Scientists at the Department of Energy’s Oak Ridge National Laboratory have found a simple, reliable process to capture carbon dioxide directly from ambient air, offering a new option for carbon capture and storage strategies to combat global warming.
Initially, the ORNL team was studying methods to remove environmental contaminants such as sulfate, chromate or phosphate from water. To remove those negatively charged ions, the researchers synthesized a simple compound known as guanidine designed to bind strongly to the contaminants and form insoluble crystals that are easily separated from water.
In the process, they discovered a method to capture and release carbon dioxide that requires minimal energy and chemical input. Their results are published in the journal Angewandte Chemie International Edition.
“When we left an aqueous solution of the guanidine open to air, beautiful prism-like crystals started to form,” ORNL’s Radu Custelcean said. “After analyzing their structure by X-ray diffraction, we were surprised to find the crystals contained carbonate, which forms when carbon dioxide from air reacts with water.”
Decades of research has led to the development of carbon capture and long-term storage strategies to lessen the output or remove power plants’ emissions of carbon dioxide, a heat-trapping greenhouse gas contributing to a global rise in temperatures. Carbon capture and storage strategies comprise an integrated system of technologies that collects carbon dioxide from the point of release or directly from the air, then transports and stores it at designated locations.
A less traditional method that absorbs carbon dioxide already present in the atmosphere, called direct air capture, is the focus of ORNL’s research described in this paper, although it could also be used at the point where carbon dioxide is emitted.
Once carbon dioxide is captured, it needs to be released from the compound so the gas can be transported, usually through a pipeline, and injected deep underground for storage. Traditional direct air capture materials must be heated up to 900 degrees Celsius to release the gas — a process that often emits more carbon dioxide than initially removed. The ORNL-developed guanidine material offers a less energy-intensive alternative.
“Through our process, we were able to release the bound carbon dioxide by heating the crystals at 80-120 degrees Celsius, which is relatively mild when compared with current methods,” Custelcean said. After heating, the crystals reverted to the original guanidine material. The recovered compound was recycled through three consecutive carbon capture and release cycles.
While the direct air capture method is gaining traction, according to Custelcean, the process needs to be further developed and aggressively implemented to be effective in combatting global warming. Also, they need to gain a better understanding of the guanidine material and how it could benefit existing and future carbon capture and storage applications.
The research team is now studying the material’s crystalline structure and properties with the unique neutron scattering capabilities at ORNL’s Spallation Neutron Source (SNS), a DOE Office of Science User Facility. By analyzing carbonate binding in the crystals, they hope to better understand the molecular mechanism of carbon dioxide capture and release and help design the next generation of sorbents.
The scientists also plan to evaluate the use of solar energy as a sustainable heat source to release the bound carbon dioxide from the crystals.
ORNL is the largest science and energy national laboratory in the Department of Energy system by acreage. ORNL is located in Oak Ridge, Tennessee, near Knoxville. ORNL’s scientific programs focus on materials, neutron science, energy, high-performance computing, systems biology and national security.
ORNL partners with the state of Tennessee, universities and industries to solve challenges in energy, advanced materials, manufacturing, security and physics.
The laboratory is home to several of the world’s top supercomputers including the world’s second most powerful supercomputer ranked by the TOP500, Titan, and is a leading neutron science and nuclear energy research facility that includes the Spallation Neutron Source and High Flux Isotope Reactor. ORNL hosts the Titan supercomputer; the Center for Nanophase Materials Sciences, the BioEnergy Science Center, and the Consortium for Advanced Simulation of Light-Water Reactors.
Oak Ridge National Laboratory research articles from Innovation Toronto
- ORNL technique could set new course for extracting uranium from seawater – December 19, 2015
- White graphene could usher in a new era in electronics and quantum devices – December 2, 2015
- New ORNL device combines power of mass spectrometry, microscopy – November 9, 2015
- Better fluorescent lighting using far less rare-earth elements – October 18, 2015
- Integrated energy demo connects 3D-printed building and 3D-printed vehicle – October 15, 2015
- New ORNL device combines power of mass spectrometry, microscopy – November 9, 2015
- Old tires can become supercapacitors – September 26, 2015
- SHAPE-SHIFTING PLASTIC – May 25, 2015
- ORNL demonstrates first large-scale graphene composite fabrication – May 18, 2015
- ORNL superhydrophobic glass coating offers clear benefits – May 13, 2015
- ORNL-led team demonstrates desalination with nanoporous graphene membrane – March 26, 2015
- Innovative, Lower Cost Sensors and Controls Yield Better Energy Efficiency – March 8, 2015
- Your Own Energy “Island?” ORNL Microgrid Could Standardize Small, Self-Sustaining Electric Grids – November 6, 2014
- New ORNL electric vehicle technology packs more punch in smaller package – October 18, 2014
- A cheaper plant-based battery is possible – Septembewr 23, 2014
- UT, ORNL Scientists’ Discoveries Could Help Neutralize Chemical Weapons – June 24, 2014
- Novel ORNL technique enables air-stable water droplet networks – May 17, 2014
- Self-cleaning solar panel coating optimizes energy collection, reduces costs
- Chaotic physics in ferroelectrics hints at brain-like computing
- ORNL-grown oxygen ‘sponge’ presents path to better catalysts, energy materials
- Beyond Silicon: Transistors without Semiconductors
- China’s Tianhe-2 is the new world champ of supercomputing
- New all-solid sulfur-based battery outperforms lithium-ion technology
- Awake Imaging device moves diagnostics field forward
- Breakthrough in hydrogen fuel production by Virginia Tech researchers could revolutionize alternative energy market
- Mystery Surrounding the Harnessing of Fusion Energy Unlocked
- Oak Ridge unveils Titan, the world’s most powerful supercomputer
- Water-wise biofuel crop study to alter plants metabolic, photosynthesis process
- Uranium supply extracted from Seawater could last for Centuries
- Boundary Between Electronics and Biology Is Blurring
- Technology Breakthrough for Geothermal
- Standoff Sensing Enters New Realm With Dual-Laser Technique
- ORNL discovers amazing electrical properties in polymers
- ORNL invention unravels mystery of protein folding
- Culturomics research uses quarter-century of media coverage to forecast human behavior
- Energy Harvesters Transform Waste Into Electricity
- New solar cell technology boosts efficiency of photovoltaics by 80%
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‘Beautiful accident’ leads to advances in high pressure materials synthesis
Unexpected results from a neutron scattering experiment at the Department of Energy’s Oak Ridge National Laboratory could open a new pathway for the synthesis of novel materials and also help explain the formation of complex organic structures observed in interstellar space.
In a paper published in the journal Angewandte Chemie International Edition, the multi-institutional team of researchers, led by Haiyan Zheng from the Center for High Pressure Science and Technology Advanced Research in Beijing, formerly of the Carnegie Institution of Washington, discuss their discovery of using high pressures—rather than high temperatures—to initiate chemical reactions.
Their research will significantly improve scientists’ understanding of complex carbon structures and may offer clues to the formation of amino acids from nonbiological processes.
“This discovery was somewhat of a beautiful accident,” said Ilia Ivanov, a research scientist at the ORNL’s Center for Nanophase Materials Sciences, a Department of Energy Office of Science User Facility.
Ivanov explains that it all began during a neutron diffraction experiment at ORNL’s Spallation Neutron Source—also a DOE Office of Science User Facility. While performing a high-pressure polymerization experiment on the chemical compound acetonitrile (CH3CN) using the SNAP instrument, researchers detected the unexpected presence of ammonia. Ammonia is a colorless gas but has a very distinct odor that can be detected in even minute quantities.
“If you put acetonitrile under high pressures, you’ll bring molecules together and see it reacting with itself, and eventually, it forms either a solid yellowish polymer or, as we found out, a black, carbon-rich material,” Ivanov said.
Acetonitrile is one of a number of organic compounds that have been discovered in outer space and is thought to be implicated in the origins of simple amino acids, one of the basic molecules of life. In a cosmic event such as an asteroid collision, the pressures and temperatures generated can be very large, and in the presence of acetonitrile, could mimic the experiment the researchers conducted at SNAP.
The formation of the yellowish polymer was the expected result of the SNAP experiment, said SNAP instrument scientist Chris Tulk, but a surprise was just ahead.
“When the sample was depressurized and the pressure cell opened, ammonia was detected. It has a very distinct scent,” Tulk said. “We thought, ‘there shouldn’t be ammonia in this sample right now.’ So we started looking for what could have happened to first form, and then release, ammonia.”
The experimental researchers then collaborated with experts in advanced electron microscopy, materials science and computing to understand the mysterious results. Based on a combination of computer simulations and microscopy, they concluded that nitrogen had left the acetonitrile sample, resulting in an enriched carbon-based material.
“The carbon material that was left was imaged using our best electron microscopes,” Ivanov said. “It had onion-like layers—one shell of carbon sheet after another. So nitrogen went somewhere, but where did it go? It escaped in the form of ammonia gas.”
Because a temperature-based catalyst is usually required to convert a polymer into another material, this ability to cause a chemical reaction through pressure alone is unusual.
“I wanted to continue doing these experiments to determine how much we could control the structure of a carbon material through pressure, not temperature,” said Ivanov, comparing the experimental conditions with those found in household pressure cookers.
“In most cases, pressure cookers still use high temperatures to help foods cook thoroughly. But with our experiments, we’ve been able to use a sort of pressure cooking at room temperature, albeit at much higher pressures.”
While a pressure cooker operates at 0.1 megapascals, these experiments used much higher pressures—up to 23,000 megapascals, which corresponds to the pressure found 650 kilometers below the Earth’s surface at the boundary between its upper and lower mantle.
“This paper is truly exciting for us,” Tulk said. “Using this process with the addition of oxygen, possibly by the addition of carbon dioxide or water into the reactants, complex carbon structures similar to the kind we suspect throughout early formation of amino acids on Earth may be realized.”
The researchers note that cross-disciplinary expertise in neutron sciences and nanoscience, together with Energy Frontier Research in Extreme Environments (EFree) Center, made the research possible. EFree is a DOE Energy Frontier Research Center.
“One without the other seemed like a one-sided mission. Two aspects of research, structure and functionality, were brought together through the synergetic work. Through joint efforts like this, we continue to help users drive the discovery of new materials and new functionalities,” Ivanov said.
the Department of Energy’s Oak Ridge National Laboratory.
A team led by Olga Ovchinnikova of ORNL’s Center for Nanophase Materials Sciences Division used a helium ion microscope, an atomic-scale “sandblaster,” on a layered ferroelectric surface of a bulk copper indium thiophosphate. The result, detailed in the journal ACS Applied Materials and Interfaces, is a surprising discovery of a material with tailored properties potentially useful for phones, photovoltaics, flexible electronics and screens.
“Our method opens pathways to direct-write and edit circuitry on 2-D material without the complicated current state-of-the-art multi-step lithographic processes,” Ovchinnikova said.
She and colleague Alex Belianinov noted that while the helium ion microscope is typically used to cut and shape matter, they demonstrated that it can also be used to control ferroelectric domain distribution, enhance conductivity and grow nanostructures. Their work could establish a path to replace silicon as the choice for semiconductors in some applications.
“Everyone is looking for the next material – the thing that will replace silicon for transistors,” said Belianinov, the lead author. “2-D devices stand out as having low power consumption and being easier and less expensive to fabricate without requiring harsh chemicals that are potentially harmful to the environment.”
Reducing power consumption by using 2-D-based devices could be as significant as improving battery performance. “Imagine having a phone that you don’t have to recharge but once a month,” Ovchinnikova said.