Study on the tolerance of low-temperature CO methanation with single pulse experiments

In this contribution, single pulse reaction experiments are discussed in the context of dynamic reactor operation and used to determine the tolerance of reactors arising from sorption effects at the catalyst surface. A defined amount of CO is dosed together with an internal standard (He) in a constant H2 stream, and the pulse response is observed with reference to the internal standard, which is representing the fluid dynamics of the injected pulse. Different responses are obtained depending on the catalyst mass (Ni/Al2O3) and the operation temperature (170°C-300°C). The tolerance of the reactor can be deduced from the experimental findings. On the one hand, the catalyst adsorption capacity determines the ability to buffer fluctuations at low reaction temperatures (𝑇<220 °𝐶), which are beneficial for full-conversion, overcoming thermodynamic restrictions. On the other hand, temperature determines the transient response of the system and is independent of the catalyst mass. From these findings the study reveals that reactors represent important buffer systems during load changes in dynamic operation modes and provide an intrinsic tolerance originating from sorption processes at the catalyst surface.