Experimental performance evaluation of an ammonia-fuelled microchannel reformer for hydrogen generation

• Miniaturized H2 production in a stand-alone microchannel reactor demonstrated.
• Performance durability and catalyst stability exhibited for >900 h.
• H2 enough to yield a fuel cell power output of 5.7 We and power density of 16 kWe L−1.
• H2-rich reformate requires clean-up of residual NH3 for PEM fuel cell.

Microchannel reactors appear attractive as integral parts of fuel processors to generate hydrogen (H2) for portable and distributed fuel cell applications. The work described in this paper evaluates, characterizes, and demonstrates miniaturized H2 production in a stand-alone ammonia-fuelled microchannel reformer. The performance of the microchannel reformer is investigated as a function of reaction temperature (450–700 °C) and gas-hourly-space-velocity (6520–32,600 Nml gcat−1 h−1). The reformer operated in a daily start-up and shut-down (DSS)-like mode for a total 750 h comprising of 125 cycles, all to mimic frequent intermittent operation envisaged for fuel cell systems. The reformer exhibited remarkable operation demonstrating 98.7% NH3 conversion at 32,600 Nml gcat−1 h−1 and 700 °C to generate an estimated fuel cell power output of 5.7 We and power density of 16 kWe L−1 (based on effective reactor volume). At the same time, reformer operation yielded low pressure drop (<10 Pa mm−1) for all conditions considered. Overall, the microchannel reformer performed sufficiently exceptional to warrant serious consideration in supplying H2 to fuel cell systems.