Researchers from the University of Cambridge have developed a method for converting carbon dioxide into clean, sustainable fuels without producing any undesired by-products or waste.
The research team previously demonstrated that biological catalysts could produce clean fuels from renewable energy sources, but at a low efficiency. But their latest breakthrough increased fuel production efficiency by 18 times in a laboratory setting, indicating that carbon emissions may be efficiently converted into green fuels without wasting energy.
Most carbon dioxide to fuel conversion processes yield undesirable by-products such as hydrogen. Although scientists can change the chemical conditions to limit hydrogen formation, this affects carbon dioxide conversion performance, resulting in cleaner fuel at the expense of efficiency.
The proof of concept produced by Cambridge uses enzymes extracted from bacteria to power the chemical reactions that turn carbon dioxide into fuel, a process known as electrolysis. Enzymes are more efficient than other catalysts, yet they are extremely sensitive to the chemical environment in which they are used. The enzymes break down and chemical reactions slow down if the local environment isn't quite perfect.
The Cambridge researchers teamed up with Universidade Nova de Lisboa, Portugal to develop a new strategy to increase electrolysis efficiency by fine-tuning solution conditions to change the environment of the enzymes.
The researchers employed computational methods to create a technique that improves carbon dioxide electrolysis. When compared to the current benchmark solution, the enzyme-based system enhanced fuel production by 18 times.
To improve the environment even more, the researchers also demonstrated how two enzymes may collaborate, with one producing fuel and the other managing the environment. They discovered that speeding up the processes with another enzyme increased efficiency while decreasing undesired by-products.
“We ended up with exactly the fuel we wanted, with no side effects and only minor energy losses, creating clean fuels at maximum efficiency,” stated Dr. Sam Cobb, the paper's first author. “By drawing inspiration from biology, we'll be able to design stronger synthetic catalyst systems, which will be necessary if carbon dioxide electrolysis is to be deployed on a wide scale.”
Professor Erwin Reisner, the study's lead author, remarked, “Electrolysis has a huge part to play in lowering carbon emissions. Instead of capturing and storing carbon dioxide, which is extremely energy-intensive, we've proven a new concept for capturing carbon and turning it into something useful in an energy-efficient way.”
