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Methane production from sewage sludge

Current situation

Sewage treatment plants currently consume mainly energy.

Sewage sludge can play a major role in a supply chain through PH2 plants.

Sewage sludge becomes green energy in the form of methane.

In this way the processes in sewage treatment plants can contribute to a circular economy in an energy efficient manner and at competitive prices.

Production of green methane from sewage sludge

Optionally the PH2 modules for sewage sludge drying and hydrogen production can be extended by a module for the energy efficient production of methane.

Sewage sludge powder is produced via sewage sludge drying. The hydrogen subsequently obtained from the sewage sludge powder (PH2 module hydrogen) is metabolized to methane in an energy efficient biological process together with carbon dioxide.

On customer´s demand a module for the innovative recovery of phosphorus developed by PH2 can be integrated in the plant in front of the module for sewage sludge drying.

The complete plant for methane production developed by PH2 consists of a maximum of four plant components in the final stage of expansion: phosphorus recovery, sewage sludge drying, hydrogen production and methane production.


Through the PH2 process sewage sludge is transformed from a problematic material into a valuable raw material for green energy.

largely pollutant neutral

Residual material of the process: slag with heavy metals. The heavy metal can still be separated. The volume of the slag depends on the proportion of sand in the sewage sludge

competitive costs


modular design

CO2 neutral

Your questions about  GREEN METHANE

What is green methane?

Green methane is produced either in a chemical process or a biological process.

How is green methane produced?

Green methane is produced from hydrogen and carbon dioxide. This can be done in a chemical process with high pressure and high temperatures. The simpler method is biological methanation. In biological methanation hydrogen and carbon dioxide are taken up by archaea and metabolized to methane. The process is exothermic and in addition to hydrogen and carbon dioxide also requires salts for the archaea. To start the process a temperature of approximately 65 °C – 90 °C is required. Another biological process is the production of methane in biogas plants. In contrast to the other two processes, the biogas from the biogas plant has to be separated from CO2 with high efforts.

Can green methane replace natural gas in the long term?

Green methane can replace natural gas in the long term.

How does electricity from renewable energies become methane?

Electricity from renewable energies is used to produce green hydrogen in electrolyzers. The green hydrogen or any other biohydrogen can be converted into methane in a chemical process or in biological methanation.

How can green hydrogen be used for methane production?

Green hydrogen can be converted to methane in a chemical process or in biological methanation.