(650g) Molten Metal Catalysts for Methane Pyrolysis
Molten metals were investigated as catalysts for the thermochemical pyrolysis of methane. Conversion of methane to hydrogen and solid carbon is demonstrated in bubble column reactors where the solid carbon can be readily separated and removed enabling continuous processes. Twenty-one molten metal systems consisting of elemental metals and binary alloys are compared for methane pyrolysis activity. Nickel-bismuth was found to be the most active catalyst, and 95% methane conversion was observed at 1060 °C in a 1.1 meter bubble column. Initial characterization of the carbon product indicated predominately sp2 graphitic carbon as the solid product. Although the hydrogen produced from partial oxidation of methane by pyrolysis retains only approximately half the combustion energy potential as complete methane combustion, pyrolysis produces CO2-free hydrogen, and catalytic molten metals may provide a means for performing reactive separation of the hydrogen from the potentially valuable carbon co-product.