Pilot- and full-scale measurements of VOC emissions from lumber drying of Inland Northwest species

摘要

Volatile organic compounds (VOCs) emitted from lumber drying operations can contribute to the formation of ground level ozone on a regional scale. Current estimates of VOC emission rates have large uncertainties. Results in this paper are reported for VOC emissions from lumber drying of Douglas-fir, ponderosa pine and grand (white) fir. Measurements were made using a university pilot-scale kiln and evaluated with respect to measurements made for a kiln at a commercial lumber mill. The measured emission factors were 0.51 g/kg(OD) for Douglas-fir, 0.7 g/kg(OD) for ponderosa pine, and 0.15 g/kg(OD) for grand fir. Measurements also showed that 10 percent or more of the VOC emitted by grand fir are aldehyde species. These data were obtained using a novel tracer ratio method that eliminates the need for ventilation flow rate measurements at the small scale and meteorological measurements or modeling at the full scale. We also report the first application of a real-time VOC instrument, the proton transfer reaction mass spectrometer, which has capabilities to measure selected VOCs, including oxygenated species, at low levels with a few seconds time resolution.