Life cycle assessment of power-to-methane systems with CO2 supplied by the chemical looping combustion of biomass

8 figures, 5 tables.-- Supplementary information available.Power-to-methane (PtM) systems may allow fluctuations in the renewable energy supply to be smoothed out by storing surplus energy in the form of methane. These systems work by combining the hydrogen produced by electrolysis with carbon dioxide from different sources to produce methane via the Sabatier reaction. The present work studies PtM systems based on the CO supplied by the chemical looping combustion (CLC) of biomass (PtM-bioCLC). Life- cycle- assessment (LCA) was performed on PtM-bioCLC systems to evaluate their environmental impact with respect to a specific reference case. The proposed configurations have the potential to reduce the value of the global warming potential (GWP) climate change indicator to the lowest values reported in the literature to date. Moreover, the possibility of effectively removing CO from the atmosphere through the concept of CO negative emissions was also assessed. In addition to GWP, as many as 16 LCA indicators were also evaluated and their values for the studied PtM-bioCLC systems were found to be similar to those of the reference case considered or even significantly lower in such categories as resource use-depletion, ozone depletion, human health, acidification potential and eutrophication. The results obtained highlight the potential of these newly proposed PtM schemes.This work was supported by Grant PDC2021-121190-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR and also by Grant PID2020-113131RB-I00 funded by MICIN/AEI/10.13039/501100011033. A.N. and L.M.G. gratefully acknowledge Grant RTI2018-096294-B-C31 funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”