Supplementary information files for "Review of the production of turquoise hydrogen from methane catalytic decomposition: optimising reactors for Sustainable Hydrogen production"

Supplementary files for article "Review of the production of turquoise hydrogen from methane catalytic decomposition: optimising reactors for Sustainable Hydrogen production"Hydrogen is gaining prominence in global efforts to combat greenhouse gas emissions and climate change. While steam methane reforming remains the predominant method of hydrogen production, alternative approaches such as water electrolysis and methane cracking are gaining attention. The bridging technology – methane cracking – has piqued scientific interest with its lower energy requirement (74.8 kJ/mol compared to steam methane reforming 206.278 kJ/mol) and valuable by-product of filamentous carbon. Nevertheless, challenges, including coke formation and catalyst deactivation, persist. This review focuses on two main reactor types for catalytic methane decomposition – fixed-bed and fluidised bed. Fixed-bed reactors excel in experimental studies due to their operational simplicity and catalyst characterisation capabilities. In contrast, fluidised-bed reactors are more suited for industrial applications, where efforts are focused on optimising the temperature, gas flow rate, and particle characterisation. Furthermore, investigations into various fluidised bed regimes aim to identify the most suitable for potential industrial deployment, providing insights into the sustainable future of hydrogen production. While the bubbling regime shows promise for upscaling fluidised bed reactors, experimental studies on turbulent fluidised-bed reactors, especially in achieving high hydrogen yield from methane cracking, are limited, highlighting the technology's current status not yet reaching commercialisation.©The Authors, CC BY 4.0本补充材料对应论文《甲烷催化分解制备绿松石氢（turquoise hydrogen）：优化可持续制氢反应器》。氢能在全球应对温室气体排放与气候变化的行动中地位日益凸显。尽管蒸汽甲烷重整（steam methane reforming）仍是当前主流的制氢工艺，但水电解与甲烷裂解等替代方案正逐渐受到关注。作为过渡性技术的甲烷裂解，因其能耗更低（仅74.8 kJ/mol，对比蒸汽甲烷重整的206.278 kJ/mol）且可副产高价值的丝状碳，引发了学界的广泛兴趣。然而该技术仍存在结焦与催化剂失活等亟待解决的难题。本综述聚焦于甲烷催化分解常用的两类反应器：固定床反应器（fixed-bed reactor）与流化床反应器（fluidised bed reactor）。固定床反应器因操作简便、便于对催化剂进行表征，在实验研究中应用广泛。相较而言，流化床反应器更适配工业场景，当前研究重点集中于优化反应温度、气体流速与颗粒表征参数。此外，针对不同流化床流态化工况的研究，旨在筛选出最适配工业化应用的工况，为制氢技术的可持续发展路径提供理论支撑。尽管鼓泡流态化工况在流化床反应器放大中展现出应用潜力，但针对湍流流化床反应器的实验研究（尤其是实现高甲烷裂解制氢产率的相关探索）仍较为匮乏，这也反映出该技术目前尚未实现商业化应用。©作者，CC BY 4.0