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

•Power-to-methane with CO2 from biomass CLC analyzed by Life Cycle Assessment (LCA).•PtM-bioCLC values of Global Warming Potential (GWP) lowest reported to date.•PtM-bioCLC makes possible to remove CO2 from atmosphere (negative CO2 emissions).•RI, POF, AC, EUT and EUM largely decreased since N in biomass is released as N2.•Generation of CO2 from biomass CLC has a very limited influence on LCA indicators. 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 CO2 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 CO2 from the atmosphere through the concept of CO2 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.