CONCEPT AND DESIGN OF A 3.5 MW PILOT-PLANT FOR HIGH-TEMPERATURE ELECTROLYSIS OF WATER-VAPOR

The high temperature electrolysis (HOTELLY) of water vapor using zirconia as a solid oxide electrolyte has been demonstrated in laboratory experiments to be a very efficient method of hydrogen production. In this paper, the thermodynamical advantages of electrolysis at very high temperatures, typically 900-1000 degree C, is briefly reviewed first. After the principal technical realization has been explained the status of the advanced cell and module development will be illustrated. The process engineering for electrolysis plants is discussed and the concept for building up electrolysis units introduced. Finally a cost examination and comparison with conventional H//2-production plants is reviewed.