Grow Your Own Oil, U.S.
Researchers hoping to ease America's oil addiction are
turning sawdust and wood chips into bio-oil, a thick black liquid that could
become a green substitute for manypetroleum products. Bio-oil can be made from
almost any organic material, including agricultural
and forest waste like corn stalks and scraps of bark. Converting the raw biomass
into bio-oil yields a product that is easy to transport and can be processed
into higher-value fuels and chemicals. "It is technically feasible to
use biomass for the production of all the
materials that we currently produce from petroleum," said professor Robert
C. Brown, director of the Office of Biorenewables Programs at Iowa State University.
The United States can grow enough fresh biomass --
more than a billion tons each year -- to supplant at least a third of its annual
petroleum use,according to an April 2005 study (.pdf) by the U.S. departments
of Agriculture andEnergy. Brown advocates turning much of that biomass -- including
scrap materials currently used in power generation -- into bio-oil to ease
dependence on foreign oil and help slow global warming.
The biomass is converted into bio-oil through a process
called pyrolysis, in which the organic scrap materials are finely ground and
heated at 400 to 500 degrees Celsius, without oxygen. In just two seconds,
about 70 percent of the material vaporizes and is condensed into bio-oil --
dark liquid resembling espresso that contains more than a hundred organic compounds.
Pyrolysis also produces a gas, which is burned to fuel
the process, and carbon-rich soot called "char," which can be burned
as fuel, used as a soil fertilizer or processed into charcoal filters or briquettes.
Researchers at the University of Western Ontario developed bio-oil as a petroleum
alternative in the early 1980s. Two of the scientists, Barry Freel and Robert
Graham, founded the Delaware company Ensyn in order to produce commercial products.
Back then, there was not much interest in renewable
energy," said David C. Boulard, Ensyn's executive vice president. So the
company focused on producing chemicals rather than fuels, and found success
with food flavorings -- especially "liquid smoke." Beyond making
food taste better, the company now uses its patented core technology, Rapid
Thermal Processing , to produce bio-oil that can be used as fuel. In addition,
resins utilized in the manufacture of plywood and particleboard can be extracted
from the bio-oil. And Boulard said he sees the potential for moreapplications.
"I believe that we're just at the tip of the iceberg," he said,
citing nutritional supplements and pharmaceuticals as possible product categories.
Ensyn plans to open its seventh and largest bio-oil
refinery this summer. Meanwhile, Canadian firm DynaMotive is producing bio-oil
fuels that are becoming economically competitive given today's high petroleum
prices. In its raw form, DynaMotive's bio-oil can substitute for light petroleum
fuel oil for use in power-generating turbines. DynaMotive is also aiming to
produce automotive fuel, which requires a bit more work. Though it competes
with petroleum crude, bio-oil is very different chemically. Instead of oxygen-free
hydrocarbons, it contains oxygen-rich substances. But bio-oil can be converted
into a mixture of carbon monoxide and hydrogen known as "syngas." And
syngas can, in turn, be processed into ahigh-grade hydrocarbon fuel, such as
automotive diesel. Alternatively, the syngas can be combined with steam to
produce pure hydrogen. In fact, Iowa State's Brown believes that bio-oil gasification
may be the most efficient means of producing large quantities of hydrogen,
should the element ever catch on as a major energy source.
DynaMotive is bullish on the syngas route because the
technology and infrastructure are well-established. Germany used gasification
to convert coal into synthetic diesel fuel during World War II. And South Africa
used synthetic fuels as a substitute for petroleum imports
during Apartheid-era economic sanctions. Today, gasification is seen as a way
to reduce pollution from coal, because the process removes much of the carbon
dioxide and otherpollutants, such as sulfur. Last
September, DynaMotive announced that researchers in Germany had succeeded in
converting its bio-oil into syngas using existing gasification facilities.
DynaMotive aims to harness growing concern over
climate change into a market for its bio-oil. For instance, a European Union
directive (.pdf) requires 5.75 percent of automotive fuel in member states
to come from biological sources by the end of 2010 and sets higher quotas for
subsequent years. And some argue that bio-oil could be better than petroleum. "Comparing
the performance of synthetic diesel with conventional diesel -- the results
are equal or better," said DynaMotive CEO Andrew Kingston.