Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Asleep in the deep: Model helps assess ocean-injection strategy for combating greenhouse effect

07.11.2005


In searching for ways to counteract the greenhouse effect, some scientists have proposed capturing the culprit—carbon dioxide—as it is emitted from power plants, then liquefying the gas and injecting it into the ocean. But there are pitfalls in that plan.



The carbon dioxide can rise toward the surface, turn into gas bubbles and vent to the atmosphere, defeating the purpose of the whole grand scheme. Even worse, if the liquid-to-gas conversion happens suddenly, the gas can bubble up in a plume and erupt—a potential hazard.

Small-scale ocean experiments have been done to investigate how the carbon dioxide (CO2) actually would behave, but such experiments are too costly and time consuming to carry out under a wide range of ocean conditions. However, a new theoretical model developed by University of Michigan researcher Youxue Zhang can be used to explore the fate of CO2 injected into oceans under various temperature and pressure conditions. Zhang’s model shows that liquid CO2 would have to be injected to a depth of at least 800 meters (about a half mile) and possibly as much as 3,000 meters (nearly two miles) to keep it from escaping.


Eruptions from injected CO2 are a serious concern, Zhang said, "because carbon dioxide is known to have driven deadly water eruptions." In 1986, a CO2-driven eruption in Cameroon’s Lake Nyos killed some 1,700 people, as well as animals in the area; two years earlier, a smaller release of CO2 from Lake Monoun in the same country resulted in 37 human deaths. The deaths were not directly caused by the explosions, but resulted from carbon dioxide asphyxiation. "Carbon dioxide is denser than air, so it settled down and flowed along the river valley, choking people and animals to death."

The challenge in designing CO2 injection strategies is figuring out how to keep droplets of the liquid from rising to 300 meters—the approximate depth at which, depending upon temperature and pressure, liquid CO2 becomes a gas. One solution is to make the droplets smaller.

"Droplets injected to a depth of 800 meters will rise, but if they are small enough they should dissolve completely before reaching the liquid-gas transition depth—assuming everything works perfectly," said Zhang, a professor of geological sciences. However, at a high injection rate, seawater full of CO2 droplets would have an average density smaller than that of surrounding seawater, creating conditions that could lead to a rapidly-rising plume. Problems also could occur if the injection device malfunctioned, producing larger droplets.

"An even safer injection scheme would be to inject into a depth of more than 3,000 meters, where CO2 liquid is denser than seawater and would sink and dissolve," Zhang said.

Calculations based on Zhang’s theory closely match observations from experiments in which remotely controlled submersibles tracked and photographed individual droplets of liquid CO2.

"Of course, you cannot do such experiments under all different conditions, at different depths and different temperatures," Zhang said. "That’s why you need a theory to be able to calculate the behavior under any conditions."

Injecting CO2 into the ocean may have environmental consequences, which must be addressed before decisions are made on whether such injections are a viable way to reduce carbon dioxide emission into the atmosphere, Zhang added.

Zhang’s work was described in a paper in the Oct. 1 issue of the journal Environmental Science & Technology. The research was partially supported by the National Science Foundation and the American Chemical Society Petroleum Research Fund.

Nancy Ross-Flanigan | EurekAlert!
Further information:
http://www.umich.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>