Long-Term Performance of Lab-Scale High Temperature Electrolysis(HTE) System for Hydrogen Production

ABSTRACT KEPRI (KEPCO Research Institute) designed and operated the lab-scale high temperature electrolysis (HTE) system for hydrogen production with 10 × 10 cm 2 5-cell stack at 750℃. The electrolysis cell consists of Ni-YSZ steam/hydrogen electrode, YSZ electrolyte and LSCF based perovskite as air side electrode. The active area of one cell is 92.16 cm 2 . The hydrogen production system was operated for 2664 hours and the performance of electrolysis stack was measured by means of current variation with from 6 A to 28 A. The maximum hydrogen production rate and current efficiency was 47.33 NL/hr and 80.90% at 28 A, respectively. As the applied current increased, hydrogen production rate, current efficiency and the degradation rate of stack were increased respectively. From the result of stack performance, optimum operation current of this system was 24 A, considering current efficiencies and cell degradations.KEY WORDS : High temperature electrolysis(고온전기분해), Hydrogen production(수소생산), Solid oxide electrolysis cell(고체산화물 전해셀), Very high temperature reactor(초고온가스로)