To preserve forest resources worldwide, we all need to be able to use wood longer. Making it last generally means we need to add some kind of preservatives. However, most wood is hard to treat with preservatives because it cannot be penetrated by the liquids. Treatment plants in Oregon and along the West Coast are at an economic disadvantage relative to East Coast plants, which use more permeable southern pine and so can process much more wood in a day (sometimes 8 times as much). In addition, there is growing worldwide political pressure against the use of preservatives that contain metallic compounds (e.g., chromated copper arsenate). This pressure may make current biocides unsuitable for use, and companies will have to move into new areas. Most possible replacements for the metallic biocides are organic compounds, but few of these are water soluble. Treatment with organic biocides in the form of supercritical fluids offers hope, because such fluids can penetrate wood as if they are gases.

Supercritical fluid treatments involve impregnating the wood with biocides at extremely high pressures. Normal commercial treatments use a pressure between 125 and 150 psi. In this project, researchers are working at 10 to 20 times those pressures. Liquid applied at such high pressures would simply crush the wood. Even supercritical fluids at such high pressure can crush some kinds of wood. The methods are still being developed and are as yet unproven. In general, the technology is considered too uncertain for any single company to risk a large investment. Therefore a number of chemical companies decided to work together with researchers in the College of Forestry to carry out the research.

The cooperative currently includes Chemical Specialties, Inc., Charlotte, North Carolina; Dow Agro Sciences, Indianapolis, Indiana; Janssen-Pharmaceutica, Washington's Crossing, New Jersey; Troy Corp., Florham Park, New Jersey; and Bayer, Pittsburgh, Pennsylvania. These chemical companies are large enough to take a broad view of the market. They also have strong European connections and recognize the need for alternatives to the current treatments. Other companies have expressed interest but not yet made commitments. Although the cooperating companies are big, the money each contributes is relatively small, about $10,000 each, so the risk of loss compared to the possible gain of a new technology is acceptable.

In the first year and a half of the cooperative's existence, the cooperators have advised researchers Jeff Morrell (Forest Products) and Keith Levien (Chemical Engineering) about their basic needs, but then left them to pursue the research. With graduate students Matthew Anderson and Philip Schneider (Forest Products) and Witoon Kittidacha (Chemical Engineering), plus visiting professor Gyu-Hyeok Kim (Korea University, Seoul, Korea), Morrell and Levien have started by looking at how pressure develops in wood, what happens with the pressures inside wood, and when collapse occurs. They argue that the first need is to understand the process, before considering specific chemicals. Thus the Forest Products researchers are looking at the fundamental behavior of the wood; the chemical engineers are examining the interactions between chemicals and the supercritical fluid. The OSU researchers know that other supercritical fluid treatments work; they have a patent for extraction using supercritical fluids that preceded the cooperative. Now they hope this project will open new possibilities.

For a project like this, collaboration is important. The research involves development in a largely unknown area, meaning that it is considered to have too high a risk of failure for competitive research awards. Consequently the only way the new processes will be investigated is by bringing sponsoring companies together. One of the deterrents and reasons that the work is considered risky is the high cost of the equipment. That high cost reflects the need to attain extremely high pressures. The cooperative is fortunate in having state-of-the-art facilities that were donated by Weyerhaeuser.

In spite of the risk that the process may never actually work, Morrell notes that it offers one of the few prospects for treating a wider array of woods, and thus a means for extending the service life of wood products and thereby conserving the world's forests.