Opportunities for the Forest Products Industries Alan W. Rudie Abstract tential forest biomass markets for fuels and higher value chemicals. The concept of sustainable harvests is not new to lumber and paper companies—they have been con- Introduction cerned about it and been practicing it for decades, long before it became the headline in a newspaper In recent decades, traditional forest products have article. After decades of static products and markets, been adversely impacted by new materials—plastic the industry is offered an opportunity to add products replacing the paper grocery bag, steel 2×4‘s penetrat- in a new business sector—fuels and chemicals. Alt- ing the dimension lumber market, TV and electronic hough paper companies have a long association with media displacing printing and writing papers, and the naval stores chemical business, this new market plastics and mineral–plastic composites penetrating will see larger volumes and more numerous product the panel and wood laminate markets. The petroleum opportunities. As with all new markets, this will cre- shortages of 2007 and concerns over the impact of ate turbulence and there will be winners and losers, burning fossil fuels on the earth‘s climate have re- but the real change is that now there can be true win- newed interests in wood-based fuel and chemical ners. Companies must have two capabilities to be products. This is an opportunity for the forest prod- among the winners. Every major forest products in- ucts industries to go on the offensive and enter new dustry already has mastered the first—they know markets in specialty chemicals, pharmaceuticals, and where the wood is and how to get it. Forest products polymers. Forest products, including wood-based companies can integrate procurement into their quali- chemicals and polymers, are well positioned to be car- ty needs and product value streams. Competitors from bon neutral (or carbon negative), sustainable, and outside the forest products industry have not mas- green solutions to global problems. A number of po- tered this—yet. The second capability is commercial tential new forest products are listed in Table 1. The experience with thermal or biochemical conversion of table is far from comprehensive; for more complete biomass into chemical products. This is a fair competi- lists see Werpy and Petersen (2004) and Hajny tion. No one has a product, no one has a process, and (1981). These potential products have been selected everyone has the opportunity to start at the same as examples of chemicals and process possibilities. time. The industry must use the integration of forest Several are established markets, already produced biomass technologies to maximize its strategic ad- from agricultural-based feedstocks. vantage and, more importantly, minimize competition The first five products in the table represent an for the higher value timber. This paper discusses po- extensive group of chemicals that have glucose as a common intermediate. They are products that can be produced using chemical and biochemical processes and are categorized by the U.S. Department of Energy Alan W. Rudie is Supervisory Research Chemist with (DOE) as sugars platform chemicals. Ethanol is obvi- USDA Forest Service, Forest Products Laboratory, Madi- ously used as a fuel and fuel oxygenate. It has also son, Wisconsin. been used to produce ethylene and butadiene. Diols Rudie 3 Table 1: Select potential new products from wood. Producta Business Statusb Prediction Driver Ethanol Commodity Pilot Likely Fuel, incentives diols Specialty Lab Probable Glucose cost Lactic acid Specialty Lab Probable Glucose cost HMF Specialty/commodity Lab Unknown Yield PHA Specialty Lab Probable Glucose cost CNC Specialty Lab Probable Compatibility MFC/NFC Specialty Commercial/lab Compatibility Diesel fuel Commodity Pilot/commercial Probable Scale/cost Methanol Commodity Pilot Probable Cost a PHA, polyhydroxyalcohols; CNC, cellulose nanocrystals or whiskers; NFC, nanofibrillated cellulose. b Status of product production from lignocellulose. Production of diols, lactic acid, and PHAs from starch is commer- cial. are used in polyesters and in products as diverse as diesel fuel (Fischer–Tropsch) and methane for syn- deicing chemicals for commercial airplanes and cos- thetic natural gas. DOE also has interest in catalyst metic products. Lactic acid is used to produce pol- reforming into methanol, longer chain length-mixed ylactic acids as a renewable and compostable plastic alcohols, and a fermentation process that produces that among other applications can replace the poly- ethanol from the product gas. styrene used in clear clamshell food containers. The- The paper focuses first on the processes— se three chemicals are normally produced by fermen- hydrolysis to produce sugars and gasification to pro- tation-like processes in which microorganisms con- vide synthesis gas for reforming. It then reviews the sume glucose and release the chemical product as a status for each of the products listed in Table 1. Much lower energy byproduct. Hydroxymethyl furfural of the DOE focus is on agricultural residuals. Wood- (HMF) and related chemicals, such as 2,5-dihydroxy sourced biomass behaves differently than straw and furan and 2,5-furanedicarboxylic acid, are produced stover in both processes, and some of these differences by chemical dehydroxylation of six-carbon sugars. are highlighted in the review. Polyhydroxyalkanoates are a polyester food storage Obviously, venturing into biomass-based chemical polymer produced directly from sugars by a number production entails considerable risk for a forest prod- of bacteria. Most notable are the copolymers of 3- ucts company of any size, but it must be recognized hydroxybuterate and 3-hydroxyvalerate sold under that not taking the opportunities biomass chemicals the trade name Biopol (Monsanto, St. Louis, Mis- offer also contains risks. First is the risk of persisting souri). in commodity product businesses that are no longer The next two products in the table, cellulose growing. Of even greater concern is the impact non- nano-crystals (CNC) and micro- (or nano-) fibrillated forest industry companies pose to the traditional busi- cellulose (NFC), are largely perceived as reinforce- nesses. All the wood biomass estimates used by the ment materials in fiber-reinforced composite prod- federal government in formulating biomass fuels poli- ucts. As a notable example, a composite produced cy have assumed wood use will be limited to slash and from fibrillated cellulose using phenol-formaldehyde thinnings produced in other harvesting or forest man- resin provided strength properties nearly identical to agement activities (Perlack et al. 2005, BR&Di 2008 ). magnesium alloy with a 10% savings in weight As part of a timber harvest process, slash is availa- (Nakagaito and Yano 2005). ble at significantly lower cost than pulp wood and The final two chemical products, diesel fuel and larger diameter wood suitable for dimension lumber. methanol, are produced by first gasifying biomass to But harvesting fuel wood as an independent process— produce hydrogen and carbon monoxide and then basically thinning the forest to reduce fire risk or im- reforming the gas into chemical products. Most inter- prove growth—is a high-cost process that cannot pro- national interest is in straight-chain hydrocarbons for vide chemical/fuel quality wood at competitive costs 4 Woody Biomass Utilization: 2009 FPS Conference Proceedings Figure 1. Estimated costs to harvest and market value of wood products. Fuelwood cost is for thinning. (Figure 1) (USDA 2005, Bolding et al. 2009). If not drolyze carbohydrates dates as far back as 1883 integrated into a harvest operation, pulp wood is the (Fleschsig 1883). Concentrated acids (H2SO4, HCl, low-cost source of woody biomass. The ultimate risk and H3PO4) are effective at hydrolyzing lignocellulose to existing forest products companies is that new en- to provide a mixture of sugar monomers and short- tries into wood-based chemicals will not understand chain carbohydrate oligomers. Lignin resists the acids the market sufficiently and end up using pulpwood- and is left as an insoluble polymer. Because the strong quality material. The industry has already observed acid is energy intensive and expensive, the process this trend with several electrical utilities that have could not be made viable without acid recovery entered the renewable power market. Federal incen- (Harris 1952). Separation of the sugars from the con- tives to promote biomass use for fuel and chemicals centrated acid and recovering acid for reuse have increase the risks because these subsidies often do been the focus of most of the strong acid research, but not apply to traditional forest products. to date there is not a commercially demonstrated acid This summary of possible opportunities discusses recovery method. Blue Fire Ethanol received one of briefly the two principal conversion methods, hydrol- the DOE Integrated Biorefinery grants awarded in ysis to glucose and thermal decomposition to pyroly- 2007 to evaluate hydrolysis with concentrated sulfuric sis oil or producer gas (synthesis gas). The paper acid using an acid recovery process developed by then discusses several specific products emphasizing Arkenol (U.S. Patent: 5,597,714) and currently under several that are already commercial products. pilot evaluation by JGC Corporation in Izumi, Japan. Concentrated acid hydrolysis also persists in the Kla- Process Methods son lignin method used to determine the lignin con- tent of wood and wood pulp (Klason 1908). Wood Hydrolysis to Glucose Dilute acid hydrolysis methods are nearly as old, The original lyrics to the Simon and Garfunkel with patent literature dating back to 1920. Because song ―The Boxer‖ contain the line ―after changes up- dilute acids are much slower, the treatments were on changes we are more or less the same.‖ Wood hy- normally carried out at elevated temperatures (160– drolysis to glucose is a good example of this maxim. 220°C) and pressures. Probably most significant in The discovery of cellulose as a polymer of glucose is dilute acid development was the Scholler (1935) pro- credited to Anselme Payen (Payen 1838).