In the pilot plants, an increase of the biogas content to 16% and a very strong decrease of the hydrogen sulphide content were demonstrated during the project period. The results indicate that it will be possible to increase the biogas yield even further by adjusting other test parameters. According to a theoretical calculation, there is a potential to increase the share of biogas to 25%.
The principle of this research is based on the introduction of (green) hydrogen into a fermenter. This hydrogen is produced on site in the digester via electrolysis. This was done during the project in two pilot plants, one in the Netherlands and the other in Germany.
The aim of this approach is to make biogas production more efficient by means of a biochemical process, so that the gas now produced has a higher quality, i.e. an increase in the methane (CH4) content and a sharp decrease in the carbon dioxide (CO2) content. Moreover, the biomass input required per unit of biogas produced is lower.
In electrolysis, besides hydrogen, oxygen is also produced. This is further used to increase the efficiency again and it is expected that the content of hydrogen sulphide (H2S) is also greatly reduced.
Based on practical implementations, the project shows that this new process can work technically and organisationally in both the Netherlands and Germany, where conditions are different. Increasing the efficiency of biogas installations is an important step forward in the production of sustainable energy, in a time of increased competition for raw materials, environmental requirements and cost pressure.
Three Dutch and three German organisations cooperated in this project (4 SME’s, a knowledge institute and a local government): 3N Kompetenzzentrum e.V., B.E.S GmbH & Co. KG, Byosis Group BV, DNL-contact GmbH & Co KG, Dankers Bio Energy BV and Province of Friesland.
The project was made possible by Interreg Deutschland-Nederland, the Dutch Ministry of Economic Affairs and Climate Change, the Niedersächsisches Ministerium für Bundes- und Europaangelegenheiten und Regionale Entwicklung and the Dutch provinces of Drenthe, Friesland, Gelderland, Groningen and Noord-Brabant.