CO₂ methanation in a slurry bubble column reactor : Reactor dynamics and reaction kinetics

The CO₂ methanation reaction is highly exothermic, which makes reactor temperature control under dynamic operation conditions challenging. To tackle this challenge, a slurry bubble column reactor (SBCR) is an attractive reactor concept: The high heat capacity of the heat transfer liquid allows for isothermal process conditions and efficient heat extraction. To assess the dynamics of such a reactor and its potentials for the PtG process, dynamic SBCR simulation will be compared with the results of a dynamic simulation of a state-of-the-art adiabatic fixed-bed reactor. In order to clarify the influence of a liquid phase on the CO₂ methanation kinetics kinetic experiments with different heat transfer liquids are carried out in a CSTR at the same partial pressures or gas concentrations in the liquid phase. It will be shown that the gas concentration in the liquid phase is the rate determining factor for the description of the three-phase methanation kinetics.
Additionally, experimental data on CO₂ methanation kinetics in a two-phase system will be provided and compared to results from three-phase system. It will be shown that the two-phase methanation kinetics can be applied to describe the three-phase methanation kinetics when the gas solubility in the heat transfer liquid is known.