Wednesday, July 23, 2008

Alaska woody biomass

In Alaska, the search for alternatives to petroleum and fossil fuels has researchers looking at the potential of a variety of raw sources, everything from fish to oilseed crops to landfills to trees. While much of the news surrounding this research focuses on the source material's utility for biofuel (such as biodiesel or biogas), petroleum is immensely valuable as a source for complex hydrocarbon compounds, from which we extract or produce high-value, specialty chemicals or substances (fertilizers, lubricants, medicines, resins, polymers, plastics, etc.). Chemical analysis of petroleum alternatives may show alternatives for these as well.

The major categories of alternative biomass resources are: agricultural (energy crops, crop residues, agricultural biosolids); forest (woody biomass crops, logging slash, wildland fuel reduction, right-of-way clearing, sawmill leftovers); urban (solid waste, wastewater and biosolids, landfill waste); and fisheries (bycatch, harvest residues). Research at SNRAS has touched on many of these.

Woody biomass, i.e., trees and other plants, is plentiful in Alaska. We have millions of acres of trees and shrubs. However, we know little about the chemical characteristics and composition of the biomass available to us.

Andres Soria, assistant research professor of wood chemistry at SNRAS, is investigating the chemical composition and characteristics of alder, birch, hemlock, yellow cedar, Sitka spruce, red cedar, white spruce, and aspen. "Depending on the origin of the woody biomass," writes Soria, "from hardwood or softwood for instance, the chemical makeup…can be completely different."

Working with kiln-dried wood provided by the Ketchikan Wood Technology Center, Soria produced bio-oil (created through supercritical methanol liquefaction) from each species. The different species produce different liquid fractions, ranging from 96% for aspen to 89% for hemlock or red aspen, and averaging 90% liquid content by weight. The advantage of using this method is that it allows for a high liquifaction rate, and the complex of biomass chemicals remain in solution (131 to 190 different compounds with boiling points less than 250˚C depending on the species tested).

The economic potential of these resources could be enormous and could help Alaska break its economic dependence on imported processed hydrocarbons, by providing a better understanding of the resources available and their suitability to specific niche markets. Deeper knowledge of our resources and the costs and benefits to using them in new ways could generate local enterprises or new agricultural or forestry industries that could increase the state's economic and environmental sustainability.

A few publications, articles, and websites regarding the potential for biomass in Alaska are available:
Arctic Vegwerks, a blog "promoting the biodiesel and vegoil community in Alaska".
Biomass Energy, Alaska Energy Authority webpage on energy from biomass, including links and references on biodiesel, municipal waste, and wood and wood waste.
Alaska Wood Energy Conference, 2007; schedule and links to presentations.
"Bioenergy Potential, from Brazil to Alaska," by Brian Yanity, Insurgent49, October 13, 2006.
•"Biomass for biofuels: not all trees are created equal," by J. Andres Soria, Agroborealis 39(2), winter/spring 2008 (PDF), p. 7.
"Fueling the Future," by Charles Westmoreland, Capital City Weekly, July 16, 2008.
Sitka Wood Utilization Center, Pacific Northwest Research Station, US Forest Service.
Wood Energy Resources, CES Rural Development wood energy link list.
Wood Utilization Research Centers, a USDA special grant program, of which SNRAS is a member center.

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