Nav: Home

Crystallization method offers new option for carbon capture from ambient air

January 09, 2017

OAK RIDGE, Tenn., Jan. 9, 2017 - 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.
-end-
The study titled, "CO2 Capture from Ambient Air by Crystallization with a Guanidine Sorbent," included Charles Seipp of ORNL and the University of Texas at Austin; Neil Williams of ORNL and the University of Tennessee; and ORNL's Michelle Kidder and Radu Custelcean.

The research was funded by DOE's Office of Science.

UT-Battelle manages ORNL for DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/.

DOE/Oak Ridge National Laboratory

Related Carbon Capture Articles:

Graphene sheets capture cells efficiently
MIT researchers have developed a new method for capturing cells on a treated graphene oxide surface, which could lead to very low-cost diagnostic systems for a variety of diseases.
Crystallization method offers new option for carbon capture from ambient air
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.
Enabling direct carbon capture
Researchers have developed a solid material that can capture carbon dioxide from the atmosphere, even at very low concentrations.
Finding ideal materials for carbon capture
Genetic algorithm can rapidly pinpoint top candidates for pre-combustion carbon capture, information that could lead to greener designs for newly commissioned power plants.
Bacteria could detect leaks at carbon capture sites
Bacteria and archaea could be used to monitor stored carbon dioxide (CO2) and convert it into useful products, such as ethanol and acetate.
Map helps maximize carbon-capture material
A map will help natural gas producers fine-tune porous materials to sequester carbon dioxide to both help the environment and reduce costs, according to Rice University scientists.
Turtle power: How hatching together avoids capture
New research has found that green turtles hatching en masse from their nests 'swamp' predators, allowing more individuals to reach the safety of the sea.
York chemists lead breakthrough in carbon capture
Scientists from the University of York have developed an innovative new green method of capturing carbon dioxide emissions from power stations, chemical and other large scale manufacturing plants.
How chameleons capture their prey
The mucus secreted at the tip of a chameleon's tongue has a viscosity 400 times larger than the one of human saliva.
Thinning out the carbon capture viscosity problem
Researchers have used computer modeling to design carbon dioxide binding materials so that they retain a low viscosity after sponging up carbon dioxide, based on a surprise they found in their explorations.

Related Carbon Capture Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".