NOVEMBER 1955
Ind. Eng. Chem., 47, 2284 (1955)
Automatic Control in Continuous Distillation
I
ARTICLES I N T H I S ISSUE
A Reeves electronic analog computer was used to determine the proper type of automatic control for a distillation column separating a feed of varying composition. A column with five theoretical plates is considered and the effects of plate holdup, fluid dynamics, true time delay in process lines, and column sampling location are taken into account. Control was accomplished by varying the column reflux ratio to maintain column compositions constant as feed composition varied. Satisfactory control was obtained with composition sampling as top plate and bottom plate, two-point sampling; as top plate, single-point sampling; and as intermediate plate, single-point sampling. Distillate, singlepoint sampling, and bottom plate, single-point sampling, gave unsatisfactory control. A R T H U R ROSE T h e Pennsylvania State University, University Park, Pa. THEODORE J. W I L L I A M S USAF I n r t . of Technology, Wrlght-Patterson Air Force Bare, Ohio
Ind. Eng. Chem., 47, 2290 (1%) Ind. Eng. Chem., 47, 2230 (1965)
Altering Soil Properties with Chemicals The symposium on soil stabilization brings together chemists, civil and chemical engineers, market development experts, government specialists, and industrial executives t o explore widely diversified aspects of chemical soil stabilization. Much of the work on chemical soil stabilization in the past has been aimed at converting soft plastic soils into traffic-bearing materials with the result that “stabilization” often refers to this restricted usage. However, processes or chemicals that alter properties such as fluid-permeability, water-wettability, compatibility, or deformability are equally important and appear closer to practical realization than does the more limited objective of “solidification.” A panel discussion of future prospects of chemicals for soil treatment is included with the symposium.
Optimum Reflux Ratio for Fractional liquid Extraction The results of studies of the effect of reflux in a twosolvent fractional liquid extraction process have been expressed qualitatively. Increasing the reflux ratio will decrease the number of stages required, but, based on maximum allowable solute concentrations in the solvents, the solvent requirements will be greater and this will increase the cross-sectional area of an extraction column. A method for defining an optimum reflux ratio is based on a consideration of the variation of solute concentrations in a fractional liquid extraction a t different reflux ratios, and this reflux ratio is compared with the reflux ratio requiring the minimum column volume. An equation is derived for calculating reflux ratio in an ideal system and applied to a nonideal system using the relative distribution a t the feed stage. Saving in the nonideal system is smaller than in the ideal system. EDWARD G. SCHEIBEL Hoffmann-La Roche, Inc., Nutley, N. J.
Ind. Eng. Chem., 47,2293 (1955)
Heat Transfer in Packed Beds
s
Ind. Eng. Chem., 47, 2282 (1956)
PILOT PLANT for Studying Corrosion Rates c
A method that closely duplicated plant conditions was needed for studying corrosion from Chlorex, which is used to separate lubricating stocks into paraffinic and naphthenic fractions and must then be removed by distillation. Corrosion coupons inserted in appropriate locations in a pilot plant still, designed to study corrosion rates and to be used as a stripping still, were used to evaluate alcohols, organic phosphates, mercaptans. and amines as inhibitors. The still has given information that would have been very costly, if acquired from plant equipment. W. R . POLLARD and J. V. LAWSON D-X Sunray 0 1 1 Co.,Tulsa, Okla.
A mathematical study was made of temperature profiles in a gas-solids bed in exchanger or reactor tubes being heated or cooled externally. The gas streams may flow in either fixed or moving beds of solids. Analytic equations were developed for predicting temperature profiles in beds under the following conditions of heating or cooling on the shell side: con- and countercurrent shell fluid, shell fluid a t constant temperature, and constant heat flux along tube height. Assumptions are rodlike gas flow, uniform gas velocity, constant effective thermal conductivity, existence of film resistance next to tube wall, and negligible thermal conduction in directions of material flows. Equations provide accurate solutions for uniform gas velocity; for nonuniform velocity average effective thermal conductivities should be used. ANDREW P. T l N G Catalytic Construction Co., Phlladelphla, Pa. --------------------______I
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November 1955
INDUSTRIAL AND ENGINEERING CHEMISTRY
53 A
Sodium Met hyla te
SPEC1ol
Packaged in airtight steel drums of 25, 50 and 200 Ibs. net Free Flowing white hygroscopic p o w d e r Sensitive to a i r a n d moisture
Packs 4.6 pounds per g a l l o n Formula NaOCH3 Formula W e i g h t
54.03
also available
Sodium Methylate SPEC 102
425 pounds
Packaged in Steel Drums
H a r s h a w warehouses h a v e b e e n geographically located a n d amply stocked to fill your orders a n d ship
net
25% solution of sodium m e t h y l a t e in m e t h a n o l
them without delay.
If
you have a
problem our technical service men Sodium Methylate Content
will work with you toward its solution.
24.5 to 25.5%
T H E H A R S H A W C H E M I C A L CO. 1945 East 97th Street, Cleveland 6, Ohio Chicago 32, Illinois
Cincinnati 13, Ohio
Lor Angeles 22, California
Detroit 28, Michigan
N e w York 17, N. Y.
Houston 11, Texas
Philadelphia 48, Pennsylvania
Pittsburgh 22, Pennsylvania
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54 A
INDUSTRIAL AND ENGINEERING
CHEMISTRY
Vol. 47, No. 11
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Preparation of tert-Alkylbenzoic Acids by Liquid Phase Catalytic Oxidation X tn-o-stage process for the synthesis of tert-alkylbenzoic acids has been developed, in which toluene is alkylated with a tertiary olefin. The resulting tert-alkyltoluene is oxidized in the liquid phase with air, using a cobalt catalyst. By varying the olefin and the alkylation catalyst, a variety of acids can be produced from readily available raw materials. p-tert-Butylbenzoic acid, the simplest member of the series, is now in commercial production. G. W. HEARNE, T. W . EVANS, V. W. BULS, and C. G. SCHWARZER Shell Development Co., Emeryville, Calif.
Sulfonation with Sulfur Trioxide. Anhydride Formation with Detergent Alkylate Freshly prepared aqueous slurries of the sodium salt of dodecylbenzenesulfonic acid, using sulfur trioxide vapor as sulfonating agent, tend to become acid on standing (“acid drift”). This study was undertaken to determine the cause of this undesirable situation and remedy it. The causative agent mas isolated and identified as the sulfonic acid anhydride. A study of the relationship between anhydride content of the product and the conditions used during sulfonation showed that anhydride could be removed from the slurry by several procedures, the most practical comprising addition of 1% by weight of water to the crude sulfonic acid. The data obtained in this study have found industrial application in the manufacture of this important type of sulfonate. E. E. G I L B E R T and BENJAMIN VELDHUIS General Chemical Division, Allied Chemical & Dye Corp., Morris Township, N. J .
Ind. Eng. Chem., 47, 2313 (1955)
Split-Treatment Softening of Water This work was undertaken to determine under what conditions split-treatment softening can be used. Equations are developed that permit, from an analysis of the raw water, evaluation of the results to be expected from split-treatment operation. Lime softening, limesoda softening, and lime-zeolite softening are considered. The use of these equations makes it possible to establish the percentage of water to be bypassed and the chemical dosages required to produce an effluent of the desired quality. Costs of split treatment can be compared with costs of conventional treatment, so that advantage can be taken of the very substantial economies frequently offered by split treatment. J. R . ROSSUM California Water Service Co., San Jose, Calif.
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Ind. Eng. Chem., 47, 2317 (1955)
I n d . Eng. Chem., 47, 2304 (1955)
*
Epoxy Esters as Plasticizers and Stabilizers for Vinyl Chloride Polymers
Fractional Carbonization of Wyoming Noncoking Coals
A new class of primary epoxy plasticizers, epoxidized diacetomonoglycerides, promising with vinyl chloride polymers, was prepared from fats and studied. Certain of these are comparable or superior to di(2ethylhexyl) phthalate and are light stabilizers. None was effective as a heat stabilizer. The commercially available epoxidized oils and esters were also examined. To broaden the study and obtain information on the relationship of structure to plasticizing ability, approximately 25 additional compounds mere prepared. The outstanding members of this last group, with respect to low temperature characteristics and efficiency, are 2ethylbutyl epoxystearate, epoxidised butyl esters of tall oil, and methoxyethyl, acetoxyethyl, glycidyl, tetrahydrofurfuryl, cyclohexyl, phenyl, and benzyl epoxystearate.
One of the main objectives of the Yatural Resources Research Institute, University of Wyoming, is development of char from noncoking coals suitable for metallurgical use. I n order to further knowledge of by-products recoverable in a charring operation, a laboratory method vias developed to carbonize suitable coals progressively and to analyze tar yields and gas quantities recoverable in several fractions with increasing carbonization temperature. Definite temperature limits were determined for tar recovery and gas quality. A practical method was developed to recover high-hydrogen gas fractions. I n producing char with 27, volatile matter from Wyoming coals, 50% of the evolved volatile matter can be recovered practically free of condensables and with a hydrogen content of 50 to 60%. A 300-pound-per-day pilot plant was built to prove these conclusions.
LEE P. W I T N A U E R , H. B. K N I G H T , W. E. PALM, R. E. KOOS, W . C. AULT, and D A N I E L SWERN Eastern Regional Research Laboratory, Philadelphia 18, Pa.
of Wyoming, Laramie, Wyo.
...........................
November 1955
EDWARD PROSTEL and NEAL R I C E Natural Resources Research Institute, University
INDUSTRIAL AND ENGINEERING CHEMISTRY
55 A
An 80-Mile Train of New Sulfuric Acid Production!
General Chemical Expands Capacity from Coast to Coast! in an expansion that extends to all points of the compass, General Chemical is providing an additional 600,000tons of Sulfuric Acid annually, with increased production facilities . .
*** **
.
West at El Segunda and Richmond, Calif. South at Baton Rwge, La. North at Valleyfield, Que.* East at Buffalo, New York In the Mid-west at Detroit, Mich., Painerville, Ohio and E. St. louis, 111.
This means approximately 12,000more tank cars of Sulfuric Acid available to meet growing requirements of industry . . . a train load 80
Boric Chemicais for American lndu
miles long! Some of these new facilities are already in production, and the others are scheduled for completion in 1956. As America's foremost producer of Sulfuric Acid, General Chemical recognizes a responsibility to keep pace with industry's need for this vital basic chemical. No matter where you are located, you are within a short, low-cost haul of a primary producing center of General Chemical Sulfuric Acid. Remember . . in emergencies and a t all times , . . General Chemical is your dependable source of Sulfuric.
.
GENERAL CHEMICAL DIVISION A L L I E D C H E M I C A L b DYE C O R P O R A T I O N 40 Rector Street, New York 6. N. Y. Offices: Albany Atlanta Baltimore 9 Birmingham * Boston Bridgeport Buffalo Charlotte Chicago Cleveland Denver Detroit Greenville (Miss.) Houston Jacksonville Kalamazoo Los Angeles Minneapolis New York Philadelphia * Pittsburgh Providence San Francisco Seattle St. Louis Yakima (Wash.) In Wisconsin: General Chemical Company, Inc., Milwaukee +In Canada: The Nichols Chemical Company, Limited Montreal * Toronto Vanrouvor For furthier information, circle amber 56 A on Readers' Servici Card, page 111 A
56 A
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 47, No. 11
WlLFI
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Ind. Eng. Chem., 47, 2322 (1965)
Four-State Economic Analysis for Use by Chemical Industry
IMESOURCES FOR THE CHEMICAL INBUSTRY I N THE EAST SOUTH CENTRAL STATES
Alabama, Kentucky, Mississippi, and Tennessee comprise the East South Central states-the ninth geographical division covered in this series of economic analyses prepared specifically for use by the chemical industry. Reports are included on the current status and trends of the chemical industry in the area and its industrial labor supply, financial institutions, and transportation facilities. Physical resources are sufficiently diverse in this part of the United States t o warrant a separate article on the subject for each of the four states.
.--------------------------Ind. Eng. Chem., 47, 2374 (1955)
Coke Formation and Its Relationship to Cumene Cracking
GENERAL TECHNICAL AND C I E N T l F l C 4RTlCLES
The catalytic dealkylation of cumene has been recognized as a specific example of hydrocarbon cracking having definite use in characterizing cracking catalysts. In this connection the relationship of coke formation to cumene cracking is of considerable interest. Pure cumene dealkylates with almost no accompanying coke formation. Coke is apparently only indirectly connected with the rate of cracking. Rather, the cracking rate depends on the concentration of strongly adsorbed inhibitor which competes with cumene for adsorption on active catalyst sites. The inhibition of cumene cracking by basic nitrogen compounds is analogous to the effect of styrene, cumene hydroperoxide, and similar inhibitors. The rate relationship obtained was: rabe (inhibited)/rate (uninhibited) = (cumene)/[ (cumene) +K(inhibitor)]. The resultsmayhave a bearing on coke-activity relationships in gas oil cracking. C. J. PLANK and D. M. NACE Socony Mobil Laboratories, Paulsboro, N. J.
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Ind. Eng. Chem., 47, 2380 (1955) Ind. Eng. Chem., 47, 2370 (1955)
Cellulose, Raw Material for Cellophane Cellulose constitutes a large percentage of the material in a sheet of cellophane. Although many forms and types of cellulose can be used, the most economical source is wood. The present-day cellophane process needs as basic raw material a “chemical cellulose” possessing a number of highly specialized characteristics. Cellulose for film manufacture should have controlled uniformity and purity consistent with lowest possible cost, be capable of giving viscose solutions of good filterability under adverse conditions of low chemical usage, and yield films of good strength, color, and clarity. These factors are discussed in the light of the complex nature and structural nonuniformities of the native cellulose fiber. R. L. M I T C H E L L Rayonier Ine., Shslton, Wash.
........................... November 1955
Cure of Carbon Black-Unsaturated Polyester Mixtures Industry reports have indicated that carbon black could not be evaluated as a reinforcing filler in unsaturated polyester resins because of its severe cure inhibition. Cure studies on polyester-carbon black mixtures in this laboratory confirm the cure inhibiting characteristics of carbon black but reveal that in the presence of certain peroxide-promoter combinations it accelerates cure. Carbon black can now be evaluated fully as a filler in unsaturated polyester resins. Also, the carbon itself can function as an additional control of cure rate and heat build up. Carbon black in these systems prolongs the shelf life of catalyzed resins but accelerates the polymerization when promoter is added. This combination of properties should interest fabricators concerned with the weathering, high speed drying, and low specific gravity of polyester castings. C. W. SWEITZER, F. L Y O N , and T. S. GRABOWSKI Columblan Carbon Co., 214-44th St., Brooklyn 32, N. Y.
INDUSTRIAL AND ENGINEERING CHEMISTRY
57 A
H CH, HO-c-e-c-ofl; I I
H
A
1
I
CHs
I
H
Characteristics: Short chain length Symmetrical Reactive
Typica I Properties :
lncreused
Crystalline Solid
Form Color
White ~124°-1300C 96y0 Minimum
M e l t i n g Point
Purity
Potential Uses: Polymeric plasticizer manufacture Polyester resin manufacture Alkyd resin modifier Interest in this isobutyraldehyde derivative has increased to such a degree that additional production has become necessary. A large pilot plant is now in operation at Longview, Texas, and semi-commercial quantities are immediately available. Write to us at Kingsport, Tennessee, for details.
other d e r i v a t i v e s of Eastman isobutyraldehyde now available include
isobutyl isobutyrate Color, APHA Ester Content Boiling Range Specific Gravity, 20°/200C Acidity, as isobutyric acid Available in pilot plant quantities
15 maximum 98% minimum 146°-1480C/760 mm 0.850-0.860 0.5% maximum
h ydroxypivaldeh yde
Eastman CHEMICAL PRODUCTS, INC. KINGSPORT, TENNESSEE subsidiary of EASTMAN KODAK COMPANY
Form Solid Color, APHA 200 maximum Assay (wet basis) SOTO minimum Assoy (dry basis) 90% minimum Available in pilot plant quantities, shipped as a wet cake fo insure sfabAify.
SALES OFFICES8 Eastman Chemical Products, Inc., Kingsport, Tenn.; New York-260 Madison Ave.; Fram2,2,4-trimethyI- 1,3-pentanedioI ingham, Masr.-65 Concord St.j Cincinnati-Carew . ._ lower; Cleveland-Terminal Tower Bldg.; ChicagoCrystalline Solid Form 3 6 0 N. Michigan Ave.; Houston-412 Main St.; St. Louis Color White -Continental Bldg. West Coast: Wilson Msyer Co., 49°-510C Melting Point Son Francisco-333 Montgomery St.; Lor AngelesPurity 9570 minimum 4800 District Blvd.; Portland-520 S. W. Sixth Ave.; Amiloblo in reseorch owntitier Salt Lake City-73 S. Main St.; Seottle--821 Second Ave. For further information, circle numbers 58 A-1, 58 A-2 on Readers' Service Card, page 111 A
58 A
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 47,No. 11
BRIEFS
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Ind. Eng. Chem., 47, 2385 (1955)
Isobaric Heat Capacities at Bubble Point
Solubility of Oxygen in White and Red Fuming Nitric Acids
Only limited experimental data are available for the heat capacity of 1,2,4- and 1,3,5-trimethylbenzenes. Such compounds are of industrial interest and thermal data for them are of practical utility. For these reasons a study of the isobaric heat capacity of these compounds was made. Heat capacities of the two trimethylbenzenes were measured in the heterogeneous region a t temperatures from 80" to 200" F. I n addition, measurements of the heat capacity of n-heptane were made in the Same temperature interval in order to check the over-all performance of the calorimeter employed. The results obtainad are in fair agreement with earlier measurements a t lower tempera tures for 1,2,4-trimethylbenzene made in this country, but were somewhat below measurements for the 1,3,5-trimethylbenzene made elsewhere.
I n studying the equilibrium 2HN03 N z O ~ HzO a knowledge of the amount of oxygen dissolved in the equilibrium mixture is helpful in calculating the equilibrium constant. No data were available on the solubility as a function of system composition, as opposed to the amount absorbed both physically and chemically. The solubility of oxygen in nitric acid solutions containing only water or only dinitrogen tetroxide as diluents has been determined a t ambient temperature (25' C.) in the pressure range 1 to 20 atm. It was found to decrease with increasing amounts of water or dinitrogen tetroxide, passing through a minimum in the region 80 t o 8573 nitric acid by weight. The results, in conjunction with other work at higher temperature, substantiate the conclusion that the solubility increases with increasing temperature in the range 25' to 88' C.
P. F. HELFREY, D. A. HEISER, and 6. H. SAGE California Institute of Technology Pasadena, Calif.
U. S. Naval Ordnance Test Station, Inyokern, China Lake, Calif.
~
A study intended to evaluate organopolysiloxane elastomers and resins as materials of construction around radiation sources of high intensity showed that vulcanization of organopolysiloxane elastomers by radiation gave rubbers of superior high temperature performance. The effects of radiation from four different sources were parallel to those reported recently for a number of organic polymers. The greatest differences mere in the precise nature of the chemical effects. The same equivalence of energy, regardless of source, was observed with dimethylpolysiloxanes as for organic polymers. The few phenomena already observed on radiating dimethylpolysiloxanes with two types of source were confirmed. E. L. W A R R I C K Mellon Institute, Pittsburgh 13, Pa.
+
ROBERT W. SPRAGUE
Ind. Eng. Chem., 47, 2398 (1955)
Ind. Eng. Chem., 47, 2388 (1955)
Effects of Radiation on Organopolysiloxanes
+
1/202,
Estimating Thermal Conductivities for Nonpolar Gas Mixtures. Simple Empirical Method I n heat transfer problems involving gases, the thermal conductivities of gas mixtures are often required. Direct measurement may be difficult or impossible. An empirical technique for estimating conductivities of mixtures of nonpolar gases is presented. Comparison with measured values from the literature shows an average error of 2.6% with a maximum error of 11.4%. Mixture thermal conductivities may be estimated quickly; only the composition of the mixture and conductivities of component gases are required. Accuracy is comparable to that of the more complicated methods which have been proposed heretofore. R I C H A R D S. BROKAW National Advisory Committee for Aeronautics Lewis Flight Propulsion Laboratory, 21000 Brdokpark Rd., Cleveland, Ohlo
Ind. Eng. Chem., 47, 2393 (1955)
Ignition Temperatures of lead Compound-Carbon Mixtures As part of an over-all study of the preignition problem, ignition temperatures of various lead compound-carbon mixtures were determined under controlled laboratory conditions. The results of such experiments are useful as a guide in selecting various classes of compounds for testing as preignition-controlling gasoline additives. Of the 21 lead compounds tested, 19 reduced the carbon ignition temperature. Those compounds commonly found in engine deposits were among the more powerful catalysts. This observation is consistent with generally accepted theories concerning preignition. Neither lead orthophosphate nor lead pyrophosphate had any noticeable effect on the carbon ignition temperature. These experiments suggest that compounds containing phosphorus would probably be the most effective preignition-controlling gasoline additives.
Ind. Eng. Chem., 47, 2401 (1955)
Variations in Processing and Physical Properties of Oil Masterbatches with Increasing Oil Content Systematic study of the effect of naphthenic oil concentration in masterbatched polymers on vulcanizates compounded with three types of blacks a t different loadings showed the best balance of physical and processing properties with maximum oil extension with raw masterbatched polymer having a RIooney viscosity of about 60 AIL-4. Detailed information is presented on variation in properties when Mooney viscosity, sulfur level, and acceleration are varied along with oil content. W. K. T A F T ,
B. G. LABBE, and R. W. LAUNDRIE Government Laboratories, University of Akron, Akron, Ohio
GEORGE J. NEBEL and PAUL L. C R A M E R General Motors Corp., Detroit, Mich. --------------------_______I
November 1955
INDUSTRIAL AND ENGINEERING CHEMISTRY
59 A
