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Theory of Molecular Fluids, Vol.I: Fundamentals.
Book
Reviews
1807
argued nor decision to act can bc obtained since these needs and actions can only bc justified in economic terms. The characterization or identification of how energy is used (“energy audit”) is the basis for optimization. Not only the data requirements are discussed but also precision of this data and the calculation of missing data. Two examples are presented and discussed to illustrate the procedure. The optimized performance of existing facilities is dealt with next, starting with minimizing waste in combustion and steam systems, two examples of areas offering ample opportunities for improvement. More important, however is effective management of energy use. Here the author argues for a system based on technical targets for each major piece of equipment (rather than historical targets i.e. savings compared with previous use) which helps with trouble-shooting and by assessing the economic impact of deviations from target, a system of priorities for actions can be devised. The way targets can be defined, rules and factors which.must be considered, and problems with implementation are succintly explained. The next phase requires investment to reduce energy use by the improvement of facilities, matching of sources and sinks and considering interactions in the whole site. Cogeneration is described including methods for assessing the potential for cogeneration on a site. Use of linear programming for complex energy systems is proposed. The methodology of thermodynamic analysis is thoroughly discussed without the use of sophisticated mathematics, searching for simple, practical results of where losses occur in several process steps commonly used, e.g. heat exchange, mixing, distillation and combustion air preheating. This analyses provide the basis for improvements in energy efficiency and by means of a variety of examples it is shown how it can be used to suggest improvements in process
sequences and plant arrangement. The economic aspects and relationships between capital and running costs are treated at length, suggesting that capital investment can actually be reduced as energy efficiency is increased. Much of the material covered provides the engineer with information which will allow him to do some creative thinking and put priorities according to potential benefits. The last two chapters are devoted to systematic design methods which integrate energy efficiency considerations with process constraints and economic factors. Two of these methods are the “process synthesis” which deals with optimum heat exchange networks and the combined thermodynamics and economics so called “thermoeconomics”. Finally, guidelines and recommendations for improving process operations are given. This is a well written book trying to tackle logically the complexities of energy conservation in the chemical industry. It sets out the scientific principles behind energy conservation measures and works through a number of examples to illustrate the arguments. It also shows that there is no foolproof, simple methodology available for true optimization of energy consumption in processes and one must still rely on the experience and ingenuity of engineers. This book should appeal to engineers involved in design and operation of chemical plant and to those involved in finding better solutions for energy conservation in the process industries. To all, the author’s message is “Any action taken for energy conservation is more likely to generate profit than doing nothing about it”.
Theory of Molecular Fluids, Vol. I: Fundamentals. By C. G. GRAY and K. E. GUBBINS. Clarendon Press, Oxford, 626 pp., ~60.00
siderable facility with mathematics a necessary prerequisite for complete understanding. Following the general analysis, a number of forms of perturbation theory are discussed. including the u-expansion and thef-expansion. Although not all such approaches are considered, those that are most generally applicable are given a sound exposition supported by a number of useful comparisons with the results of computer simulation. The main text is completed by a review of integral equation methods extending from the Percus Yevick approximation for hard-sphere atomic fluids to the reference interaction site model for molecular fluids. The role and interrelationship of the various approximations are nicely described and the advantages and disadvantages of the methods are succinctly summarised. There can be no doubt that this book is an essential reference volume for those actively involved in the field of the molecular theory of fluids. It is well written, carefully prepared. remarkably free of errors and contains an extensive bibliography. However. there must be some doubt that this particular volume will be immediately useful to experimentalists as the authors claim. It is not an easy book to read because, by the nature of the subject, the level of mathematical detail often dominates simple physical argument. Judged on the forward references of this book, the second volume. dealing with applications would seem to be more appropriate for the experimentalist. Nevertheless, the virtues of the summary given in this book of the theory of molecular fluids make it a desirable acquisition despite its high price.
That a volume of some 600 pages should be just the first part of a treatise on the theory of molecular fluids is, in part, an indication of the enormous growth of activity in this area, but it is also a result of the commendable rigour with which the authors of this book have treated the subject. The volume represents a comprehensive and up-to-date treatment of fundamental theories of the equilibrium properties of dense molecular fluids and the relationship of these properties to the forces between molecules. The topic of intermolecular forces in polyatomic systems is treated in a more complete form than in many texts. Although there is some emphasis on the representation of potential energy surfaces rather than on the origin of the forces, there is also a clear discussion of multipolar, dispersion and induction interactions. The treatment is generally set out in the form of spherical harmonic expansion, although other representations are considered. This approach is then consistent with that adopted in later sections where a number of topics have been completely reworked using the same expansion. This unified approach has obvious advantages and is supported by an admirably extensive set of appendices setting out the requisite mathematics. The results of statistical mechanics necessary for later developments are given in Chapter 3 which deals with the various possible distribution functions for a molecular fluid in both the canonical and grand canonical ensemble. The starting point for the treatment will be familiar to all who have undergone a basic course in the subject, but the development moves rapidly and a reader will find a con-
The Electricity Council Research Capenhurst, Chester, U.K.
Imperial College of Science London SW7, U.K.
C. L. LOPEZ-CACICEDO Centre
W. A. WAKEHAM and Technology
Reviews
1807
argued nor decision to act can bc obtained since these needs and actions can only bc justified in economic terms. The characterization or identification of how energy is used (“energy audit”) is the basis for optimization. Not only the data requirements are discussed but also precision of this data and the calculation of missing data. Two examples are presented and discussed to illustrate the procedure. The optimized performance of existing facilities is dealt with next, starting with minimizing waste in combustion and steam systems, two examples of areas offering ample opportunities for improvement. More important, however is effective management of energy use. Here the author argues for a system based on technical targets for each major piece of equipment (rather than historical targets i.e. savings compared with previous use) which helps with trouble-shooting and by assessing the economic impact of deviations from target, a system of priorities for actions can be devised. The way targets can be defined, rules and factors which.must be considered, and problems with implementation are succintly explained. The next phase requires investment to reduce energy use by the improvement of facilities, matching of sources and sinks and considering interactions in the whole site. Cogeneration is described including methods for assessing the potential for cogeneration on a site. Use of linear programming for complex energy systems is proposed. The methodology of thermodynamic analysis is thoroughly discussed without the use of sophisticated mathematics, searching for simple, practical results of where losses occur in several process steps commonly used, e.g. heat exchange, mixing, distillation and combustion air preheating. This analyses provide the basis for improvements in energy efficiency and by means of a variety of examples it is shown how it can be used to suggest improvements in process
sequences and plant arrangement. The economic aspects and relationships between capital and running costs are treated at length, suggesting that capital investment can actually be reduced as energy efficiency is increased. Much of the material covered provides the engineer with information which will allow him to do some creative thinking and put priorities according to potential benefits. The last two chapters are devoted to systematic design methods which integrate energy efficiency considerations with process constraints and economic factors. Two of these methods are the “process synthesis” which deals with optimum heat exchange networks and the combined thermodynamics and economics so called “thermoeconomics”. Finally, guidelines and recommendations for improving process operations are given. This is a well written book trying to tackle logically the complexities of energy conservation in the chemical industry. It sets out the scientific principles behind energy conservation measures and works through a number of examples to illustrate the arguments. It also shows that there is no foolproof, simple methodology available for true optimization of energy consumption in processes and one must still rely on the experience and ingenuity of engineers. This book should appeal to engineers involved in design and operation of chemical plant and to those involved in finding better solutions for energy conservation in the process industries. To all, the author’s message is “Any action taken for energy conservation is more likely to generate profit than doing nothing about it”.
Theory of Molecular Fluids, Vol. I: Fundamentals. By C. G. GRAY and K. E. GUBBINS. Clarendon Press, Oxford, 626 pp., ~60.00
siderable facility with mathematics a necessary prerequisite for complete understanding. Following the general analysis, a number of forms of perturbation theory are discussed. including the u-expansion and thef-expansion. Although not all such approaches are considered, those that are most generally applicable are given a sound exposition supported by a number of useful comparisons with the results of computer simulation. The main text is completed by a review of integral equation methods extending from the Percus Yevick approximation for hard-sphere atomic fluids to the reference interaction site model for molecular fluids. The role and interrelationship of the various approximations are nicely described and the advantages and disadvantages of the methods are succinctly summarised. There can be no doubt that this book is an essential reference volume for those actively involved in the field of the molecular theory of fluids. It is well written, carefully prepared. remarkably free of errors and contains an extensive bibliography. However. there must be some doubt that this particular volume will be immediately useful to experimentalists as the authors claim. It is not an easy book to read because, by the nature of the subject, the level of mathematical detail often dominates simple physical argument. Judged on the forward references of this book, the second volume. dealing with applications would seem to be more appropriate for the experimentalist. Nevertheless, the virtues of the summary given in this book of the theory of molecular fluids make it a desirable acquisition despite its high price.
That a volume of some 600 pages should be just the first part of a treatise on the theory of molecular fluids is, in part, an indication of the enormous growth of activity in this area, but it is also a result of the commendable rigour with which the authors of this book have treated the subject. The volume represents a comprehensive and up-to-date treatment of fundamental theories of the equilibrium properties of dense molecular fluids and the relationship of these properties to the forces between molecules. The topic of intermolecular forces in polyatomic systems is treated in a more complete form than in many texts. Although there is some emphasis on the representation of potential energy surfaces rather than on the origin of the forces, there is also a clear discussion of multipolar, dispersion and induction interactions. The treatment is generally set out in the form of spherical harmonic expansion, although other representations are considered. This approach is then consistent with that adopted in later sections where a number of topics have been completely reworked using the same expansion. This unified approach has obvious advantages and is supported by an admirably extensive set of appendices setting out the requisite mathematics. The results of statistical mechanics necessary for later developments are given in Chapter 3 which deals with the various possible distribution functions for a molecular fluid in both the canonical and grand canonical ensemble. The starting point for the treatment will be familiar to all who have undergone a basic course in the subject, but the development moves rapidly and a reader will find a con-
The Electricity Council Research Capenhurst, Chester, U.K.
Imperial College of Science London SW7, U.K.
C. L. LOPEZ-CACICEDO Centre
W. A. WAKEHAM and Technology