Mechanisms of terpene release during sawdust and flake drying

"February 2000.""Submitted to Holzforschung.

Low-VOC drying of softwood

"April 1998.""Submitted to 11th International Drying Symposium, Thessaloniki, Greece, August 19-22, 1998.

Transition metal catalysed Grignard-like allylic activation across tetragonal tin(II) oxide

The reaction of allyl halide and a carbonyl compound under the aegis of tetragonal tin(II) oxide and catalytic d8, d10 metal complexes provides the corresponding homoallylic alcohol, via a novel allyl tin intermediate

Implementing Strategies for Drying and Pressing Wood Without Emissions Controls

Drying and pressing wood for the manufacture of lumber, particleboard, oriented strand board (OSB), veneer and medium density fiberboard (MDF) release volatile organic compounds (VOCs) into the atmosphere. These emissions require control equipment that are capital-intensive and consume significant quantities of natural gas and electricity. The objective of our work was to understand the mechanisms through which volatile organic compounds are generated and released and to develop simple control strategies. Of the several strategies developed, two have been implemented for OSB manufacture over the course of this study. First, it was found that increasing final wood moisture by about 2-4 percentage points reduced the dryer emissions of hazardous air pollutants by over 70%. As wood dries, the escaping water evaporatively cools the wood. This cooling tapers off wood when the wood is nearly dry and the wood temperature rises. Thermal breakdown of the wood tissue occurs and VOCs are released. Raising the final wood moisture by only a few percentage points minimizes the temperature rise and reduces emissions. Evaporative cooling also impacts has implications for VOC release from wood fines. Flaking wood for OSB manufacture inevitable generates fines. Fines dry out rapidly because of their high surface area and evaporative cooling is lost more rapidly than for flakes. As a result, fines emit a disproportionate quantity of VOCs. Fines can be reduced in two ways: through screening of the green furnish and through reducing their generation during flaking. The second approach is preferable because it also increased wood yield. A procedure to do this by matching the sharpness angle of the flaker knife to the ambient temperature was also developed. Other findings of practical interests are as follows: Dielectric heating of wood under low-headspace conditions removes terpenes and other extractives from softwood; The monoterpene content in trees depend upon temperature and seasonal effects; Method 25A emissions from lumber drying can be modeled from a knowledge of the airflow through the kiln; A heat transfer model shows that VOCs released during hot-pressing mainly originate from the surface of the board; and Boiler ash can be used to adsorb formaldehyde from air streams

An algorithm for estimating contact angle

"February 1995.""Submitted to Langmuir.