Engineers at the University of Illinois Chicago have developed a low-cost artificial leaf that can trap carbon dioxide 100 times more efficiently than current methods. This artificial leaf works in the real environment, unlike other carbon capture systems that work in labs using pure carbon dioxide from pressure tanks.
It takes carbon dioxide from more diluted sources, such as air and flue gas from coal-fired power plants, and converts it into fuel and other products.
“Our artificial leaf system can be deployed outside the lab, where it has the potential to play a significant role in reducing greenhouse gases in the atmosphere thanks to its high rate of carbon capture, relatively low cost, and moderate energy, even when compared to the best lab-based systems,” said Meenesh Singh, assistant professor of chemical engineering in the UIC College of Engineering and corresponding author on the paper.
The scientists redesigned a basic artificial leaf system with affordable materials to include a water gradient with a dry side and a wet side across an electrically charged membrane, based on a previously published theoretical notion.
Inventors started working on a brilliant idea that would change the way we utilize energy in our homes and offices more than 150 years ago. This idea revolutionized building design, lengthened the normal workday, and sparked the creation of new industries.
Our artificial leaf system can be deployed outside the lab, where it has the potential to play a significant role in reducing greenhouse gases in the atmosphere thanks to its high rate of carbon capture, relatively low cost, and moderate energy, even when compared to the best lab-based systems.
Meenesh Singh
It also paved the way for new energy advancements in everything from power plants to electric transmission lines to home appliances and motors. The light bulb, like many great innovations, cannot be attributed to a single person. The light bulbs we use in our homes today are the result of a series of incremental refinements on previous innovators’ ideas.
On the dry side, an organic solvent binds to accessible carbon dioxide, resulting in a bicarbonate (baking soda) concentration on the membrane. These negatively charged ions are drawn across the membrane toward a positively charged electrode in a water-based solution on the membrane’s wet side when bicarbonate builds up.
The bicarbonate in the liquid solution dissolves back into carbon dioxide, which can then be discharged and used for fuel or other purposes. The electrical charge is employed to accelerate bicarbonate transport across the membrane.
The UIC scientists discovered that the system, which is small enough to carry in a backpack, has a very high flux rate of carbon capture when compared to the surface area required for the reactions, which is 3.3 millimoles per hour per 4 square centimeters.
Even while only a small amount of electricity (0.4 KJ/hour) was required to power the reaction, it outperformed rival systems by more than 100 times, using less energy than a 1 watt LED lightbulb.
They assessed the cost at $145 per ton of CO2, which is in accordance with Department of Energy recommendations that the cost should not exceed $200 per ton.
“It’s particularly exciting that this real-world application of an electrodialysis-driven artificial leaf had a high flux with a small, modular surface area,” Singh said.
“This means that it has the potential to be stackable, the modules can be added or subtracted to more perfectly fit the need and affordably used in homes and classrooms, not just among profitable industrial organizations. A small module of the size of a home humidifier can remove greater than 1 kilogram of CO2 per day, and four industrial electrodialysis stacks can capture greater than 300 kilograms of CO2 per hour from flue gas.”
In “Migration-assisted, moisture gradient method for ultrafast, continuous CO2 capture from dilute sources at ambient settings,” published in Energy & Environmental Science, UIC scientists describe the design of their artificial leaf and the results of their trials.
The research is supported by a Department of Energy grant (DE-SC-0022321). The Office of Technology Management at UIC has filed a patent application titled “Artificial photosynthetic systems for integrated carbon capture and conversion.”
Co-authors of the paper from UIC, Argonne National Laboratory, Oklahoma State University and Braskem are Aditya Prajapati, Rohan Sartape, Tomas Rojas, Naveen Dandu, Pratik Dhakal, Amey Thorat, Jiahan Xie, Ivan Bessa, Miguel Galante, Marcio Andrade, Robert Somich, Marcio Rebouças, Gus Hutras, Nathalia Diniz, Anh Ngo and Jindal Shah.
