Technology

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
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

Technological feasible does not equate to economic reality. Woody biomass will only be used for higher value products if the quality of the raw material is as good as that currently 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 handling larger trees. As a result the transport of this low quality, low value raw material much more than 50 miles is often not economically viable. If transport is not a limiting factor the quality of the raw material often is.

Lumber produced from small diameter trees is highly prone to warp. 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 low quality is due to 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 (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.

Therefore, adding value to woody biomass is challenging not because of technological challenges but because of the low value and low quality of the material relative to biomass from other sources.

Wood pellet manufacturing

Lumber from small diameter logs, Sierra Forest Products, Terra Bella, CA

Composting at Viramontes Express, Chino, CA

Wood savings for animal bedding, California Wood Shavings, Sonora, CA