Abstract

Two classes of hybrid/thermochemical water splitting processes for the production of hydrogen and oxygen have been proposed based on (1) metal sulfate - ammonia cycles (2)metal pyrosulfate - ammonia cycles. Methods and systems for a metal sulfate MS04 - NH3 cycle for producing H2 and 0 2 from a closed system including feeding an aqueous (NH3)4SO3 solution into a photocatalytic reactor to oxidize the aqueous (NH3)4SO3 into aqueous(NH3)2S04 and reduce water to hydrogen, mixing the resulting aqueous (NH3)2S04 with metal oxide (e.g. ZnO) to form a slurry, heating the slurry of aqueous (NH4)2S04 and ZnO(s)in the low temperature reactor to produce a gaseous mixture of NHs and H20 and solid 10 ZnS04(s), heating solid ZnS04 at a high temperature reactor to produce a gaseous mixture of SO2 and 0 2 and solid product ZnO, mixing the gaseous mixture of SO2 and 02 with an NH3 and H20 stream in an absorber to form aqueous (NH4)2SO3 solution and separate O2 for aqueous solution, recycling the resulta

Document Type

Patent

Patent Number

US 8,691,068

Application Serial Number

12/267,569

Issue Date

4-8-2014

Current Assignee

UCFRF

Assignee at Issuance

UCFRF

College

Florida Solar Energy Center (FSEC)

Department

FSEC

Filing Date

11-8-2008

Assignee at Filing

UCFRF

Filing Type

Nonprovisional Application Record

Donated

no

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