Sodium bicarbonate (NaHCO3) was used as a catalytic solution and the solid-state sodium borohydride (NaBH4) were stored in a reacting chamber. The NaHCO3 solution was injected when the hydrogen is needed. The hydrogen generation rate was measured as various conditions such as the temperature, and the concentration and injection speed of NaHCO3 solution. The hydrogen generation was initiated immediately when the NaHCO3 solution was injected. The hydrogen generation rate and NaBH4 conversion increased with increasing the NaHCO3 concentration but decreased with increasing the injection speed of NaHCO3 solution. Based on above results, a prototype of hydrogen generation system was developed. The system consisted of a chamber containing solid NaBH4 particles, an aqueous NaHCO3 tank, a liquid pump, valves, cooling fans and sensors. The liquid pump supplied the NaHCO3 solution to the NaBH4 chamber through an injector. The temperature and pressure of the NaBH4 chamber were monitored during the reaction and maintained into 70 degrees C and 2 bar, respectively. The liquid pump was stopped when the pressure reached 2 bar, while it was restarted to generate hydrogen when the pressure was less than 2 bar because the fuel cell consumed hydrogen during the operation. The hydrogen generation system can provide the stable hydrogen to operate the fuel cell. (C) 2015 Elsevier Ltd. All rights reserved.
