BOOKS
3
the latest shade of COLORLITH table tops |SJ ow yoix can. decorate your laboratory with table tops ι one of tJhree bright, fresh colors tliat bring a new attractiveness to work- ' ing areas- Johns- Mlanville's Color- lith is furnished in fashionable Char- coal Gray, rich Cameo Brown and now . . . a sparkling new light tone—Surf Green. Colorlith is an asbestos-cement material specially developed by Johns- Manville for table tops„ funae hoods and other laboratory work spaces. It has a high resistance to most chemicals—acids, alkalies and solvents. It has excellent tensile, shear and compressive strength and resists shattering, flaking and impact. Colorlith is easy to machine with ordi- nary metal-working tools. ~No elaborate protective coating is necessary,, but easy- to-apply, wipe-on finishes can be applied after installation. They sare recommended for Surf Green and Caaaieo Brown tops. Available through leading manufacturers of laboratory equipment. For their names and descriptive folder EL-62A, write Johns-Man ville, Box 60, New ^«jp York 16, N. Y. In Canada, Port 1ΪΛ| Credit (Toronto), Ontario. mMA Johns-IVianvilie BOOKS COLORLITH Production Extracting The separation of compounds "by eountercurrent liquid-liquid extraction is a well established technique in o r - ganic chemistry. It is an invaluable tool in the isolation, purification, axid identification of compounds and is widely used in pharmaceutical aimd other fine chemical research. Since the probability of two different com- pounds having identical distribution coefficients is zero, the adherence of any compound to a theoretical distribu- tion pattern can be taken as a n indica- tion of purity. Small or suspected deviations can be amplified by an expansion of t h e distribution pattern. The literature contains numerous works by organic and physical chemists describing the laboratory techniques and the theo- retical treatment of data in this appli- cation of eountercurrent liquid distri- bution. Chemical engineers, on t h e other hand, have developed methods for the design of continuous equipment for fractionation by liquid-liquid ex- traction as applied to production units. Insufficient consideration has b&en given to the laboratory techniques for developing liquid-liquid extraction processes for production. A new book entitled "Liquid-Liquid Extraction" has been written by L. Alders as a laboratory manual to fill this need, In addition, the book covers the theoreti- cal aspects of liquid extraction proc- esses in their application to commercial design. The author does not discuss any of the chemical, physical, or eco- nomic factors involved in the selec- tion of solvents for an extraction process and probably assumes that this Irad been established by previous research. He also gives no discussion of the Craig eountercurrent distribution apparatus nor of how the data obtained therefrom can be used for the development studies. Instead, he describes a complete pro- cedure whereby all fundamental data required can be determined using sep- aratory funnels and shows that "by proper manipulation it is theoretically possible to carry out a continuous eountercurrent extraction in a number of funnels approximately equal to h.-alf the number of stages. The reader is not cautioned that in practice this manipu- lation may be too complicated to he followed by the average laboratory worker, and an improperly placed fum- nel in the later stages of the operation can vitiate hours and even days of pre- paratory work. The book covers the ordinary ex- traction for removal in which a solute is transferred from one solution to an- other by multiple contacting with fresh solvent (called "cross-current" extrac- tion) and by eountercurrent flow of the two liquids through the successive stages. Fractionation by single solvent extraction with reflux is also covered and the author proposes a new criterion called "selective power" for rating the effectiveness of different solvents in this process. The function gives a constant value for all coexisting phases in the heptane-toluene-aniline system. The function increases as the mutual solubilities of the solvent systems be- comes greater and may be related to the relative distribution at complete immiscibility. Thus, a high selective power does not necessarily indicate a large relative distribution because a high mutual solubility of the phases may actually give a low relative distri- bution under the operating conditions of the process. Fractionation of mixtures by two- solvent extraction which is receiving increasing consideration as a practical separation process has been treated only lightly in other text books on liquid extraction, in spite of the fact that it is a universal tool applicable to all mix- tures. The operating cost of this proc- ess is intermediate between fractional distillation and chromatographic ad- sorption and it therefore merits consid- eration where ordinary fractional distil- lation is difficult or impossible. The latter situation exists when the mixture forms an azeotrope, is nonvolatile, or is unstable under the practical range of distilling conditions. The book takes cognizance of the importance of this process by devoting nearly half the pages to fractionation by liquid extraction. The mathemati- cal derivations may be difficult for the laboratory worker to follow because they start directly with the concept of steady state. This is no handicap to the chemical engineer but by develop- ing the derivation from the continual extraction pattern in separatory funnels the relationships may be brought closer to the laboratory worker for whom the book apparently is intended. The final rigorous solution is, of course, unavoid- ably complicated. The description and selection of laboratory equipment for investigating liquid extraction as a continuous proc- 5210 C&EN NOV. 2 8, 1955 New Surf Green
Transcript of BOOKS
the latest shade of
COLORLITH table tops
|SJ ow yoix can. decorate your laboratory with table tops
ι one of tJhree bright, fresh colors tliat bring a new
attractiveness to work-' i n g areas- J o h n s -
Mlanville's Colorl i th is furnished in
f a s h i o n a b l e Charcoal Gray, rich Cameo
Brown and now . . . a sparkling new light tone—Surf Green.
C o l o r l i t h is an a s b e s t o s - c e m e n t material specially developed by Johns-Manville for table tops„ funae hoods and other laboratory work spaces. It has a high resistance to most chemicals—acids, alkalies and solvents. It has excellent tensile, shear and compressive strength and resists shattering, flaking and impact.
Colorlith is easy to machine with ordinary metal-working tools. ~No elaborate protective coating is necessary,, but easy-to-apply, wipe-on finishes can be applied after installation. They sare recommended for Surf Green and Caaaieo Brown tops. Available through leading manufacturers of laboratory equipment. For their names and descriptive fo lde r EL-62A, wri te Johns-Man ville, Box 6 0 , New ^ « j p York 16, N . Y. In Canada, Port 1 Ϊ Λ | Credit (Toronto), Ontar io . mMA
Johns-IVianvilie
BOOKS
COLORLITH
Production Extracting The separation of compounds "by
eountercurrent liquid-liquid extraction is a well established technique in o r ganic chemistry. It is an invaluable tool in the isolation, purification, axid identification of compounds and is widely used in pharmaceutical aimd other fine chemical research. Since the probability of two different compounds having identical distribution coefficients is zero, the adherence of any compound to a theoretical distribution pattern can be taken as an indication of purity.
Small or suspected deviations c a n be amplified by an expansion of t h e distribution pattern. The literature contains numerous works by organic and physical chemists describing t h e laboratory techniques and the theoretical treatment of data in this application of eountercurrent liquid distribution. Chemical engineers, on t h e other hand, have developed methods for the design of continuous equipment for fractionation by liquid-liquid ex traction as applied to production units.
Insufficient consideration has b&en given to the laboratory techniques for developing liquid-liquid extraction processes for production. A new book entitled "Liquid-Liquid Extraction" has been written by L. Alders as a laboratory manual to fill this need, In addition, the book covers the theoretical aspects of liquid extraction processes in their application to commercial design. The author does not discuss any of the chemical, physical, or economic factors involved in the selection of solvents for an extraction process and probably assumes that this Irad been established by previous research. He also gives no discussion of the Craig eountercurrent distribution apparatus nor of how the data obtained therefrom can be used for the development studies.
Instead, he describes a complete procedure whereby all fundamental data required can be determined using sep-aratory funnels and shows that "by proper manipulation it is theoretically possible to carry out a continuous eountercurrent extraction in a number of funnels approximately equal to h.-alf the number of stages. T h e reader is n o t cautioned that in practice this manipulation may be too complicated to he followed by the average laboratory worker, and an improperly placed fum-nel in the later stages of the operation
can vitiate hours and even days of preparatory work.
The book covers t he ordinary extraction for removal in which a solute is transferred from one solution to another by multiple contacting with fresh solvent (called "cross-current" extraction) and by eountercurrent flow of the two liquids through the successive stages. Fractionation by single solvent extraction with reflux is also covered and the author proposes a new criterion called "selective power" for rating the effectiveness of different solvents in this process. T h e function gives a constant value for all coexisting phases in the heptane-toluene-aniline system. The function increases as the mutual solubilities of the solvent systems becomes greater and may b e related to the relative distribution at complete immiscibility. Thus, a high selective power does not necessarily indicate a large relative distribution because a high mutual solubility of the phases may actually give a low relative distribution under the operating conditions of the process.
Fractionation of mixtures by two-solvent extraction which is receiving increasing consideration as a practical separation process has been treated only lightly in other text books on liquid extraction, in spite of the fact that it is a universal tool applicable to all mixtures. The operating cost of this process is intermediate between fractional distillation and chromatographic adsorption and it therefore merits consideration where ordinary fractional distillation is difficult or impossible. The latter situation exists when the mixture forms an azeotrope, is nonvolatile, or is unstable under the practical range of distilling conditions.
The book takes cognizance of the importance of this process by devoting nearly half the pages to fractionation by liquid extraction. The mathematical derivations may be difficult for the laboratory worker to follow because they start directly with the concept of steady state. This is no handicap to the chemical engineer but by developing the derivation from the continual extraction pattern in separatory funnels the relationships may b e brought closer to the laboratory worker for whom the book apparently is intended. The final rigorous solution is, of course, unavoidably complicated.
The description and selection of laboratory equipment for investigating liquid extraction as a continuous proc-
5 2 1 0 C & E N N O V . 2 8, 1955
New
Surf Green
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BOOKS
ess is inadequate, the author apparently assuming that a suitable laboratory for investigation of these processes is available t o the worker. Also, operating procedures for this equipment would be valuable to the laboratory worker embarking on a n investigation program, and they are not mentioned specifically.
The effect of the different variables on the operation of a two-solvent fractionation may, however, be deduced from tlie theoretical derivations and the curves presented in the text. The reader with sufficient tenacity to wade through the mathematical treatments in the latter part of the book will emerge with a thorough knowledge of the process of fractional liquid extraction.
Liquid—Liquid Extraction. L . ALDERS. χ -f 206 pages. Elsevier Press, 402 Lovei t Blvd., Houston, Tex. 1955. $5.5C. Reviewed by ϋ.. G. SCHEIBEL, York Process Equipment Co .
NEW B O O K S Boltzmann's Distribution Law. E. A.
GUGGENHEIM. 61 pages. Interscience Publishers, Inc., 250 Fifth Ave., New York 1, N. Y. 1955. $1.50.
Topics discussed in detail include ideal monatornic and diatomic gases, equiparti-tion of kinetic energy, simple crystals, phase equilibrium of a single substance, and dielectric constant of a gas, and chemical equilibrium in a gas.
Reflections of a Physicist. 2nd edition. P. W. BRIDGIW£AN. xiv -j- 576 pages. Philosophical Library, Inc., 15 East 40th St., New York, Ν. Υ. 1955. $6.00.
Extension of the operational approach to problercis in other fields than physics.
The National Formulary. 10th edition, xliii -}- 867 pages. American Pharmaceutical Association, 2215 Constitution Ave., N.W., Washington 7, D. C. 1955. $9.00. '
Gives monographs on drugs, chemicals, and préparations. Also includes general tests, processes, and apparatus.
1954 Vacuum Symposium Transactions. Committee on Vacuum Techniques, ix -f- 147 pages. Committee on Vacuum Techniques, Inc., Box 1282, Boston 9, Mass. 1955. $10.
New equipment and instrumentation, methods and techniques for obtaining high vacuum technology, vacuum system applications and processes, standards, and nomenclature.
Safety in Industry. D. I. MACFAKLÂNE. 71 pages. Philosophical Library, Inc., 15 East 40th St., New York, Ν . Υ. 1955. $6.0Q.
Covers dangers of rotating machinery, need for guards on. presses and similar machines; control of dust and fumes; types of modern protective clothing; precautions against diseases; damage to the eyes and harmful radiations from x-rays and radioactive substances; and good lighting and flooring.
5212 C * E N NOV. 28, I95E
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