Parametric analysis of a high-temperature solar-driven propane steam reformer for hydrogen production in a porous bed catalytic reactor

In this study, a solar-driven porous bed catalytic reactor (PBCR) is investigated with the aim of propane reforming and hydrogen production using a clean energy source. The process consists of two major parts: a PBCR equipped with internal heating tubes and a parabolic dish collector (PDC) with its cylindrical cavity receiver (CCR) to supply the thermal energy required for the reforming process. A proper heat transfer fluid (HTF) is thermally charged in the CCR and discharged in the PBCR. In addition to the reforming reaction, the reversible water-gas shift (WGS) reaction takes place in the PBCR. In the reverse WGS, hydrogen produced in the previous stage is consumed and undesired carbon monoxide is generated. This unfavorable condition should be controlled to restrict the production of undesirable byproducts. In the present study, two CCR and PBCR parts are modeled/ simulated using the CFD approach, and then validated using available experimental data. After model validation, the impacts of critical parameters such as inlet gas temperature, pressure and composition, bed porosity, PDC aperture diameter, and HTF circulation rate within the system on the performance of the entire system are assessed. Propane conversion, hydrogen yield, and carbon monoxide selectivity (CMS) are chosen as the system's performance indicators. At optimal conditions, for an inlet pressure of 100 Pa and temperature of 300 K, inlet propane mass fraction of 0.05, bed porosity of 0.3, PDC aperture diameter of 3 m, and HTF circulation rate of 0.05 kg/s, the time average propane conversion, hydrogen yield, and CMS during a typical day and a part of nighttime are obtained at about 62.93 %, 10.326, and 1.0122 %, respectively.