Use of molten salt to separate carbon from a molten metal catalyst

Method for producing solid carbon and hydrogen gas by molten metal pyrolysis of hydrocarbons, the method comprising:

• (i) feeding a stream of hydrocarbon into a pyrolysis reactor through a catalytic layer of molten metal to pyrolise the hydrocarbon into solid carbon and hydrogen gas;
• (ii) feeding a stream of molten salt into the pyrolysis reactor to separate the solid carbon from the molten metal
• (iii) collecting a product gas containing hydrogen gas that evolves from the reactor;
• (iv) collecting a mixture comprising solid carbon and molten salt;
• (v) separating the mixture obtained in step (iv) into a product comprising solid carbon and separated salt
• wherein the separation step (v) involves separating solid carbon from the separated salt by filtering and/or washing the mixture with an aqueous liquid to obtain a product comprising pure solid carbon and a separated salt, and wherein the separated salt is recycled into the reactor as part of step (ii).