Production of "Green Natural Gas" Using Solid Oxide Electrolysis Cells (SOEC): Status of Technology and Costs

This paper gives arguments in favour of using green natural gas (GNG) as storage media for the intermittent renewable energy sources. GNG is here defined as being CH4, i.e. methane, often called synthetic natural gas or substitute natural gas (SNG), produced using renewable or at least CO2 neutral energy sources only.

Also dimethyl ether (DME = (CH3)2O), which might be called Liquefied Green Gas, LGG, in analogy to Liquefied Petroleum Gas, LPG, because DME has properties similar to LPG. It further gives a short review of the state of the art of electrolysis in general and SOEC in particular. Production of synthesis gas (H2 + CO) from CO2 and H2O using SOEC technology is evaluated.

GNG and LGG can be produced from synthesis gas (or short: syngas) by means of well established commercially available catalysis technology. Finally, estimations of costs and efficiencies are presented and the relative importance of cost and efficiency is briefly discussed.