An improved process for H2SO4 decomposition step of the sulfur-iodine cycle

Öztürk, Ilhan; Hammache, A.; Bilgen, E.

doi:10.1016/0196-8904(94)00036-y

Cited by 40 publications

(8 citation statements)

References 2 publications

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“…With that in mind, the process pressure was dropped to 12 bar, which was typical for older sulfuric acid decomposition process designs (e.g. Öztürk et al [25]). Under the bayonet concept, the high pressure (40-90 bar, depending on the NGNP heat source design) would be on the outside (helium side), putting the silicon carbide walls in compression, for which they should be wellsuited.…”

Section: Discussionmentioning

confidence: 99%

Hybrid sulfur cycle flowsheets for hydrogen production using high-temperature gas-cooled reactors

Gorensek

2011

International Journal of Hydrogen Energy

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Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950°C, the other 750°C. Performance was improved (over earlier flowsheets) by assuming that use of a more acidtolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion®, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950°C case, dropping to 39.9% for the 750°C case.Highlights for "Hybrid sulfur cycle flowsheets for hydrogen production using hightemperature gas-cooled reactors" Two hybrid sulfur cycle flowsheets are presented that combine a bayonet decomposition reactor with a proton exchange membrane electrolyzer. Aspen Plus material and energy balances are provided. One flowsheet can be used with a 950°C reactor to make hydrogen at 44.0% to 47.6% net thermal efficiency, HHV basis. The other flowsheet can be used with a 750°C reactor to make hydrogen at 38.0% net thermal efficiency, HHV basis. *HighlightsHybrid sulfur cycle flowsheets for hydrogen production using high-temperature gas-cooled reactors Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950°C case, dropping to 39.9% for the 750°C case.Keywords: Hydrogen production; nuclear heat application; hybrid sulfur cycle; process flowsheet; Aspen Plus; proton exchange membrane electrolyzer; bayonet decomposition reactor * Tel.: (803)

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Section: Discussionmentioning

confidence: 99%

Hybrid sulfur cycle flowsheets for hydrogen production using high-temperature gas-cooled reactors

Gorensek

2011

International Journal of Hydrogen Energy

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“…Also, all components used are in the fluid state, and therefore could be used for continuous operation. The first step in this cycle is the production of H 2 SO 4 and HI [28]. Recycled I 2 from Step 3 and SO 2 from Step 2 react with water for the production of H 2 SO 4 in a counter-current reactor.…”

Section: Hydrogen Production Processesmentioning

confidence: 99%

Investigation of an integrated hydrogen production system based on nuclear and renewable energy sources: Comparative evaluation of hydrogen production options with a regenerative fuel cell system

Orhan

Babu

2015

Energy

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“…Finally, the two-step cycle based on cerium oxides (CeO 2 /Ce 2 O 3 ) was first demonstrated in 2006 by Abanades and Flamant [84], consisting of two chemical steps: (1) (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), which induced also a partial sublimation of CeO 2 . The reduced material was pounded into powder (50-150 µm) for the hydrolysis tests.…”

Section: Non-volatile Metal Oxide Cyclesmentioning

confidence: 99%

Metal Oxides Applied to Thermochemical Water-Splitting for Hydrogen Production Using Concentrated Solar Energy

Abanades

2019

ChemEngineering

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Solar thermochemical processes have the potential to efficiently convert high-temperature solar heat into storable and transportable chemical fuels such as hydrogen. In such processes, the thermal energy required for the endothermic reaction is supplied by concentrated solar energy and the hydrogen production routes differ as a function of the feedstock resource. While hydrogen production should still rely on carbonaceous feedstocks in a transition period, thermochemical water-splitting using metal oxide redox reactions is considered to date as one of the most attractive methods in the long-term to produce renewable H2 for direct use in fuel cells or further conversion to synthetic liquid hydrocarbon fuels. The two-step redox cycles generally consist of the endothermic solar thermal reduction of a metal oxide releasing oxygen with concentrated solar energy used as the high-temperature heat source for providing reaction enthalpy; and the exothermic oxidation of the reduced oxide with H2O to generate H2. This approach requires the development of redox-active and thermally-stable oxide materials able to split water with both high fuel productivities and chemical conversion rates. The main relevant two-step metal oxide systems are commonly based on volatile (ZnO/Zn, SnO2/SnO) and non-volatile redox pairs (Fe3O4/FeO, ferrites, CeO2/CeO2−, perovskites). These promising hydrogen production cycles are described by providing an overview of the best performing redox systems, with special focus on their capabilities to produce solar hydrogen with high yields, rapid reaction rates, and thermochemical performance stability, and on the solar reactor technologies developed to operate the solid–gas reaction systems.

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An improved process for H2SO4 decomposition step of the sulfur-iodine cycle

Cited by 40 publications

References 2 publications

Hybrid sulfur cycle flowsheets for hydrogen production using high-temperature gas-cooled reactors

Hybrid sulfur cycle flowsheets for hydrogen production using high-temperature gas-cooled reactors

Investigation of an integrated hydrogen production system based on nuclear and renewable energy sources: Comparative evaluation of hydrogen production options with a regenerative fuel cell system

Metal Oxides Applied to Thermochemical Water-Splitting for Hydrogen Production Using Concentrated Solar Energy

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