Researchers at Lawrence Livermore National Laboratory wanted to improve the process of using electrochemical reactors to turn carbon dioxide into useful fuels and other materials such as ethanol and ethylene. In the past, teams trying to improve the process focused on finding the right catalysts and materials to use in the reactors. The LLNL team, however, looked at changing the reactor itself and using 3D printing in its search for the right design.
The team used projection micro-stereolithography and other photochemical-based 3D printing processes to build and test reactor designs quickly, then make changes to the design to improve the process and repeat the build-and-test cycle. The overall goal was to improve mass transport for delivering reactants to the reactor and removing unwanted chemicals from it.
In tests, the newly redesigned reactors were able to achieve high yields of ethylene (3.67%) and record levels of ethanol (3.66%).
Several 3D-printed reactors, each small enough to fit in the palm of a hand, could eventually be combined to create electrolyzers the size of a refrigerator and significantly lower the cost of CO2-based materials.
“Our vision is to take the best catalysts that are developed using fundamental science and create reactors that make best use of them,” says Sarah Baker, group leader for LLNL’s Materials for Energy and Climate Security group. “This work shows that catalyst performance is dictated by the entire reactor, not just the catalysts. The ability to print the reactors and change features like CO2 flow path and reactor volume allowed rapid feedback to address hypotheses about reactor design. This type of feedback also can help in scaling the reactors.”
The team now wants to work with industry to explore 3D printing other reactor components, such as electrodes, to advance reactor performance and scale up the technology.