Biogas and biomethane

Biogas is a combustible mixed gas composed primarily of methane. It is produced by the fermentation of biomass, such as biowaste, manure, and other agricultural residues. Through processing and refining biogas, biomethane can be produced, which has a higher methane content - while pure biogas typically contains between 40 and 75% methane, biomethane contains at least 96% methane. This gives it the same chemical properties as conventional natural gas, allowing it to be injected and stored in the gas grid in any quantity.

Hydrogen

Hydrogen is usually found in bonded forms, such as water (H2O), from which it can be separated through industrial processes. Colors are used to describe the hydrogen produced using different methods.

Green hydrogen: Produced from water using electrolysis powered only by renewable electricity. It is climate-neutral and renewable, releasing no CO₂.
Blue and turquoise hydrogen: Non-renewable but climate neutral, serving as interim solutions until green hydrogen is available in sufficient quantities.
Grey hydrogen: Produced from hydrocarbons, releasing CO₂ in the process. It is the most common form of hydrogen production but is not climate neutral.

Hydrogen in its pure form is gaseous. It can be stored in large quantities for long periods and can be transported via the gas grid.

Synthetic gas

Synthetic gas, consisting of hydrogen (H2) and CO₂, is produced using power-to-gas technology. To produce it, excess renewable electricity is sent through the grid to a plant, where water is split into oxygen and H2 by electrolysis. The H2 is then converted to synthetic gas by methanation. CO₂ is sourced from local facilities, such as wastewater treatment plants. The resulting synthetic gas can be transported in the gas network, stored long-term in gas storage facilities, and used like conventional natural gas or renewable biogas.

Gas