Power-to-methane (PtM) systems may allow mitigating the fluctuations in renewable energy supply by storing the energy in the form of methane. In these systems, hydrogen produced by electrolysis is combined with carbon dioxide from different sources to produce methane through Sabatier reaction. The present work analyzes PtM systems based on CO2 supply from Chemical Looping Combustion (CLC) units running on biomass (PtM-bioCLC). Life-cycle-assessment of PtM- bioCLC systems was done to evaluate their environmental impact respect a specific reference case. It was concluded that the configurations proposed have the potential to decrease the value of the climate change indicator, the global warming potential (GWP), to the lowest values reported to date in literature. Moreover, the possibility to effectively remove CO2 from the atmosphere realizing the concept of CO2 negative emissions was also demonstrated. Besides GWP, up to 16 LCA indicators were also evaluated and their values for the PtM-bioCLC systems analyzed were similar to those found in the reference case or even significantly lower in some of the categories such as resource use/depletion (RUE), ozone depletion (POF), human health (RI), acidification (AC) and eutrophication (EUT and EUM). 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”

6 figures, 2 tables.-- Work presented at the 6th International Conference on Chemical Looping, 19-22 September 2022, Zaragoza, Spain.

Peer reviewed