A team of scientists has devised a new technology that turns carbon dioxide into a variety of useful chemical substances, while at the same time producing sizeable amounts of electrical energy. Recently published in Science Advances journal, the current research could help reduce environmentally-harmful CO2.
At present, techniques for large-scale carbon capture, utilization and sequestration (or CCUS) are fairly limited, with available methods often requiring large amounts of energy to actually trap carbon dioxide from the atmosphere. Additionally, there is a lack of efficient technologies that could convert the noxious substance into usable compounds, once it has been captured.
As a solution, a team of researchers from Cornell University turned to electrochemical cells, in order to develop a system that could single-handedly trap atmospheric CO2 as well as generate electrical energy. According to the scientists, the system would comprise of a metallic anode and a cathode containing both carbon dioxide and oxygen as active ingredients.
The anode and the cathode in turn undergo a series of complex electrochemical reactions, thereby turning CO2 into carbon-based chemicals and producing usable power. Similar research, in the past, relied on electrochemical cells with anodes made up of a combination of magnesium, lithium and sodium. These cells, however, failed to be of much use in the capture and processing of carbon dioxide. Speaking about the current study, Archer said:
It then occurred to us to use aluminum, which is the third most abundant element in Earth’s crust.
In addition to being inexpensive, aluminum is significantly less reactive than either sodium or lithium, making it a lot safer to work with. The newly-developed contraption features an anode fashioned out of aluminum foil and a specially-designed stainless steel mesh that serves as a highly-porous, conductive cathode. The cathode, in this case, allows both oxygen and CO2 to travel through it.
The system also contains an electrolyte that acts as a bridge between the cathode and the anode. During laboratory testing, the electrochemical cells managed to generate nearly 13 Ah (i.e. ampere-hour) of power, per gram of carbon captured from the atmosphere. As pointed out by the scientists, the system worked properly, without requiring high temperatures or any kind of catalyst.
Furthermore, the technology allowed the researchers to convert the trapped CO2 into aluminum oxalate that can in turn be used to generate oxalic acid, a chemical that has a variety of industrial uses. Theoretical evidence, however, shows that incorporating additional compounds at the cathode would likely lead to the production of a range of other usable substances. The team added:
It’s a versatile product that’s a nice starting material for plastics and so forth.
One of the major drawbacks of the technology is that the cell’s electrolyte ceases to work upon exposure to water. This might indeed be an issue, especially since a large portion of the carbon dioxide emanating from power plants and factories is actually saturated with moisture. The team is currently looking for a electrolyte, whose efficiency remains unchanged even when exposed to water.
Via: IEEE Spectrum