The global battle against climate change requires undertakings by countries all over the world to reduce carbon dioxide (CO2) emissions down to zero level by the mid century. Currently though, the United States is still way behind in achieving such an objective. Mainly because the country is run by a president who believes global warming and the resulting climate change is just a hoax.
Nonetheless, two chemical engineers from the Massachusetts Institute of Technology (MIT) have developed a new process by which CO2 can be captured and then alternately released.
The technique was developed by Sahag Voskian, an MIT Postdoctoral Associate at the Department of Chemical Engineering, in collaboration with T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering at MIT. Professor Hatton also co-directs MIT’s Center for Carbon Capture, Utilization and Storage, with a focus on the development of varying technologies for the purification of air, water, and other substances significant to the environment.
According to Professor Hatton, the process developed by Voskian during his PhD, can capture and alternately release CO2. Through an electrochemical system, CO2 in the air that passes through a stack of charged electrochemical plates will be absorbed, whilst requiring only small swings in voltage to carry out the separations.
The MIT Ralph Landau professor further described the process as one that can happen under ambient conditions, without requiring thermal pressure or chemical additions. Professor Hatton says the revolutionary CO2 carbon capture system simply applies the power of electrochemical approaches, by using a stack of very thin sheets that are active on both surfaces and contained in a box that can be connected to an electrical source.
According to Professor Hatton, a company registered as Verdox has in fact, been set up to commercialize the CO2 capture process. The company’s mission is to develop a pilot-scale plant in the next few years. The device they developed is quite easy to scale up as it only requires making more electrodes to increase capacity.
What Makes MIT’s CO2 Capture Device Different from Other Existing Systems
As a revolutionary tool that will be introduced in removing carbon dioxide from the air, the new method can work on gas at any concentration level, even at the roughly 400 parts per million currently present in the atmosphere. .
The design of the device basically comes as a large, specialized battery comprised by a stack of electrodes coated with a compound called poly anthraquinone, a substance composited with carbon nanotubes.
Once the specialized battery charges up, its chemically coated electrodes will absorb carbon dioxide carried by the stream of air passing through them, which the battery can later release by discharging. When in actual operation the device would alternate between absorbing CO2 during charging and then blowing out the concentrated carbon dioxide during discharging.
Unlike most methods that require high concentrations when removing CO2 from a stream of air, the system developed by MIT chemical engineers can work with low-level concentrations, making it less expensive, and more importantly, less energy-intensive.
Sahag Voskian says their carbon capture device consistently uses only one (1) gigajoule of energy per ton of captured CO2. Other existing carbon capture technologies consume varying energy, ranging between 1 to 10 gigajoules per ton; dependent on the carbon dioxide concentration being processed.
Voskian, the MIT Postdoctoral Associate, also remarked that the electrodes can be produced using standard chemical processing methods, which is unlike other systems that require manufacturing in a laboratory setting.
Voskian says the process has been developed in a very cost-effective way. Adaptation techniques for large quantity electrode production is by way of roll-to-roll manufacturing process like a newspaper printing press.