Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New material captures carbon at half the energy cost

12.03.2015

Technology spin-off could capture carbon more efficiently from power plants or submarines

UC Berkeley chemists have made a major leap forward in carbon-capture technology with a material that can efficiently remove carbon from the ambient air of a submarine as readily as from the polluted emissions of a coal-fired power plant.


The diamine-appended metal-organic framework before and after binding of carbon dioxide. The view is a cross section through one of the pores of the MOF, showing diamine molecules (containing blue nitrogen atoms) attached to metal (manganese) atoms (green). Carbon dioxide molecules (grey carbon atoms with two red oxygen atoms) bind through a cooperative mechanism akin to a chain reaction along the pore surfaces. Some H atoms (white) are omitted for clarity.

Credit: Graphic by Thomas McDonald, Jarad Mason, Jeffrey Long/UC Berkeley

The material then releases the carbon dioxide at lower temperatures than current carbon-capture materials, potentially cutting by half or more the energy currently consumed in the process. The released CO2 can then be injected underground, a technique called sequestering, or, in the case of a submarine, expelled into the sea.

"Carbon dioxide is 15 percent of the gas coming off a power plant, so a carbon-capture unit is going to be big," said senior author Jeffrey Long, a UC Berkeley professor of chemistry and faculty senior scientist at Lawrence Berkeley National Laboratory. "With these new materials, that unit could be much smaller, making the capital costs drop tremendously as well as the operating costs."

The material, a metal-organic framework (MOF) modified with nitrogen compounds called diamines, can be tuned to remove carbon dioxide from the room-temperature air of a submarine, for example, or the 100-degree (Fahrenheit) flue gases from a power plant.

"It would work great on something like the International Space Station," Long said.

Though power plants are not now required to capture carbon dioxide from their emissions, it will eventually be necessary in order to slow the pace of climate change caused by fossil-fuel burning. If the planet's CO2 levels rise much higher than they are today, it may even be necessary to remove CO2 directly from the atmosphere to make the planet livable.

Long and his colleagues describe how the new materials -- diamine-appended MOFs -- work in this week's issue of the journal Nature.

From flue gas to submarines

Power plants that capture CO2 today use an old technology whereby flue gases are bubbled through organic amines in water, where the carbon dioxide binds to amines. The liquid is then heated to 120-150 degrees Celsius (250-300 degrees Fahrenheit) to release the gas, after which the liquids are reused. The entire process is expensive: it consumes about 30 percent of the power generated, while sequestering underground costs an additional though small fraction of that.

The new diamine-appended MOFs can capture carbon dioxide at various temperatures, depending on how the diamines are synthesized, and releases the CO2 at only 50 C above the temperature at which CO2 binds, instead of the increase of 80-110 C required for aqueous liquid amines. Because MOFs are solid, the process also saves the huge energy costs of heating the water in which amines are dissolved.

MOFs are composites of metals -- in this case, magnesium or manganese -- with organic compounds that, together, form a porous structure with microscopic, parallel channels. Several years ago, Long and his lab colleagues developed a way to attach amines to the metals in an MOF to produce pores of sufficient diameter to allow CO2 to penetrate rapidly into the material. They found that MOFs with attached diamines are very different from other carbon-capture materials, in that the CO2 seems to load into the material very quickly at a specific temperature and pressure, then come out quickly when the temperature is raised by 50 C. In the new paper, UC Berkeley graduate students Thomas McDonald and Jarad Mason, together with other co-workers, describe how this works.

"This material is unique in that it binds CO2 in a cooperative mechanism," Long said. "When the first CO2 starts to adsorb at a very specific pressure, all of a sudden it facilitates more CO2 adsorption, and the MOF rapidly saturates. That is really a different property from any other CO2 adsorbent based on amines.

"Then," he added, "if you raise the temperature by applying heat, at some temperature all the CO2 will come flooding off."

Long's team found that the diamines bind to the metal atoms of the MOF and then react with CO2 to form metal-bound ammonium carbamate species that completely line the interior channels of the MOF. At a sufficiently high pressure, one CO2 molecule binding to an amine helps other CO2 molecules bind next door, catalyzing a chain reaction as CO2polymerizes with diamine like a zipper running down the channel. Increasing the temperature by 50 degrees Celsius makes the reaction reverse just as quickly.

The pressure at which CO2 binds to the amines can be adjusted by changing the metal in the MOF. Long has already shown that some diamine-appended MOFs can bind CO2 at room temperature and CO2 levels as low as 300 parts per million.

The current atmospheric concentration of CO2 is now 400 parts per million (ppm), and policy-makers in many countries hope to reduce this below 350 ppm to avoid the most severe impacts of climate change, from increasingly severe weather events and sea level rise to global average temperature increases of 10 degrees Fahrenheit.

'We got lucky'

Last summer, Long co-founded a startup, Mosaic Materials, to use the new technology to radically reduce the cost of chemical separations, with plans in the works for a pilot study of CO2 separation from power plant emissions. This would involve creating columns containing millimeter-size pellets made by compressing a crystalline powder of MOFs.

"We're also hoping to develop something that might be tested in a submarine," Long said. That would pave the way for eventual scale-up to capturing CO2 from natural gas plants, which produce emissions containing about 5 percent CO2, to the higher concentrations of coal-fired power plants.

"We got lucky," he said. "We were just trying to find a simple way to attach these amines to our MOF surface, because they are one of the best compounds for selectively binding CO2 in the presence of water, which can be a problem in flue gas. And it just happens we got the right length in the amine to make these one-dimensional chains that bind CO2in a cooperative manner."

Long suggested as well that the findings may have relevance for the fixation of CO2 by plants, owing to striking structural similarities between the magnesium-based MOF and the naturally occurring CO2-fixing photosynthetic enzyme RuBisCO.

###

Long also received assistance from colleagues at Zhejiang University in Hangzhou, China; the University of Turin in Italy; the University of Minnesota in Minneapolis; the Université Grenoble Alpes and the Centre National de la Recherche Scientifique in France; the Norwegian University of Science and Technology in Trondheim, Norway; and the École Polytechnique Fédérale de Lausanne in Switzerland.

The work is supported by grants from ARPA-E and the U.S. Department of Energy-funded Center for Gas Separations Relevant to Clean Energy Technologies, an Energy Frontier Research Center operated jointly by UC Berkeley and LBNL.

Media Contact

Robert Sanders
rlsanders@berkeley.edu
510-643-6998

 @UCBerkeleyNews

http://www.berkeley.edu

Robert Sanders | EurekAlert!

Further reports about: CO2 CO2 levels EMISSIONS MOF amines coal-fired power dioxide power plant power plants

More articles from Materials Sciences:

nachricht Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University

nachricht Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>