System and method used for producing high purity hydrogen via concentrated-solar-energy-driven high-temperature bubbling-type methane direct pyrolysis

The invention discloses a system and a method used for producing high purity hydrogen via concentrated-solar-energy-driven high-temperature bubbling-type methane direct pyrolysis. According to the method, collecting lens is used for concentrating of sunlight onto a heat absorber so as to generate a high temperature heat source, a heat carrying fluid is introduced into the heat absorber, and is used for delivering high temperature heat energy into a specially-made bubbling-type reactor; in the specially-made bubbling-type reactor, production of solid state carbon nanoparticles and hydrogen gasis realized via methane direct pyrolysis, the carbon nanoparticles are left in the specially-made bubbling-type reactor and are collected, a mixed gas of hydrogen gas and unreacted methane is delivered into a hydrogen gas separator to obtain high purity hydrogen gas; the heat carrying fluid discharged from the specially-made bubbling-type reactor is relatively high in temperature, so that the heatcarrying fluid is used fo