Hydrogen production technologies will provide a means through which nuclear energy can be used to reduce the nation's critical vulnerability on imported petroleum. Eventually, hydrogen may be a major transportation fuel through the use of fuel cells in automobiles. However, even today, the annual demand for hydrogen in the US is about 13 million tons, primarily for the production of fertilizers, for the upgrading of low quality crude oils and for the removal of sulfur to meet increasingly stringent environmental requirements. As we come to rely on poorer grades of crude oil and on the Athabasca oil sands, the demand for hydrogen in the petroleum industry will grow significantly. Average crude oils require 1 to 2 kg of H2 per barrel, heavy crudes 2-3 kg per barrel and the oilsands 3-5 kg per barrel. Today, 95% of our hydrogen is produced through the steam reforming of natural gas. Both the increasing price of natural gas and the need to reduce CO2 emissions will promote the nuclear production of hydrogen. The development of High Temperature Electrolysis (HTE) of steam for the production of hydrogen using nuclear energy has progressed through a series of experiments and analyses during the past year. The purpose of these experiments was to demonstrate the feasibility of using solid-oxide electrolytic cells to efficiently split steam into hydrogen and oxygen, while developing the economies of scale and long operating life needed by successful commercial devices. These tests have increased in scale from button cells through 10 and 25 cell single stacks and, most recently, to the testing of a dual stack containing 2 x 60 cells. The year began with a long-duration test of the “Half-Module,” which demonstrated the viability of the technology planned for the HTE Integrated Laboratory-scale (ILS) experiment. The ILS will eventually have three modules of four 60-cell stacks each. The Half-Module thus consisted of half of one of the ILS modules. The Half Module was fabricated at Ceramatec, Inc. in Salt Lake City and tested at their facility from June through September of 2006. The unit ran for 2040 hours, mostly at steady state except for minor interruptions due to power outages and testing of the stacks are a variety of current and voltage conditions. Hydrogen production was 1.21 normal m3/hour at the beginning of the test, dropping to 0.65 normal m3/hour at the end of the test. For about 800 hours of the test the stacks were operated in “co-electrolysis” mode, in which the stacks are supplied with steam and carbon dioxide, producing carbon monoxide and hydrogen (synthesis gas). Synthesis gas (“syngas”) can be used in the Fischer-Tropsch process for the producing of synthetic liquid, hydrocarbon fuels. Construction of the ILS experiment is taking place during the summer of 2007, with initial shakedown testing planned for late August and the production of the first hydrogen at the end of September. Initially the ILS will have only one module (four stacks of 60 cells each) and will not have integrated heat recovery and hydrogen separation/recycle components. Eventually the ILS will include heat exchanger to recover the 800º C heat of the hydrogen and oxygen for use in heating the incoming water to steam. In addition, the ILS will incorporate condensation tanks or high temperature porous membranes for the separation of hydrogen from the residual steam. The residual steam and a small amount of hydrogen will be re-circulated to the electrolytic stacks where the hydrogen will maintain reducing conditions at the nickel-cermet electrode. Another aspect of HTE research are the analysis of degradation mechanisms The lifetime of the electrolysis cells is being limited by corrosion, transport of impurities into the electrodes and delaminations of the electrodes from the electrolyte. The HTE project is conducting progressively longer tests followed by post-test analyses to determine the causes and to find better formulations of the cell materials. Computational Fluid Dynamics (CFD) analysis and flowsheet modeling provide further insights into the operation of electrolytic cells. CFD is being used to determine the best ways to reduce thermal stresses over the area of the cells and to assure that the steam is properly distributed in our progressively larger stacks and the tubular cells. Flowsheet modeling is being used to model complete hydrogen production plants as driven by a variety of reactors. By electrolyzing both CO2 and steam at the same time in a process known as Syntrolysis, we can produce H2 and CO, “synthesis gas,” which can be reacted over catalysts in the Fischer Tropsch reaction to form diesel fuel, jet fuel, synthetic lubricating oils and many other hydrocarbons. The synthesis of fuels from a variety of carbon sources in forward locations is important to reducing fuel logistics requirements for the Navy and Air Force. In addition, the production of synthetic fuels through nuclear hydrogen is a means for reducing our civilian dependence on imported oil while continuing to use the existing liquid transportation fuel infrastructure.

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