Scale-up of an additively manufactured reactor concept for catalytic methanation with in-situ tar co-reforming of biogenic syngas

• 15-kW Scale-up of the initial 5-kW reactor concept • Experimental characterization of the 3D-printed ADDmeth4 methanation reactor • Steady-state and transient operation • Optimization of operational parameters • In-situ co-reforming of tar components reaching a removal rate of up to 95 % in a part load setting The market introduction of renewable methane is hindered by the high production cost of green SNG. One of the major cost factors is the extensive gas cleaning necessary for the methanation of biogenic syngas. A scaled-up version of a 3D-printed reactor system is proposed in order to reduce such gas cleaning costs. The ADDmeth reactor system can operate tolerating the use of tar-laden syngas, as it is specifically designed to reform tar components in-situ within the reactor. A scale-up of the reactor concept is realized by running several of the triangular reactor cells in parallel. The 15 kW reactor ADDmeth4 consists of three ADDmeth3 reactor cells, that are adapted and optimized for the scale-up. The new reactor design aims at a more efficient use of the space within the reactor. A new improved steam generator design is used to overcome limitations in cooling. The structural stability is validated using finite elements analysis with a resulting minimum safety factor of 4.43. In ADDmeth4 experiments the total tar content of the syngas was reduced by 95 % in a part load setting at 5 kW. However, this reduction potential decreases at full load. Residual tar is likely removed in the condensation step. The transient behavior of the reactor’s scale-up approach allows for a use of the reactor in fluctuating operating modes. The reactor concept can also be used in Power-to-Gas or biogas upgrading scenarios, reaching a high methane yield in just one step. The results indicate that the reactor scale-up will increase its performance. Both the temperature profile and efficiency improve, the latter due to the decrease in outer surface area through which potential losses occur.