“Power to Gas” could be one of the crucial solutions for an high exploitation of the renewable energy by converting electricity into hydrogen and combining it with CO2 through the Sabatier reaction. RSE has focused its research on ex-situ biomethanation, particularly on Trickle Bed Reactors (TBR). In RSE’s “Biological Methanation” Laboratory in Milan, installed during the previous research phase (PTR 2019-2021), the first reactor (R1) was successfully inoculated, and atmospheric pressure experimentation produced methane within 70 hours of inoculation. During the actual research period (PTR 22-24), RSE has started different experimental campaigns aimed at optimizing methane production (MPR).

Detailed monitoring of wastewater has provided valuable insights into key biological process parameters, including alkalinity levels, volatile fatty acids, volatile solids, total solids, and Chemical Oxygen Demand (COD). These data have allowed for the modulation of operating conditions, providing an in-depth view of the microbial population’s health inside the methanation reactor.

Optimizing the supply of macronutrients and micronutrients has been a key element for the experiment’s success. The analysis has demonstrated that varying the quantities and concentrations of nutrient solutions impacts methane production, highlighting the importance of accurate control over feeding conditions to maximize reactor performance.

The achieved results showed high methane purity levels and MPR values near those reported in the literature as reference performances. The experimentation will be extended with the goal of achieving even higher MPR and stabilizing its long-term value, identifying the optimal configuration for plants of this scale.

The Report is available on the Italian site