Abstract: A system for producing hydrogen and a carbon nanoproduct includes a hydrocarbon feed gas supply configured to supply a hydrocarbon feed gas at a selected flow rate, a reactor having a hollow reactor cylinder with an enclosed inlet adapted to continuously receive the hydrocarbon feed gas, a reaction chamber in fluid communication with the inlet, and an enclosed outlet in fluid communication with the reaction chamber adapted to discharge a product gas comprised of hydrogen and unreacted hydrocarbon feed gas, along with the carbon nanoproduct. The system also includes a catalyst transport system adapted to move a selected amount of a metal catalyst through the reaction chamber at a rate dependent on the flow rate of the hydrocarbon feed gas to form the product gas. The system also includes a carbon separator adapted to separate the carbon product from the product gas and from the metal catalyst.