Production of hydrobromic acid from bromine, methane and steam for hydrogen production. 1997 annual report, December 15, 1996--January 31, 1998

摘要

The solar-driven reaction between bromine and steam was studied. The goal was to make hydrobromic acid for hydrogen production and energy storage use via a reversible, high efficiency hydrogen/bromine fuel cell. While the reaction was technically successful and was demonstrated at NREL, it was determined to be uneconomical in today's economy due to present high capital costs of the solar hardware. In an effort to provide for an interim process that can be utilized to produce hydrogen and store energy until the cost of solar hardware decreases, SRT's process was modified to include the addition of methane. The new concept entails (i) reaction of bromine with methane and steam to produce hydrogen bromide and carbon dioxide and (ii) electrolysis of the stored hydrogen bromide for production of H(sub 2(g)) and recovery of Br(sub 2(1)). Electrolyzers are available today for the electrolysis of HBr. In addition, a vendor for a reversible H(sub 2)-Br(sub 2) fuel has been identified. Most components of the envisioned system are commercially available. At present, the reactor needs the most development. In the SRT process, the electrical power required to split water is reduced effectively in half by the production of hydrogen bromide. The SRT concept is very attractive from an economic viewpoint as well. A reversible electrolytic fuel cell employed in the SRT process is capitalized via its use in load leveling by the utility. Thus, the price of SRT- produced hydrogen reflects only the cost of methane, reactor system capital costs and off-peak electrical power.