MEASUREMENT OF VOC EMISSIONS FROM PONDEROSA PINE LUMBER USING COMMERCIAL AND LABORATORY KILNS

Abstract

The 1990 U.S. Clean Air Act has increased the need to know what is emitted from dryers, but measuring emissions on a commercial scale is difficult and expensive. A laboratory method would allow closer control over the process and allow process variables to be studied with reduced variability and at a lower cost. In this research project, the total hydrocarbon emissions from a commercial lumber dry kiln are compared with those from a laboratory lumber dry kiln. The results showed that when the same drying schedules were used to dry matched charges of ponderosa pine lumber (2-inch nominal thickness by random width), the commercial kiln emitted an average of 2.21 g of hydrocarbon (reported as carbon) per kilogram of oven-dried wood (kg_ODwood), while the laboratory kiln averaged 1.49 g/kg_ODwood. The spectra of monoterpenes emitted from each dryer were similar. These results indicate that emissions measured in this laboratory kiln can be used to represent those from commercial-scale lumber dry kilns if an appropriate scale-up factor is used.

Keywords:

• Method 25A
• Wood
• Monoterpenes
• Air pollution
• Volatile organic compounds

ACKNOWLEDGMENTS

The authors wish to acknowledge Boise Cascade in Emmett, ID, and CSI Carter-Sprague in Beaverton, OR, for assistance on the project. This work was funded by USDA Competitive Grant 95-37500-2302. This is paper 3386 of the Forest Research Laboratory, Oregon State University, Corvallis, OR.