying both heartwood and sapwood samples. The increased VOC emissions from drying lumber sawn from heartwood wasdue to the higher initial concentrations of terpenes in the heartwood tissue of the loblolly pine.