Detailed analysis of the operational characteristics of the steam reformer and water–gas shift reactors for 5 kW HT-PEMFCs

The reactors designed for 5-kW high-temperature polymer electrolyte fuel cells are able to evaluate the performance of the steam reformer and each water–gas shift reactor independently. The goal of the experiments is to obtain the best overall performance for steam reforming while minimizing the CO concentration and maximizing the hydrogen yield. For this purpose, the performance of the steam reforming reactor unit with two types of flow paths was evaluated while evaluating the performance of various series of component combinations of the high-, middle-, and low-temperature shifts. Via experiment, thermal control followed by the appropriate heating and cooling mechanism is key to successful reaction performance. In addition to an individual unit-based experiment, numerical analyses were executed to understand the local chemical performance inside a reactor unit. These numerical analyses show good agreement with the experimental data measured at the outlet and provide a comprehensive detailed internal reaction mechanism such as the thermal conditions and CO concentration effect. Both experiments and numerical analyses can fundamentally improve the reaction performance by finding the optimal values of many control parameters.