熔融介质裂解天然气制氢和高值碳研究进展

Research Progress of Melting Medium Cracking Hydrogen Production via Natural Gas and High-Value Carbon

氢气是实现“双碳”战略目标的重要能源载体,目前的制氢方式以天然气水蒸气重整制灰氢为主,难以继续实现大规模推广。天然气裂解制氢将CH4中的碳转化为固体碳材料,结合可再生能源供能,可实现不排放二氧化碳的制氢路线。从天然气制氢中极具工业化应用前景的熔融介质裂解技术出发,分析了“双碳”背景下该技术相较于传统制氢技术的优势,指出影响熔融介质法裂解天然气制氢的关键因素是碳税和碳产物价格,并进一步综述了催化剂在提高制氢效率、高值碳产物类型和分布方面的进展。熔融法催化剂主要包括单金属、合金、盐及复合催化剂四大类。金属类催化剂具有较高的效率,但其碳产物中的金属杂质难以回收;而盐类催化剂则相反。因此,开发既具有高催化活性又易于回收的复合催化剂是促进熔融法工业化的关键。

Hydrogen is the key energy for realizing the“carbon neutrality”and“carbon peak”target.At present,we mainly use steam reforming of natural gas to produce grey hydrogen,which cannot be promoted at a large scale.Natural gas cracking for hydrogen production converts the carbon in CH4 into solid carbon material,and combined with renewable energy supply,the hydrogen production method without carbon dioxide emission can be realized.Also,the advantages of molten medium cracking technology relative to traditional hydrogen production technology under the background of“carbon neutrality”and“carbon peak”target were analyzed.It was pointed out that the key factors affecting the hydrogen production from molten medium cracking natural gas were carbon tax and carbon product price.The progress of catalyst in improving the efficiency of hydrogen production,types and distribution of high-value carbon products was further reviewed.Melting catalyst mainly involves single metal,alloy,salt and composite catalyst as well.Metal catalysts enjoy high efficiency,yet it is difficult to recover metal impurities in carbon products.The opposite is true for salt catalysts.Therefore,the development of composite catalysts with high catalytic activity and easy recovery remains key to promote the industrialization of melting process.