As a result of the 1990 amendments to the Clean Air Act, the EPA can impose progressively stricter air emission standards on all industries. Tests with a pilot-scale kiln that was fitted with a water cooled condenser indicated that approximately 50 percent of the VOC's were trapped in the condensate. VOC emissions from the drying of southern yellow pine wood consist primarily of monoterpenes. A study of the seasonal variation of monoterpenes in the heartwood and sapwood of Loblolly pines is in progress.
Preliminary results indicate that the heartwood contains more monoterpenes than the sapwood.
Insufficient data are available to draw a conclusion relative to seasonal influences. Biofiltration is the microbial degradation of contaminants in an air stream and is much less expensive than the current incineration technologies. Researchers at the FPL have isolated microorganisms capable of degrading wood VOC's. Further studies are evaluating the effect of temperature on biodegradation efficiencies. Successful application of biofiltration would provide huge cost savings to wood industries operating dry kilns and wood hot pressing operations.