Guayule: Is This Desert Shrub a Fuel of the Future?
By Marcia Wood
February 20, 2009
Superb natural latex from a desert
shrub called guayule (why-YOU-lee) makes high-quality gloves, medical devices,
and other in-demand natural rubber products.
But guayule may also prove to be an economical, environmentally friendly
source of another valuable resourceenergy. That's according to
Agricultural Research Service (ARS)
M. McMahan at the agency's
Regional Research Center in Albany, Calif.
Bioenergy can be made from ground-up guayule stems and branches, left after
their white, rubber-rich latex has been removed, McMahan noted. The
leftoversa soft, light brown sawdust-like material called
bagasseprovide 8,000 to 9,000 Btu per pound, about the same as charcoal.
McMahan's collaborators include ARS chemist
M. Holtman at the Albany center, who has already made small amounts of
ethanol from guayule, and chemical engineer
Boateng at the ARS
Regional Research Center in Wyndmoor, Pa. Boateng is looking into
converting guayule bagasse into bio-oil or synthetic gas.
Guayule offers many biofuel benefits. It isn't a food or feed crop, so using
it for energy production won't compete with those uses. Guayule shrubs can be
harvested for the first time as early as two years after planting, and are
ready to harvest again in about another year and a half.
Guayule's bagasse and latex are available year round. The only other biofuel
feedstock available continuously right now is garbage (municipal solid waste).
In addition, guayule thrives in hot, dry ecosystems where many other biofuel
crops wouldn't grow well. The hardy shrub requires less fertilizer than other
crops currently produced in the desert Southwest. Even though a few herbicides
are needed while the plants are getting established, once that happens, there's
no need for moreor for chemicals that target harmful insects, fungi, or
worms called nematodes.
more about this research in the February 2009 issue of Agricultural
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture.