Biological biogas upgrading to biomethane
Biogas is the product of anaerobic biodegradation of wastewater sludges: it is composed by methane (CH4) and carbon dioxide (CO2).
Biogas upgrading to biomethane is a process in which you remove the CO2 from biogas in order to obtain a fuel (biomethane, which is almost 100% CH4);
the biomethane thus obtained can be used as transport fuel or can be injectied into the gas distribution network; thus biogas upgrading can be considered as a renewable source of methane.
Biological upgrading is a quite innovative and promising technology, still at the research stage, to transform CO2 into methane.
It is based on a biochemical anaerobic reaction, mediated by Archaea, between hydrogen (to be added) and CO2, to produce CH4 and water.
As a result, a higher methane output is obtained from the biogas plant, at a much higher CH4 content.
Hydrogen has to be produced by water electrolysis, fed on surplus renewable energy. It is a promising technology to be studied in a wastewater treatment plant (WWTP),
as the oxygen released from water electrolysis can be recovered in the biological aerobic stage of waste water treatment.
Planned activities within PerFORM WATER 2030
The experimental activities regarding the biological upgrading from biogas to biomethane are part of the
Recovery of energy and materials research line included in PerFORM WATER 2030.
A pilot scale reactor is being built and will be operated along the project under different operating conditions.
It will be continuously fed with biogas (taken from the full scale anaerobic digestor), and H2 (hydrogen) produced by a dedicated water electrolyzer, located in the same container.
Objectives and expected results
Upgrade of biogas up to 90% CH4 and above.
Identification of the key parameters that determine the stability of the process.
Development of a model for the biological process control.
Description of the activities
Design and construction of an anaerobic pilot scale reactor and a water electrolyzer, controlled to operate under variable conditions.
Start-up, operation and monitoring (on and off line) of the pilot, biochemical test and sequencing.
Modelling (Petersen’s matrix based) of the process and feasibility evaluation.
Pilot site
The experimental activities will be located at San Giuliano Milanese West WWTP (Wastewater treatment plant) operated by CAP Group.
For further information, please refer to the specific web-page dedicated to demonstration sites of PerFORM WATER 2030.
Partners involved
SEAM engineering leads the design, construction and installation of the pilot scale plant, while Politecnico di Milano provides the engineering design basis of the pilot plant and lead the experimental and modelling activities. HyDEP provides a dedicated in situ water electrolyzer, to supply hydrogen.
Go to the "Science & Tecnology" section for further information
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