A high-efficiency, auto-thermal system for on-board hydrogen production for low temperature PEM fuel cells using dual reforming of ethanol

• Enhanced production of ethanol by adding a second reformer.
• Detailed simulation model develop to study feasibility of system.
• Comprehensive heat integration of subsystems.
• Improved efficiency of the dual reformer system established through simulation.

On-board reforming of liquid fuels is essential for improved driving range of fuel cell-powered vehicles. There is increasing demand for such vehicles to be fuelled from renewable energy sources. In the present paper, we propose an efficient reformer system for hydrogen production from ethanol. Reforming is an endothermic process, and high temperatures, well above the operating temperatures of PEM or equivalent fuel cells, are required for sufficient catalytic activity for reforming reactions. We use Co-Fe/ZnO catalyst to carry out the reforming at around 500 °C and a combustor of excess fuel as well as directly-fed ethanol to generate the high temperatures required for reforming. It is shown through simulations that introducing a second reformer to extract more hydrogen from the methane obtained from the first reformer improves the overall efficiency. ASPEN-based simulations show that the overall efficiency of an optimized dual reformer system can be as high as 48.47%.