Production costs for synthetic methane in 2030 and 2050 of an optimized Power-to-Gas plant with intermediate hydrogen storage

The publication gives an overview of the production costs of synthetic methane in a Power-to-Gas process. The production costs depend in particularly on the electricity price and the full load hours of the plant sub-systems electrolysis and methanation. The full-load hours of electrolysis are given by the electricity supply concept. In order to increase the full-load hours of methanation, the size of the intermediate hydrogen storage tank and the size of the methanation are optimised on the basis of the availability of hydrogen. The calculation of the production costs for synthetic methane are done with economics for 2030 and 2050 and the expenditures are calculated for one year of operation. The sources of volume of purchased electricity are the short-term market, long-term contracts, direct-coupled renewable energy sources or seasonal use of surpluses. Gas sales are either traded on the short-term market or guaranteed by long-term contracts. The calculations show, that an intermediate storage tank for hydrogen, adjustment of the methanation size and operating electrolysis and methanation separately, increase the workload of the sub-system methanation. The gas production costs can be significantly reduced. With the future expected development of capital expenditures, operational expenditure, electricity prices, gas costs and efficiencies, an economic production of synthetic natural gas for the years 2030, especially for 2050, is feasible. The results show that Power-to-Gas is an option for long-term, large-scale seasonal storage of renewable energy. Especially the cases with high operating hours for the sub-system methanation and low electricity prices show gas production costs below the expected market prices for synthetic gas and biogas

CNG und LNG aus biogenen Reststoffen – ein Konzept zur ressourcenschonenden Kraftstoffproduktion

Es wurde ein Verfahren entwickelt, das die Umwandlung von Reststoffen zu methanbasierten Kraftstoffen unter höchstmöglichem Erhalt des biogenen Kohlenstoffs mithilfe von elektrischer Energie aus erneuerbaren Quellen ermöglicht. Waldrestholz, Stroh und Klärschlamm wurden als besonders relevante Einsatzstoffe identifiziert. Durch die hochintegrierte Kopplung von Vergasung, Hochtemperaturelektrolyse und Methanisierung wird der biogene Kohlenstoff aus den Edukten nahezu vollständig in das Produkt Methan überführt. Die Gestehungskosten sind dabei mit denen gegenwärtig eingesetzter Technologien vergleichbar und liegen bei Großanlagen im Bereich üblicher Werte der Biomethanerzeugung

Evaluation of Organic and Ionic Liquids for Three-Phase Methanation and Biogas Purification Processes

Three ionic liquids {butyl-trimethyl-ammonium bis­(trifluoromethylsulfonyl)­imide [N₁₁₁₄]­[BTA], 1-methyl-1-propyl-piperidinium bis­(trifluoromethylsulfonyl)­imide [PMPip]­[BTA], and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [EMIM]­[Tf]} and two heat-transfer oils [dibenzyltoluene (DBT) and polydimethylsiloxane (trade name X-BF)] were evaluated for use in the three-phase methanation and the biogas purification processes. The density, viscosity, and surface tension of these liquids were measured and modeled as a function of the temperature. The solubilities of H₂, CO, CO₂, and CH₄ in these five liquids were also obtained under different pressures and temperatures. Additionally, the criteria required for each of the two processes considered were identified: the three-phase methanation process requires a thermally stable liquid with a low vapor pressure and a high H₂, CO₂ and CO solubility, while the biogas purification process requires a highly selective CO₂ solubility liquid at ambient temperature. From the evaluation of both the experimental data and the process requirements, the most suitable liquid for each of the aforementioned processes was identified. For the three-phase methanation process, the two ionic liquids [N₁₁₁₄]­[BTA] and [PMPip]­[BTA] and the two heat-transfer oils DBT and X-BF met the minimum requirements, while [EMIM]­[Tf] showed promising potential for the biogas purification process

CNG und LNG aus biogenen Reststoffen – ein Konzept zur ressourcenschonenden Kraftstoffproduktion

Es wurde ein Verfahren entwickelt, das die Umwandlung von Reststoffen zu methanbasierten Kraftstoffen unter höchstmöglichem Erhalt des biogenen Kohlenstoffs mithilfe von elektrischer Energie aus erneuerbaren Quellen ermöglicht. Waldrestholz, Stroh und Klärschlamm wurden als besonders relevante Einsatzstoffe identifiziert. Durch die hochintegrierte Kopplung von Vergasung, Hochtemperaturelektrolyse und Methanisierung wird der biogene Kohlenstoff aus den Edukten nahezu vollständig in das Produkt Methan überführt. Die Gestehungskosten sind dabei mit denen gegenwärtig eingesetzter Technologien vergleichbar und liegen bei Großanlagen im Bereich üblicher Werte der Biomethanerzeugung