Renewable hydrogen from ethanol by a miniaturized nonthermal arc plasma-catalytic reforming system

Ethanol–water mixtures were reformed directly into H2-rich gas without extra heat source with conversion rates of 69.8% and 88.0% by nonthermal arc plasma and plasma-catalytic reactors, respectively. The plasma reactor consists of a Laval nozzle electrode and a central electrode. The ethanol, water and air mixtures were mixed by a spray nozzle, and then introduced into the Laval nozzle. In terms of energy efficiency, the optimal reforming condition was determined to be O/C ∼ 0.5 and S/C ∼ 1.0 with an ethanol input rate of ∼0.10 g s−1. Furthermore, it is also found that applying Ni/γ-Al2O3 catalyst just at the downstream of the discharge region contributed to a better conversion extent and a higher hydrogen production rate, while the power consumption increased slightly, thus the specific energy required for hydrogen production reduced from 68.5 to 40.1 kJ mol−1 at O/C = 0.44, S/C = 1.28 and inlet ethanol = 0.10 g s−1. This reforming technology has promising prospects not only for low-cost hydrogen generation and efficiency improvement for inner combustion engine, but also for many other potential chemical applications, such as nanophase material preparation and solar fuel cell manufacturing.