Achieving Hydrogen Production through Solid Oxide Electrolyzer Stack by High Temperature Electrolysis

Abstract

Based on the reversal reaction of solid oxide fuel cells (SOFC), high temperature electrolysis (HTE) is an effective way for large-scale and low cost hydrogen production. The problem restricted the development for HTE is the stability of steam supplying, conversion rate of steam to H2, hydrogen production rate and the durability of solid oxide electrolysis cells (SOECs) and stacks. To solve the problems mentioned above, a steam and gas fogged mixer (SGFM) was designed which can be used for not only experimental HTE but also large-scale hydrogen production. A 30-cell SOEC stack was tested combined with the mixer for 1000 hours at 800oC with an electrolysis current of 4 A. The steam-to-hydrogen conversion (SC) rate was calculated to be 70% by determining the water amount at the inlet and outlet of the hydrogen electrode. The hydrogen production rate was 99.3 NL/h.