| Biomass in California: Is it a Valuable Resource? By John R. Shelly, Ph.D.
Biomass is everywhere! Every forest, agriculture, and urban community contains a component of biomass. However, the term is not well defined and often means different things to different people. In the forest community, biomass is nearly synonymous with the use of woody materials to generate electricity. However, it is much more than fuel chips for combustion power plants. I like to think of biomass as any biological plant or plant byproduct that accumulates in quantities great enough to create a hazard or disposal problem or plants that are grown as an energy or feedstock crop. Following this definition, the major sources of biomass in California include forest–based harvesting residue, wood manufacturing residue, chaparral, urban lignocellulosic wastes (removals and prunings of city trees, yard waste, and woody–fiber consumer waste), and agricultural residue. Biomass is an important issue in California due to excessive accumulations in forest and wildland regions that may have an adverse effect on ecosystem health and often increase the fire hazard. It has a direct effect on wildfire and the resultant catastrophic losses to structures, the environment, and the potential loss of human life. The California Department of Forestry and Fire Protection estimates that over 2.5 million people and 1 million structures are at risk from wildland fires. It is generally recognized that past forest management practices, drought conditions, and beetle infestations have resulted in an unprecedented accumulation of biomass in many urban, wildland, and forest regions. Undoubtedly, bio-mass is an important component of the ecosystem and and the definition of what constitutes an excessive accumulation is continually being debated. What is clear, however, is that as biomass levels increase, the fire risk increases and fuel reduction efforts are warranted. The reduction of forest–based biomass as a potential solution to many wildfire and forest health problems creates a new concern—what to do with the biomass we remove. The traditional biomass disposal methods of burning or landfill (especially in urban areas) face many economic and environmental restraints limiting use. The operating and containment costs, reduction in allowable burn days, air quality concerns, and extremely high fuel load levels found in many regions may limit the use of prescribed burning. Additionally, forest–based biomass utilization is an important issue in California because it may help offset the high cost of fuel reduction. Unfortunately, as reported by the UC Forest Products Laboratory, the options are limited for many conventional products because of the low quality material properties of much of the biomass. From a technical point of view, combustion processes appear to be the most viable, but current economic realities limit their use. Since the early 1970s the biomass–based electricity power plants have played a vital role. At their peak, biomass and co–generation plants (those that produce both electricity and process energy for manufacturing) had a total capacity of 975 megawatts of electricity, which used about 16 million tons (wet basis) of biomass per year from all sources. Another possible energy production method receiving serious attention is the conversion of biomass to ethanol. A strong demand is expected for ethanol as a clean burning gasoline additive, but very little ethanol is produced in California. In a feasibility study initiated by the Quincy Library Group, it was determined that an adequate supply of biomass existed within a 25 mile radius of several potential sites to support a successful 15 million gallons per year. This is approximately 10 percent of the current western ethanol needed in the northern Sierra of California. Using forest–based biomass in other conventional products is technically feasible but unlikely because of raw material quality concerns, high manufacturing costs, and/or market conditions. For example, densified solid fuels such as pellets and briquettes are presently made from manufacturing wood waste and could be made from other biomass materials, but the over capacity of the industry and the uncertain future of the fuel pellet market make this a risky venture. Compost and mulch are often a popular solution, especially in urban areas, but the market is close to saturation. Small diameter trees could be made into conventional lumber but the manufacturing costs would be high and the lumber would be low quality. Combining wood fibers with plastic polymers, cement, or other inorganic binders have the potential to use a wide variety of raw material sources, including biomass materials, but presently, only pulpwood quality wood fibers are being used. These fiber/polymer and particle/cement mixtures can be molded into a variety of shapes and sizes to make a wide assortment of products. The potential of these mixtures is just beginning to be explored. There appears to be little disagreement that large quantities of biomass exist and that the volume is
increasing rapidly. However, the question, “is it a valuable resource” remains unanswered. Many products could potentially
use biomass–based raw materials, but with sufficient quantities of higher quality raw materials available, this is
unlikely unless incentives are available to the manufacturers. Creative approaches to biomass reduction and utilization
must consider:
This article first appeared in Forestland Steward, Summer 1998. California Biodiversity News: Volume 8, Number 2 |