MAY 1958
I/EC
Briefs
The why, w h a t , and significance of technical articles in this issue. Clip these Briefs for r e a d y reference a n d easy filing on a 3 X 5 or other suitable card
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CHEMISTRY AND CHEMICAL ENGINEERING IN THEORY AND PRACTICE
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I/EC Brief
I/EC Brief
MACHINE COMPUTATION IN PETROLEUM RESEARCH
I n d . E n g . C h e m . 5 0 , 721-4 (1958)
Computer Analysis of Wax Manufacture and Storage I n d . E n g . C h e m . 50, 712-18 (1958)
A mathematical model has been developed to determine the additional equipment required to expand a complex manufacturing operation and show how equipment investment should be divided between expanding process units and increasing tankage to satisfy increased demand for wax products. The model is based on a series of equations which schedules operations to produce, store, and blend the dozen components required to satisfy the widely fluctuating customer demand for 20 major wax blends. These equations are the basis of an electronic data-processing machine program which simulates day-to-day plant operations to meet the predicted demand pattern. Demand data are computergenerated using statistical and Monte Carlo techniques. Future applications of the model include computer scheduling of actual plant operations to provide more efficient use of process equipment, lower inventory carrying costs, and superior service to customers.
Engineering Design on a Computer Computers are used in engineering to improve designs, get jobs done sooner, free engineers for other work, and increase consistency. IBM 650 programs include design of heat exchangers, fractionators, and cracking furnaces, determination of motor acceleration characteristics, and estimation of vessel costs. In improving designs, savings may be of million-dollar magnitude where a large unit can be optimized as a whole, but much lower where programs cover only portions of the design. Several weeks of elapsed time have been saved on a number of projects, and the programming work is breaking even on a manpower basis. Computers are used increasingly to improve designs rather than to save large amounts of manpower or elapsed time. They are of great value in engineering work, if well-planned programs are developed by engineering experts.
J A M E S E. B O R N E R T e c h n i c a l Service Division, Esso S t a n d a r d Oil C o . , L i n d e n , N . J .
E. J . H I G G I N S , J . W . K E L L E T T , a n d L. T . U N G Esso Research a n d E n g i n e e r i n g C o . , L i n d e n , N . J .
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I n d . Eng. C h e m . 50, 725-9 (1958)
Machine Solution of a Boundary Value Problem for a Continuous Arosorb Process
I n d . E n g . C h e m . 50, 719-20 (1958)
Computer Use in Pilot Plant Calculations
The Arosorb process for separating aromatics from saturates by selective adsorption on silica gel consists of two steps—adsorption and desorption. By using a simplified model of the adsorption zone of a moving-bed column, rate equations based on a Langmuir isotherm have been solved on an IBM 650 computer. Comparison of these solutions with the analogous solutions for batch adsorption suggests a method of finding directly the height of a moving-bed adsorption zone from the results of a batch experiment.
A computer program has been designed and used to process data from a catalyst-testing pilot plant with a great saving in time. A feature of the program, which should probably be included in all programs of this type, is the editing and review of the raw run sheet data prior to and during their processing. Some of this can be done automatically. L. S. S T A N T O N , E. B. R E I D , a n d H . F. M A S O N C a l i f o r n i a Research C o r p . , R i c h m o n d , C a l i f .
A . W . P O L L O C K , M . F. B R O W N , a n d C . W . D E M P S E Y S u n Oil Co., Philadelphia 3, Pa.
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VOL. 50, N O . 5
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I/EC Brief
I/EC Brief Ind. Eng. Chom. 50, 730-6 (1958)
Multicomponent Distillation Calculations on a Large Digital Computer
Ind. Eng. Chem. 50, 753-62 (1958)
Chemical Cost and Profitability Estimation—1957
In multicomponent rectification, many simultaneous alge braic equations are to be solved. Large digital machines are capable of solving simultaneous equations of high order. The mass and enthalpy balances are solved in a simul taneous fashion by an iterative procedure requiring for light hydrocarbon rectifications an assumption on the col umn temperature distribution to initiate the calculations. Thus far four or five iterations are sufficient to obtain com plete compositions on every tray of better than engineering accuracy. These calculations have been performed for a five-compo nent mixture on the Univac Scientific Model 1103 in about 40 seconds with a column of 15 trays. The method may also be applied to columns with multiple feeds and drawoffs and a 51-plate column with two feeds and one side stream has been investigated. NEAL R. AMUNDSON and ARLENE J . PONTINEN Remington Rand Univac, Univac Park, St. Paul, Minn.
This Annual Review on chemical engineering economics again covers oral and written presentations in the field of investment, operating cost, and profitability estimation for the process industries. It includes an annotated bibli ography covering 329 items, a subject index, and an analysis of the citations. Economic evaluation continues to be plagued by the variety of relevant publications and too few published re ports of certain major presentations during the year. Tech niques useful in this area are still in various stages of devel opment. Published discussions indicate considerable lack of communication from one group of readers to another. To add to the problems, while techniques are generally not considered confidential, actual data on a given process or product may not be divulged in the literature until the information is practically obsolete. JAMES B. WEAVER Economic Evaluation Department, Atlas Powder Co., Wilmington, 99, Del.
I/EC Brief
I/EC Brief Ind. Eng. Chem. 50, 763-6 (1958)
Ind. Eng. Chem. 50, 737-40 (1958)
Continuous Distillation Calculations by Relaxation Method
Recovery of Uranium from Stainless Steel Fuel Elements
Conventional calculation methods for continuous distil lation sometimes encounter difficulty when they are pro grammed for solution by an automatic digital computer, because of the difficulty in choosing values for successive trials of these trial and error calculations. The relaxation procedure is an entirely new method for calculating product compositions in multicomponent con tinuous distillation, when feed conditions, flow rates, plate efficiency, number of plates, and reflux ratio are established. The method is suited for problems involving multiple feed or take-off streams, extremes of concentration, multiple columns, and automatic control applications.
This investigation was undertaken to provide data re quired for the "head-end step" of a process for recovering uranium from spent uranium dioxide stainless steel fuel. The step consisted of dissolution of the stainless steel cladding in sulfuric acid, dissolution of the uranium oxide fuel in nitric acid-sulfuric acid mixture, and a single solvent extraction cycle using 10% tributyl phosphate in a hydro carbon diluent to separate the uranium from the stainless steel components. This treatment was designed to be compatible with further solvent extraction processing to be carried out in the chemical processing facilities at the reactor test station in Idaho.
ARTHUR ROSE, ROBERT F. SWEENY, and VERLE N. SCHRODT Pennsylvania State University, University Park, Pa., and Applied Science Laboratories, Inc., 140 North Barnard St., State College, Pa. (End of Symposium)
L. W. NIEDRACH, A. C. G L A M M , M. E. BRENNAN, and B. E. DEARING Knolis Atomic Power Laboratory, General Electric Co., Schenectady, Ν. Υ.
I/EC Brief
I/EC Brief
Ind. Eng. Chem. 50, 767-70 (1958)
Preparation and Properties of the Alkylene Carbonates Ind. Eng. Chem. 50, 741-52 (1958)
Use of Computers in Reactors Design Tedious stepwise calculations are involved in the design for liquid phase, first-order endothermic reactions carried out in either batch or flow-type tubular reactors heated by condensing vapors. To eliminate this difficulty a set of nomographs has been produced on the basis of solutions obtained with an IBM 650 digital computer. An analytical treatment of certain special cases has been developed. D. S. BILLINGSLEY, W. S. McLAUGHLIN, Jr., N. E. WELCH, and C. D. HOLLAND Department of Chemical Engineering, Agricultural and Mechanical College of Texas, College Station, Tex.
The alkylene, or 1,2-glycol, carbonates can be obtained readily from the corresponding 1,2-epoxides and carbon dioxide. In undertaking to develop a satisfactory manu facturing process it was necessary to provide a superior catalyst for the reaction. Quaternary ammonium halides were highly active cat alysts, which enabled virtually quantitative yields of alkyl ene carbonates to be obtained. A pilot plant was con structed for an investigation of the proposed process. Summarized operating results are given. Ethylene carbonate and propylene carbonate are now available commercially. In its reactions ethylene carbonate may behave as an ester or undergo cleavage' to yield hydroxyethyl derivatives. The alkylene carbonates are highly polar solvents, particularly useful for obtaining solutions of organic polymers. W. J. PEPPEL Jefferson Chemical Co., Inc., Austin, Tex.
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I/EC Brief
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Ind. Eng. Chem. 50, 785-92 (1958 Ind. Eng. Chem. 50, 771-6 (1958)
Cross Linking of Butadiene-Acrylate Polymers by Alkaline Earth Hydroxides This work was undertaken to obtain alternative routes to carboxylic elastomers by improving vulcanization systems for copolymers of butadiene and acrylates. The speed of cross linking copolymers of butadiene and acrylic esters by basic oxides and hydroxides is greatly increased by polyhydroxy compounds, particularly lower aliphatic diols. Still faster cures result from incorporating small amounts of 2-cyanoethylacrylate which undergoes very rapid alkaline hydrolysis. High strength gum-stock vulcanizates can now be ob tained from copolymers prepared using conventional anionic soaps without risk of prevulcanization during compounding and molding. W. COOPER and T. B. BIRD Dunlop Research Centre, Birmingham, England
Control of Degradation in Oil-Extended Styrene-Butadiene Rubber Degradation of conventional iron-containing oil-masterbatch can now be effectively inhibited by small amounts of inexpensive magnesium compounds. Magnesium soaps are added to the extending oil prior to emulsification and cocoagulation of the latex-oil emulsion blend or magnesium sulfate is added to the coagulating acid. Magnesium levels of 125 to 500 p.p.m. generally imparted heat aging stability equal to that of the oil-free base polymer. Magnesium soaps caused a slight retardation of cure, but had little or no apparent effect either on processability or vulcanizate quality at optimum cure. Magnesium compounds are believed to retard degrada tion of raw oil-masterbatch by blocking a homogeneous catalytic oxidative effect caused by polymer-soluble iron salts. R . J . REYNOLDS Shell Development Co., Emeryville, Calif.
I/EC Brief
I/EC Brief Ind. Eng. Chem. 50, 793-6 (1958)
Ind. Eng. Chem. 50, 777-80 (1958)
Oxidation of fert-Butylcyclohexane to Dibasic Acids with Nitrogen Dioxide Because aliphatic dibasic acids have become important intermediates in the manufacture of diesters for synthetic lubricants or plasticizers, their synthesis by the direct oxidation of alkylcyclohexanes has been studied. In par ticular, the oxidation of ter
