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Energy & Fuels 2001, 15, 1322-1323
Book Reviews Annual Review of Energy and the Environment, Volume 25. Edited by Robert H. Socolow, Dennis Anderson, and John Harte. Annual Reviews, Palo Alto, CA, 2000; pp 857 + xiii. ISBN 0-8243-2325-4. This volume is the 25th in an ongoing series; many of the previous volumes are likely to be familiar to readers of This Journal. Like its predecessor volumes, this one opens with a “prefatory biography” and then has a number of chapters grouped into several major theme areas. In this year’s volume, the biography is by Wallace Broecker, summarizing in an anecdotal way his career in studying the impact of oceans on global climate change. Even readers not directly working in this area will find Broecker’s contribution interesting. The major themes treated are grouped into resources and technology, policy, international and regional issues, environmental science (which actually has only one chapter, on water vapor feedback in global warming), energy end-use and conversion, and risks and impacts. As is true of any volume of collected contributions, the style and quality of writing vary from one chapter to another but are generally good. The illustrations are also of good quality and are fairly large; data are not buried in postage-stamp-sized graphs, for example. The individual chapters have extensive citations to the literature; the median number of citations must be close to a hundred. The vast majority of literature cited dates from the mid-1980s through 2000. Therefore, the chapters would be good starting points for someone interested in quickly getting up to speed on the recent literature of a particular topic. This volume also has lists of contributing authors and chapter titles for the whole 25-volume series published to date. This book is certainly recommended for acquisition by the library of any institution or organization with an interest in energy, especially the impact of energy technology on the environment. An individual considering purchasing it for his or her personal collection should be guided by the relevance of the chapters or theme areas. Harold Schobert EF010129+ 10.1021/ef010129+
L. L. Sloss and I. M. Smith: “Trace Element Emissions”, Report CCC/34, IEA Coal Research, London, United Kingdom, June 2000, 83 pp. R. M. Davidson: “Modes of Occurrence of Trace Elements in Coal”, Report CCC/ 36, IEA Coal Research, London, United Kingdom, June 2000, 36 pp + CD-ROM. Reviews The topical reports published by IEA Coal Research provide the coal research community with a series of in-depth reviews of key research topics of importance to coal utilization and related environmental issues. The reports are always timely, well written, thoroughly researched, and, importantly, international in scope. I am sure that I am just one of many researchers who often avail themselves of this unique service provided by IEA Coal Research to gain a quick familiarity with an important research area. Both of the IEA Coal Research reports reviewed here deal with trace elements in coal. However, whereas the report on trace element emissions by Sloss and Smith follows the traditional format and summarizes recent results from various groups around the world, the report on modes of occurrence of elements in coal by Davidson is a departure from the normal
style and content of previous reports in that it is more highly focused and summarizes material that is largely unpublished. Separate reviews of each report are given below. As is typical in this series, both reports are printed in an attractive color format that makes them a pleasure to read. The reports are priced as follows: £255 (∼$400) for nonmember countries; £85 (∼$130) for member countries; and £42.50 (∼$65) for educational establishments within member countries. Such prices are reasonable given the wealth of information contained in such high-quality reports. (a) L. L. Sloss and I. M. Smith: “Trace Element Emissions” The report consists of seven chapters. A short introductory chapter sets the scope of the review and its relationship to other recent IEA Coal Research reports on similar topics. It also emphasizes the point that mercury emissions will most likely be the most important issue arising from trace element emissions from coal utilization. In the second chapter, the authors focus on placing in perspective the trace element emission problem arising from coal power plants with respect to emissions of trace elements from global sources, both natural and anthropogenic. The third chapter concentrates on summarizing the various national and international legislation and agreements that are in place with respect to trace element emissions. An important point is made that whereas coal combustion is typically in compliance with those national standards currently in place for trace element emissions from stationary sources, specific controls for mercury may yet be warranted, as the percentage of mercury emissions arising from coal combustion sources can be expected to increase as controls are increasingly applied to limit emissions of mercury from other sources. The fourth chapter is concerned with sampling and analysis, the importance of which cannot be overemphasized, since such methods will be used to determine compliance or noncompliance if emission standards should be legislated for trace elements from coal combustion. In this chapter, the authors review current methods for trace element analysis, including continuous emission monitors for mercury and other trace elements, and discuss their limitations. In chapters five and six, the authors present current information about the retention of trace elements in various combustion and gasification configurations (different fuel types, combustor types, environmental control devices, etc.). These two chapters summarize succinctly a wealth of data about the behavior of trace elements in combustion and gasification units. The final chapter reviews potential control options that might be implemented specifically for mercury and other trace elements, over and above their serendipitous capture in environmental control devices designed for reducing particulate or SOx and NOx emissions. The control options considered include fuel switching and cofiring, coal cleaning, modification of existing pollution control systems, and development of new control technologies for mercury (oxidation, carbon-based and limebased sorbents, selenium-based filters). This report by Sloss and Smith is easy to read, despite being crammed full of data and information, and, in my opinion, presents a broad and balanced overview of the current situation regarding trace element emissions. This report deserves to find a place on the reference shelf of any researcher who needs a comprehensive survey of the current state of the science. (b) R. M. Davidson: “Modes of Occurrence of Trace Elements in Coal” This report is a summary of a collaborative research project on the determination of modes of occurrence of trace elements
Book Reviews in coal set up within the auspices of the IEA Clean Coal Sciences program and coordinated by Les Dale of CSIRO, Australia. The seven groups worldwide who participated in the collaboration were requested to determine the modes of occurrence of trace elements of environmental significance in four coals using their methodology of choice. The project commenced in 1996 and was completed in late 1999, at which time each group submitted its final report to IEA Coal Research. The data and information contained in these informal reports form the basis of Davidson’s review. The individual reports are included as supplementary material on a CD-ROM (in Acrobat Reader 4.0.pdf format) that accompanies the IEA Coal Research report. The report consists of six chapters. A short introductory chapter establishes the scope and reasons for the project, as well as listing the participating laboratories. The second chapter describes the four coals and summarizes their proximate and ultimate analyses. Also included here are semiquantitative data for the major minerals in each coal determined by X-ray diffraction or scanning electron microscopy methods, including CCSEM. Trace element concentrations for 13 elements (Be, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Hg, and Pb) are summarized and compared in the third chapter. A fourth chapter discusses the various methods of sample fractionation used and their usefulness for determination of elemental modes of occurrence. Both physical separation and sequential leaching (chemical separation) methods were explored by various groups. Although the three sequential leaching methods were similar in concept, they were sufficiently different to make direct comparison difficult. The fifth chapter is basically the raison d’eˆ tre of the report. In it, Davidson compares and contrasts the results on the modes of
Energy & Fuels, Vol. 15, No. 5, 2001 1323 occurrence inferred by the different groups for the 13 trace elements listed above, as well as for Al, Si, Fe, and S. It is sobering indeed to discover that for some elements, notably Be, Co, Ni, and Sb, there is virtually no agreement among the different methods as to the mode of occurrence. For other elements, notably the chalcophilic elements (Cu, Zn, Cd, Hg, As), there is a reasonable consensus that these elements do form sulfides or are associated with pyrite. A final chapter, entitled “Conjectures and Conclusions”, is largely a listing of the caveats of which the reader should be aware in trying to draw specific conclusions from this collaborative work. Davidson has done yeoman-like work in pulling this report together from such disparate and, in many instances, conflicting individual reports, and one cannot fault him for appearing tentative in his conclusions. As is evident from his report, the state of the art of element speciation is not nearly as good as we would like it to be, and much of the reason for this must arise from naı¨vete´ in our understanding of how elements can occur in coal. It is clear that not only do we not know the chemical species of some elements with any certainty, but there is also much yet to learn about the physical structure of coal and its interrelationship with inorganic species (particularly, organically associated species). Only when we have a much clearer understanding of this relationship can we hope to develop speciation methods that will provide consistent results. Perhaps this report will stimulate the necessary research. F. E. Huggins EF010033F 10.1021/ef010033f
