Monday, March 20, 2006

Sawdust into oil?

Nothing new really, I read my first article on this a few years back. However, Wired ran with the story today so I thought I would put a bit of it here.

Grow Your Own Oil, U.S.
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.

DOE Report: Biomass Oil Analysis: Research Needs and Recommendations {PDF}
Demonstrate and optimize commercial bio-distillate production Bio-distillation research was ranked number one for several reasons. The benefits of producing bio-distillates from using existing infrastructure are significant. Production and distribution costs can be minimized and key political barriers are addressed. Bio-distillates can become a premium additive, where the additional value may offset the higher cost inputs. Biomass oils could displace higher cost
refinery streams. A stand-alone fuel composed of bio-distillates could even be possible. Emission benefits of either the additive or the stand-alone fuel are not known at this time and need to be identified. So long as existing refinery processes are used, global warming benefits are highly likely based on previous diesel and soy biodiesel life cycle analyses. There are a large number of technical issues that need to be resolved before this technology can be commercialized. What level of incentive would be necessary to breakeven with vegetable oil feedstocks? Why types of
logistical issues limit oil displacement, if any? What are the feedstock quality issues? What is the oil displacement potential?

Biomass: Hope and Hype
A recent report by the National Resources Defense Council and researchers at Dartmouth and Princeton projects that by 2050, in part through harvesting both protein and cellulose from corn and switchgrass, existing agricultural land could both supply our food needs and replace gasoline with ethanol.

Unless it's done carefully, however, deriving fuels from biomass could destroy crop lands through erosion, increase air pollution -- and even increase our dependence on fossil fuels. For example, one of the steps in processing biomass, distillation, requires heat. In the short term, inexpensive coal may appear to be a good energy source for this, says John Reilly, associate director for research at MIT's Joint Program on the Science and Policy of Global Change. But this would cancel out one of the primary benefits of biomass: carbon released by burning biofuels is offset by the carbon captured by growing crops, leading to near-zero total carbon emissions. Using coal for distillation would destroy this balance. In one scenario, Reilly says that "68 percent of the carbon you think you're saving is actually being emitted through other processes." Likewise, using gasoline or diesel to transport biomass from widespread farms and other agricultural facilities to processing centers would change the overall carbon equation.

Other Links:
Thermo-Chemical Conversion of Biomass
Biomass Energy Foundation
The Veggie Van Organization

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