(278d) Catalytic Methane Decomposition: Effect of Carbon Yield on Particle Properties and Fluidization Characteristics

Hydrogen production (Turquoise H₂) through the direct decomposition of methane has been receiving a lot of attention recently, as it produces carbon in solid form during the reaction process, eliminating the need for carbon dioxide capture and storage. Moreover, when transition metal catalysts are used, crystalline carbon can be produced, which can be utilized as a conductive material, potentially contributing to a reduction in the cost of hydrogen production. This technology typically utilizes fluidized bed reactors for the continuous production of hydrogen and carbon, where understanding the changes in particle properties and the resulting hydrodynamic characteristics within the reactor is very important for reactor design. This study aimed to investigate whether selective discharge of high-yield carbon particles is possible in the continuous methane catalytic decomposition reaction. For this purpose, particles with different carbon yields (based on a total weight change of particles/weight of fresh catalyst) around from 0 (Fresh Cat.) to 1000 wt.% were prepared in batch mode reaction. These were used to observe changes in particle properties (size, density, shape) according to carbon yield, and the mixing and separation characteristics according to fluidizing gas velocity changes were examined in a bubbling fluidized acrylic reactor with mixed carbon particles. Based on these results, an operational methodology for application to continuous processes was proposed.

(This work was supported by the Technology Innovation Program (20010853) funded By the Ministry of Trade, Industry & Energy (MOTIE, Korea) and was also conducted under the framework of the research and development program of the Korea Institute of Energy Research (C4-2404)).