Four different configurations of a 5 kW class shell-and-tube methane steam reformer with a low-temperature heat source

• Published in: International journal of hydrogen energy 2018-03, Vol.43 (9), p.4546-4562
• Main Authors: Yun, Jinwon, Cho, Kyungin, Lee, Young Duk, Yu, Sangseok
• Format: Article
• Language: English
• Subjects: Hybrid fuel cell system; Hydrogen production; Low temperature characteristics; Methane steam reformer; Shell and tube heat exchanger; SOFC (solid oxide fuel cell)
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2018.01.069

The methane steam reforming reaction is an extremely high endothermic reaction that needs a high temperature heat source. Various fuel cell hybrid systems have been developed to improve the thermal efficiency of the entire system. This paper presents a low temperature steam reformer for those hybrid systems to maximize the utilization of energy from a low temperature waste heat source. In this study, the steam reformer has a shell and tube configuration that is divided into the following zones: the inlet heat exchanging zone, the reforming zone and the exit heat exchanging zone. Four different configurations for methane steam reformers are developed to examine the effect of heat transfer on the methane conversion performance of the low temperature steam reformer. The experimental results show that the overall heat transfer area is a critical parameter in achieving a high methane conversion rate. When the heat transfer area increases about 30%, the results showed elevated dry mole fractions of hydrogen about 3% with about 30 °C rise of reformer outlet temperature. •The four types of a shell-and-tube methane steam reformer were designed.•The non-reactive low-temperature heat source was supplied for the reformers.•The performance of reformer is significantly affected by heat transfer parameters.•The optimized geometric parameters and configurations can improve the performance.