NewBooks CrystalIizat ion J. W. MULLIN.268 pages. Butterworth, Inc. 7235 Wisconsin Ave., Washington 14, D. C. 1961. $11.00. Reviewed by W. C. SAEMAN,Olin Mathieson Chemical Corp., New Haven 4, Conn.
COVERAGE
IN this book is limited to commonplace and easily available information about crystallization, and discussion of more obscure, but equally important, aspects is absent. Where the author elaborates on more specific aspects, the accent is on laboratory procedure. Also, the academic rather than the industrial aspect is emphasized. Consequently, the book does not meet the author’s stated objective-i.e., to serve as a manual for process chemists and engineers. I t does, however, have limited usefulness for introducing the novice to a list of select and representative references. Commonplace concepts such as density, viscosity, heat capacity and content, freezing, boiling, and melting points, and heat of solution and evaporation are discussed, but important industrial concepts such as settling rate, density of suspension, kinetics of elutriation, or desupersaturation rate are not. Industrial crystallizer control is not mentioned. Instead, chapter 8 on crystal sizing is limited to sieving and sampling. Also, obsolete designs are included, such as the Howard crystallizer [U. S. Patent 1,559,703, (Nov. 3, 1925)] which lacks important features for competitive use, and in this reviewer’s opinion need not be included in a modern text. Also, the book contains notable errors in viewpoint-e.g., it should be pointed out that industrial crystallizers do not operate under equilibrium conditions, and neither yields, purity, or composition of product can be definitely determined from phase equilibrium. Final performance can be evaluated only by operation of the crystallizer system. T h e author perpetuates a n arbitrary basis of scale-up, found in the literature, which is based on dimensional analysis derived from mix-
ing technology. This disregards the fact that in scale-up this concept must be subordinated to other more important considerations. I t is difficult to reconcile such statements: that scale-up should be attempted under a constant hydraulic regime (sic) and, on the other hand, that this condition cannot be maintained within the scope of the dimensionless ratios proposed. For further clarification of scale-up, the reader is referred to a more recent article [I/EC 53,12-22 (1961)]. The book does not differentiate between advantages and disadvantages of the different equipment shown. Diagrams of Krystal equipment, dating back several decades, still show a preference for operation with classified suspensions, even though this method severely handicaps performance. Industrial Krystal units are usually operated with mixed suspensions, and the newer Swenson DTB design is supplanting the older design using tangential mixing. Despite differences in appearance, both these designs use a common underlying theory. T h e author does not mention this, even though it is discussed in the references he cites.
Industrial Organic Nitrogen Compounds MELVIN J. ASTLE. 392 pages. Reinhold Publishing Corp., New York 22, N. Y . 1961. $14.00. Reviewed by ROGER W. SANFTNER,Old Greenwich, Conn. F O R SYNTHESIS chemists in the general field of organic nitrogen compounds, this book is a useful addition to the literature. However, nonindustrial investigators are cautioned that many of the subjects treated are not normally considered industrial. Also, much of the material relating to commercial processes is buried in general presentations, and frequently more space is devoted to laboratory preparative methods than to commercial routes. Generally speaking, the material is adequately presented. The author has tried to emphasize descriptive
material, and excluded theoretical and mechanistic presentations. This should be welcomed by synthesis chemists. T h e title of the book suggests that author and publisher were not in full accord relative to the intended audience. Professor Astle states that the book is a n “attempt to summarize the chemistry of most types of organic nitrogen compounds,” whereas the publisher touts the book as a “comprehensive survey of all compounds of present and potential commercial significance.” Actually, it reflects the author’s description, and confusion will result unless it is recognized that the book is precisely what the author intended. For the industrial chemist, the book will be valuable probably because the author did not arbitrarily exclude content based on subjective definitions of what might constitute a n industrial composition or route. The capricious requirements of the market place and economics all too often necessitate re-evaluations of products and processes. Future usefulness of the work would have been limited severely had not Dr. Astle wisely obviated the constraints of present commercial technology. This is emphasized in the section dealing with nitriles where it is stated that the addition of hydrogen cyanide to acetylene as a route to acrylonitrile “is being adopted in all new plants being built.” Although the book represents considerable effort, it is unfortunate that the author did not provide incisive analysis of the subject matter, but merely chose to assemble the scope and depth of this body of literature. Selectivity is evident in the cited references, but criteria for inclusion and omission are not indicated. Therefore, the book represents a comprehensive but not a complete survey of the field. I t is regrettable that a book appearing in 1961 should include only references terminating in 1958. T h e index is rather weak, and users of the work will be frustrated by this oversight. However, the book does fill a gap in the literature and probably will become a familiar text in libraries. VOL. 53, NO. 12
DECEMBER 1961
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