Improvement of three-phase methanation reactor performance for steady-state and transient operation

•The performance of a slurry bubble column reactor used as a methanation reactor was investigated.•Optimal process conditions for substitute natural gas production were identified.•The dynamic behavior of the reactor was investigated using inlet gas velocity step changes to simulate load variation.•The reactor showed rapid adaptation while maintaining an isothermal temperature profile.

The performance of a slurry bubble column reactor was evaluated for its application as a methanation reactor. The influences of the reactor pressure (5 to 20 bar), temperature (275 to 325 °C), gas velocity (0.8 to 1.6 cm/s), catalyst concentration (1.6 to 9 vol.%) as well as reactant partial pressures (H2/CO2 ratio from 3.8 to 6.3) on the reactor performance were assessed and optimal process conditions for substitute natural gas production were identified. An increase in pressure, temperature, and H2/CO2 ratio improves the reactor performance. The optimal catalyst concentration depends on the operating conditions. Under the experimental conditions of the work presented in this paper, a concentration of 6.5 vol.% led to the highest conversion rates.Additionally, the dynamic behavior of the three-phase methanation reactor was investigated using inlet gas velocity step changes to simulate load variation of a power-to-gas facility. The reactor showed rapid adaptation while maintaining an isothermal temperature profile.