BIOMETANOGÉNESIS
Using biological methanation of biogas CO2 to transform biogas into biomethane so it can be put it into the gas network and convert renewable electric energy into a storable energy vector like biomethane
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Using biological methanation of biogas CO2 to transform biogas into biomethane so it can be put it into the gas network and convert renewable electric energy into a storable energy vector like biomethane
Links:
The general goal of the original project consists of transforming biogas (and hydrogen) into biomethane through biocatalysis using an advanced bioreactor that maximises gas transfer in the liquid medium using pressure.
In the project, the most promising biocatalyzer in terms of methane production using biogas was identified after screening 4 potential strains. It is a thermophilic methanogen that also underwent an adaptive evolution. Thanks to a specific protocol of forced evolution developed by CENER, it was completely adapted to the biogas substrate through successive steps.
AIN and CENER have designed, built and validated an advanced laboratory bioreactor that can work at a pressure of 10 bar, which maximises the solubility of the gasses (H2 and CO2) in the liquid medium, which implies greater substrate availability and, consequently, higher performance, which results in a higher concentration of CH4 in the output flow. Not only was an advanced bioreactor designed and built from scratch, it was also an active process where the problems that arose in assembly and operation were directly converted into improvements applicable to the laboratory bioreactor or the pilot version (100l).
The biological production of methane in the advanced laboratory bioreactor was validated using continuous biogas fermentation, where performance near 90% was achieved. That shows that the design chosen for the ad hoc bioreactor that was built improves upon stirred-stick bioreactors for this use case, and it is a hopeful sign because, despite needing more effort to achieve stable performance over time, the microorganisms have all their nutritional and micronutritional needs covered, which improves their growth.
In addition, Lurederra designed a real biogas cleaning system, that makes it so there are no inhibiting concentrations of contaminants and it can be fermented by the methanogens without growth limitations.
The general goal was met, and the door has been opened to developing and improving this technology to cover the real current need to reduce greenhouse gasses (CO2).