Page 311 - Synthetic Fuels Handbook

CHAPTER 10

FUELS FROM WOOD

Biofuels are presently the only renewable source of liquid transportation fuels and offer
many potential environment and economic benefits. The production of the raw biomass
material and its subsequent conversion to fuels creates local jobs, provides regional eco-
nomic development, and can increase farm and forestry incomes. Biofuels also offer many
environment benefits including reduction of carbon dioxide emissions associated with
global climate change and improved waste utilization. The chemical composition of many
biofuels also leads to improved engine performance and reduces unwanted pollutants such
as carbon monoxide and unburned hydrocarbons. Billions of liters of ethanol are used annu-
ally for transportation fuels, and biodiesel is gaining popularity in some regions.
Biomass (Chap. 8) is a catch-all term that also includes wood and is generally made up
of woody plant residue and complex starches. The largest percentage of biomass used to
create energy is wood, but other bioproducts, such as fast-growing switchgrass (Chap. 9), are
being investigated as sources of energy. The three largest sources of biomass used for fuel
are cellulose, hemicellulose, and lignin. Biomass processing results in the end-products,
biochemical products, biofuels, and biopower, all of which can be used as fuel sources. The
production of biochemical products involves converting biomass into chemicals to produce
electricity; biofuels are biomass converted into liquids for transportation; and biopower
is made by either burning biomass directly (as with a wood-burning stove) or converting
it into a gaseous fuel to generate electric power. Currently, production of electricity from
biomass constitutes 3.3 percent of the United States’ energy supply.
In fact, it is confidently predicted that wood will remain a major renewable resource for
man’s future (Youngs, 1982).

10.1 HISTORY

Of all of the alternate energy sources (relative to fossil fuels) the use of wood predates the
others and dates from prebiblical times (pre-4000 B.C.). In peace and in war, in the Old
and the New World, man first turned to wood for his basic needs and later learned to use
advanced science to employ wood as his most sophisticated raw material, being infinitely
versatile and an easily renewable source.
The manner in which wood was used by early cultures is difficult to determine, as wood
artifacts have largely disappeared. Certainly the use of wood for fire is one of the first and
most significant contributions of this resource to the development of society. No doubt
man built early pole structures from the small trees growing along the rivers and later he
would build more solid structures from planks, turf, mud, and adobe. The Scandinavians
developed the basic principles of timber framing which were probably known in Europe in
the Bronze Ageand framing eventually became the preeminent method of wood building in
the Western World, reflecting developments in structural engineering that had been worked
out with wood mostly through trial and error.

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