Catalytic methane decomposition is a novel approach to produce hydrogen (H2) and solid carbon without CO2-emissions as it occurs in nowadays conventional process for hydrogen production, i.e., steam methane reforming (SMR). The use of a carbonaceous catalyst mitigates the issue of deactivation by coking, which is very pronounced when using metal-based catalysts. In this project, catalytic methane pyrolysis will be investigated on three scales: the molecular, the particle and the reactor scale. A microkinetic analysis will be performed to gain insights in the reaction mechanism and to aid the identification of the active sites. Literature data will be used for this purpose at first, supplemented by novel experimental data obtained on a new test rig to support microkinetic model development. The catalyst properties will be related to the model parameters to assess their impact on the kinetics. On the particle scale, the growth mechanism of the catalyst particles and the reduction of the surface area will be investigated. Mass and heat transfer limitations will be assessed and accounted for in the reactor model. Various reactor types can and will thus be explored, ranging from the classical (benchmark) fixed-bed reactor to innovative electrothermal fluidized-bed reactors, relying on different heating techniques, such as resistive heating, electrothermal and/or induction heating. The potential electrification of hydrogen production will also be assessed, among others to render the reactor more scalable.