Energy & Fuels 2002, 16, 529
529
Book Reviews The Sulfur Problem: Cleaning up Industrial Feedstocks. By Diane Stirling. Royal Society of Chemistry: London; 2001. 93 pp. The book entitled “The Sulfur Problem: Cleaning up Industrial Feedstocks” by Diane Stirling is a monograph published by the Royal Society of Chemistry. The book is 93 pages long and consists of a brief introduction followed by chapters entitled “Catalytic Hydrodesulfurization”, “Adsorption and Absorption of H2S”, “Clean up of Sulfur Dioxide”, “Synthesis and Characterization of Solid Sorbents”, “Surface Energies and Interactions Between Particles”, and last, “Determination of the Sulfur Sorption Capacity of Solid Sorbents.” Each chapter is referenced. The book is nicely presented, with a strong binding, and a handsome cover. According to the reverse cover, the main objectives of the book are “to demonstrate the importance of eliminating sulfur contaminants from the environment and the measures necessary to effect this.” The book develops by presenting a succinct description of the environmental and health problems associated with increased levels of SO2 in the atmosphere, followed by a description of the chemistry and technology needed to reduce the sulfur content of feedstocks via hydrodesulfurization (HDS), and a description of both the theoretical and practical aspects of capturing both SO2 and H2S from gas streams. Environmental chemistry, synthetic chemistry of sorbents, solid-state chemistry, catalysis, and analytical chemistry are all blended within this book to address this problem. The book starts of with a serious error on page 1, where we are told that coal contains H2S. H2S is not generally found in coal although there is at least one notable exception, an Australian coal. The author relies on a reference by Manahan to support the statement. The presence of H2S in coal would make coal mining substantially more hazardous than it already is. Nevertheless, the chapter recovers nicely from this early mistake and goes on to present a well thought out description of the problem. The intent of the second chapter is to provide a brief overview of some of the concepts of catalytic hydrodesulfurization over a sulfide catalyst. It is only partially successful in conveying the role played by this process. Ideas of catalyst structure, reaction mechanisms, and process conditions are outlined, but errors, misinterpretations, and misleading statements mar the text. Missing are discussions that would place hydrodesulfurization in context as a major and essential refinery process that protects everything downstream of it from reformer to catalytic converter. An appreciation of its history of development and practice, its key role in the refining process, the extent of its application, its success in producing fuels and feedstocks with acceptably low sulfur content, and the challenges to be faced in the future are not to be found. The molecular pathways for sulfur removal from thiophene are given, but the discussion fails to capture many critical points among the relationships between mechanism and process performance. Some of the space could be better used discussing general principles rather than unlikely mechanistic pathways. This chapter has limited value as a resource on HDS. In the chapter entitled “Adsorption and Absorption of H2S” the authors have included most of the important techniques
for liquid scrubbing. There is no mention of other techniques for sulfur reduction that employ nitrites, aldehydes, and metal oxide slurries. A key article entitled “Natural gas production: Performance of commercial technology for removing small amounts of hydrogen sulfide” by D. Leppin is not mentioned in the chapter. The section on solid sorbents is incomplete. There have been many advances in both high and low-temperature solid sorbents during the past 10 years that are either not mentioned or inadequately described. Pilot scale testing has been performed with zinc ferrite sorbents, zinc titanate sorbents, and zinc oxide sorbents. Fixed bed zinc oxide sorbents have performed well in the temperature range of 500 to 1000 °F. Fluidized bed zinc titanate sorbents have performed well in the high temperature range >1000 °F. Regenerable zinc oxide sorbents are commercially available. These sorbents have performed well during multicycle tests. Much of this work is not adequately discussed. The chapter entitled “Clean up of Sulfur Dioxide” is rudimentary. It attempts to discuss various techniques to remove sulfur dioxide from flue gas. There is a voluminous literature on flue gas desulfurization. It is uncertain why the author only reports on the specifics of certain techniques while others are not mentioned. Those techniques that are discussed are inadequately referenced. Similarly, those techniques that are discussed are inadequately described. Key information is not given, such as temperature, flow compositions, and scale of testing. For example, discussion of the Dowa Process should at least mention the reaction temperature. The same is true of the cerium work described in the booksno temperature or flow conditions are given. While the chapter entitled “Surface Energies And Interactions Between Particles” is somewhat informative and provides a brief introductory overview of some of the more important forces influencing the behavior of particles in solution and factors that affect crystal growth, its relationship to the focus of the book is not clearly established. The author makes no attempt to tie the discussion in this chapter to the discussion of sulfur removal in other chapters. The only relevancy of this chapter is established in the preface to the book where it states that properties of small particles in solution are important in the synthesis step (of materials for sulfur cleanup). There is no attempt to tie the discussion to the synthesis step. The discussion in this chapter relies heavily on ref 4. It would have been better to expand upon the information contained in the other chapters instead of inserting a chapter in such a way that it has little benefit to the understanding of the rest of the text. When the discussion in the book depends on a more detailed knowledge of interparticle interactions, referring the reader to ref 4 would seem to be adequate. The title, subtitles, and concept of the book are of great interest. The book simply does not deliver what is promised. Curt M. White, Ranjani V. Siriwardane, Bradley C. Bockrath, Jim S. Hoffman, Henry W. Pennline, and John Baltrus, National Energy Technology Laboratory EF0100552 10.1021/ef0100552
