The Medium Density Fiberboard or MDF industry in North America is facing many challenges, largely as a result of the weak housing market. Residential construction is 20 percent below 2006 levels and it is not likely that an improvement will happen before mid 2008. Rising imports of secondary wood products from China and other low costs countries also have a detrimental impact on the North American production of furniture, mouldings, and other secondary wood products. In an environment of fierce international competition, Canadian and other foreign mills exporting to the USA are usually absorbing the exchange losses themselves, rather than losing the sale to a competitor. In addition, the MDF industry has to grapple with expensive and ever stiffer environmental regulations. We expect upward pressure on prices during the next five years, particularly from 2008 onwards, as environmental standards increase the cost of resins and demand escalates. The companies specializing in higher value added products are doing better. Therefore, the North American MDF industry is progressing by way of shifting its production towards higher value-added products. We have developed an innovative process of treating wood chips with a dilute solution of oxalic acid, patent pending, for the production of MDF, which compared to the control is more resistant to water infiltration in 24 hour swelling and water adsorption tests. The process not only produces value added MDF with increased strength, reduced moisture content, reduced energy consumption, etc. with reduced manufacturing cost but also further increases the profitability of this industry by producing a stream of carbohydrate resource that can be converted into cellulosic ethanol and other value added chemicals. The proposed research fits both USDAs crosscutting priorities, Agriculturally related manufacturing technology and alternative and renewable energy. Making ethanol from cellulose dramatically expands the types and amount of available material for ethanol production and would not compete with food supplies. Presently ethanol is made where grain is available. An ethanol manufacturing facility could be co located with a MDF plant. Additional societal impact will be gained if material from overcrowded forests is proven suitable for the process. The rural economic development will be an advantage, but if material thinned from our forests can be used then the health of the forests and help in prevention of forest fires will also be increased. This will enhance our resource base by providing new carbohydrate for fermentation and health of the environment by improving our standing forests. Each new identified source of carbohydrate that can be converted into fuels and chemicals will help to increase our energy independence. Cellulose ethanol production will also provide additional greenhouse gas emissions reductions. OBJECTIVES: The overall goal of the proposed research is to demonstrate the use of woody biomass in simultaneously producing fermentable sugars and MDF, while maintaining the enhanced structural value present in the residual material. The value of the carbohydrate resource is in the production of useful fuels and chemicals. The specific objectives for the proposed research are to optimize the conditions at the pilot-scale for carbohydrate release from red pine and other wood species supplied by our industrial partners, while maintaining the enhanced water adsorption and composite strength characteristics for a commercial application. Then to determine the optimal conditions for fermentation of the hydrolysates that are released as a function of the oxalic acid treatments and finally to investigate to better understand the surface chemistry of the oxalic acid and DEO treated fibers in order to be able to apply the best resins for the new MDF product in a pre-commercial setting with help from industrial partners H2H, Flakeboard, and Knight-Celotex to determine the optimal resin conditions for the oxalic acid and DEO MDF product. APPROACH: The goal will be to obtain enough information to be able to model the process for carbohydrate release and MDF performance at the pilot scale. The best results for testing various MDF production scenarios will be used for the optimization. The conditions with maximal carbohydrate release with retention of strength and water adsorption properties will be determined and tested at the predicted optima. Carbohydrates will be analyzed in the aqueous extracts by direct HPLC analysis and also after a 4 percent secondary hydrolysis of the extract. Acetate and oxalate concentrations will be determined in the aqueous extracts and also on the wood fiber. These data will adequately assess the value of the MDF and the suitability of the carbohydrate solutions recovered for use in fermentation. The work plan thus far has been to explore the conditions for treatment of red pine. The limitations for other species of wood might be different and need to be explored. Data derived in Phase 1 for red pine will be used as a starting point for testing other species. In particular southern pine softwood MDF, hardwood MDF and small diameter, plantation-grown material from forest thinning will be tested and evaluated. We will use standard MDF preparation and testing techniques as well as board fabrication. For performance evaluations and test methods, we will use density and moisture content, verticle density profiles, thickness and swell, and absorption water soak. We will test for bending strength, modulus of elasticity, and internal bonding. Each tested combinations of species, treatment, resin, and process parameters will involve 3 to 6 replicate boards depending on the performance criteria being evaluated. Using the methods detailed in ASTM D1037, matched-replicate specimens for each tested property/characteristic are obtainable from each MDF board manufactured. Collection of hydrolysates will be immediately after each treatment through hot water circulation though the treated wood chips in order to rinse the biomass of hemis. The hemicellulose extracts are removed at an approximate solids content of 1 percent, which will be concentrated to a fermentable solids content with the newly constructed RO system funded by BPI in order to meet the requirements of the hemicellulose dilute extracts from the oxalic acid treatments. The hydrolysates will be detoxified and fermented. The fibers will be analyzed for surface characteristics and chemistry
