Emissions of the greenhouse gas carbon dioxide into the atmosphere need to be reduced to curb climate change. Carbon capture and utilization could help to achieve this goal. Integrating the capture and conversion of CO₂ into a single, combined approach could offer economic and environmental benefits.

David J. Heldebrant, Pacific Northwest National Laboratory (PNNL), Richland, WA, USA, and colleagues have developed such an integrated system, converting captured CO₂ to methane using a water-lean, post-combustion solvent, i.e., N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (2-EEMPA). Using 2-EEMPA, the CO₂ is first captured, and then the CO₂-rich solvent is mixed with H₂ and hydrogenated in the presence of a commercial Ru/Al₂O₃ catalyst.

This process converts > 90 % of CO₂ to give hydrocarbons, mostly methane. The integrated process could increase the thermal efficiency and reduce the capital investment needed compared with a standard process. According to the researchers, this highlights the energetic and economic benefits of integrated capture and conversion.

• Integrated Capture and Conversion of CO₂ to Methane using a Water‐lean, Post‐Combustion CO₂ Capture Solvent,
  David Heldebrant, Jotheeswari Kothandaraman, Johnny Saavedra Lopez, Yuan Jiang, Eric D. Walter, Sarah D. Burton, Robert A. Dagle,
  ChemSusChem 2021.
  https://doi.org/10.1002/cssc.202101590