Environmental Engineering Reference
In-Depth Information
9
Biomass Fuels and Raw Materials
Wood supplied virtually all the energy needed for space and water heating, cooking,
and a growing range of artisanal manufactures and industrial processes for far
longer than most people think. Fossil fuels were known, both in Asia and in Europe,
since antiquity, but the i rst society in which coal became more important than wood
was England of the early seventeenth century—and that remained a great exception.
Reasonably reliable estimates and actual output statistics show that in France,
coal began to supply more than half of all fuel needs only sometime during the
mid-1870s, and in the United States the tipping point came in the mid-1880s. Fossil
fuels gained more than half the Japanese energy supply in 1901, in Russia only
during the early 1930s (Smil 2010b). Nearly smokeless and sulfur-free, charcoal was
a preferred fuel for indoor heating and cooking; in China it was also the raw mate-
rial for making an indispensable material of that ancient civilization, its black
writing ink.
But charcoal's most important use was in smelting metals: it was the only metal-
lurgical fuel used to reduce copper, tin, lead, and iron ores. The Bronze Age (bronze
is an alloy of copper and tin) began nearly 6,000 years ago, while iron items i rst
appeared appear more than 3,000 years ago. Several ancient societies had even
solved the difi cult challenge of making high-quality steel by reducing cast iron's
carbon content, and medieval artisans could produce high-quality swords in Ky¯t¯
or Damascus (Verhoeven, Pendray, and Dauksch 1998). But until large blast fur-
naces made it possible to mass produce iron utensils, tools, implements, and
machines, all societies lived through millennia of a wooden age: steel became inex-
pensive only during the last generation before World War I (Smil 2005).
Charcoal's inefi cient production was a leading contributor to extensive defores-
tation, i rst in the arid Mediterranean and in northern China, and during the early
modern era also in Atlantic and Central Europe. And traditional biomass fuels
remain the dominant or only source of heat energy for hundreds of millions of poor
 
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