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Title: Comparison of electrolytic, thermochemical, and other hydrogen-production processes

Abstract

An overview is presented of the following six hydrogen production process categories: catalytic steam reforming of light hydrocarbons; partial oxidation of less-reactive feedstocks such as coal and heavy oil; reaction of active metals or metal hydrides with water or acids; electrolysis of water; thermochemical hydrogen cycles; and photolysis of water. These processes are compared technically, and to the extent possible, economically.

Authors:
;
Publication Date:
Research Org.:
Institute of Gas Technology, Chicago, IL (USA)
OSTI Identifier:
5823235
Report Number(s):
NP-2902132
ON: DE82902132
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; HYDROGEN PRODUCTION; COMPARATIVE EVALUATIONS; COST; ELECTROLYSIS; PARTIAL OXIDATION PROCESSES; PHOTOLYSIS; STEAM REFORMER PROCESSES; THERMOCHEMICAL PROCESSES; CHEMICAL REACTIONS; DECOMPOSITION; LYSIS; PHOTOCHEMICAL REACTIONS; REFORMER PROCESSES 080100* -- Hydrogen-- Production

Citation Formats

Carty, R., and Whaley, T. Comparison of electrolytic, thermochemical, and other hydrogen-production processes. United States: N. p., 1981. Web.
Carty, R., & Whaley, T. Comparison of electrolytic, thermochemical, and other hydrogen-production processes. United States.
Carty, R., and Whaley, T. 1981. "Comparison of electrolytic, thermochemical, and other hydrogen-production processes". United States. doi:.
@article{osti_5823235,
title = {Comparison of electrolytic, thermochemical, and other hydrogen-production processes},
author = {Carty, R. and Whaley, T.},
abstractNote = {An overview is presented of the following six hydrogen production process categories: catalytic steam reforming of light hydrocarbons; partial oxidation of less-reactive feedstocks such as coal and heavy oil; reaction of active metals or metal hydrides with water or acids; electrolysis of water; thermochemical hydrogen cycles; and photolysis of water. These processes are compared technically, and to the extent possible, economically.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1981,
month = 1
}

Technical Report:
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  • This assessment was prepared to determine what impacts would result from (further) materials research for thermochemical hydrogen production. In this context, materials are those materials of construction that would be used for plant equipment such as heat exchangers, reactors, and the like. Process chemicals and catalysts are not within the scope of this study.
  • The Thermochemical Hydrogen Program at the Los Alamos Scientific Laboratory is continuing its investigation of practical schemes to decompose water thermochemically for production of hydrogen. Current efforts were directed to experimental studies of reactions relevant to the sulfuric acid-hydrogen bromide thermochemical cycle. The use of insoluble bismuth sulfate as a means of concentrating aqueous sulfuric solutions is also under investigation. Preliminary calculations show a significant cycle efficiency increase if solid sulfate and subsequent sulfur trioxide decomposition steps replace the sulfuric acid concentration and decomposition steps proposed in other cycles.
  • The Los Alamos Scientific Laboratory's (LASL) program to study thermochemical processes for hydrogen production from water consists of three major areas: cycle evaluation and developing new methodology to evaluate thermochemical cycles. The Thermochemical Cycle Evaluation Panel is being assisted to perform engineering and economic analyses of selected cycles. Analytical and experimental studies are made in direct support of the two cycles selected for early development and evaluation. The cycles are the hybrid sulfuric acid cycle (Westinghouse) and the sulfuric acid-iodine cycle (General Atomic (GA)). One study is directed at heat penalties associated with drying sulfuric acid solutions, a significant problemmore » in both cycles. Oue analysis indicates that the precipitation of an insoluble, anhydrous metal sulfate could significantly reduce such heat penalties. Experimental studies are being made of the precipitation and decomposition of bismuth sulfate, which appears to be a promising candidate. Use of fusion energy sources from the production of synthetic fuels (hydrogen) is being evaluated. Thermochemical cycle input data are being provided in the form of cycle thermal requirements to design study groups at each laboratory being supported by DOE Office of Fusion Energy. Initially, a hybrid sulfuric acid cycle with a bismuth sulfate decomposition step at high temperature is being explored.« less
  • Thermochemical cycles for hydrogen production have been investigated at the Los Alamos National Laboratory since the early 1970s. The work consists of experimental and engineering research to define cycles that can be coupled feasibly to high-temperature heat sources for water-splitting to produce hydrogen and oxygen. Process development is sponsored by the Department of Energy, Division of Energy Storage System (STOR). In recent months, our efforts were directed toward improving the design and operation of our 1-in-diam laboratory-scale quartz rotary kiln. Our results from the decomposition of bismuth oxysulfate in the kiln have been shown the technical feasibility of solid sulfatemore » decomposition in a flow mode with recycled feed in residence times less than 2 min. Other work included (1) engineering studies that compared the published estimates of capital costs and process efficiencies for hydrogen production by thermochemical means and by electrolysis, (2) review of two thermochemical cycles for hydrogen production, and (3) coordination of US contributions to the annual International Energy Agency Technical Workshop on Thermochemical Processes.« less
  • The work described in this report was accomplished during the period October 1, 1978-March 31, 1979, on a DOE-sponsored program aimed at developing efficient and economic thermochemical cycles for hydrogen production from a variety of high-temperature energy sources such as fusion, fission, and solar energy. Most of the effort was applied to a study of the Los Alamos Scientific Laboratory (LASL) hybrid bismuth sulfate cycle. The work included a conceptual design of the cycle, made to obtain performance parameters, and experimental work done to verify the design conditions. A 50% efficiency was obtained when an improved cycle design was coupledmore » to a fusion energy source at 1500/sup 0/K. The improved design was based on a reduction endothermic requirement for Bi/sub 2/O/sub 3/ . 2SO/sub 3/ decomposition and a lower voltage for SO/sub 2/ electrolysis that should result at lower acid concentrations. Experimental results showed an endothermic heat requirement of +172 kJ/mol for the decomposition of Bi/sub 2/O/sub 3/ . 2SO/sub 3/ to Bi/sub 2/O/sub 3/ . SO/sub 3/ and SO/sub 3/. Reaction times for bismuth sulfate decomposition were determined as a function of temperature. At 1240 K, <1.5 min were required for the first two stages of decomposition from Bi/sub 2/O/sub 3/ . 3SO/sub 3/ to Bi/sub 2/O/sub 3/ . SO/sub 3/. In tests made to determine the feasibility of decomposing Bi/sub 2/O/sub 3/ . 2SO/sub 3/ in a fluidized bed, the solid particles agglomerated when heated. Solid particles suitable for fluidization will be sought through new approaches.« less