A methanol–steam reformer (MSR) can safely provide hydrogen-rich fuel for a fuel cell system. Since the operating temperature of an MSR is relatively low, convective heat transfer is typically used to provide thermal energy to the endothermic reactions in the MSR. In this study, the use of phase change heat transfer to provide thermal energy to the endothermic reactions was investigated, which enhanced the temperature uniformity longitudinally along the MSR. ANSYS Fluent^® software was used to investigate the performance of the reforming reactions. A comparative analysis using sensible heat and latent heat as the heat supply sources was performed. Using latent heat as a heat source achieved a lesser temperature drop than sensible heat that was under 5.29 K in the outer pipe. Moreover, a sensitivity analysis of methanol–steam-reforming reactions that use phase change heat transfer in terms of the carbon ratio, gas hourly velocity (for the inner and outer pipes of the MSR), inlet temperature (inner and outer pipes), reactor length, and operating pressure (inner pipe) was performed. When the phase change energy of water vapor is used, the wall temperature of the MSR is conveniently controlled and is uniformly distributed along the channel (standard deviation: 0.81 K). Accordingly, the methanol conversion rate of an MSR that uses phase change energy is ~4% higher than that of an MSR that employs convective heat transfer.

Due to its low operating temperature, the performance of a methanol steam reformer depends on efficient thermal integration. In particular, the integration of the evaporator is crucial to enhance thermal efficiency. This paper presents two different configurations to utilize thermal energy for evaporation of methanol/water mixture. The reformer system is composed of a methanol steam reformer, a burner, and two different evaporators such as internal evaporator and external evaporator. Moreover, since the performance of the reforming system strongly depends on thermal utilization, a heat recovery module is designed for methanol reforming system with internal evaporator. The heat duty and steam to carbon ratio (S/C) are the variables for evaluation of its suitability. The experimental results indicate that the internal evaporator with the auxiliary heat recovery module provides stable conditions over wide operating ranges.

A methanol steam reformer converts methanol and steam into a hydrogen-rich mixture through an endothermic reaction. The methanol reformer is divided into a reaction section and a heat supply section that transfers thermal energy from 200 to 300 °C. This study presents the behavior of the methanol steam reforming reaction using the latent heat of the steam. A numerical analysis was separately conducted for two different regimes assuming constant heat flux conditions. A methanol steam reformer is an annulus structure that has a phase change heat transfer from an outer tube to an inner tube. Different from the steam zone temperature in the tube, the latent heat of steam condensation decreases, and there is a gradual between-wall temperature decrease along the longitudinal direction. Since the latent heat of steam condensation is very sensitive to the requested heat from the reformer, it is necessary to consider a refined design of a methanol reformer to obtain a large enough amount of heat by steam condensation.

Proton Exchange Membrane Fuel Cell (PEMFC) has advantages that other energy sources don’t have, and recently, it has been spotlighted in many industries such as transportation and power generation. However, although much research has been conducted on PEMFC, studies on operating conditions of bipolar plates in cells have been insufficient. Most of the studies that have been