​Capturing the CO₂ present in industrial process emissions or in renewably-sourced biomass to convert it into synthetic fuels like methane and chemical precursors like methanol could play a major role in the energy transition. Design optimizations can improve the methanation reaction efficiency while reducing the form factor of the reactor itself. And additive manufacturing is better suited to the complex geometry of a heat exchanger-reactor than conventional industrial processes like stamping, machining, and welding.

The researchers at CEA-Liten explored how additive manufacturing could be leveraged to make a methanation reactor with a complex geometry optimized for maximum thermal exchange and, therefore, better control of the methanation reaction. The researchers fine-tuned a selective laser melting technique in the lab before using it to make the optimized reactor. The exchanger, which contains channels with complex geometries designed to boost the exchange surface area, was produced in a single step. The usual assembly processes were eliminated, making the 3D-printed parts less prone to leaks than conventional parts.

The prototype was developed in partnership with AddUp and was made using the FormUp350 3D printer at the FAMERGIE metal 3D printing lab, which specializes in energy applications. The manufacturing processes were modified for 304L stainless steel to ensure optimal cost, reduce the time it takes to print the parts, and obtain the desired surface states. The next step will be to conduct methanation tests on a CEA test bench to measure the heat exchanger-reactor's performance. CEA researchers are also working on finding the best balance between additive manufacturing and conventional HIP-type technologies to optimize manufacturing processes, costs, and lead times.