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CHEMISTRY AND CHEMICAL ENGINEERING IN THEORY AND PRACTICE The why, what, and significance of technical articles in this issue. Clip these Briefs for r e a d y reference and easy filing on a 3 X 5 or other suitable card
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Rocket Propellants I n d . Eng. C h e m . 49, 1337 (1957)
I n d . E n g . C h e m . 49, 1331 (1957)
Fluorine-Derived Chemicals as Liquid Propellants
Utilization of High-Energy Fuel Elements
Fluorine a n d its derivatives—the halogen fluorides, nitrogen trifluoride, a n d oxygen difluoride—should be among the most powerful oxidizers for use with a p p r o p r i a t e fuels like h y d r a z i n e a n d ammonia, to propel rockets. Fluorine is substantially superior in performance to oxygen a n d nitric acid, a n d would b e equaled only b y some fuel combinations with ozone. Fluorine will inevitably become an important rocket chemical. T h e r e remains the task of learning to produce it cheaply, h a n d l e a n d ship it safely, and exploit it effec tively in reliable engines. Resources available to the missile industry a r e adequate for any contemplated test p r o g r a m that can now b e p r e dicted.
Theoretical considerations indicate that only derivatives of lightweight elements should be considered for superior high-energy liquid propellants. Boron-containing materials offer high promise for such uses, a n d a program of research a n d development in these fields is in progress. This endeavor has resulted in a series of liquid fuels known as H E F , which are currently being developed. Success also has b e e n achieved in developing other n e w propellants a n d these, along with the H E F fuels, are being evaluated for use in new missile a n d aircraft systems. E A R L A. W E I L M U E N S T E R O l i n M a t h i e s o n C h e m i c a l C o r p . , Niagara Falls, Ν . Υ .
J . F. G A L L Pennsalt C h e m i c a l s C o r p . , P h i l a d e l p h i a , Pa. I n d . E n g . C h e m . 49, 1333 (1957)
Applied Research and Product Development for Rocket Propellants
I n d . Eng. C h e m . 49, 1339 (1957)
Liquid Rocket Propellants. Is There an Energy Limit?
In developing rocket propellants safety is the first con sideration, b u t other requirements must b e satisfied: e n e r g y released p e r unit weight a n d volume of propellant, variation of b u r n i n g rate with t e m p e r a t u r e a n d pressure, physical properties, ease of ignition, p r o p e r t y changes d u r i n g storage a n d handling, a n d method of installing in rocket motor. After laboratory tests, pilot plant tests determine safety of materials on a larger scale, followed b y scale-up of in gredients, with special provision for remote control in early stages. Tests on a static r a n g e a n d finally on the flight r a n g e , u n d e r all conditions to be met in field use, eliminate many materials, b u t enough develop to provide a steady advance. Much progress has b e e n m a d e , b u t greater achievements are a h e a d .
Answers to five questions are offered: W h a t a r e the a d vantages to b e derived from high energy propellants in j e t propulsion? W h e r e do liquid chemical rocket propellant systems available today fit in a rocket propellant energy listing? What higher e n e r g y values can be achieved from molecular self-energizing systems? W h a t are the funda mental obstacles to development a n d application of these u p p e r limit chemical systems? W h a t will be the chemical constituents of future high e n e r g y chemical systems? T h e r e is an e n e r g y limit to liquid rock;et propellants, set u p b y the laws of chemistry a n d physics. Molecular dissociation, molecular weight, a n d molecular b o n d energies are the triple agents at the e n e r g y b a r r i e r . But we a r e not yet at that b a r r i e r a n d may expect n e w engines of h i g h e r specific impulse t h a n those now available.
A L L E N R. D E S C H E R E Redstone Arsenal Research Division, R o h m & Haas C o . , H u n t s v i l l e , A l a .
J . F. T O R M E Y Rocketdyne, A Division of N o r t h A m e r i c a n A v i a t i o n , I n c . , Canoga P a r k , C a l i f .
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Ind. Eng. Chem. 49, 1349 (1957) Ind. Eng. Chem. 49, 1344 (1957)
Homogeneous Solid Propellants and the Chemical Industry Homogeneous solid propellants have a long and honorable history of military application, and this is expected to continue. New methods of manufacture have been devised as needed, and the chemical industry is able to meet production requirements. The large installed capacity will need some modification as newer and larger weapons are used, but the basic facilities for production of nitrocellulose and nitroglycerin are there. The significant raw materials— cellulose, glycerol, and nitric acid—are available, and the requirements for a future war will probably be substantially below the peaks of World War II. LYMAN G. BONNER Hercules Powder Co., Wilmington, Del.
Continuous Cold Trap for Fluoride Volatility Processing of Uranium Reprocessing of enriched uranium solid fuels by both volatilization from a fused salt, and sorption-desorption purification, requires final condensation of uranium hexafluoride in a solids condenser or cold trap. Work has been done to develop a fluidized condenser for a continuous cold trap. Using the system, iodine-nitrogen, and an internally cooled fluidized bed of inert carrier, tests showed that a fluidized cold trap design is feasible. In addition to the potential advantage of continuous operation, the fluidized condenser principle may reduce heat transfer area requirements b y more than a factor of 10 w h e n compared with a. batch cold trap. J. C. BRESEE and P. R. LARSON Engineering Practice School, Massachusetts Institute of Technology, Oak Ridge, Tenn.
Ind. Eng. Chem. 49, 1355 (1957)
Ind. Eng. Chem. 49, 1345 (1957)
Chemical Lessons Learned from Nike Ajax Development The Army's Nike started coming off the production line before its developers were sure it could satisfy certain operating requirements. These suspicions were later confirmed and a major overhaul of the propellant system was undertaken. The fuel was changed from JP-3 to JP-4 and small amounts of unsymmetrical dimethylhydrazine were added to increase reactivity. The oxidizer was changed from white fuming nitric acid to red fuming nitric acid. Addition of slight amounts of hydrofluoric acid to the nitric acid reduced the corrosion rate on aluminum and stainless steel essentially to zero. R. B. CANBRIGHT Douglas Aircraft Co., Inc., Santa Monica, Calif.
Liquid-Liquid Extraction of Zinc Chloride from Sulfate with Furfural Feasibility has been studied for separating zinc chloride and zinc sulfate in aqueous solution by liquid-liquid extraction, using furfural as the solvent. The process has practical as well as theoretical interest. Over the temperature range studied, 25° to 75° C , furfural shows excellent selectivity for the separation. Degree of extraction is increased by raising salt concentration and lowering temperature. Distribution coefficients up to about 0.7 were obtained. Removing essentially all the zinc chloride in zinc sulfate solutions by furfural extraction at moderate solvent ratios is practical. Complete removal of chloride could be accomplished by extraction in conjunction with other methods of separation such as evaporation, crystallization, and precipitation. LEO GARWIN and JAMES M . WINTERBOTTOM Oklahoma A. and M. College, Stillwater, Okla.
Ind. Eng. Chem. 49, 1348 (1957)
Place of the Chemical Industry in Missile Systems Planning To design a successful ballistic missile, experts are needed in subsonic and hypersonic aerodynamics, servomechanisms, metallurgy, electronics, electrical engineering, mathematics, chemistry, dynamics, geophysics, and radar as well as rocket propulsion. The problems facing the missile system coordinator deal with subsystems for which production facilities exist in the U. S., production of new subsystems where basic engineering information is lacking, and interaction between subsystems. The major factors in selecting a missile system for a given mission are cost, reliability, and time interval between the decision to fire a missile and the launch. The challenge to the chemical industry is to get information the missile industry needs, develop better fuels and materials of construction, and make the knowledge available. S. A. JOHNSTON and H. R. LAWRENCE Ramo-Wooldridge Corp., Los Angeles, Calif.
Ind. Eng. Chem. 49, 1361 (1957)
Preparation of Lubricating Oil Additives from Dimercaptothiadiazole 2,5-Dimercapto-l,3,4-thiadiazole is a versatile intermediate for preparing bearing-corrosion inhibitors. It is easily converted from an oil-insoluble compound to oil-soluble derivatives by substituents on one or both mercaptan groups. Five classes of derivatives were made: thioethers, amine salts, thioesters, thioacetals, and polysulfides. In addition to inhibiting corrosion of copper-lead bearings, most derivatives prevent the corrosion of silver by active sulfur compounds. ELLIS K. FIELDS Research Department, Standard Oil Co. (Indiana), Whiting, Ind.
End of Symposium
VOL. 49, NO. 9
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Ind. Eng. Chem. 49, 1384 (1957)
Ind. Eng. Chem. 49,1365 (1957)
Long-Term Operating Characteristics of Anion Exchange Resins Anion exchange resins of all origins exhibit some degree of chemical instability. Studies indicate that quaternary ion exchange resins lose strongly basic groups via an autoxidation mechanism wherein peroxide radicals attack the amine structure. Formation of free radicals can b e initiated by energy adsorption, and their growth depends upon forma tion of peroxidic radicals b y reaction with oxygen or more aggressive oxidants such as chlorine or chromic acid. Con tact with dilute hydrogen peroxide can be used as a rapid test method for evaluating the oxidation resistance of experi mental resins. Degradation of the quaternary group results in a perma nent loss of quaternary capacity which cannot b e restored by any known methods. Fouling with complex natural organic acids can cause appreciable temporary capacity losses, which can be overcome by suitable treatment. NORMAN W. FRISCH and ROBERT KUNIN Rohm &. Haas Co., Philadelphia, Pa.
Structure and Formation of Lignin After several years work, attention was concentrated on an artificial lignin prepared from coniferyl alcohol and similar to Bjorkman lignin. Isohemipinic acid, obtainable from both Iignins in about the same yields, is formed largely from a structural unit composed of a phenylpropane unit connected in the beta position to the 5 position of the next similar entity. Pino resinol is believed to be a source of m-hemipinic acid which appears in small quantities if the Iignins are first treated with acid. The initial steps of lignin formation go from shikimic to prehenic acid to phenylpyruvic acid which is convertible to phenylalanine. Direct polymerization probably does not occur. Thus, lignin forms by a continuous dehydrogenation condensation via dimeric intermediates. KARL FREUDENBERG University of Heidelberg, Germany
Ind. Eng. Chem. 49, 1373 (1957)
New Curing System for Silicone Rubber Improved performance and fabrication of silicone elasto mers have been obtained b y a n e w curing system. T h e cure is obtained and controlled through pendant alkenyl and methyl groups b y means of a peroxide-induced free radical mechanism. Vinyl and cyclohexenyl groups attached to silicon are among the alkenyl groups which have been studied. Ditert-alkyl peroxides have been employed as novel curing agents which are effective exclusively through the polymer unsaturation. The cross link is a trimethylene bridge in the case of the vinylsiloxy group. The concentration of vinyl groups has an extensive effect on the properties of the cured elastomers. Extremely low compression sets, ability to cure thick sections, and carbon black—filled stocks characterize this n e w system. The unique carbon black-filled silicone stocks exhibit very high electrical conductivity, which is essentially unaffected by milling or processing techniques. M. L. DUNHAM, D. L. BAILEY, and R. Y. MIXER Silicones Division, Union Carbide &. Carbon Corp., P.O. 44, Tonawanda, Ν. Υ. LIGN IN
Ind. Eng. Chem. 49, 1385 (1957)
Outstanding Problems in Lignin Chemistry Klason's hypothesis that Iignins may be related to simple compounds of the coniferyl alcohol type has been confirmed by extensive researches of Adkins, Harris, Freudenberg, and Hibbert, and ultraviolet absorption studies of Herzog, Hillmer, Aulin-Erdtman, and Lange. Holmberg's suggestion that the most important reactions of lignin are due to occurrence of benzyl alcoholic groups is generally accepted, but not directly proved. T h e author's hypothesis that Iignins are formed in vivo by d e hydrogenation of precursors of coniferyl alcohol type is not substantiated by factual evidence. More work is needed, especially to establish the nature of the nonaromatic regions. Biochemical studies will shed light on the biogenesis and structure of Iignins, but are hampered by difficulty of identifying Iignins. Our views of the structure of Iignins are still largely based on analogies, exclusions, and specula tion. HOLGER ERDTMAN Kungl. Tekniska Hbgskolan, Institutionen for Organisk Kemi, Stockholm 70, Sweden
Ind. Eng. Chem. 49, 1377 (1957)
Structural Elements of Lignin In the lignin molecule dimeric units show the guaiacylgIycerol-/3-guaiacyl ether, phenylcoumaran, pinoresinol, or diphenyl structures. About every third guaiacyl nucleus is phenolic, and benzyl alcoholic groups or benzyl alkyl ethers indicate seats of typical lignin reactions, such as sulfonation and alkylation. T h e chain is terminated b y a coniferyl alcohol or aldehyde group, one coniferyl aldehyde group for about 35 phenylpropane monomers being present in Bjorkman lignin. Dimerized or polymerized coniferyl alcohol may replace unsaturated e n d groups, linking two or more polymeric chains. Cross linking may be caused by aryl (/3)-alkyl C—C bonds or dialkyl ether groupings. T h e presence of 0.18 carbonyl group per methoxyl, compared with the small amount of coniferyl aldehyde, requires carbonyl groups in saturated side chains; their actual positions cannot be stated with certainty.
Ind. Eng. Chem. 49, 1387 (1957)
Mechanism of Lignification To investigate the possible relation between the biogenesis of methyI-/>-methoxycinnamate, lignin, and aromatic amino acids, shikimic acid, labeled with carbon-1 4 in positions 2 and 6 of its cyclohexene ring, was incorporated in a sugar cane plant. T h e lignin was isolated and oxidized to vanillin, and the distribution of carbon-14 determined by selective degradation. T h e distribution of activity in the aromatic ring agrees with the original distribution of carbon-14 in the six-membered ring of the shikimic acid— i.e., the cyclohexene ring was converted directly into the aromatic ring systems of lignin without randomization of the carbon atoms. W. J . SCHUBERT and F. F. NORD Fordham University, New York 58, Ν. Υ.
ERICH ADLER Chalmers University of Technology, Goteborg, Sweden
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Ind. Eng. Chem. 49, 1388 (1957)
Lignin Color Reactions
Ind.
Eng. Chem. 49, 1393 (1957)
Lignosulfonates in Sulfite Spent Liquors
The group of lignin responsible for color reaction of wood with phenols and aromatic amines is considered a coniferyl aldehyde type. It is known also that wood shows Schiff's aldehyde color reaction. That wood powder acetylated by acetic anhydride shows no Schiff's color reaction might result from diacetylation of the aldehyde group. The color reaction can be restored after acetylated wood is immersed in dilute alkaline solution. The aldehyde groups of cinnamic and coniferyl aldehyde can be acetylated, and show the same behavior toward Schiff's reagent. For coniferyl aldehyde methyl ether, however, no acetylation occurs. Therefore, structure of coniferyl aldehyde in protolignin was re-examined. It was ascertained that the double bond in coniferyl aldehyde is already present in protolignin, that the phenolic hydroxyl group is not free, and that the aldehyde group is bare and not acetalyzed. TOKURO NAKAMURA and SADAO KITAURA Kyushu University, Fukuoka, Japan
Isolation and Fractionation Hardwoods such as aspen are used for making pulp by the sulfite process and information is needed on utilizing products in the spent liquors. Solvent-extracted whole sulfite spent liquor and amineextracted lignosulfonates from spruce and aspen were fractionated by paper chromatography, and after drying, the chromatograms were observed under short-wave ultraviolet light. Data on composition and ultraviolet absorption are given together with a chromatogram and corresponding ultraviolet curves for fractions of lignosulfonates extracted from aspen liquor. By this method, lignosulfonates having normal methoxyl content can be obtained in higher yield and relatively purer form than has been possible heretofore. E. E. HARRIS and DAVID HOGAN Marathon Corp., Rothschild, Wis.
Ind. Eng. Chem. 49, 1394 (1957)
Ind. Eng. Chem. 49, 1389 (1957)
Stability of Methoxyl Groups in Wood and Lignin
Reaction of Chlorine Dioxide and a Lignosulfonic Acid
Methoxyl groups in lignin can be characterized by the extent of hydrolysis to methanol in a given time under various conditions; however, it is necessary to determine methanol precisely in very dilute solutions by special analytical methods. Certain known substances were hydrolyzed with 5% and 20% sodium hydroxide and 44% hydrochloric acid. Alkaline hydrolysis was used to characterize methoxyl groups in pine and beech woods. Both artificial and native lignins were investigated. Alkaline hydrolysis splits off a relatively small percentage of methoxyl from acetone lignin, but considerably more from other lignins. Acid or alkaline hydrolysis of lignin preparations leaves part of the methoxyl content in the residue.
Oxidation by chlorine dioxide of a lignosulfonic acid isolated from spruce wood was studied to gain information about bleaching residual lignin derivatives in sulfite pulps. Sulfonic acid groups in the lignosulfonic acid were of two types—about half were removed as sulfuric acid and not as the expected, low molecular weight, aliphatic sulfonic acid. The other half was retained in a complex mixture of oxy lignosulfonic acids, about 20% of which could not be dialyzed through cellophane. Diffusion phenomena must play a notable part in technical bleaching with chlorine dioxide. The ultraviolet absorption maximum at 280 mju characteristic of unoxidized lignosulfonic acids was eliminated; therefore, when pulps are bleached with chlorine dioxide, determinations of residual lignosulfonic acids, based on this principle, would be in error.
A. v. WACEK, W. LIMONTSCHEW, and CHR. AAS Technical University of Graz, Graz, Austria
D. M. S M I T H and C. B. PURVES McGIII University and Pulp and Paper Research Institute of Canada, Montreal, Canada
Ind. Eng. Chem. 49, 1391 (1957)
Action of Mineral Acid on Lignin and Model Substances of Guaiacylglycerol-/3-aryl Ether Type
Ind. Eng. Chem. 49, 1395 (1957)
Lignin and Lignin-Carbohydrate Complexes Extraction from Wood Meal with Neutral Solvents
Guaiacylglycerol-(S-aryl ether structures have been suggested as an essential part of the lignin molecule. An attempt was made to estimate the frequency of such structures in Bjorkman lignin and in a lignin preparation extracted from spruce wood meal by heating with dioxanewater (9 to 1)—0.2^ hydrochloric acid, 1-hour reflux. Ethanolysis of guaiacylgIycerol-/3-guaiacyl ether and similar model substances yielded the Hibbert monomers. When heated 1 to 48 hours with the dioxane-water-hydrocbloric acid mixture (acidolysis), guaiacol was liberated and mixtures of reaction products were formed, characterized by an increasing C—CH3 content and containing a-hydroxypropioguaiacone, vanilloyl methyl ketone, and guaiacyl acetone. Similar acidolysis of the lignins yielded an ether-insoluble and an ether-soluble fraction. With increasing time both showed increasing phenolic hydroxyl and C—CH3 groups.
Except for Brauns' native lignin, grinding wood to release lignin for extraction has been unsuccessful. However, by milling a sufficiently small quantity of wood with a nonswelling liquid in a vibrational ball mill, half the lignin of Norway spruce was extracted using aqueous dioxane. This milled-wood lignin, different from Brauns' and having a molecular weight of about 11,000, is a slightly creamcolored powder containing small amounts of sugars. It has a structure similar to lignin derivatives isolated under mild conditions, and dissolves rapidly on sulfonation in a sulfite cook at all pH. Subsequent extraction with dimethylformamide gives lignin-carbohydrate complexes—slightly grayish white powder containing up to one third lignin. The remainder is hemicellulose.
ERICH AOLER, J . M. PEPPER, and E. ERIKSOO Chalmers University of Technology, Goteborg, Sweden
ANDERS BJORKMAN Billeruds AB, Saffle, Sweden
VOL. 49, NO. 9
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Ind. Eng. Chem. 49, 1409 (1957)
Ind. Eng. Chem. 49, 1399 (19S7)
Alkaline Hydrogenation Pulping If wood meal or chips are cooked with sodium hydroxide liquor and simultaneously hydrogenated catalytically by using nickel catalysts, characteristics and limitations of the pulping process are the same as those of a soda cook. However, almost 40% of the lignin fraction consists of distillable phenols—remainder is a thermoplastic phenolic resin that can be melted repeatedly over a range of 90° to 150° C. The proportion of low molecular weight phenols is greater if hydrogénation is carried out during the pulping process rather than on the isolated liquor. The catalyst can be kept in a separate chamber during the pulping process rather than being mixed with the pulp, or—with more difficulty—it can be separated from the pulp magnetically. IGOR SOBOLEV, H. G. ARLT, Jr., and CONRAD SCHUERCH State University College of Forestry at Syracuse University, Syracuse 10, Ν. Υ.
Thermal Diffusion Efficiency and Separation of Liquid Petroleum Fractions Low efficiency is an obstacle in commercially separating liquid mixtures by the thermal diffusion process. To determine if this obstacle is limiting, two vertical ther mal diffusion columns were designed and operated to achieve thermal efficiencies which approach thermody namic limits. These limits were independently established by measuring ordinary diffusion coefficients and thermal dif fusion constants for two binary mixtures of cetane with 1,1,2,2-tetrachloroethane and 1-methylnaphthalene. Heat dissipation required for separating several petroleum fractions was determined. These fractions included Coastal distillate and residual oils, Middle Eastern distillate and residual oils, and paraffin scale wax. JAMES R. WHITE and ALBERT T. FELLOWS Research and Development Laboratory, Socony Mobil OH Co., Inc., Paulsboro, N.J.
Ind. Eng. Chem. 49, 1401 (1957)
Flow Properties of Lignosulfonates Flow measurements of lignosulfonate solutions were made to obtain information related to their colloidal properties. Shear-rate behavior for hard- and soft-wood lignosul fonates shows Newtonian flow behavior even in 35% solu tions. Solutions of 30 and 40% have a viscosity of only 100 to 150 cp., indicating that particles in solution are not com posed of chains. From flow and shear-rate data it was deduced that lignosulfonate particles in solution are rigid ellipsoids having protruding short chains which contain sulfonate and hydroxyl groups capable of hydrogen bonding. Performance data corroborate the superior use charteristics of two modified aspen lignosulfonates over those of hemlock on the basis of rheological properties. W. C. BROWNING Research Department, Marathon Corp., Rothschild, Wis.
End of Symposium
Ind. Eng. Chem. 49, 1419 (1957)
Rate of Propagation of Propane-Air Flames Irradiated with a 10,000-Curie Gold Source Bunsen flames of premixed propane and air were irradi ated with a gold source having an initial strength of about 10,000 curies. Both the flame zone and the propane-air mixture were exposed to the radiation. The rate of propagation of the flame was increased up to 50% by the radiation. The flame speed diminished rapidly to the normal value as the source decayed below 10,000 curies. The effect of radiation appeared to be about the same over a range of propane to air mass ratios from 0.055 to 0.080 and a range of pressures from 4 to 10 inches of mercury absolute. The effect is attributed to beta radia tion, as the estimated number of ion pairs produced by beta radiation greatly exceeds the number produced by gamma radiation. S. W. CHURCHILL, ALEXANDER WEIR, Jr., R. L. GEALER, and R. J . KELLEY University of Michigan, Ann Arbor, M i c h . Ind. Eng. Chem. 49, 1423 (1957)
Ind. Eng. Chem. 49, 1402 (1967)
Solvent Extraction of Lignite and Carbonization of Lignite Extracts The production of synthetic liquid fuels by the extraction of lignite and carbonization of lignite extracts was investi gated experimentally. Extracts of lignite were prepared by the use of organic solvents and these extracts were destructively distilled at atmospheric pressure, yielding 52% (based on dry lignite) as liquid product. The effects of certain variables in the extraction step were investigated. The function of the solvents employed is primarily that of hydrogen transfer agents, and gaseous hydrogen could replace, at least in part, the hydrogen transfer agent. N. W. FRANKS, E. I. CROWLEY, and H. J . ELDER Gulf Research &. Development Co., P.O. Box 2038, Pittsburgh 30, Pa.
Emission Spectra of Propane-Air Flames Irradiated with a 1000-Curie Gold Source The effect of nuclear radiation on propane-air flames at low pressures was investigated experimentally. The source of radiation was 30 grams of irradiated gold wire with an initial strength of 1000 curies. Both the preflame mixture and the flame zone were irradiated intensely. The number of ion pairs produced by beta radiation greatly exceeded that produced by gamma radiation. Emission spectra of flat flames were measured quantitatively at a series of elevations through the flame. The emission at 4315 A. due to CH was increased up to 30% and the emis sion at 5165 A. due to C2 up to 150% by the radiation. The emission at 3063 A. due to OH was not affected significantly. The maxima in the emission due to O. and OH occurred at an earlier stage in the irradiated flames than the maxima in the emission due to CH. ALEXANDER WEIR, Jr., S. W. CHURCHILL, L. F. ORNELLA, and M. E. GLUCKSTEIN The University of Michigan, A n n Arbor, M i c h .
(Continued on page 21 A)
VOL. 49, NO. 9
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Ind. Ind.
E n g . C h e m . 49, 1429 (19S7)
Non-Newtonian Fluid Flow— Relationships between Recent Pressure-Drop Correlations The applicability of the generalized Reynolds number to Bingham plastic and "power-law" non-Newtonians is shown in detail. This analysis supports the general utility of this dimensionless group and clarifies the relationships between this approach and other more restricted methods of correlation. To this same end, the exact mathematical relationships between the fluid property parameters in the generalized Reynolds number (the flow behavior index, n', and the consistency index, K') and the corresponding descriptive parameters of Bingham plastics (the yield value, r„ and coefficient of rigidity, 7;) and of power-law fluids, have been derived. A. B. M E T Z N E R University of Delaware, N e w a r k , D e l .
Ind.
Effects at 1 atm. were determined for three added agents on the boiling curve for methanol. The heat source, a steam-heated horizontal copper tube having a '/^-inch outside diameter, was used as a resistance thermometer to determine its own average temperature. Concentrations of the added agents were varied from 0 to 1 % and methanol AT, from 50° to 175° F. Each agent and also bits of wood, gasket cement, and other impurities shifted the boiling curve. Maximum heat flux increased from a normal of 154,000 to 214,000 B.t.u. per hour per square foot and critical Δ Τ rose from 64° to 95° F. For transition boiling regions, heat flux increases were most pronounced—e.g., at a Δ Τ of 160° F., they in creased 700% by adding 1% of cationic agent. These effects cannot be attributed to interfacial tensions as some workers have proposed; none of the agents altered surface tensions or contact angles.
Eng. C h e m . 49, 1433 (1957)
T h e electrification of heptane flowing through poly(vinyl chloride) tubing was measured for Reynolds numbers from 300 to 4000. Tube lengths were varied from 3 to 18 feet and tube radii from 0.034 to 0.111 inch. The charges developed on the tubing and in the effluent liquid were measured and found to be equivalent. The rate of charge separation was found to be independent of tube length and proportional to the radius squared, hence, to the area. The Helmholtz equation for the current of convection, which is derived according to the ionic double layer theory, satisfactorily explains the experimental data provided that the zcta potential is assumed to be a linear function of Reyn olds number. An explanation for this is offered. An im portant contribution was noted from the plasticizer present in the tubing or in the fluid. N . K E L L E R a n d H . E. H O E L S C H E R
D e p a r t m e n t of C h e m i c a l E n g i n e e r i n g , Johns H o p k i n s University, B a l t i m o r e 18, M d . Ind.
Heat Transfer to Boiling Methanol—Effect of Added Agents
A. J . L O W E R Y , J r . , a n d J . W . W E S T W A T E R University of Illinois, U r b a n a , I I I .
Development of Static Charges in a Nonconducting System
H.
Eng. C h e m . 49, 1445 (1957)
Ind.
Eng. C h e m . 49, 1451 (1957)
False Viscosity in Cellulose Acetate Solutions "False viscosity," found in concentrated solutions of ace tates from wood celluloses, results in solution viscosities greater than those predicted from experience with cotton linters acetates of comparable intrinsic viscosity. This article describes a practical method of measuring this false viscosity in commercial and experimental celluloses. A straight line results when logarithms of viscosities in concentrated acetone solutions are plotted against intrinsic viscosities for cellulose acetate from a given base cellulose. The ratio of the slope of this line to that of a comparable line from acetates from cotton linters, less 1.00 and multiplied by 100, gives a false viscosity number which is a character istic of the cellulose. Wood pulps with false viscosity numbers above 15 are not acceptable for commercial acetylation. G . A . R I C H T E R a n d L. E. H E R D L E E a s t m a n Kodak Co., Rochester, Ν . Υ .
E n g . C h e m . 49, 1439 (1957)
Equilibria for the System, EthanolaminesHydrogen Sulfide—Water Equilibrium data are required to design equipment which uses ethanolamine solutions to remove hydrogen sulfide from gases. Little has been published on the triethanolamine system, and information on mono- and diethanolamine systems is limited. In this investigation, the three ethanolamines in solutions ranging from 5 to 50% of ethanolamine by weight were measured for partial pressures of hydrogen sulfide between 5 X 10~* mm. of mercury and 8 atm., and temperatures between 80° and 160° F. Approximate values for ionization constants of the ethanol amines in this temperature range are derived from the data. A method for consistently interpolating and extrapolating the data is presented. Interpolations should be satisfactory for engineering design, and extrapolations as a guide in some calculations.
Ind.
Eng. C h e m . 49, 1453 (1957)
Flow Lines in Atmospheric Diffusion In a sense, flux of matter in turbulent diffusion is a flow phenomenon, and therefore the question arises: How far can concepts of streamlines and equipotential lines be applied? Generally known methods for attacking such problems were applied to turbulent diffusion from a con tinuous point source into a steady wind. On the basis of normal cross-wind distribution of concen tration, but allowing for reasonably general standard deviations, expressions are developed for streamlines, pseudopotential surfaces, and surfaces of equal concentra tion. G. T . CSANADY Wollongong College, New S o u t h Wales University of Technology,. New S o u t h Wales, A u s t r a l i a
K E N T O N A T W O O D , M . R. A R N O L D , a n d R. C. K I N D R I C K T h e G i r d l e r C o . , Louisville, K y .
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