Briefs
MARCH 1957
I/EC
l/EC's articles on . . .
CHEMISTRY AND CHEMICAL ENGINEERING IN THEORY AND PRACTICE
The why, what, and significance of technical articles in this issue. Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
. . . begin on page 3 2 2
(Ind. Eng. Chem. 49, 334 1957)
Phosphoric Acid by the Clinker Process
STAFF-INDUSTRY COLLABORATIVE REPORT
Dried and ground phosphate rock and strong sulfuric acid are mixed to form a puttylike solid and convert calcium oxide to calcium sulfate anhydrite with a slight excess of sulfuric acid. The reaction product is heated at 200° to 240° C. for 20 to 60 minutes to form a hard clinker. Phosphoric acid is separated from insoluble calcium sulfate by countercurrent extraction. Strong (50% phosphorus pentoxide) phosphoric acid is produced directly without concentration. Mineral food supplements can be manufactured without fluorine removal. Phosphoric acid may be recovered by either filters or leach tanks. Total process time is less than 60 minutes, compared to many hours by other wet processes. Almost 90% complete evolution of fluorine from rock makes possible recovery of a valuable by-product. C. C. LEGAL, Jr., J . N. PRYOR, T. O. TONGUE, and P. L. VELTMAN Davison Chemical Co., Baltimore 3, M d .
Ind. Eng. Chem. 49, 322 (1957)
Boron Chemicals from Searles Lake Brines Production of boron chemicals has more than doubled in the past decade, but real growth lies ahead as chemists succeed in developing new organoborons and as boron finds its place in such applications as fuels and radiation shielding. The U. S. has about 95% of the world's boron reserves. American Potash & Chemical Corp., one of three major basic producers, recovers crude borax from brines of Searles Lake by fractional crystallization from partially evaporated brine. The crude borax is then refined into sodium tetraborate decahydrate and sodium tetraborate pentahydrate by close temperature control in vacuum crystallizers. Anhydrous borax is also produced by heating borax to its fusion temperature to drive off water of hydration.
Ind. Chem. Eng. 49, 338 (1957)
Soap and Detergent Pilot Plant The new Colgate-Palmolive Co.'s pilot plant is described in detail, and problems which occurred in the design and construction of the plant are discussed. Flowsheets are given for five different typical soap and detergent pilot plant units, and photographs show details of special equipment. A general discussion of pilot plant operation points out some problems. There is also a brief discussion of the correlations which have been established between pilot plant experimental results and factory production. ROBERT F. HEALD Colgate Palmolive Co., Jersey City, N. J .
GORDON H. BIXLER and D W I G H T SAWYER
VOL. 49, NO 3
»
MARCH 1957
11 A
BRIEFS
Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 49, 347 (1957)
Distillation Improvement by Control of Phase Channeling in Packed Columns The large detrimental effect of a small amount of channeling in packed columns has been analyzed and simple equipment designed to control channeling and to increase efficiency. A packed tower has a higher efficiency when interdistributor screens are placed within the packed bed. Over 50 theoretical plates were obtained in a packed bed 6 inches in diameter and 12 feet high with protruded stainless steel packing when operating near the flood point. The efficiency is even greater at lower vapor velocities. The use of interdistributor screens is an inexpensive method of improving the efficiencies of packed towers. R. E. M A N N I N G and M. R. CANNON Department of Chemical Engineering, The Pennsylvania State University, University Park, Pa.
Ind. Eng. Chem. 49, 360 (1957)
Solvent Extraction of Wax and Ursolic Acid from Cranberry Skins Cranberry skins were extracted in a continuous countercurrent solvent extraction pilot plant by trichloroethylene and ethylene dichloride to remove a mixture of waxes and ursolic acid. Because of the low solubility of the solute a solvent-feed ratio of 25 was found to be desirable. The skins were extracted by the conventional method by trichloroethylene and by a cyclic process involving reuse of the solvent by trichloroethylene and ethylene dichloride. In this cyclic process the hot solution from the extractor was cooled to precipitate part of the solute and then heated and used as a solvent. Extraction costs are estimated to be approximately 37.5 cents per pound of solute. LIONEL K. ARNOLD and PONG R. HSIA Iowa Engineering Experiment Station, Iowa State College, Ames, Iowa
Ind. Eng. Chem. 49, 350 (1957)
Electrolytic Preparation ot Periodate Oxystarch A convenient, inexpensive electrolytic method has been devised for preparing periodate oxystarch. Starch, suspended in the anolyte of a divided cell, was completely oxidized to oxystarch by periodic acid formed electrolytically from iodic acid present; only 7.5% of the theoretical quantity was required for efficient conversion. Optimal conditions for the electrolysis were found by investigating the effect of current density, time, temperature, pH, concentration of iodic acid and starch, and diaphragm and anode composition. A quantitative yield of product was obtained at relatively high current efficiency with low loss of oxidant. Anolyte filtrates were effectively recycled a number of times; oxidant could be recovered if desired. The procedure may also be useful for the periodate oxidation of other polysaccharides or organic substances.
Ind.
Eng. Chem. 49, 364 (1957)
Water-Soluble Ethylhydroxyethylcellulose Coetherification with ethylene oxide improves the water ; solubility of ethylcellulose considerably and the resultant cellulose ether, ethylhydroxyethylcellulose, has been produced commercially in Sweden since 1945. Method of manufacture and analytical problems are outlined briefly, but physicochemical properties are treated more fully. In many of its properties, such as solubility only in cold water, it resembles methylcellulose, but in this article, emphasis is placed on differences and properties for which few data have been available. INGVAR JULLANDER Research Laboratory, Mo och Domsjo AB Ôrnskëldsvik, Sweden
C. L. MEHLTRETTER, J . C. RANKIN, and P. R. WATSON Northern Utilization Research Branch, U. S. Department of Agriculture, Peoria, III. Ind. Eng. Chem. 49, 355 (1957)
Carbonization of Agglomerating Coals in a Fluidized Bed In a pilot plant program for a continuous, fluidized-bed process for low-temperature carbonization of Alabama coking coals, agglomeration was best overcome by internal blending of raw coal with a stream of at least 10 parts of hot char. Heat was provided by internal combustion of char with air. Internal combustion in the presence of volatile products did not appreciably reduce tar yields. Yields were 1600 pounds of fuel char, 21 gallons of tar, and 13,000 cubic feet of 140 B.t.u. gas per ton of coal charged. Typical tar had a specific gravity of 1.10 and a pitch content of 51.8%. Distillable oil from tar contained 28.5% tar acids, 2.9% tar bases, and 68.6% neutral oil. Neutral oil contained 8.1% olefins, 47.3% aromatics, and 44.6% saturated hydrocarbons. This one-vessel process, integrated with a conventional steam boiler should produce tar at a break-even cost of $0.07 per gallon. E. W. LANG, H. G. S M I T H , and CARL BORDENCA Southern Research Institute, Birmingham, Ala.
Ind. Eng. Chem. 49, 369 (1957)
Pyromellitic Dianhydride in Curing of Epoxy Resins Pyromellitic dianhydride, used in combination with other anhydrides such as maleic or phthalic anhydride to overcome the incompatibility of pyromellitic dianhydride in epoxy resins, gave cured resins with exceptionally high heat distortion temperatures. These temperatures (200° C. for pyromellitic-phthalic anhydride and 250° C. for pyromellitic-maleic anhydride) are higher than those obtained with other commonly used epoxy curing agents. Resins cured by the pyromellitic-maleic anhydride mixture showed much better resistance to prolonged heat aging than did resins cured with the pyromellitic-phthalic anhydride mixtures. Physical and electrical properties were good and chemical resistance was excellent. R. B. FEILD and C. F. ROBINSON Eastern Laboratory, Explosives Department, E. I. du Pont de Nemours &• Co., I n e , Gibbstown, N.J.
VOL. 49, NO. 3
·
MARCH 1957
13
A
BRIEFS
Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 49, 374 (1957)
1,2,6-Hexanetriol in Alkyd Resins 1,2,6-Hexanetriol, a new polyol made by the dimerization of acrolein followed by hydrolysis and hydrogénation, has been studied for use in alkyd resins for surface coatings. Compared to glycerol alkyds, hexanetriol alkyds yield films which are softer but decidedly more flexible. This excellent flexibility has permitted the combination of hexanetriol baking alkyds with large proportions of aminoformaldehyde resins. These combinations are characterized by 61ms having excellent retention of flexibility, impact resistance, and color upon being subjected to simple aging, heat-aging, or overbaking. In outdoor exposure tests, the use of hexanetriol in place of glycerol in air-drying alkyds gave films having better gloss retention and greater resistance to cracking and chalking.
SYMPOSIUM ON INDUSTRIAL GASES
ROY W. TESS, RICHARD D. HARLINE, and THOMAS F. M I K A Shell Development Co., Emeryville, Calif.
Ind. Eng. Chem. 49, 379 (1957)
Acrylonitrile in Styrenated Alkyd Resins Styrenated alkyds have a prominent place in the coating resin field because of their fast drying qualities, high gloss, and excellent chemical resistance. Their use in certain applications, however, has been limited by low resistance to oils, greases, and hydrocarbon solvents. Therefore, acrylonitrile as a partial replacement for styrene was investigated. Interpolymers were prepared by allowing acrylonitrile and styrene or methylstyrene to react in different ratios with a linseed and with a double distilled tall oil fatty acidmodified glycerol phthalate alkyd resin. Increasing the proportion of acrylonitrile improved solvent resistance, drying rate, and resistance to chalking and bronzing in enamels during early stages of exterior exposure.
Ind. Eng. Chem. 49, 387 (1957)
Cyclic Catalytic Reforming Process The United Gas Improvement Co.'s cyclic catalytic reforming process uses a fixed catalyst bed and operates on the cyclic principle. It reforms natural gas, propane, butane, gasoline, naphtha, and kerosine to produce a high hydrogen-content carrier gas for mixing with other gases to obtain the desired chemical composition for meeting gas utility sendout requirements. Recently, tests have been made to produce 500- to 1000-B.t.u. gases from Diesel oil, gas oil, and Bunker C oil. This process also produces ammonia synthesis gas from natural gas. C. G. MILBOURNE and C. B. GLOVER United Engineers & Constructors, Inc., Philadelphia, Pa.
J. C. PETROPOULOS, L. E. CADWELL, and W. F. HART American Cyanamid Co., Stamford, Conn.
Ind. Eng. Chem. 49, 382 (1957)
Polyvinyl Alcohol) as an Emulsifying Agent in Vinyl Polymerizations The emulsifying action of poly (vinyl alcohol) is well known in the preparation of poly (vinyl acetate) emulsion. Fine particle latices can be obtained by polymerizing other vinyl monomers emulsified with poly(vinyl alcohol). Polystyrene latices have been prepared using a low viscosity poly(vinyl alcohol) containing residual acetate groups in conjunction with an anionic surface-active agent. Polyv i n y l chloride) latices have also been formed in the presence of a medium viscosity poly(vinyl alcohol) containing no residual acetate groups. Butadiene-styrene copolymer latices have been obtained with emulsifier combinations similar to those used to prepare the polystyrene products. J. N. COKER Electrochemicals Department, E. I. du Pont de Nemours &. Co., Inc., Niagara Falls, Ν. Υ.
Ind. Eng. Chem. 49, 392 (1957)
Recovery of Sulfur Dioxide from Flue Gases Four processes for recovering sulfur dioxide in useful form from coal combustion gases were investigated on a small scale. In the direct and indirect sulfuric acid processes, either a combination of manganese ion and ozone is used to catalyze oxidation, or sulfur dioxide is absorbed and oxi dized by a slurry of regenerated manganese oxide. In the direct ammonium sulfate process, a combination of manganese ions and ozone is used to catalyze oxidation; in the direct phosphatic fertilizer process, sulfur dioxide is absorbed by a slurry of rock phosphate to render the phos phate soluble. All except the last process appear technically feasible; however, the indirect sulfuric process is most promising. GRADY TARBUTTON, J. C. DRISKELL, T. M.JONES, F. J. GRAY, and C. M. S M I T H Division of Chemical Development, Tennessee Valley Authority, Wilson Dam, Ala.
VOL. 49, NO. 3
·
MARCH 1957
15 A
BRIEFS
Clip these Briefs for r e a d y reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 49, 396 (1957) Ind. Eng. Chem. 49, 411 (1957)
Kinetics of Carbon Gasification This article extends to temperatures of 1500° and 1700° F. experimental data on the kinetics of interaction between hydrogen-steam mixtures and low temperature char. These data and those previously reported have been integrated into a single empirical correlation which fits the mass of data collected on differential rates of char gasification. The correlation is valid over the temperature range of 1500° to 1700° F., pressure from 1 to 30 atm., and gas compositions ranging from 10% hydrogen in steam mixtures to pure hydrogen. Data are also presented on surface area and reactivity of char, showing that surface area developed by gasification of char is independent of gas composition. The mechanism of methane formation is discussed. This information should be useful in interpreting and extrapolating to commercial design, pilot plant data on char gasification. C. W. ZIELKE and EVERETT GORIN Research and Development Division, Pittsburgh Consolidation Coal Co., Library, Pa.
New Still and Method for Determining Vapor-Liquid Equilibrium Vapor-liquid equilibrium data for a given system are often not available and are difficult to obtain by conventional methods. A new apparatus and method capable of giving reliable equilibrium compositions are described. The apparatus is a modification of the conventional recirculation type. The method depends upon a knowledge of the weight and com position of the liquid phase before and after a sample of vapor has been taken. The composition of the liquid is determined by referring its boiling temperature to a previ ously constructed temperature-composition curve. Data for the acetone-methanol and allyl alcohol-water systems are reported and compared with literature data. BILLY G. HARPER and JOHN C. MOORE Texas Division, Dow Chemical Co., Freeport, Tex.
Ind. Eng. Chem. 49, 404 (1957
Koppers-Hasche Pilot Plant Producing Natural Gas Substitute and Low Heating Value Gas The Koppers-Hasche furnace can reform hydrocarbon gases for producing either natural gas substitute or gases of low calorific value. This article, the first on cyclic noncatalytic operation for producing city gas by this process, describes pilot plant tests for reforming natural gas and propane. Heating requirements for the pilot plant are about 25% of the feed requirements for reforming. Maximum effi ciencies are obtained at space velocities of 600 and 700 and reaction temperatures of about 2500° F. Carbon contained in the gas leaving the reformer, 3 to 4% by weight of feed, is readily removed by conventional gas cleaning equipment.
Ind. Eng. Chem. 49, 415 (1957)
Linear Boiling Point Relationships Linear boiling point relationships were observed among various series of simple aliphatic compounds, RX, where R varies within a series. Boiling point temperatures can be found by the simple equation, t — py + q, where p and q are constants depending on functional group X, and y is a constant which varies with change in alkyl group R. Dis crepancies occurring are discussed on the basis of association and resonance. YOSHIRO OGATA and MASARU TSUCHIDA Department of Industrial Chemistry, Kyoto University, Yoshida, Kyoto, Japan
J. F. FARNSWORTH, G. M. BRETZ, and G. V. McGURL Koppers Co., Inc., Verona, Pa.
Ind. Eng. Chem. 49, 410 (1957)
Changes in Iron Catalyst and the Fischer-Tropsch Synthesis A precipitated iron and copper oxide—potassium carbonate catalyst and both reduced and nitrided samples of a pro moted, fused iron oxide of the type used in ammonia syn thesis were investigated. After synthesis, precipitated catalysts had virtually no surface area or pore volume. For reduced catalysts, con verted largely to magnetite and carbides, total volume increased, but pore volume and surface area were nearly zero. Nitrided catalysts had a small pore volume and sur face area, but total volume was relatively large. Thus, changes in iron catalysts during synthesis may be extensive and must be considered when designing FischerTropsch process equipment. KARL G. STEIN, GORDON P. THOMPSON, and ROBERT B. ANDERSON Division of Solid Fuels Technology, Bureau of Mines, Bruceton, Pa.
Ind. Eng. Chem. 49, 418 (1957)
Thermal Conductivity of Liquids Determinations of thermal conductivity were carried out as part of a program to supply physical data on coal tar compounds. A general equation for commercial distillates is proposed: ΙΟ5 Κ = 32 - 0.02 t cal./cm. sec. ° C. Many of the values for pure samples of coal tar compo nents have not been previously recorded; those which bave are in good agreement with earlier workers, at 20° C. Al though there is good agreement in the literature on values at room temperature, high temperature data show wide divergences, resulting in uncertainty as to the variation of thermal conductivity with temperature. D. K. H. BRIGGS Coal Tar Research Association, Gomersal, nr. Leeds, Yorks, England
VOL. 49, NO. 3
·
MARCH 1957
17 A
BRIEFS
Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 49, 437 (1957) Ind. Eng. Chem. 49, 422 (1957)
Physical Properties of Asphalts in Thin Films To investigate the concept that asphalts in thin films behave like solids, the force per unit area necessary to break an asphalt film contained between two flat steel surfaces was determined at 17 ° F. At film thicknesses between 0.002 and 0.007 cm. rupture occurred without indication of flow and asphalts behaved like solids. For a given asphalt the logarithm of film strength increased linearly with the logarithm of film thick ness to a maximum and then decreased. Relation between bearing strength and asphalt content of sand-salt mixtures prepared with two asphalts varies with film strength and thickness. Calculated film thicknesses at optimum asphalt content are of the same order of magnitude as optimum film thicknesses between steel surfaces. CHARLES MACK Research Department, Imperial Oil, Ltd., Sarnia, Ontario, Canada
Ind. Eng. Chem. 49, 428 (1957)
Variation of Heat-Transfer Coefficient with Length for Inclined Tubes in Still Air In determining film coefficients of heat transfer from a hot surface to air, measuring the surface temperature is essen tial. Attaching thermocouples to the heating surface gives only approximate results. A method for determining the surface temperature of the tube has been developed, which allows accurate measure ment without attaching anything to the surface. Temperature distribution and calculated local film co efficients for free convection along a typical tube (0.125 inch in outside diameter and 0.095 inch in inside diameter) were obtained for horizontal, vertical, and inclined posi tions. Identical tubes of average length showed the highest average heat transfer coefficient when vertical and the lowest when inclined at about 75 degrees from horizontal. ERICH A. FARBER and H. O. RENNAT University of Florida, Gainesville, Fla., and University of Wisconsin, Madison, Wis. Ind. Eng. Chem. 49, 441 (1957)
Measuring Solids Concentration in Fluidized Systems by Gamma-Ray Absorption
Permeation, Diffusion, and Solubility of Methyl Bromide and Isobutene in Polyethylene
Knowledge of solids concentrations in fluidized systems is often important in design and operation of processes embodying fluidization. A gamma-ray absorption tech nique, developed for measuring density and density dis tribution within pilot plant and commercial scale units, is applicable to all heterogeneous systems; the equipment, mounted externally, does not interfere with the process under study. An equation expressing average density along any path in terms of path length, mass absorption coefficient, and radiation intensity under flow and nonflow conditions was developed from the Lambert-Beers law of exponential absorption. The density pattern is obtained either graphically or analytically from a number of such measurements. Use of the gamma-ray technique is illus trated by its application to a transverse section of a catalyst riser in a fluid catalytic cracking unit.
In permeation of methyl bromide and of isobutene through polyethylene films, in some regions of pressures and temperatures the permeability constant increases with decreasing temperature. This is due to the plasticizing effect of the sorbed gas which increases the diffusion con stant D, and to the deviation from Henry's solubility law at higher concentration of the sorbed vapor. Indications are that this phenomenon is general. Study of sorption isotherms of the systems methyl bromide—polyethylene and isobutene-polyethylene show that the Flory-Huggins equation applies well to these systems assuming, however, that only the amorphous regions of the polymer are involved in the sorption process. On this basis the interaction parameter, μ, was determined to be 1.32 for the methyl bromide -polyethylene system and 0.84 for the isobutene-polyethylene system.
R. N. BARTHOLOMEW and R. M. CASAGRANDE Shell Oil Co., Inc., Houston, Tex.
I. SOBOLEV, J . A. MEYER, V. STANNETT, and M. SZWARC State University of New York College of Forestry, Syracuse 10, Ν. Υ. Ind.
Ind. Eng. Chem. 49, 432 (1957)
Spontaneous Ignition Temperature of Hydrocarbons The spontaneous ignition of hydrocarbons on hot surfaces and their vapor-phase oxidation in a flowing system may proceed through the same chemical intermediates, if physi cal factors are suitably considered. This work attempts to establish such a relationship. The spontaneous ignition temperatures are greatly dependent on the surface-volume ratio of the apparatus; this dependence and the effect of pressure can be con veniently illustrated by a three-dimensional diagram. The values for the minimum spontaneous ignition tempera ture of various hydrocarbons correlate well with the relative case of oxidizing these hydrocarbons in a vapor-phase flowing system as judged from product analysis. DONALD E. SWARTS and M I L T O N ORCHIN Applied Science Department, University of Cincinnati, Cincinnati 21, Ohio
Eng. Chem. 49. 445.(1957)
Swelling of Nitrile Rubbers by iso octane-Toluene Blends A 70 to 30 by volume blend of iso-octane and toluene is commonly used to evaluate the resistance of a rubber to gasoline. The swelling of the rubber caused by the solvent mixture is an important criterion of this resistance. The relative distribution of the solvent components between the solvent phase and the rubber was investigated, using vul canized gum nitrile rubbers of various acrylonitrile con tents and radioactive toluene. Toluene is preferentially absorbed from the mixtures. The results obtained indicate by interpolation that if a rubber of about 40% acrylonitrile content was immersed in the 70 to 30 blend, the volume ratio of iso-octane and toluene in the nitrile rubber at equilibrium would be 11 to 89. With a 50 to 50 blend, very little iso-octane would be absorbed, and all the solvent in the swollen nitrile rubber would be toluene. The tendency for preferential absorption of toluene lessens as acrylonitrile content is decreased. ROSS E. MORRIS and PAUL T. WAGNER Mare Island Naval Shipyard, Vallejo, Calif.
VOL. 49, NO. 3
·
MARCH 1957
19 A
