An overview of production of hydrogen and carbon nanomaterials via thermocatalytic decomposition of methane

The ever-increasing global demand for energy and functional materials, coupled with the growing threat of global warming, necessitates the development of new technologies for the largescale production of green energy carriers and materials. ThermoCatalytic Decomposition (TCD) of methane is an environmentally and economically favorable approach to produce hydrogen and valuable carbon nanomaterials simultaneously, without direct greenhouse gas emissions. The chemical kinetics of TCD can be captured by considering the maximum reaction rate and deactivation factor. However, additional studies are required to obtain a deeper understanding of the deactivation mechanisms that limit catalyst performance over time. Moreover, the development of sustainable catalysts that align with the desired application of the carbon product is essential. In order to advance the development of TCD reactors and processes, further research is urgently needed. The challenges that need to be addressed include the impact of catalyst particle growth on the reaction and reactor performance. Fluidized bed reactors (FBRs) are considered the most viable units for TCD, but require comprehensive experimental and modeling studies to assess and overcome the design and operational challenges. Numerical modeling is crucial for designing, optimizing, and evaluating TCD reactors and processes. Coupled Computational Fluid Dynamics-Discrete Element Method models with intraparticle models such as MultiGrain Model, can provide a more representation view of the complex multiscale phenomena of TCD in FBRs, enabling researchers and engineers to explore effectively different reactor concepts and designs.