ALGAE COULD FUEL CARS AND JOBS

(Photo: CSIRO)
Wednesday, 18 March 2009 17:32
CSIRO Energy Transformed researcher Dr Tom Beer and his team discovered the humble organisms’ green credentials during a detailed life-cycle analysis of the benefits of algal biodiesel.


"Our research has shown that under ideal conditions it is possible to produce algal biodiesel at a lower cost and with less greenhouse gas emissions than fossil diesel," Dr Beer said.

"The greenhouse gas reductions are the result of avoiding the use of a fossil resource for fuel production, capturing methane produced by the processed algae to generate energy and taking into account the potential greenhouse gas offsets from industry."

Algae thrive on carbon dioxide (CO2), which means that environmentally damaging CO2 emissions from industry could also become a useful resource.

Algal biodiesel could also offer a number of other benefits.

"Making biodiesel from algae removes the issue of competing land use because the facilities would not be established on land that might otherwise be used to grow food and the algal farm has a very low environmental impact in comparison to crops that are grown for biodiesel," Dr Beer said.

"Our study also found that the establishment of a 500 hectare algal biodiesel plant in a rural area might create up to 45 jobs and provide opportunities to diversify in the agricultural sector."

The CSIRO Energy Transformed Flagship is working with a number of partners, both national and international, to develop a strong algal biofuel research program.

"The Flagship’s research has made significant progress in a short time and our extensive biofuels program will continue to develop solutions that result in a secure fuel future for Australia," Dr Beer said.

Despite the global interest in the production of biodiesel from algae, further research is required to create a viable industry with widespread uptake and impact.

"Although the findings of our study are very promising, challenges still exist in relation to cost, infrastructure needs and the scale of production required to make algal plants feasible," Dr Beer said.

"We see biodiesel from algae as one potential option for sustainable fuel production amongst a range of other technologies."

CSIRO

SUNLIGHT TURNS CARBON DIOXIDE TO METHANE

(Photo: Penn State)
Tuesday, 17 March 2009 16:18

Burning fossil fuels like oil, gas and coal release large amounts of carbon dioxide, a greenhouse gas, into the atmosphere. Rather than contribute to global climate change, producers could convert carbon dioxide to a wide variety of hydrocarbons, but this makes sense to do only when using solar energy.


"Recycling of carbon dioxide via conversion into a high energy-content fuel, suitable for use in the existing hydrocarbon-based energy infrastructure, is an attractive option, however the process is energy intense and useful only if a renewable energy source can be used for the purpose," the researchers note in a recent issue of Nano Letters.

Craig A. Grimes, professor of electrical engineering and his team used titanium dioxide nanotubes doped with nitrogen and coated with a thin layer of both copper and platinum to convert a mixture of carbon dioxide and water vapor to methane. Using outdoor, visible light, they reported a 20-times higher yield of methane than previously published attempts conducted in laboratory conditions using intense ultraviolet exposures.

The chemical conversion of water and carbon dioxide to methane is simple on paper -- one carbon dioxide molecule and two water molecules become one methane molecule and two oxygen molecules. However, for the reaction to occur, at least eight photons are required for each molecule.

"Converting carbon dioxide and water to methane using photocatalysis is an appealing idea, but historically, attempts have had very low conversion rates," said Grimes who is also a member of Penn State's Materials Research Institute. "To get significant hydrocarbon reaction yields requires an efficient photocatalyst that uses the maximum energy available in sunlight."

The team, which also included Oomman K. Varghese and Maggie Paulose, Materials Research Institute research scientists and Thomas J. LaTempa, graduate student in electrical engineering, used natural sunlight to test their nanotubes in a chamber containing a mix of water vapor and carbon dioxide. They exposed the co-catalyst sensitized nanotubes to sunlight for 2.5 to 3.5 hours when the sun produced between 102 and 75 milliwatts for each square centimeter exposed.

The researchers found that nanotubes annealed at 600 degrees Celsius and coated with copper yielded the highest amounts of hydrocarbons and that the same nanotubes coated with platinum actually yielded more hydrogen, while the copper coated nanotubes produced more carbon monoxide. Both hydrogen and carbon monoxide are normal intermediate steps in the process and as the building blocks of syngas, can be used to make liquid hydrocarbon fuels.

When the team used a nanotube array with about half the surface coated in copper and the other half in platinum, they enhanced the hydrocarbon production and eliminated carbon monoxide. The yield for these dual catalyst nanotubes was 163 parts per million hydrocarbons an hour for each square centimeter. The yield from titania nanotubes without either copper or platinum catalysts is only about 10 parts per million.

"If we uniformly coated the surface of the nanotube arrays with copper oxide, I think we could greatly improve the yield," said Grimes.

Grimes also found that lengthening the titanium dioxide tubes, which for other applications increases yield, does not improve results.

"We think that distribution of the sputtered catalyst nanoparticles is at the top surface of the nanotubes and not inside and that is why increased length does not improve the reaction," says Grimes.

Although all these experiments were done with nitrogen-doped titanium dioxide nanotubes, the researchers conclude that the nitrogen did not enhance the conversion of carbon dioxide to hydrocarbons. The catalysts, however, did shift the reaction from one that used only the energy in ultraviolet light to one that used other wavelengths of visible light and therefore more of the sun's energy.

The researchers are now working on converting their batch reactor into a continuous flow-through design that they believe will significantly increase yields.

The researchers have filed a provisional patent on this work.

Penn State

U.S.-LED, INTERNATIONAL RESEARCH TEAM CONFIRMS ALPS-LIKE MOUNTAIN RANGE EXISTS UNDER EAST ANTARCTIC

(Photo: Zina Deretsky / NSF)

Wednesday, 11 March 2009 10:33
Flying twin-engine light aircraft the equivalent of several trips around the globe and establishing a network of seismic instruments across an area the size of Texas, a U.S.-led, international team of scientists has not only verified the existence of a mountain range that is suspected to have caused the massive East Antarctic Ice Sheet to form, but also has created a detailed picture of the rugged landscape buried under more than four kilometers (2.5 miles) of ice.

"Working cooperatively in some of the harshest conditions imaginable, all the while working in temperatures that averaged -30 degrees Celsius, our seven-nation team has produced detailed images of last unexplored mountain range on Earth," said Michael Studinger, of Columbia University's Lamont-Doherty Earth Observatory, the co-leader of the U.S. portion of the Antarctica's Gamburstev Province (AGAP) project. "As our two survey aircraft flew over the flat white ice sheet, the instrumentation revealed a remarkably rugged terrain with deeply etched valleys and very steep mountain peaks."

The National Science Foundation (NSF), in its role as manager of the U.S. Antarctic Program, provided much of the complex logistical support that made the discoveries possible. NSF also supported U.S. researchers from Columbia University, Washington University in St. Louis, Pennsylvania State University, the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas, the U.S. Geological Survey (USGS) and the Incorporated Research Institutions in Seismology (IRIS).

The initial AGAP findings--which are based on both the aerogeophysical surveys and on data from a network of seismic sensors deployed as part of the project--while extremely exciting, also raise additional questions about the role of the Gamburtsevs in birthing the East Antarctic Ice Sheet, which extends over more than 10 million square kilometers atop the bedrock of Antarctica, said geophysicist Fausto Ferraccioli, of the British Antarctic Survey (BAS), who led the U.K. science team.

"We now know that not only are the mountains the size of the European Alps but they also have similar peaks and valleys," he said. "But this adds even more mystery about how the vast East Antarctic Ice Sheet formed."

He added that "if the ice sheet grew slowly then we would expect to see the mountains eroded into a plateau shape. But the presence of peaks and valleys could suggest that the ice sheet formed quickly--we just don't know. Our big challenge now is to dive into the data to get a better understanding of what happened" millions of years ago.

The AGAP survey area covered roughly 2 million square kilometers of the ice sheet.

The initial data also appear to confirm earlier findings that a vast aquatic system of lakes and rivers exists beneath the ice sheet of Antarctica, a continent that is the size of the U.S. and Mexico combined.

"The temperatures at our camps hovered around -30 degrees Celsius, but three kilometers beneath us at the bottom of the ice sheet we saw liquid water in the valleys," said AGAP U.S. Co-leader Robin Bell, also of Lamont Doherty. "The radar mounted on the wings of the aircraft transmitted energy through the thick ice and let us know that it was much warmer at the base of the ice sheet."

The AGAP data will help scientists to determine the origin of the East Antarctic Ice Sheet and the Gamburtsevs' role in it. It will also help them to understand the role the subglacial aquatic system plays in the dynamics of ice sheets, which will, in turn, help reduce scientific uncertainties in predictions of potential future sea level rise. The most recent report of the Intergovernmental Panel on Climate Change (IPCC) said that it is difficult to predict how much the vast ice sheets of Greenland and Antarctica will contribute to sea-level rise because so little is known about the behavior of the ice sheets.

The data also will be used to help locate where the world's oldest ice is located.

The AGAP discoveries were made through fieldwork that took place in December and January, near the official conclusion of the International Polar Year (IPY), the largest coordinated international scientific effort in five decades. Ceremonies marking the conclusion of IPY fieldwork will take place in Geneva, Switzerland on Feb. 25.

NSF is the lead U.S. agency for IPY. Through the Antarctic Program, NSF manages all federally funded research on the southernmost continent.

Fully in the spirit of IPY, noted Detlef Damaske of Germany's Federal Institute for Geosciences and Natural Resources, teams of scientists, engineers, pilots and support staff from Australia, Canada, China, Germany, Japan, the U.K. and the U.S. pooled their knowledge, expertise and logistical resources to deploy two survey aircraft, equipped with ice-penetrating radar, gravimeters and magnetic sensors as well as the network of seismometers, an effort that no one nation alone could have mounted.

"This is a fantastic finale to IPY," added Ferraccioli.

Bell meanwhile, noted that AGAP is "emblematic of what the international science community can accomplish when working together."

In one of the most ambitious, challenging and adventurous 'deep field' Antarctic IPY expeditions, AGAP scientists gathered the terabytes of data needed to create images of the enigmatic Gamburtsevs, first discovered by Russian scientists in 1957 during the International Geophysical Year (IGY), the predecessor to IPY.

While the planes made a series of survey flights, covering a total of 120,000 square kilometers, the seismologists flew to 26 different sites throughout an area larger than the state of Texas using Twin Otter aircraft equipped with skis, to install scientific equipment that will run for the next year on solar power and batteries.

The seismology team, from Washington University, Penn State, IRIS, and Japan's National Institute of Polar Research, also recovered ten seismographs that have been collecting data since last year over the dark Antarctic winter at temperatures as low as -73 degrees Celsius (-100 degrees Fahrenheit).

"The season was a great success," said Douglas Wiens, of Washington University in St. Louis. "We recovered the first seismic recordings from this entire part of Antarctica, and operated seismographs over the Antarctic winter at temperatures as low as -100 F for the first time. Now, we are poring over the data to find out what is responsible for pushing up mountains in this part of Antarctica."

National Science Foundation