December 2004

E-Mail This Article Printer-Friendly Version

A new look at high-temperature electrolysis: Researchers at the Idaho National Engineering and Environmental Laboratory (INEEL) and Ceramatec, Inc., Salt Lake City, UT say they have demonstrated the feasibility of splitting water - steam - to make hydrogen in a three-year project using 800 deg. C (1,600 deg. F) heat in a small demonstration unit that simulates the temperatures from a future high-temperature nuclear reactor that doesn’t exist so far. At a late-November press conference in Salt Lake City, INEEL lead researcher Steve Herring said such a high-temperature system has the potential to achieve overall conversion efficiencies of 45-50%, compared to 30% for conventional electrolysis. The basic trick is to introduce raw heat as energy to help split the water instead of using higher-cost electricity only, an approach first experimented with by General Electric in the late 1960s and investigated a decade later in Germany in the so-called “Hot Elly” (High Operating Temperature Electrolysis - The Hydrogen Letter June, July ‘87). In this new effort, a so-called hybrid solid oxide fuel cell operates essentially in reverse as an electrolyzer, employing an electrically charged ultra-thin zirconia polycrystal membrane that extracts hydrogen from the steam. The device features a stack architecture of alternating flat cells and gas distribution plates developed by the company for NASA, and it can produce both electricity and hydrogen. A recently announced DoE grant of almost $2 million to Ceramatec will be used to scale up the hybrid SOFC 100 times. INEEL expects to build the high temperature reactor in 2017. Early economic analysis indicates the technology could produce hydrogen at a cost of somewhere between $1 and $2.50/kg - equivalent to the energy content of a gallon of gasoline. Contacts: INEEL, Teri Ehresman, 208/526-7785, ehr@inel.gov; Ceramatec, Joseph Hartvigsen, 801/978-2163, jjh@ceramatec.com.