Temperature effects on the properties of solid carbon from natural gas pyrolysis in molten tin

Natural gas pyrolysis produces hydrogen and solid carbon at high temperatures in an oxygen-free environment. This study has evaluated the characteristics of solid carbon obtained from the pyrolysis of methane and natural gas by using molten tin (Sn) at 900–1000 °C. Material characterization outcomes revealed that solid carbon produced at 1000 °C has a spherical morphology. At this temperature, methane and natural gas pyrolysis have resulted in the arrangement of nanocrystalline carbon spheres with average sizes of 635 and 287 nm, respectively. Similarly, pyrolysis at 900 °C and 950 °C has yielded nanocrystalline carbon featuring diverse morphologies such as spheres, fibrous, and irregularly shaped particles. Thermogravimetric analysis revealed that solid carbon products obtained from methane and natural gas pyrolysis at 1000 °C have higher thermal stability compared to commercial carbon black N991. Surface area analysis has indicated that solid carbon from natural gas pyrolysis at 1000 °C has 4.3- and 5.3-times higher surface area compared to the commercial carbon black N991 sample and graphite flakes, respectively. These findings offered insights into optimizing pyrolysis reactor design and operation to generate valuable solid carbon by-products while maximizing hydrogen production.

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