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Woody Biomass Utilization
Woody biomass makes up a large portion of the total biomass picture in California and much of the western United States. In addition to the manufacturing residues of the wood processing industry and post-consumer woody waste materials, a virtually untapped biomass resource is stored in our forests. Much of this forest biomass creates a high wildfire fuel hazard.  If this biomass can be diverted to a market or use it could help to recover some of the cost of important wildland fuel reduction projects.
The technology exists to make a wide variety of products from woody biomass. These include (from lowest value/least processing to highest value/most processing).  
  • Soil additives and amendments (mulch, compost, etc.)
  • Firewood and fuelwood
  • Combustion fuel for biomass power plants
  • Solid wood products (lumber and roundwood)
  • Densified fuels such as wood pellets and fire logs
  • Non-structural composite products including wood/plastic lumber and wood/cement products
  • Composite products such as particleboard and medium density fiberboard (MDF)
  • Engineered wood products such as laminated veneer lumber (LVL) and oriented-strand board (OSB)
  • Pulp chips for paper products
  • Organic chemicals including alcohol (ethanol, methanol), cellulose-based compounds, turpentine, tannins, pharmaceuticals, fragrances, and the basic building blocks for many plastics
Unfortunately technological feasible does not equate to economic reality. Woody biomass will only find its way into the higher value products if the quality of the biomass as a raw material is as good as the current raw material being used or if it can be provided at lower cost and still produce a product of acceptable quality. The costs of gathering and processing multiple small trees to produce a unit of product are much higher than the costs associated with larger trees. As a result the transport of this low quality, low value raw material much more than 50 miles is major challenge requiring creative transport solutions. Even if transport is not a limiting factor the quality of the raw material often is.
Lumber produced from small diameter trees is often of inferior quality as it is highly prone to warp. For example, small diameter trees perform better if left in the round form and used for preservative treated poles or posts and even as round structural timbers than they do as lumber. The inherent properties of small trees that are responsible for the low quality include high proportions of juvenile wood (first 10 to 15 years of a trees growth), reaction wood, and knots. The effect of these properties can be minimized if the trees are broken down into small particles and reconstituted into products with the inferior traits distributed randomly throughout the product. Such products include paper, composite panels (MDF and particleboard), plywood, parallel-strand lumber, and laminated veneer lumber. Unfortunately the market for these products is very limited in California as higher quality fiber is readily available from manufacturing residues and larger trees for the few such manufacturing facilities in the state (1 pulp mill and 2 composite panel plants). The raw material requirements are not as strict for chemical production from biomass but the bio-refineries that could process organic chemicals from woody biomass are not yet commercial and most of the efforts into the production of organic chemicals from biomass is focused on agricultural crops such as corn and soybeans.
 
The main use of biomass today is as a fuel for California’s biomass powerplants that represent about 2% of the state’s electrical generation capacity. These biomass plants use about 5 million bone-dry tons of biomass per year, however much of this is from biomass sources other than the forest, such as, agricultural residues, urban woody waste, and sawmill residues. The forest biomass is currently the most expensive fuel for the power plants and the market structure will not support transport of much more than 50 miles from the forest to the biomass powerplant. The forests could provide much more of the resource for electricity generation. Recent estimates derived by the California Biomass Collaborative suggest that nearly 10 million bone dry tons of forest-based biomass could be made available on an annual sustainable basis, enough to double current production. However, without incentives to offset the costs associated with producing the fuel and to encourage the investment in new plants it is unlikely the future will see much increase in current levels.
The recognized need to reduce wildland fuel hazards combined with reality of the commercial biomass powerplant markets have led to a renewed interest in smaller scale woody biomass solutions that can often be closer to the fuel source. Of particular interest are systems that generate electricity as well as use the excess heat produced (combined heat and power). New designs in biomass combustion and gasification/combustion systems sized from ½ to 2 megawatts are available that can provide heat and electricity for manufacturing or a small community using from 5 to 40 tons of biomass per day (depending on system size and biomass moisture content). Systems smaller than ½ megawatt may also be appropriate for use in public buildings in remote areas where fuel and electricity costs are high.
 
The challenges for using woody biomass are many and the economic opportunities limited. Although there is a long list of products that could be produced from woody biomass there are often competing raw materials to make these products that are of higher quality and lower cost.  The solutions to providing more opportunities for woody biomass are to encourage the use in efficient energy conversion facilities (powerplants, heat and power systems, etc.), use small diameter trees in their round form instead of trying to produce lumber, support the research and development needed to encourage investment in higher value fiber uses for composite materials (such as composite panels and wood fiber/plastic products), and continue the search for cost-effective chemical processing to biofuels and other organic chemicals. 
This website aims to show what you work is going on in California and to provide answers to questions.