With a worldwide need for reduction of greenhouse gas emissions, hydrogen gas has become a primary focus of energy researchers as a promising substitute of nonrenewable energy sources. For instance, use of hydrogen gas in fuel cells has received special technological interest particularly from the transportation sector, which is presently dominated by fuel oil. It is not only gaseous hydrogen that is in demand, but the need for liquid hydrogen is growing as well. For example, the aerospace industry uses liquid hydrogen as fuel for space shuttles. The use of liquid hydrogen during a single space shuttle launch requires about 15,000 gallons per minute, which is equivalent to about forty-five hydrogen trailers, each with 13,000 gallons capacity. The hydrogen required to support a single Mars mission would be at least ten times that required for one space shuttle launch. In this work, we provide mass and energy balances, major equipment sizing, and costing of a hybrid CuO-CuSO4 plant with 1000 MW (≈ 30,240 kg/hr) H2 production capacity. With a 90% annual availability factor, the estimated hydrogen production rate is about 238,412 tons annually, the predicted plant efficiency is about 36%, and the estimated hydrogen production cost is about $4.0/kg (not including storage and transportation costs). In addition to hydrogen production, the proposed plant generates oxygen gas as a byproduct with an estimated flowrate of about 241,920 kg/hr (equivalent to ≈ 1,907,297 tons annually). We also propose a novel technology for separating SO2 and SO3 from O2 using a battery of redundant fixed-bed reactors containing CuO impregnated in porous alumina (Al2O3). This technology accommodates online regeneration of the CuO. Other practical approaches for gaseous separation are also examined including use of ceramic membranes, liquefaction, and regenerable wet scrubbing with slurried magnesium oxide or solutions of sodium salts such as sodium sulfite and sodium hydroxide. Finally, we discuss the applicability of high-temperature nuclear reactors as an ideal fit to providing thermal energy and electricity required for operating the hybrid thermochemical plant with high overall system efficiency.

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