Grow Your Own Oil, U.S.
Wired Magazine
By Seán Captain | Also by this reporter
02:00 AM Mar, 20, 2006 EST
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 many petroleum 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 and Energy.
Brown advocates turning much of that biomass -- including scrap materials currently used in power generation -- into bio-oil to ease America's 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 -- a 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 more applications.
"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 a high-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 other pollutants, such as sulfur.
Last September, DynaMotive announced that researchers in Germany had succeeded in converting its bio-oil into synthetic gasoline 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.