Natural gas from fossil sources has to be substituted by climate neutral gases to contribute to CO2-reduction in our future energy system. Pyrolysis of natural gas is a well-known technical process to produce carbon. Production of hydrogen from natural gas pyrolysis has gained interest in research and energy technology in the near past. If the carbon by-product of this process can be used for material production or can be sequestrated, the produced hydrogen has a minimum carbon footprint. This article is a literature review on the state of the art of methane / natural gas pyrolysis process developments.