hypochlorite and sodium chloride crystals, which are hard to separate. The French process makes use of fractional crystallization to separate sodium chloride from the calcium hypochlorite product found in the reaction medium. Sodium chloride crystals thus produced are about y40 the size of calcium hypochlorite crystals. The two thus are separated easily by décantation with simple, small-volume equipment. In the process, three raw materials—slaked lime, caustic soda, and chlorine—are converted to neutral calcium hypochlorite, the desired product, and a by-product sodium chloride. Slaked lime containing at least 97% calcium hydroxide is suspended in recycled mother liquor, called dibasic mother liquor, that contains a low concentration of hypochlorite ion and is almost saturated with respect to chloride ion. The milk of lime (calcium hydroxide suspension) formed is added simultaneously to the mother liquors resulting from separation of the two products. The recycled hypochlorite ion makes possible the precipitation of dibasic calcium hypochlorite with the lime. The grain size of this hypochlorite—Ca(C10)2 · 2Ca(OH)2—is controlled by the presence of a bed of preformed crystals during precipitation. This dibasic suspension is concentrated to collect the dibasic
mother liquor for subsequent preparation of the milk of lime and washing of the sodium chloride by-product. The thickened dibasic suspension and caustic soda are chlorinated simultaneously: Ca(C10)2. 2Ca(OH)2 + 4NaOH + 4C12 — 3Ca(C10)2 + 4NaCl + 4H 2 0 This reaction is conducted in the presence of preformed neutral calcium hypochlorite and sodium chloride crystals at a temperature not exceeding 20° C. The two types of crystals formed are separated with a slow-agitation decanter. The suspension, enriched with sodium chloride, is treated with part of the dibasic mother liquor collected during concentration of the dibasic suspension to dissolve most of the calcium hypochlorite produced. After drying or filtration, the salt can be reused in electrolysis (to make chlorine and caustic soda). The resulting mother liquor, called clarifying mother liquor, is recycled to precipitation of the dibasic compound. The hypochlorite suspension is dried or filtered, and the resulting mother liquor, called neutral mother liquor, also is recycled to precipitation of the dibasic compound as well as to chlorination. The hypochlorite cake is granulated and dried. D
New catalysts cut polyolefins costs Cost cutting by polyolefin makers is receiving a boost from new high-yield, high-efficiency catalysts developed jointly in Italy and Japan. In addition to saving production costs, the jcatalysts have permitted process simplification and provided better products in the bargain. These improvements are expected to keep polyolefins competitive with other construction and fabrication materials for some time to come. At the recent national meeting of the American Chemical Society in Atlanta, Cipriano Cipriani, director of product development for El Paso Polyolefins Co., illustrated the improvements in catalysts and processes for polypropylene production. Most existing process variations, such as liquid and slurry, will benefit. In El Paso's case, the process in question was a bulk monomer process, which has been extensively upgraded with the introduction of a new catalyst system developed by Italy's Montedison and Japan's Mitsui in 1979. The exact composition of
Protein Functionality in Foods
the catalyst system hasn't been disclosed. Commercial trials with the improved catalyst system reveal that the deashing step in the older process can be eliminated completely along with the auxiliary solvent recovery and recycle systems. Nearly 65% of the total energy required by the older process was consumed in the solvent recovery system's distillation units. This energy requirement is eliminated. Consequently, makeup solvents and treatment chemicals are no longer needed. High polymer yields provided by the new catalysts eliminate the need for catalyst residue removal and cleanup. The improved yield is attributed to direct synthesis of at least 95% crystalline polymer, a considerable improvement over the older process. Total steam requirements were reduced 85%, with most of it being saved through elimination of the solvent recovery systems. Electrical energy consumption was simultaneously reduced 12%. D
ACS S y m p o s i u m Series N o . 147 John P. C h e r r y , Editor Southern Regional Research USDA
Center,
Based on a symposium sponsored by the Division of Agricultural and Food Chemistry of the American Chemical Society. Since functionality is such a high priority research area, this book will be useful to food processors, engineers, chemists, and physicists. This fourteen-chapter volume updates and presents new information on the physicochemistry of functionality, the roles of protein for improving the functional properties of foods, and the application of data from model test systems to actual food ingredients. CONTENTS Protein Functionality · Color · Flavor Volatiles as Measured by Rapid Instrumental Techniques · Texturization · Solubility and Viscosity · Adhesion and Cohesion · Gelation and Coagulation · Whippability and Aeration · Water and Fat Absorption · Emulsifiers: Milk Protein · Emulsification: Vegetable Proteins · Nutrient Bioavailability · Enzyme Modification of Proteins · Multiple Regression Modelling of Functionality
332 pages (1981) Clothbound $36.75 LC 81-97 ISBN 0-8412-0605Order from: SIS Dept. Box 49 American Chemical Society 1155 Sixteenth St., N.W. Washington, D.C. 20036 or CALL TOLL FREE 800-424-6747 and use your credit card.
April 27, 1981 C&EN
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