Corrosion and Stability of Methane Pyrolysis Reactor Materials for Turquoise Hydrogen

다국어 초록 (Multilingual Abstract)

As global efforts toward carbon neutrality intensify, 'turquoise hydrogen' has emerged as a promising technology for producing hydrogen without carbon dioxide emissions through the thermal decomposition of methane. This thermal decomposition process, which requires temperatures exceeding 1000 °C, presents a significant challenge: severe corrosion of the reactor inner walls when in contact with molten catalysts. To address this issue, our study analyzed the corrosion behavior of various candidate materials to identify core reactor components capable of long-term stability in such extreme environments. To simulate the harsh environment of molten catalysts, we designed and constructed a specialized corrosion test reactor featuring a simplified crucible mounting system. Candidate materials, including high-temperature resistant alloys and high-purity inorganic compounds, were selected for evaluation. The experimental setup incorporated high-temperature heating elements and a PID control system to maintain a stable environment at temperatures up to 1100 °C. Our results revealed distinct differences in stability between material classes: Metallic materials exhibited significant degradation, characterized by reduced specimen diameters, surface discoloration, and exfoliation due to reactions with the molten catalyst. In contrast, a specific compound material demonstrated exceptional chemical stability, maintaining its structural integrity even under ultra-high temperature exposure. Scanning electron microscopy (SEM) analysis confirmed that this specific material system maintained smooth surface states, and energy-dispersive X-ray spectroscopy (EDS) measurements verified its physical and chemical stability by showing inhibited penetration of catalyst components. Hence, the present research proves that specific heat-resistant materials are the most suitable alternatives for the inner walls and core components of methane pyrolysis reactors. The established corrosion database and testing system will serve as essential foundational data for material selection in large-scale plants, ensuring the long-term durability of turquoise hydrogen production processes.