Abstract:
A large amount of carbon dioxide will be generated by the traditional coal gasification and methane reforming for hydrogen production, which does not meet the requirements of the “dual carbon” goals. Coupling renewable energy generation with electrolysis of water to produce hydrogen is currently the best technical solution. However, renewable energy generation has defects such as fluctuating energy output and difficulty in storage, which makes its large-scale application still face many difficulties. Therefore, a zero-carbon hydrogen production technology using natural gas as raw material has been attracted much attention. This process only produces hydrogen and solid carbon without releasing greenhouse gases, making it a bridge from fossil fuel to renewable energy for hydrogen production. The key issues faced by the industrial application of methane pyrolysis technology have been reviewed, including the impact of different types of catalysts and regeneration methods on industrialization, the advantages and disadvantages of different industrialization schemes, as well as the practical application and economic analysis of solid carbon products. Unlike nickel and cobalt catalysts, iron catalysts and carbon materials are inexpensive and non-toxic, which are one of the important advantages for their industrial application. Hydrogen regeneration technology is the best choice for catalyst recycling, as the introduction of external gases do not be required and the regenerated catalyst can work stably. In a liquid bubble column reactor, carbon can be continuously removed, thus avoiding reactor blockage caused by carbon agglomeration, and this reactor has great industrial potential. Unlike the carbon dioxide capture and storage required in the steam methane reforming process, a large amount of energy consumption do not be reqired by methane pyrolysis, and the sale of solid carbon will greatly reduce the cost of hydrogen production from methane pyrolysis. In addition, the future development trends and suggestions of this technology have been given, and the further clarification of the reaction mechanism and rate-limiting steps of methane pyrolysis, the influence of impurities in natural gas, and the selection of industrial processes and the rational utilization of solid carbon will all be the key research directions in the future.