EC Briefs

MAY 1957

I/EC Briefs I/EC's articles en . . .

CHEMISTRY AND CHEMICAL ENGINEERING IN THEORY AND PRACTICE The why, what, and significance on 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 786

Ind. Eng. Chem. 49, 807 (1957) Ind. Eng. Chem. 49, 786 (1957)

Centrifugal Boiler Compression Still A compression still which dispenses with the conventional boiler-condenser employs shallow, rapidly rotating cones of thin sheet metal over which the feed solution is spun in extremely thin layers, more than doubling the distillate obtainable from a given expenditure of power. Many tons of sea water have been distilled with a tem­ perature differential of 3 ° F. and an over-all heat transfer coefficient of 2500 to 3500 B.t.u./(hr.)(sq. ft.)(° F.) without the formation of scale. Experiments have b e e n extended successfully with rotors 4.5 and 8 feet in diameter. T h e more interesting parameters of the n e w stills are described. K. C. D. H I C K M A N 136 Pel ham Road, Rochester 10, Ν. Υ.

Catalytic Liquid-Phase Hydrogénation Effects of known variables were experimentally evaluated in a kinetic study of catalytic liquid-phase hydrogénation in a semiflow system. It is concluded that in the major part of the work, observed rate of reaction was controlled by mass transfer of hydrogen from the bulk solution to the solid-liquid interface. The criterion that effects of mass transfer are eliminated w h e n observed reaction rate is independent of stirring speed, is a necessary but not sufficient condition. Data given indicate the importance of hydrodynamic factors for such stirred systems, which must be more fully explored before fundamental relationships useful for engineering design can be formulated. R. H. PRICE and D. B. SCHIEWETZ University of Cincinnati, Cincinnati, Ohio

Ind. Eng. Chem. 49, 813 (1957)

CHEMICAL PROCESSES

Ind. Eng. Chem. 49, 801 (1957)

Mononitration of p-Cymene The nitration of ^-cymene is unique because of ease of oxidation and dependence o n reaction temperature and emulsification. Information obtained for /r-cymene should also be useful with other easily oxidized hydrocarbons. The yield of mononitro compounds is a sensitive function of process conditions. A yield of 89% can be obtained by nitration at 10 ° C , mole ratio of nitric acid to cymene of 0.9, weight ratio of sulfuric acid to cymene of 4.0, initial concentration of sulfuric acid of 85 weight %, and intense agitation of the nitration mixture. Emulsification plays a much more important role in the nitration of cymene, and hence other easily oxidized compounds, than in the case of b e n z e n e and toluene. KENNETH A. KOBE and EUGENE M . LANGWORTHY University of Texas, Austin 12, Tex.

Catalytic Hydrogénation of Methyl Laurate to Lauryl Alcohol Optimum conditions for hydrogenating methyl laurate to the corresponding alcohol were studied—type, amount, and method of preparing catalyst, together with temperature, pressure, and time. The most effective catalyst was prepared from copper nitrate and sodium dichromate by calcining the precipitated copper chromate at 300° C. under carefully controlled conditions. Using 4 % of this catalyst at a temperature of 300° C. and pressure of 2700 pounds per square inch, the hydrogénation rate was fast, and a theoretical yield of over 90% of alcohol was obtained. Repeated hydrogénations re-using the same catalyst gave no loss of catalytic activity and yields of alcohol were sustained. These results suggest that a commercial-scale continuous hydrogénation process could be developed for rapidly converting various fatty esters to their corresponding alcohols in good yields. JAMES M . CHURCH and MOHAMED A. ABDEL-GELIL Department of Chemical Engineering, Columbia University, New York, Ν. Υ .

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Ind. Eng. Chetn. 49, 818 (1957)

Rapid Conversion of Anhydrite to Gypsum During a study of natural conversion of anhydrite to gypsum, a rapid hydration process was developed. From laboratory data on the effects of particle size, seed­ ing, ratio of solid to liquid, activation, temperature, agita­ tion, time, and washing, conditions of hydration were out­ lined. Pulverized anhydrite, with minor gypsum, in a slurry of 10 to 50% solids in a solution, 0.5 to 0.75M sodium sulfate or 0.5 to 1.0M potassium sulfate (also saturated with calcium sulfate), is agitated below 30° C. for 1 to 7 hours; after nitration, the solids are washed with water or saturated calcium sulfate solution. The alkali sulfate activator may be recycled. The increased rate of gy psification may be caused by for­ mation and decomposition of one or more intermediate double salts. R. K. LEININGER, ROBERT F. CONLEY, and WAYNE M . BUNDY Indiana Department of Conservation, Geological Survey, Bloomington, I n d .

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Ind. Eng. Chem. 49, 832 (1967)

Effect of Process Conditions on Formation of Isomers in Nitration of Cfriorobenzene T h e mononitration of chlorobenzene was studied to determine the effect of nitrating conditions on the formation of mononitrochlorobenzene isomers. A mixture of nitric and sulfuric acids was used and vari­ ables included nitric acid content of nitrating acid, ratio of nitric acid to chlorobenzene, sulfuric acid strength, nitration temperature, and nitration time cycle. In the range of conditions investigated, concentration of nitric acid, ratio of nitric acid to chlorobenzene, and nitration time had little influence on the final distribution of nitrochlorobenzene isomers. Formation of />-nitrochlorobenzene could be related to the sulfuric acid strength and nitration temperature by the expression: % PNCB = [0.13 - 0.0027 (% HsSOJ] / + 70.6 HAROLD H. BIEBER and W. FRED SCHURIG Polytechnic Institute of Brooklyn, Brooklyn, Ν. Υ. Ind. Eng. Chem. 49, 838 (1967)

Ind. Eng. Chem. 49, 822 (1957)

Synthesizing crV-Piperitone from Ethyl Acetoacetate A commercial process for manufacturing S7-piperitone is proposed to supplement the present natural sources from essential oils. An improved synthesis consists of alkylating ethyl aceto­ acetate with isopropyl bromide to form ethyl a-isopropyl acetoacetate, which is further alkylated with 1,3-dichloro2-butene in anhydrous b e n z e n e , using metallic sodium dis­ persed in bo-octane as the condensing agent to form ethyl «-isopropyl a-(-y-chlorocrotyl)acetoacetate. The benzene— iso-octane solution of the condensation product is refluxed with concentrated sulfuric acid to form nY-piperitone. With steam distillation of this reaction mixture, Λ-piperitone was recovered in 40% yield, based on ethyl a-isopropyl acetoacetate. S. LESLIE MISROCK and JAMES M. CHURCH Department of Chemical Engineering, Columbia University, New York, Ν. Υ.

• nd. Eng. Chem. 49, 825 (1957)

Operating Variables in Hydrogenating Cottonseed Oil Cottonseed oil was hydrogenated in a dead-end hydrogenator over wide ranges of temperatures, pressures, nickel catalyst concentrations, and agitation. Sufficient agitation was provided in most runs to eliminate mass transfer resist­ ances. When the mass transfer resistances were negligible, rate of hydrogénation was directly proportional to pressure and catalyst concentration and linear with respect to temperature. Effects of the operating variables were determined for selectivity and iso-oleic acid formation. A mechanism for selectivity is proposed, based on preferential physical adsorption of linoleic acid as compared to oleic acid. T h e mechanism of Allen and Kiess explains isomerization. T h e rate-controlling step of hydrogénation is probably the surface reaction between atomic hydrogen which may be chemisorbed, and physically adsorbed unsaturated fats. I B R A H I M A. ELDIB and LYLE F. A L B R I G H T University of Oklahoma, Norman, Okla.

Vapor Phase Hydration of Ethylene Oxide over Acidic Ion Exchange Resin Catalysts The mechanism and kinetics of the catalyzed vapor phase hydration of ethylene oxide to glycols were studied on Amberlite IR-120 and IRC-50 cation exchange resins (H + form) as catalysts; catalyst particle diameters, 0.25 and 0.71mm.; 110° to 200° C ; modified Reynolds numbers, 10 to 60; molar ratios, steam ethylene oxide, 7.5 to 32; total pressure, 1.2 atm. Below 110° C. ethylene oxide was physically absorbed; from 110° to 140° C. weak chemisorption prevailed; above 140° C. stronger chemisorption took place. For this reason the rate-controlling mechanisms changed at about 110° and 140° C. Between these temperatures distribution of pro­ ducts and reaction rate are controlled by mass transfer of products from surface of catalysts into gas stream; competi­ tion between reactants and products for adsorption sites; and rate of chemical reaction between adsorbed reactants. G. E. H A M I L T O N and A. B. METZNER University of Delaware, Newark, Del.

Ind. Eng. Chem. 49, 847 (1967)

Kinetics of the Ethyl Alcohol-Lactic Acid Reaction Ethyl lactate is an important solvent and intermediate in the purification of lactic acid by esterification and hy­ drolysis. Kinetic data are essential for the design of an esterification reactor. Studies with 85% analytical grade lactic acid and absolute ethyl alcohol show that a rate equation can be derived from sealed tube data to be used in design of a flow reactor for esterification of lactic acid with ethyl alcohol. A kinetic study of the reaction between 44% technical grade lactic acid and commercial 190-proof ethyl alcohol in sealed tubes showed that temperature, concentration of sulfuric acid catalyst, and mole ratio of ethyl alcohol to lactic acid are important variables. Experimental kinetic data fitted an equation of the form ke = X/(A — b)(A — b — X), where A — b is the original titratable acidity. RALPH A. TROUPE and E M I L Y DiNULLA Northeastern University, Boston, Mass.

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Ind. Eng. Chem. 49, 869 (1957)

Ind. Eng. Chem. 49, 856 (1957)

Organic and Other Nonaqueous Solvents as Processing Media for Making Inorganic Chemicals

Nitrogen Purification

Organic and other nonaqueous solvents are increasingly important processing tools either as media for facilitating certain inorganic reactions or as extractants for recovery or purification. An example is the almost quantitative decomposition of barium or strontium sulfate by calcium chloride in concen­ trated aqueous solutions, with recovery of either barium chloride or strontium chloride by methanol or methanolethylene glycol solvent. A most important example of purification by organic solvent extraction is that connected with a process for manu­ facturing reactor grade uranium compounds by extracting pure uranium nitrate from an impure aqueous solution by ethyl ether.

Because oxygen is detrimental to reactions in low-tem­ perature emulsion polymerization systems, oxygen-free nitrogen is employed to purge the vapor space of the reactors. In order that commercial nitrogen may be used for this purging operation, the gas is deoxygenated by scrubbing it with an aqueous solution of sodium dithionite. A packed absorption column located in the pilot plant is employed for the gas scrubbing operation. A scrubbing solution, buffered with trisodium and tripotassium phosphate and containing zinc sulfate and 7.2 pounds of sodium dithionite in 100 pounds of water, purified about 40,000 cubic feet of commercial nitrogen of an oxygen content of about 0.10% to less than 0.03% of residual oxygen, and lasted for 12 days before the sodium dithionite was depleted.

R. MORRIS SHREVE Purdue University, Lafayette, Ind.

MURRAY REICH and HARRY KAPENEKAS University of Akron, Government Laboratories, Akron, Ohio.

Ind. Eng. Chem. 49, S61 (1957)

High Pressure Gas-Handling Equipment for Autoclaves in Chemical Research From initial work with no more than an autoclave and a cylinder of compressed gas, requirements for improved flexibility and efficiency led to construction of permanent gas-handling systems. Equipment and procedures are described for handling gases as required in medium to high pressure laboratory chemical research. Provision is made for mixing gases, boosting the pressure, and measuring the rate of consump­ tion while maintaining constant autoclave pressure. Such equipment very greatly increases the versatility and research productivity of an autoclave installation. ROBERT D. GOODWIN Research Laboratories, Air Reduction Co., Inc., Murray Hill, N. J .

Ind. Eng. Chem. 49, 874 (1957)

Safe Handling of Triisobutylaluminum and Isobutylaluminum Chlorides Alkylaluminum compounds are becoming industrially important as catalysts for low-pressure polyethylene. They are extremely hazardous because of their reactivity, and must be protected from air, moisture, and other compounds with active hydrogen atoms by blanketing with inert gas during handling. Fire and personnel-burn hazards are increased by the possibility of exothermic addition reactions and metathetical reactions that liberate gases. Special techniques have been developed for handling these compounds. J. E. KNAP, R. E. LEECH, A. J. REID, and W. S. T A M P L I N Carbide and Carbon Chemicals Co., South Charleston, W. Va.

Ind. Eng. Chem. 49, 880 (1957)

Ind. Eng. Chem. 49, 865 (1957)

Distribution of Metal Contaminants on Cracking Catalysts

Carbonization of Anthracene and Graphitization of Anthracene Carbons

Contamination by metallo-organic compounds from heavy or residual charge stocks causes serious decrease in catalyst selectivity. A study of metal deposition during vapor and liquid phase feed operation on pelleted clay and synthetic bead catalyst shows a sharp negative gradient in metals concentration from the periphery to the center of the catalyst. From 40 to 6 0 % of deposited metal is within 35 microns of the outer surface; 10% is within 5 microns. As this distribution holds over a wide range of metal content, the size of the catalyst pellet is important. These circumstances, with the rubbing attrition in com­ mercial moving b e d cracking, lead to a significantly lower equilibrium metal content of the catalyst than if contami­ nant metal distribution in catalyst pellets were uniform.

To study the processes by which graphitizable chars and carbons are produced, anthracene chars were prepared in several different ways, calcined at temperatures u p to 1000° C , and finally graphitized at about 2500° C. Cal­ culated x-ray diffraction parameters of the carbons and graphite were used for comparing the structural changes induced by the varying conditions employed. Anthracene chars prepared at about 500° C. have interlayer spacings of 3.44 A. and well denned (002) peaks ai shown by high ratios of l/IP. However, biphenyl chars prepared in the same way have much higher interlayer spacings and lower I/lp ratios. Because anthracene chars are highly graphitizable and biphenyl chars are not, for­ mation of a well-ordered initial cbar is essential for the pro­ duction of an easily graphitized carbon.

J. E. McEVOY, T . H. M I L L I K E N , and G. A. MILLS Houdry Process Corp., Marcus Hook, Pa.

C. R. KINNEY, R. C. NUNN, and P. L. WALKER, Jr. Department of Fuel Technology, The Pennsylvania State University, University Park, Pa.

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Ind. Eng. Chem. 49, 885 (1957) Ind. Eng. Chem. 49, 904 (1957)

Nitric Acid Dissolution of Thorium Kinetics of Fluoride-Catalyzed Reaction

Factors Affecting Filtration Test for Sugars

The penetration rate of thorium metal by boiling nitric acid was measured as a function of the concentrations of acid, fluoride catalyst, and dissolved thorium. The fluoride con­ centration was the most important variable, the dissolving rate in 13M nitric acid increasing from 1 mg. per hour per sq. cm. in the absence of fluoride to over 10,000 mg. per hour per sq. cm. at 0ΛΜ fluoride. T h e rate also increased with increasing nitric acid and reached a maximum at about l$M. Dissolved thorium inhibited the reaction, presum­ ably by complexing the free fluoride. Aluminum had a similar effect. The dissolution rate of thoria was found to be much less than that of thorium. "Integral" dissolvings were also made, and an empirical mathematical equation was derived to correlate these results and facilitate application. ROBERT LEE MOORE, C. A. GOODALL, J. L. HEPWORTH, and R. A. WATTS, Jr. Hanford Atomic Products Operation, General Richland, Wash.

The filtering characteristics of diatomaceous silica are affected by the presence of various salts in aqueous or sugar solutions. This accounts partially for more rapid filtration of solutions of high ash content sugars reported by Kortschak. Filterability increases with concentration and with the valence of the cation of the chlorides added to solu­ tions of refined and raw sugars, at about p H 6. At lower p H values filterability of a number of raw sugars increased, but the same sugars showed increases, decreases, or sub­ stantially no change in filterability in solutions that were neutral or adjusted to pH 8. It is important to establish the quantitative effect of salts and pH upon filterabilities of sugar solutions determined with filter aids. R. T. BALCH Sugarcane Products Laboratory, U. S. Department of Agriculture, Houma, La.

Electric Co.,

Ind. Eng. Chem. 49, 907 (1957) Ind. Eng. Chem. 49, 888 (1957)

Rheological Behavior of Thorium Oxide Slurries in Laminar Flow The flow behavior of aqueous thorium oxide slurries is an integral part of the information needed in designing the blanket system of a thorium oxide slurry breeder reactor. As a result of an investigation designed to determine these rheological properties, it was found that thorium oxide slurries are plastic non-Newtonian fluids at ambient tem­ peratures. The viscosity can be expressed in terms of shear stress, τ, and concentration, S. P. R. CROWLEY and A. S. KITZES Oak Ridge National Laboratory, Oak Ridge, Tenn.

Cellulose Swelling Measured by Benzene Retention Knowledge of degree of swelling of cellulose by polar reagents is important in the development of procedures for converting cellulose into its derivatives. Results demon­ strate that this degree of swelling can be measured by de­ termining the sorption of benzene after displacement of the polar reagent with liquid benzene. This benzene retention varies widely, depending o n the prior history of the starting cellulose, the nature of the swelling agent, and the conditions under which swelling is accomplished. Methods described offer a means for deciding the best preswelling conditions for each type of cellulose and for the processing procedures being con­ sidered. GEORGE A. RICHTER, LLOYD E. HERDLE, and WAINO E. WAHTERA Eastman Kodak Co., Rochester, Ν. Υ.

Ind. Eng. Chem. 49, 894 (1957)

Radial Heat Transfer in Packed Beds Radial temperature profiles were measured by passing air and ammonia through tubes packed with alumina and steel spheres. Using an IBM card-programed computer, effective thermal conductivities were calculated from tem­ perature profiles at two bed depths; k, showed considerable change with radial position, the values decreasing rapidly near the tube wall. When compared with results obtained from temperature profiles, calculations based on theory predict the effects of particle size and gas and solid properties reasonably well, but the maximum in k, at an intermediate radial position is not reproduced. Application of the theory requires infor­ mation for mass velocity, Peclet number, and void fraction profiles and convection heat transfer coefficient between particle and gas. Inadequate data for some of these quanti­ ties may explain poor agreement between experimental and theoretical results. S. S. KWONG and J . M . S M I T H Purdue University, Lafayette, Ind.

Ind. Eng. Chem. 49, 913 (1957)

Toxicity of ^^-Unsaturated Carbonyl Compounds to Microorganisms An important aspect of the biochemical oxidation of an industrial waste is the toxicity of components to micro­ organisms. The toxicities of heavy metals and a few organic materials have been extensively examined. Other organic materials which are toxic to animals and are probably toxic to microorganisms have not been evaluated. This consideration supplied the reason for study of the toxicity of α,/3-unsaturated carbonyl compounds to micro­ organisms. These materials are seriously toxic to micro­ organisms. T h e concentration of «,3-unsaturated carbonyl compounds in any biochemical oxidation system must be carefully controlled. VERNON T . STACK, Jr. Development Department, Carbide and Carbon Chemicals Co., South Charleston, W. Va.

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