The report describes the design of a pilot plant for testing ex situ biological methanation reactors. This activity is part of the broader Power to Gas topic, which assigns a key role to the reduction of CO2 using hydrogen produced via electrolysis in achieving the decarbonization goals established by the Paris Agreement (COP21). The plant, aimed at experimenting with process improvements (particularly suitable for applications involving the use of biogas), will be installed in the experimental area of RSE’s Milan headquarters and will be able to accommodate up to 3 test reactors. Each reactor will be capable of operating at temperatures between 35 and 80 °C and pressures between 1 and 10 bar, with hydrogen and CO2 flow rates of 320 and 80 NL/h, respectively. The plant will also be equipped to operate with synthetic biogas.

RSE is particularly interested in trickle-bed reactors, which consume less energy than stirred reactors and are potentially capable of producing high-quality gas suitable for injection into the grid. Therefore, alongside the definition of the system layout and the sizing of the main plant components (gas analysis system, nutrient supply, gas supply, etc.), the first two trickle-bed reactors were designed, each with an active volume of approximately 38 liters.

The appropriate instrumentation for effective performance monitoring (with measurement uncertainty suitable for the experimental purposes) and safe plant operation has been identified. Additionally, a preliminary scheme for the acquisition and control system has been outlined, defining the operational states, operating modes, and main control chains.