Comparison of Synthetic Natural Gas Production Pathways for the Storage of Renewable Energy

This chapter provides an overview of sustainable pathways for synthetic natural gas (SNG) production and evaluates and compares the three most relevant routes, namely the biochemical, the thermochemical, and the electrochemical pathways in terms of technologies, efficiency, economics, and market maturity. The three options, including process steps, important framework conditions, and process parameters as well as specifications are explained. Besides the stand-alone concepts, combined or hybrid systems are investigated and applied in different combinations. The status quo of the different concepts varies significantly regarding market maturity levels and geographical extension as well as historical background. To measure and evaluate evolving technologies, technology readiness levels (TRLs) have been introduced. Comparing the conversion efficiencies of the three production pathways proves complex due to different feed streams. Economic analysis, evaluation, comparison, and discussion of SNG production options prove difficult due to the limitations caused by the different stages of development of the technologies.