Heat-Integrated Reactor Concepts for Hydrogen Production by Methane Steam Reforming

摘要

Steam reforming of hydrocarbons is the major source of hydrogen on an industrial scale. Conventional, large scale, processes for hydrogen production are not optimal for the decentralized, standalone supply of hydrogen for fuel cell systems. Their major drawback is limited thermal efficiency due to restricted heat recovery from the reformer effluents. A promising approach to overcome these limitations is the utilization of multifunctional reactor concepts, integrating the major reaction steps and process heat management. Coupling endothermic and exothermic reactions into heat-integrated processes can be realized in different ways. One possible design is based on micro-structured devices employing recuperative heat exchange between the process streams. A comparable specific performance and functionality can be achieved with adiabatic fixed-bed reactors, operating in a transient mode. A major issue for both alternatives is the proper axial distribution of the process heat. Novel design solutions, developed in our group, are reviewed in this paper. Detailed simulation studies, as well as proof-of-concept experiments, confirm their feasibility and potential to significantly enhance the efficiency of the process.