Researchers from Cornell University have developed a new carbon capture method that not only converts carbon dioxide into useful components but also creates electricity with the help of oxygen.
In a study published in the journal Science Advances, Lynden Archer and Wajdi Al Sadat detailed the development of an aluminum-carbon dioxide power cell assisted by oxygen that utilizes electrochemical reactions in sequestering and converting carbon dioxide and creating electricity.
The power cell uses aluminum as the anode while carbon dioxide and oxygen were mixed to become the cathode. Aluminum was the perfect choice for the anode because it is abundant in supply, safer to use than other metals and lower in cost than sodium and lithium while still offering energy density comparable to lithium.
Most carbon-capture systems in place today typically capture carbon in solids or fluids, which are then depressurized or heated to release carbon dioxide. The gas is then compressed before being transported either for reuse in industries or to be sequestered below the ground.
According to Archer, their study presents a possible shift in the usual practice of capturing carbon, adding that simply devising a carbon-capture method that generates electricity as well is in itself important.
A lot of people understand the benefits of carbon-capture technology but there are roadblocks to adopting it. In electrical power plants, for instance, regenerating the fluids needed to capture carbon can consume up to 25 percent of the facility's energy output. Additionally, there's the cost associated with transporting the captured gas.
The researchers reported that the power cell they came up with is capable of generating 13 ampere hours for every gram of porous carbon in the cathode, with a 1.4-volt discharge potential. This kind of energy production is comparable to what battery systems with the highest energy density levels are capable of.
Alongside electricity, the power cell generates superoxide intermediates when carbon dioxide reduction occurs at the cathode. When the superoxide is combined with inert carbon dioxide, a carbon-carbon oxalate is formed, which is commonly used in various industries, like metal smelting and pharmaceuticals.
However, there is a drawback: the electrolyte connecting the anode and cathode. The liquid is highly sensitive to water so the researchers are working on developing electrochemical systems that use electrolytes that are less water-sensitive.
The study was carried out with assistance from the Cornell Center for Materials Research. It received funding support from the King Abdullah University of Science and Technology Global Research Partnership Program.
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