This article originate from my contributions to Energiris, a Belgian citizens’ cooperative committed to accelerating the energy transition. As part of our mission to inform and raise awareness among both co-owners and the general public, we regularly publish educational content on topics related to sustainable energy.
The original article was published in French and Dutch, reflecting the multilingual context of our cooperative. By sharing them here in English, I also wish to reflect my personal commitment to a more sustainable and better-informed society.
Originally published on the Energiris website, in the ‘Read for you’ section as part of our technology watch on solar innovations. – 10 june 2024
Article published by ‘Techniques de l’ingénieur’ on 8 January 2024 (in french) Optimising the recovery of CO2 from biogas to produce methane | Techniques de l’Ingénieur (techniques-ingenieur.fr)
A laboratory at the University of Pau and Pays de l’Adour has developed a dynamic model to optimise the recovery of CO2 present in biogas for the production of methane. This model is capable of controlling all the parameters of the methanisation unit, as well as all the operating variables of the methanation process.
Biogas, produced by methanisation from agricultural waste, mainly contains methane. However, it also contains CO2, the proportion of which varies between 30 and 50% depending on the nature of the biomass. Currently, most operating units release this CO2 into the atmosphere.
As part of the Optimeth project, the Thermal Energy and Processes Laboratory (LaTEP) at the University of Pau and Pays de l’Adour has developed a numerical model. This model makes it possible to predict all the system’s operating variables over a given period of time in order to optimise a criterion, such as the cost of producing this methane, while imposing constraints, such as meeting the methane demand of an end consumer. This tool will facilitate control and planning.
To produce methane from CO2, the Sabatier reaction must be carried out, which involves adding hydrogen to CO2. For this operation to be completely ‘green’, the hydrogen must be produced from a renewable source, such as solar panels or wind turbines, which supply electricity to a water electrolyser. Weather conditions are one of the main parameters to be taken into account, as they influence the production of renewable energy, which is by nature intermittent. For example, in the event of a lack of sunshine and the risk of running out of hydrogen, the model will be able to calculate the optimal volume of hydrogen storage so that this gas is never in short supply, in order to carry out the Sabatier reaction.
In addition, weather variations, particularly the outside temperature, have an impact on the methaniser. Inside the reactor, anaerobic bacteria are responsible for producing biogas. This dynamic model will prevent the catalytic reactor in the methane generator from overheating.
In short, this research aims to maximise the use of CO2 from methanisation, thereby contributing to a more sustainable and efficient approach to methane production.
Beyond my role at Energiris, I place great importance on sharing knowledge. I have always considered education to be an essential tool for helping everyone better understand energy issues and the concrete solutions available to us. Sharing what I discover and making complex topics accessible to others is also my way of contributing to a fairer, more inclusive transition.