Biogas — produced from anaerobic digestion of organic matter — contains a mixture of gases, with methane and carbon dioxide as the predominant components. To use biogas as a fuel source, purification of the gas is typically needed to remove CO2 and other contaminants to reach high methane concentrations. Traditional separation methods are effective, but can be energy-intensive and produce chemical waste. Researchers have now introduced a porous crystalline material, called TAMOF-1, as a strong candidate for the selective capture of CO2 in biogas purification.
The research was led by J. R. Galán-Mascarós, a professor at the Institute of Chemical Research of Catalonia (ICIQ; Tarragona; www.iciq.org), Sofia Calero, a professor at the Eindhoven University of Technology and Stefano Giancola at Orchestra Scientific, with contributions from a broad consortium of European institutions.
TAMOF-1 is a member of the metal organic framework (MOF) family of materials, which are known for their porous structures and high surface areas. What distinguishes TAMOF-1 is its homochirality, structural stability and ability to selectively adsorb CO2 over methane under ambient conditions. In trials, TAMOF-1 achieved a CO2 uptake of over 4 mmol/g. and a CO2/CH4 selectivity greater than 40, placing it among the more effective physisorbents reported to date.
TAMOF-1 functions by a dual-site adsorption mechanism. At lower concentrations, CO2 binds to copper centers within the framework. When these sites are occupied, additional molecules are hosted within the open channels, engaging in weaker interactions with various functional groups. This arrangement facilitates both high selectivity and low-energy regeneration.
“What makes TAMOF-1 truly promising is the combination of its selective CO2 uptake with the possibility of regenerating the material under mild conditions,” says Prof. Galán-Mascarós. “This balance between performance and energy efficiency is essential if we want to move closer to practical, viable solutions for carbon capture.”
The framework can be cycled with minimal energy input, which is an advantage over traditional chemical absorption techniques. Most absorbents need a thermal cycling to recover CO2. TAMOF-1 is an adsorbent, which works by physisorption, and is able to release the purified CO2 by small pressure differences, or even by flowing a gas through it at constant temperature.
TAMOF-1 is synthesized from low-cost, water-soluble and non-critical raw materials, including a derivative of the natural amino acid L-histidine and copper(II) salts. Its robustness under humid and acidic conditions further strengthens its case for practical deployment.
This research forms part of the SUPERVAL project, funded by the European Union through the Horizon Europe program. The material and its applications are being explored commercially through Orchestra Scientific (www.orchestrasci.com), a spin-off company founded by ICIQ and ICREA (www.icrea.cat). This work was published in Nature Communications in April, 2025.