The Hydrogen Economy

Gregory, D. P.

doi:10.1038/scientificamerican0173-13

Cited by 87 publications

(30 citation statements)

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“…Reaction (6), which has already been adopted for use in the Mark-9 process at the Joint Nuc1ear Research Center, Ispra,5-8 at 500-600°C (one atmosphere) at a relatively high reaction rate; and the Fea04 produced is in the form of fine (2)(3) partic1es. Hence, this reaction will be worth serious attention.…”

Section: Ferrous Chloride and Hydrogenmentioning

confidence: 99%

Hydrogen economy from the viewpoint of nonferrous extractive metallurgy

Tanaka

Shibayama²,

Kiuehi³

1975

JOM

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Uncertainties in the worldwide supply and economics of petroleum-based fuels prompt a consideration of hydrogen as reactant and fuel for metallurgical processes.E NGINEERS concerned with the technology and economics of metal extraction are acute!y aware of two factors which are working to bring about major changes in this large industry: energy and pollution contro!. The present paper will, through the subject ofhydrogen economy, show one path which may be taken in the future to counteract these factors while at the same time provide intrinsic technical and economic benefits. Weshali first briefly consider the question of primary energy, since this is of direct and immediate concern to all extractive metallurgical processes.The historie usage of fue! for metallurgical processes has evolved from carbon, as charcoal, through coal, coke and finally to oil and natural gas. Nuclear energy presents a probable alternative but not on a wide scale, at least for the immediate future.Looking to the future of petroleum, which will remain a major primary energy source for some years, we see growing apprehension over supply. Enormous worldwide consumption is rapidly depleting resources. Moreover, political and military factors render uncertain even those resources which remain. As a result, modern petroleum-dependent economies seem to be shifting to an age of synthesis of an extremely large amount of energy.With regard to the problem of environmental pollution, we in]apan are well aware that the rapidly increasing amounts of industrial wastes, particularly those from fossil fuels, have reached the limit of the cleansing ability of nature. This has forced a change in the customary concept of values which, in the past, always gave preference to economics.The two factors, energy availability and environment, have led to two corresponding technological thrusts. The first is the obvious development of new fossil fuel resources. The second, in many ways related to the first, is the improvement of pollution control techniques and, at the same time, a tendency to change to ever cleaner energy sources.The above discussion concerns chiefly the primary energy sources which, as we have no ted, will tend to shift from fossil fuel to nuclear fuel over the intermediate future. Secondary energy sources must also, however, be considered. This is especially true in and for the process metallurgie al industry, and it is at this point that we wish to open our consideration of hydrogen.Many general remarks 1 • 4 have already been published regarding the viability of hydrogen as a secondary energy source. From these, we can list the following properties of hydrogen viewed as a fuel:1) It exists in indefinite supply in the form of water. 2) It produces negligible pollutants on combustion. 3) Its use does not disturb the cyclic system of nature. 4) As an energy carrier, its storage and transportation properties are both superior to electric power.6-JOM, DECEMBER 1975

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Section: Ferrous Chloride and Hydrogenmentioning

confidence: 99%

Hydrogen economy from the viewpoint of nonferrous extractive metallurgy

Tanaka

Shibayama²,

Kiuehi³

1975

JOM

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“…Energy storage in the form of a compact fuel [such as hydrogen, eq. (3)] would reduce transportation problems and make the stored energy available in many forms [17]. An artificial chemical system could in principle improve on natural photosynthesizers: although the energy storage process in plants has an efficiency of 6 to 8% [2], much of the stored energy is then used in metabolism.…”

Section: Photoredox Processesmentioning

confidence: 99%

“…Reactions (17) and (18) may be applied readily to an energy storage scheme. For example, if the system is to produce hydrogen, the reactions A + H+ ÷ A + 1/2 H2 or (19) M+H+÷M+l/2H2 (20) may be used.…”

Section: Photoionizationmentioning

confidence: 99%

“…M++A÷M+A (21) M+D+M+D (22) In Gafney and Adamson's work [51], N was Ru(bpy) (bpy = 2,2'-bipyridine) and A was Lehn and Sauvage used [53,54] a rhodium(III) complex as electron acceptor and triethanolamine to reduce the Ru(bpy)3+ produced in reaction (17). By far the most popular reagent for oxidative quenching of Ru(py)* has been methylviologen (l,l'-dimethyl-4,4'-bipyridinium, or "paraquat"; abbreviated here as Ru(bpy)* + y2+ Ru(bpy) + MV+ (23) Ru(bpy) + MV+ Ru(bpy) + pj2+ (24) The rate constants 7< and k24 are respectively 2.4 x lO [55] and 8.1 x lO M's1 [56], so that either Ru(bpy)or MV+ must be efficiently scavenged to prevent reaction (24).…”

Section: Photoionizationmentioning

confidence: 99%

“…An excited state M* of a metal complex M may undergo oxidation or reduction on reaction with an electron acceptor A or donor D, respectively: M*+A÷M++A (17) M*+D÷M+D+ (18) A reaction of the former type (17) was first observed by Gafney and Adamson in 1972 [51]. Many other examples of both (17) and (18) have confirmed that M* is thermodynamically both a better oxidant and a better reductant than M, which is readily understood in terms of simple molecular orbital descriptions of electronic structure.…”

Section: Photoionizationmentioning

confidence: 99%

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Solar energy storage reactions involving metal complexes

Maverick¹,

Gray²

1980

Pure and Applied Chemistry

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-Photochemical properties of transition metal complexes are discussed as they relate to possible schemes for energy storage. Complexes of copper(I) with r-acceptor ligamds have been used to sensitize isomerizations of organic molecules, and there is room for considerable further investigation in this area. Electron transfer reactions have been more intensively studied. These reactions fall into three broad categories: ionization, oxidative addition/reductive elimination, and excited state electron transfer. Experiments in the first two categories have ierally led to rather poor storage efficiency and have required ultraviolet light. But long-lived excited states of coordination compounds can participate in chemical reactions with high efficiency, and such systems are promising for solar energy storage. Specific systems of this type that are discussed in detail involve electron transfer quenching of the lowest emissive excited states of Ru(2,2'_bipyridine), M (diisocyanoalkane) (M=Rh,Ir), and Mo6Cl.

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Hydrogen (Fuel)

2005

Van Nostrand's Encyclopedia of Chemistry

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The Hydrogen Economy

Cited by 87 publications

References 0 publications

Hydrogen economy from the viewpoint of nonferrous extractive metallurgy

Hydrogen economy from the viewpoint of nonferrous extractive metallurgy

Solar energy storage reactions involving metal complexes

Hydrogen (Fuel)

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