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PREFACE TO HYDROGEN: ITS TECHNOLOGY AND IMPLICATIONS

The United States, Western Europe, Japan, and several other countries are presently faced with an energy shortage due largely to an imbalance of energy consumption over fossil energy production. This problem was dramatized in October 1973 during the Arab embargo on the shipment of oil to the United States and the resultant large increases in the price of crude oil. This shortage in energy supply was then termed the "energy crisis." It was a clear demonstration of the nation's dependence on imported petroleum and its vulnerability on both political and economic grounds. It is clear that the above problems would worsen in the future unless more attention and effort are directed toward increasing domestic energy production from both depletable and nondepletable sources and reducing energy consumption.

In the short-term, until the year 2000, coal and nuclear energy are expected to play dominant roles in meeting the energy shortage despite the environmental restrictions that hamper the production and consumption of high-sulfur coal and similar difficulties (siting and radioactive waste disposal) that have slowed the development of nuclear energy. In the long-term, beyond the year 2000, it is imperative that all forms of renewable energy be developed. These include solar energy, in such forms as wind, ocean thermal gradients, and biomass; geothermal energy; and fusion.

A major problem with several of the renewable energy sources is that they are intermittent and their energy density is low; thus, there is a need for an energy carrier that can act as both a storage and transportation medium to connect the energy source to the energy consumer. Many of the renewable energy forms, together with coal and fission exhibit their energy in the form of heat release. It is necessary to develop an energy carrier, other than electricity, to supply the transportation sector as well as overcome the problems of electrical storage.

Hydrogen, the lightest element, has been suggested as the energy carrier of the future. In itself, it is not a primary energy source but rather serves as a medium through which a primary energy source (such as nuclear or solar energy) can be stored, transmitted, and utilized to fulfill our energy needs. There are several distinct advantages to the use of hydrogen as an energy medium. It can be made from water, an inexhaustible resource. On combustion, water is the main product; thus, hydrogen can be regarded as a clean, nonpolluting fuel. Indications from current research efforts suggest that hydrogen may be produced from high-temperature heat sources at an efficiency greater than that of electrical generation, thereby making hydrogen a more economical energy source than electricity. Technology has already been developed for storing hydrogen as a pressurized gas, a cryogenic liquid, or in the form of a metal hydride. Systems for transporting hydrogen as a gas or a liquid have been developed with liquid hydrogen playing a major part in NASA's putting a man on the moon. Finally, hydrogen is of value as a chemical intermediate, being used in fertilizer manufacture, methanol synthesis, and petroleum treatment. This area of hydrogen utilization represents 3% of today's energy consumption and is expected to grow by a factor of five by the year 2000. The above concept of using hydrogen is termed the "hydrogen energy economy" and has been receiving an increasing amount of attention from energy scientists and engineers in the United States and abroad.

This series in five volumes represents a serious attempt at providing information on all aspects of hydrogen at the postgraduate and professional level. It discusses recent developments in the science and technology of hydrogen production; hydrogen transmission and storage; hydrogen utilization; and the social, legal, political, environmental, and economic implications of hydrogen's adoption as an energy medium. Although there are several reports of selected studies on hydrogen as a fuel, this is the first comprehensive reference book that covers a wide range of topics of notable interest and timely importance.

Volume I of the series discusses such topics as hydrogen production from fossil fuels, nuclear energy, and solar energy. Hydrogen production technology from water by traditional methods such as water electrolysis and newer attempts to split water thermochemically are included with details of current research efforts and future directions.

Volume II provides detailed design information on systems necessary for the storage, transfer, and transmission of gaseous and liquid hydrogen. Cost factors, technical aspects, and models of hydrogen pipeline systems are included together with a discussion of materials for hydrogen service. Metallic hydride gaseous storage systems for the utility and transportation industry are covered in detail, and the design Dewars and liquid hydrogen transfer systems are examined.

Volume III focuses on hydrogen's properties and provides in one location all of the hydrogen data measured and compiled by the National Bureau of Standards, Cryogenic Division. The properties are individually discussed, and tables of data are provided. The properties of slush hydrogen are also included.

Volume IV covers the present and future uses of hydrogen. Hydrogen has been suggested as a prime candidate for both air and surface transportation. In the utility industry, hydrogen systems for peak shaving promise to play an important future role. Both present and future domestic and industrial applications of hydrogen are surveyed. These include present uses in ammonia and methanol synthesis and future uses in the direct hydrogasification of coal to synthetic natural gas. Important to all of these applications are the safety considerations in the use of hydrogen to allow for public acceptance of hydrogen's role as an energy medium.

Volume V is primarily concerned with the nontechnical aspects of hydrogen. Economics of hydrogen energy systems will play a major part in determining the time frame for hydrogen's adoption. Cost analyses of such systems with return on investment considerations are surveyed from the point of view of production, transmission, and storage of hydrogen. The environmental, political, social, and legal implications of new secondary energy forms such as hydrogen are discussed with reference to governmental energy policy, the social costs of energy production and use, and the public's acceptance of a hydrogen energy medium.

The unusually broad nature of hydrogen demands the expertise that could only be provided by a wide authorship; thus, some of the authors are the original authorities in their respective fields. Although the subject matter treated in each chapter is, in general, the author's research work and his critical review of the state-of-the-art, the authors have had complete freedom in choosing the particular important areas to be emphasized. As a result, some chapters treat the subject matter in more detail than others with a greater emphasis on the engineering or design aspects of a particular system. Therefore, each chapter possesses its own special feature and appealing points. Due to the limited space in the series, the editors have encouraged each author to supply an extensive list of references at the end of his chapter for the benefit of interested readers. Detailed author and subject indexes have been provided at the end of each volume.

The editors, while striving to avoid duplication, have allowed some degree of overlap in certain of the chapters for the sake of continuity and allowing the reader to view a particular topic from two or more points of view. Further volumes on the topic of hydrogen are planned, and we wish to hear from our readers as to areas that might have been neglected or deserve a special chapter on their own.

We would like to express our sincere thanks to these authors and the staff of CRC Press, Inc. in particular Mrs. Gayle Tavens and Miss Sandy Pearlman, for their efforts in making these volumes possible. Lastly, we would like to thank our wives, Patricia R. Cox and Ruth S. Williamson, for their encouragement and help during the time it took to edit these five volumes.

Authors: K. E. Cox, K. D. Williamson, Jr.