Dynamic modeling of an integrated reformer membrane fuel cell system

Abstract

Although hydrogen is considered as the perfect energy source for the future due to its pollution free operation in fuel cell powered automobile/stationary applications, considerable efforts are still in development to prevent direct on-board storage of the fuel due to several inevitable challenges. On-site production of hydrogen using suitable reforming techniques and purification using membrane separation appears to be an acceptable choice to overcome this challenge. Even though several works have been reported separately on the dynamic and steady state modeling of reformer, membrane separation, and fuel cell subsystems, only very few have discussed the possibility of integrating the units to operate as a single entity. This study addresses the mathematical modeling and dynamic analysis of the integrated reformer membrane fuel cell system to be used in both portable as well as stationary applications. Autothermal reforming, which has the ability to circumvent the heat requirement problem of the endothermic steam reforming, has been selected as the fuel processing subsystem while gas separation using palladium membrane has been considered as a suitable option for hydrogen gas purification. Low temperature polymer electrolyte membrane fuel cell (PEMFC) is the power generation subsystem. A case study of the integrated unit powering a fuel cell vehicle assuming an idealized driving power profile is examined and a suitable control strategy to operate the system based on the load demand has been implemented.