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.
Recently the biogas purification at biomethane has received a great deal of interest. The technologies that can be used for the upgrading from biogas to biomethane and the use of CO2 are well known and consolidated.
The biggest challenge is to demonstrate the economic and environmental sustainability of the processes.
The simultaneous capture of CO2 and its reuse can be a new step towards more sustainable processes.
The experimental activities regarding the chemical upgrading from biogas to biomethane are part of the
Recovery of energy and materials research line included in PerFORM WATER 2030.
The pilot scale plant will test a CO2 capture process developed at UNIMIB (Universit√† degli Studi di Milano-Bicocca), in which CO2 adsorption take place through chemical solvents derived from low environmental impact processes.
In particular, we will work on the upgrading process of biogas to biomethane in order to obtain an optimization of the process performance through the use of the upgrading plant developed by UNIMIB specifically for the application to biogas coming from anaerobic digestion from purification sludge.
At the same time, an extensive analysis of the possible uses of CO2 recovered from the upgrading process will be carried out, with a strong focus on uses for manufactoring industrial products within the "green chemistry" sector.
The possibility of re-using CO2 produced directly on site, in the Bresso wastewater treatment plant, will also be tested in cooperation with UNIMIB-DISAT (see for further information).
The work carried out by MATER-UNIMIB started with a small-sized laboratory plant (a few liters / hour) supported by a small reactor containing microalgae to optimize the CO2 capture conditions (temperature, solution concentration, gas flows). The parameters thus obtained will then be used for the pre-industrial demonstrator plant (few m3/hour) which is being installed at the Bresso wastewater treatment plant operated by CAP Group.
Demonstrate that it is possible and economically viable to produce, in small-scale plant, biomethane to be used for vehicles.
Demonstrate that it is economically possible to use the CO2 extracted from biogas during the upgrading process for applications such as the growth of microalgae used in water purification processes.
Laboratory activities are being carried out at MATER Department of UNIMIB.
A pilot scale plant for CO2 capture is being installed at the Bresso wastewater treatment plant.
Performance optimization of the upgrading process depending on biogas produced by CAP Group.
Analysis of the possible uses of the recovered CO2 within the "green chemistry" sector.
MATER Department of Universit√† degli Studi di Milano - Bicocca has made its knowledge and
its patented CO2 capture methodology based on the chemical washing of CO2-containing mixtures available for biogas upgrading to biomethane.
The captured CO2 is then supplied to a small reactor containing microalgae as food for optimizing their growth. Microalgae thus obtained are then used in the experimental activities regarding emerging micropollutants removal from treated WW effluent (see for further information).
CAP Group makes available the Bresso WWTP.
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