Dry Water Could Make a Big Splash Commercially, Help Fight Global Warming

Dry Water Could Make a Big Splash Commercially, Help Fight Global Warming

  12:40:00 AM    Science Lover

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An unusual substance known as "dry water," which resembles powdered sugar, could provide a new way to absorb and store carbon dioxide, the major greenhouse gas that contributes to global warming, scientists reported at the 240th National Meeting of the American Chemical Society.

Powdered material called "dry water" could provide a new way to store carbon dioxide in an effort to fight global warming. (Credit: Ben Carter)

The powder shows bright promise for a number of other uses, they said. It may, for instance, be a greener, more energy-efficient way of jumpstarting the chemical reactions used to make hundreds of consumer products. Dry water also could provide a safer way to store and transport potentially harmful industrial materials.

"There's nothing else quite like it," said Ben Carter, Ph.D., researcher for study leader Professor Andrew Cooper. "Hopefully, we may see 'dry water' making waves in the future."

Carter explained that the substance became known as "dry water" because it consists of 95 percent water and yet is a dry powder. Each powder particle contains a water droplet surrounded by modified silica, the stuff that makes up ordinary beach sand. The silica coating prevents the water droplets from combining and turning back into a liquid. The result is a fine powder that can slurp up gases, which chemically combine with the water molecules to form what chemists term a hydrate.

Dry water was discovered in 1968 and got attention for its potential use in cosmetics. Scientists at the University of Hull, U.K. rediscovered it in 2006 in order to study its structure, and Cooper's group at the University of Liverpool has since expanded its range of potential applications.

One of the most recent involves using dry water as a storage material for gases, including carbon dioxide. In laboratory-scale research, Cooper and co-workers found that dry water absorbed over three times as much carbon dioxide as ordinary, uncombined water and silica in the same space of time. This ability to absorb large amounts of carbon dioxide gas as a hydrate could make it useful in helping to reduce global warming, the scientists suggested.

Cooper and colleagues demonstrated in previous studies that dry water is also useful for storing methane, a component of natural gas, and may help expand its use as a future energy source. In particular, they hope that engineers can use the powder to collect and transport stranded deposits of natural gas. This also exists on the ocean floor in the form of gas hydrates, a form of frozen methane also known as the "ice that burns." The powder could also provide a safer, more convenient way to store methane fuel for use in vehicles powered by natural gas. "A great deal of work remains to be done before we could reach that stage," Carter added.

In another potential new application, the scientists also showed that dry water is a promising means to speed up catalyzed reactions between hydrogen gas and maleic acid to produce succinic acid, a feedstock or raw material widely used to make drugs, food ingredients, and other consumer products. Manufacturers usually have to stir these substances together to get them to react. By developing dry water particles that contain maleic acid, Cooper and colleagues showed that they could speed up the acid's reaction with hydrogen without any stirring, resulting in a greener, more energy-efficient process.

"If you can remove the need to stir your reactions, then potentially you're making considerable energy savings," Carter said.

Prof. Cooper's team describes an additional new application in which dry water technology shows promise for storing liquids, particularly emulsions. Emulsions are mixtures of two or more unblendable liquids, such as the oil and water mixture in mayonnaise. The scientists showed that they could transform a simple emulsion into a dry powder that is similar to dry water. The resulting powder could make it safer and easier for manufacturers to store and transport potentially harmful liquids.

Carter noted that he and his colleagues are seeking commercial or academic collaboration to further develop the dry water technology. The U.K. Engineering and Physical Sciences Research Council (EPSRC) and the Center for Materials Discovery provided funding and technical support for this study.

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Carbon Capture Has A Sparkling Future, New Findings Show

Carbon Capture Has A Sparkling Future, New Findings Show

  9:39:00 PM    Science Lover

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Carbon dioxide gas can dissolve in underground water
-- like bottled sparkling water.
(Credit: iStockphoto/Dirk Rietschel)

New research shows that for millions of years carbon dioxide has been stored safely and naturally in underground water in gas fields saturated with the greenhouse gas. The findings – published in Nature April 1 – bring carbon capture and storage a step closer.

Politicians are committed to cutting levels of atmospheric carbon dioxide to slow climate change. Carbon capture and storage is one approach to cut levels of the gas until cleaner energy sources are developed.

But the risks around the long-term storage of millions of cubic metres of carbon dioxide in depleted gas and oil fields has met with some concern, not least because of the possibility of some of the gas escaping and being released back to the atmosphere. Until now, researchers couldn't be sure how the gas would be securely trapped underground.

Naturally-occurring carbon dioxide can be trapped in two ways. The gas can dissolve in underground water – like bottled sparkling water. It can also react with minerals in rock to form new carbonate minerals, essentially locking away the carbon dioxide underground.

Previous research in this area used computer models to simulate the injection of carbon dioxide into underground reservoirs in gas or oil fields to work out where the gas is likely to be stored. Some models predict that the carbon dioxide would react with rock minerals to form new carbonate minerals, while others suggest that the gas dissolves into the water. Real studies to support either of these predictions have, until now, been missing.

To find out exactly how the carbon dioxide is stored in natural gas fields, an international team of researchers - led by the University of Manchester - uniquely combined two specialised techniques. They measured the ratios of the stable isotopes of carbon dioxide and noble gases like helium and neon in nine gas fields in North America, China and Europe. These gas fields were naturally filled with carbon dioxide thousands or millions of years ago.

They found that underground water is the major carbon dioxide sink in these gas fields and has been for millions of years.

Dr Stuart Gilfillan, the lead researcher who completed the project at the University of Edinburgh said: "We've turned the old technique of using computer models on its head and looked at natural carbon dioxide gas fields which have trapped carbon dioxide for a very long time."

"By combining two techniques, we've been able to identify exactly where the carbon dioxide is being stored for the first time. We already know that oil and gas have been stored safely in oil and gas fields over millions of years. Our study clearly shows that the carbon dioxide has been stored naturally and safely in underground water in these fields."

Professor Chris Ballentine of the University of Manchester, the project director, said: "The universities of Manchester and Toronto are international leaders in different aspects of gas tracing. By combining our expertise we have been able to invent a new way of looking at carbon dioxide fields. This new approach will also be essential for monitoring and tracing where carbon dioxide captured from coal-fired power stations goes when we inject it underground – this is critical for future safety verification."

Professor Barbara Sherwood Lollar of the University of Toronto and co-author of the study hopes the new data can be fed into future computer models to make modelling underground carbon capture and storage more accurate.

The work was funded by the Natural Environment Research Council and the Natural Sciences and Engineering Research Council of Canada.

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Journal reference:

1. Stuart M. V. Gilfillan, Barbara Sherwood Lollar, Greg Holland, Dave Blagburn, Scott Stevens, Martin Schoell, Martin Cassidy, Zhenju Ding, Zheng Zhou, Georges Lacrampe-Couloume & Chris J. Ballentine. Solubility trapping in formation water as dominant CO₂ sink in natural gas fields. Nature, 2009; 458 (7238): 614 DOI: 10.1038/nature07852

Adapted from materials provided by Natural Environment Research Council, via EurekAlert!, a service of AAAS.

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'Ice That Burns' May Yield Clean, Sustainable Bridge To Global Energy Future

'Ice That Burns' May Yield Clean, Sustainable Bridge To Global Energy Future

  9:46:00 AM    Science Lover

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Gas hydrates, known as "ice that burns," may provide a clean,
sustainable fuel source in the future.
(Credit: J. Pinkston and L. Stern/US Geological Survey)

In the future, natural gas derived from chunks of ice that workers collect from beneath the ocean floor and beneath the arctic permafrost may fuel cars, heat homes, and power factories. Government researchers are reporting that these so-called "gas hydrates," a frozen form of natural gas that bursts into flames at the touch of a match, show increasing promise as an abundant, untapped source of clean, sustainable energy.

The icy chunks could supplement traditional energy sources that are in short supply and which produce large amounts of carbon dioxide linked to global warming, the scientists say.*

"These gas hydrates could serve as a bridge to our energy future until cleaner fuel sources, such as hydrogen and solar energy, are more fully realized," says study co-leader Tim Collett, Ph.D., a research geologist with the U.S. Geological Survey (USGS) in Denver, Colo. Gas hydrates, known as "ice that burns," hold special promise for helping to combat global warming by leaving a smaller carbon dioxide footprint than other fossil fuels, Collett and colleagues note.

Last November, a team of USGS researchers that included Collett announced a giant step toward that bridge to the future. In a landmark study, the USGS scientists estimated that 85.4 trillion cubic feet of natural gas could potentially be extracted from gas hydrates in Alaska's North Slope region, enough to heat more than 100 million average homes for more than a decade.

"It's definitely a vast storehouse of energy," Collett says. "But it is still unknown how much of this volume can actually be produced on an industrial scale." That volume, he says, depends on the ability of scientists to extract useful methane, the main ingredient in natural gas, from gas hydrate formations in an efficient and cost-effective manner. Scientists worldwide are now doing research on gas hydrates in order to understand how this strange material forms and how it might be used to supplement coal, oil, and traditional natural gas.

Although scientists have known about gas hydrates for decades, they've only recently begun to try to use them as an alternative energy source. Gas hydrates, also known as "clathrates," form when methane gas from the decomposition of organic material comes into contact with water at low temperatures and high pressures. Those cold, high-pressure conditions exist deep below the oceans and underground on land in certain parts of the world, including the ocean floor and permafrost areas of the Arctic.

Today, researchers are finding tremendous stores of gas hydrates throughout the world, including United States, India, and Japan. In addition to Alaska, the United States has vast gas hydrate deposits in the Gulf of Mexico and off its eastern coast. Interest in and support of hydrate research is now growing worldwide. Japan and India currently have among the largest, most well-funded hydrate research programs in the world.

"Once we have learned better how to find the most promising gas hydrate deposits, we will need to know how to produce it in a safe and commercially-viable way," says study co-author Ray Boswell, Ph.D. He manages the National Methane Hydrate R&D Program of the U.S. Department of Energy's National Energy Technology Laboratory in Morgantown, W. Va. "Chemistry will be a big part of understanding just how the hydrates will respond to various production methods."

One of the more promising techniques for extracting methane from hydrates involves simply depressurizing the deposits, Boswell says. Another method involves exchanging the methane molecules in the "clathrate" structure with carbon dioxide. Workers can, in theory, collect the gas using the same drilling technology used for conventional oil and gas drilling.

Under the Methane Hydrate Research and Development Act of 2000, the U.S. government has already spent several million dollars, in collaboration with universities and private companies, to investigate gas hydrates as an alternative energy source. Scientists are particularly optimistic about the vast stores of gas hydrates located in Alaska and in the Gulf of Mexico. Research is also accelerating under the U.S. Department of Energy and USGS to better understand gas hydrate's role in the natural environment and in climate change.

"Gas hydrates are totally doable," Collett says. "But when and where we will see them depends on need, motivation, and our supply of other energy resources. In the next five to ten years, the research potential of gas hydrates will be more fully realized."

* They will present research on gas hydrates in Salt Lake City, Utah on March 23, 2009 at the American Chemical Society's 237th National Meeting. It is among two dozen papers on the topic scheduled for a two-day symposium, "Gas Hydrates and Clathrates," March 23-24.

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