Research


If Not US, Wood Europe?


Uncle Sam After investing $4.5 million to make biomass oil from wood scraps, the United States may be forced to sell the technology abroad, Dr. Daniel J. O'Neil warns.

As director of the Energy and Materials Sciences Laboratory at Georgia Tech, O'Neil encouraged the development of a patented biomass conversion process known as "entrained flow pyrolysis."

Non-polluting and economically practical, the process is believed to be the world's most efficient biomass conversion system, yielding up to 60 percent oil on a dry basis (72 percent on a wet basis), from wood scraps and other agricultural refuse. Further, the process is simple and operates at relatively low temperatures. Earlier biomass technology, also developed at Georgia Tech, produces roughly 30 percent oil.

And yet, O'Neil reports, U.S. manufacturers have expressed little interest in the technology, despite rising domestic oil prices which make the Georgia Tech process commercially attractive. Europeans are more highly motivated to perfect new energy technologies since they pay about $42 per barrel for oil--twice the U.S. price, he notes. O'Neil says Georgia Tech has discussed a technology transfer with several European organizations in Belgium, Denmark, Germany and Spain.

"This technology will probably be commercialized by a foreign entity," O'Neil says. "Five years from now, we'll probably end up buying U.S. technology back from a foreign-owned company. That's the irony."

What makes the Georgia Tech process so efficient? In a conventional biomass conversion system, O'Neil explains, wood scraps move slowly through a large, cross-sectional reactor, producing large quantities of charcoal. To harvest more oil and less charcoal, Tech researchers modified the process by pushing finely-ground wood particles rapidly through a high-temperature reactor.

Since the wood produces oil as a primary product and the oil has little time to degrade into gases or charcoal, O'Neil says, roughly 60 percent has been converted into biomass oil, which is suitable for use in industrial heaters, boilers, or kilns. The technique also generates lesser quantities of valuable charcoal and low-BTU gas. In the future, O'Neil predicts the process will be improved to produce gasoline and specialty chemicals.

If half of the unused wood residues produced annually in the U.S. were converted in a Georgia Tech system operating at just 40 percent yield, O'Neil says, about 98 billion tons of biomass oil--the equivalent of 412 million barrels of crude petroleum--could be produced.

Mending Broken Hearts

A new tool for assessing leaky heart valves may soon help doctors gauge problems without diagnostic surgery, says Dr. Ajit P. Yoganathan, co-director of the Bioengineering Center at Tech. Once perfected, the technique could bolster the battle against heart enlargement, certain types of high blood pressure and other disorders caused by leaky valves.

Used in conjunction with conventional ultrasound Doppler imaging, the new technique is believed to be the first quantitative, non-invasive method for measuring the volume of blood leaking from human or artificial heart valves.

The Georgia Tech method employs a mathematical formula and basic engineering principles to calculate the volume of leakage.

Yoganathan's unique blood-flow duplicator, a system of mechanical valves and pumps representing a human heart, has provided preliminary information to validate the formula. In both steady-state and pulsating-flow models, Yoganathan says, mathematical/Doppler predictions corresponded well with volume measurements of simulated blood flow.

Ongoing research is addressing more complicated leaks, which may encounter physical obstructions that alter flow patterns.

Chaos in Chemical Reactions

Chemists may have to find new ways of describing certain non-linear chemical reactions, thanks to the new science of chaos.

Developed over the past 20 years, chaos is the study of non-linear phenomena that share common characteristics, such as randomness.

Dr. Ronald F. Fox, a physicist and chaos researcher at Tech, believes that chaos may exist in certain chemical reactions.

In most chemical reactions, the component materials eventually seem to assume an equilibrium state at which no further reactions take place. However, sensitive light-scattering instruments still detect significant molecular activity. Though such activity is of no importance in most cases, those tiny perturbations can be magnified into large fluctuations if the system becomes chaotic.

"When you have a chaotic system, the fluctuations that are normally very small become very large," Fox explains. "There is extreme sensitivity to the initial conditions, and that sensitivity shows itself in the growth of the fluctuations."