Briefs

The process also permits recovery of sitosterol. Previous process for separating these sterols was chemical, ... ment of reboiler control hardware hav...
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Briefs Short summaries of original and contributed articles indicating reason for doing work, what was done and how, and significance

STAFF-INDUSTRY COLLABORATIVE REPORT I

Separation of Sterols by Countercurrent Crystallization

Continuous Solids Feed

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The problem of delivering solids from a common feed source con. tinuously and uniformly to a series of parallel fluidized beds is solved through the movement by dense phase flow of the solids through multiple tubes. The driving force for such movement may be supplied by the pressure drop of a carrier gas through the solid. The rate is controlled by changing either the size of the outlet orifice of the transfer tube or the carrier gas flow rate. Empirical design equationsfor moving ground oil shale are presented.

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Upjohn uses a IO-stage, semicontinuous, solid-liquid countercurrent extraction process to extract stigmasterol selectively from materials containing mixed sterols having nearly identical physical properties. The process gives over 85% yield of 97% or higher purity stigmasterol. The process also permits recovery of sitosterol. Previous process for separating these sterols was chemical, involved use of expensive, corrosive chemicals, and gave relatively low yields, Upjohn uses the stigmasterol as the preferred steroidal starting material for synthesis of progesterone, from which a variety of commercially valuablesteroidscan be produced. Upjohn is a substantial factor in the $200 million plus steroids business.

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ARTHUR POULOS, I. W. GREINER, and G. A. FEVIG Ind. Eng. Chem. 53, 949-62 (1961)

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DAVID S. KOONS and B. E. LAUER University of Colorado, Boulder, Colo. Ind. Eng. Chem. 53,970-4 (1961)

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Automatic Control of Distillation Columns

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Recent studies of distillation columns show that many operational problems exist because of improper regulation of the system heat inputs. Both theoretical studies and tezts on operating columns show that better regulation and control of the reflux heat, the feed heat, and the reboiler heat can result in more improvements than a cursory inspection indicates. Satisfactory control of the heat inputs has long been difficult because means for proper measurements have not been available. The internal reflux computer, the feed enthalpy computer, and rearrangement of reboiler control hardware have been developed to overcome these difficulties. These control systems provide an economically feasible means for achieving improvement in column operation.

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Failure of Thick-Walled Pressure Vessel

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Because of the increased pressures and temperatures to which pressure vessels are being subjected at present and the still further increases contemplated in the near future, it is necessary to understand the behavior of materials. I n this way, better design methods may be established. For this purpose, failures of pressure vessels were examined, particularly those cases where the failures occurred under controlled conditions. One such case is discussed here.

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0. E. LUPFER and M. W. OGLESBY Phillips Petroleum Co., 8-8, Phillips Research Center, Bartlesville, Okla. Ind. EnQ. Chem. 63, 863-9 (1961)

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E DWARDJSAI BEL Department of Mechanics, Rensselaer Polytechnic Institute, Troy, N. Y. Ind. Eng. Chem. 53, 975-8 (1961)

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GUIDE FOR AUTHORS, published in December 1960 issue, pigc 1057. gives copy rcquiremcnts to bc observed i n prcparing manuscriprs for considcration. Manuscript (2 copics) should bc w b mittcd ro rhc Editor, 115s Sixtccnrh Sr., N.W., Washington 6,D. C. The Amcrican Chcmical Socicty assumcs no rcsponsibiliry for thc statcmcnts and opinions adrinccd by contributors to its publicarions. Vicws cxprcsscd in rhc editorials arc rhosc of the cditors and do nor ncccssarily reprcseot rhe official position of rhc American Chemical Society. 1961 Subscriprion Ratcs

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bccnuse copy is "missing from filcs." Pubiishcd monthly by rhc American Chcmical Socicty, from 20th and Norrhampton Sts., Easton, Pa. Exccurivc officcs, Editorial Hcadquarrcrs, a d Circularion Dcpartmcnt, 1155 Sixrccnth S t . , N.W., Washington 6, D. C. Advertising Offihcc: 430 Park Ave., New York 22, N. Y . Branch Editorial Offices: 36 South Wabash A v c . , Chicago 3, Ill,; 518 Mslrost Blde;., 1121 Walker S t . , Houston 1, Tcx., 733 Third Avc., Kcw York 17, N. Y . ; 703 Mechanics' Inscirutc Bldg., 57 Post Sr., San Francisco 4, Calif.; 77 Sooth Aodlcy Sr , London W.1. CHANGE OF ADDRESS: Notify Circularion Dcparrmcnr. American Chcmical Socicty, 1155 Sixteenth Sr. N.W. Washingroo 6, D. C. Such notification should include both old and new addresscs andpostal Lone numbcr, if any. Thc American Chcmical Socicty also publishes: Ana&i d Chmmrrrgv, Chemical Absrracts Scrvice, Cbsmrcsiand Engrnerrrng Now, Chrmiral Riuhw,, Cbmxcd Titirr, J o u m d of Agricultural and Ford C h e i r t r r , Journrl of rhr Amerrcan Chainicsl Secirry, J o w d o j Cbrmicai D,cumr?t ition, Journal o j Chsrnrrai and Engrnsrrung Data, The Journal o j Ofgnnrc Cbrmirtrg. and Tbe Journal of Pbyriral Cbrmrrir,.

VOL. 53, NO. 12

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DECEMBER 1961

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pays off for Hercules and Beckman Such important space programs as the APOLLO and Lunar Spacecraft (NASA) the Nova booster (NASA) involve many new and complex problems. Only advanced research can solve them. Hercules Powder Company has employed the Beckman EASE Analog Computer to help the research staff find answers for these problems. The EASE installation has been used to study control systems and trajectory simulations for advanced missile systems. It has also been used to evaluate the Hercules concept of large solid propellant booster motors used in the Apollo and Nova projects, and in basic research on such diverse developments as pentaerythritol, triethyl, aluminum, and ammonia production techniques.

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INSTRUMENTS INC.

BERKELEY DIVISION RICHMOND, CALIFORNIA

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Circle

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INDUSTRIAL AND ENGINEERING CHEMISTRY

NO. 12 on Readers’ Service Card

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Sulfuric Acid-Optimized Contact Manufacture

Conditions in Hydrorefining Coal-Tar Naphthalene

Consideration has been given to the general problem of determining how a chemical plant should be run for optimum performance, The most profitable operation can be achieved through a computer plantsimulation program designed to reflect shifting uncontrollable variables. A mathematical model of a contact H2SO4 plant was constructed. Versatility of the model was assured by the development of a method for correlating performance of one catalyst with reference to others. Limitations of the "steepest ascent" method were encountered when attempting to reach the point of best operation. Alternate methods of exploring the response surface were employed to keep within practical limits set by the assumed equipment. Simple "control equations," suitable for use i n closed loop plant computer-controllers, were derived to relate the controllable and uncontrollable variables.

Coal-tar naphthalene in crude form may be readily upgraded, tar acids and tar bases removed, and the sulfur content reduced markedly by proper choice of variables i n hydrorefining with cobalt molybdate on alumina. It was found that 220 volumes of crude naphthalene could be hydrorefined at a temperature of 490" C., a pressure of 175 p.s Lg., a contact time of 5 seconds, and a hydrogen-to-feed mole ratio of 5-to-1, without any loss in efficiency i n tar acid, tar base, and sulfur removal. A typical product after distillation contained 14-p.p.m. sulfur, 0.06-wt. % t a r bases, and no detectable tar acids, and had a crystallizing point of 79.2' C. GERALD GILBERT, RICHARD C. WEIL, and RICHARD H. HUNTER Applied Research Laboratory, U. S. Steel Corp., Monroeville, Pa.

ARTHUR C. H O M M E and DONALD F. O T H M E R Polytechnic Institute of Brooklyn, Brooklyn 1, N. Y. Ind. Eng. Chem. 53, 979-84 (1961)

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Ind. Eng. Chem. 53, 993-6 (1961)

Chlorination of Monazite

A catalytic vapor-phase procedure is described for the synthesis of cyanogen, a reactive chemical intermediate, by the oxidation of hydrogen cyanide with nitrogen dioxide. Among the effective catalysts are lime glass beads and compounds of sodium, magnesium, calcium, and silver on supports of low surface area. The selectivity for cyanogen approached 100% and the nitrogen dioxide was completely consumed i n runs with a magnesium-containing catalyst at 200" to 350" C. at atmospheric pressure with hydrogen cyanide in excess. The reaction can be the basis of an economical, continuous process for producing cyanogen because the by-product nitric oxide can readily be oxidized to nitrogen dioxide and recycled.

A laboratory scale chlorination of Egyptian monazite sand, 89% purity, was carried OUI at 900" C. i n a horizontal tube furnace. Ninety eight per cent of the thorium content of monazite was attacked and condensed as thorium chloride (99.2% purity) at the temperature range from 850" to 475" C. The purity of thorium chloride was more or less unaffected by the purity of monazite concentrate used, while that of the lanthanons decreased with decreasing the purity of monazite as the chlorides of calcium and magnesium remained admixed with the lanthanon chlorides. 0. M. HILAL and F. A. EL GOHARY National Research Centre, Dokki, Cairo

WILLIAM L. FIERCE and WALTER J. SANDNER The Research Center, The Pure Oil Co., Crystal Lake, 111.

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Ind. Eng. Chem. 53, 997-8 (1961)

A rigorous calculation method has been developed for applying the absorption transfer unit to double-phase resistance problems. The rigorous method and other methods are compared i n a number of situations. Single-phase resistance cases are included.

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STANFORD W. BRIGGS School of Chemical Engineering, Purdue University, Lafayette, Ind.

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Rigorous Application of Absorption Transfer Unit

Ind Eng. Chem. 53, 988-90 (1961)

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A New Method for the Synthesis of Cyanogen

Ind. Eng. Chem. 53,985-7 (1861)

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Recovery of Uranium from Calcium Nitrate by Continuous Ion Exchange A study was made of the recovery of uranium from nitrate salt solutions by continuous countercurrent anion exchange. The nitrate system is the most commonly used nuclear chemical processing system, and standard stainless steel equipment can be used for it. Production rate was found to be only about one eighth as fast i n the nitrate system as i n the chloride, even after giving the nitrate system the benefit of higher temperature operation. A 99% yield for uranium was indicated for a 10-foot-long bed of 20 to 50 mesh anion exchange resin at 60" C. with a feed rate of 250 gallons per hour per square foot The advantages and disadvantages of of 6.25N Ca(NO&-O.SN "Os. the nitrate and chloride systems should be compared for each application to make a choice. I R W I N R. H l G G l N S Chemical Separations Corp., P. 0. Box 1031, Oak Ridge, Tenn. Ind. Eng. Chem. 53, 999-1002 (1961)

VOL. 53, NO. 12

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DECEMBER 1961

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YEAF

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195E

1961

I LBS. per DOLLAR

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Chart based on tridecyl alcohol prices. l e e table below for full details.

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LOWER PRICES MEAN YOUR DOLLAR BUYS UP TO 60% MORE ALCOHOL THAN IN 1952! Expanded facilities, increased sales and production economies have enabled Enjay to pass substantial savings along to its oxo alcohol customers over the Years- The table at right shows YOU how much more isooctyl, decyl, or tridecyl alcohol your dollar buys today as compared to 1952. A t the same time, the quality of Enjay alcohols is constantly being improved. Enjay also stands ready

with technical assistance on any problems you may have. These a r e two added advantages of dealing with a leader in the chemical field. For more information on the full line of Enjay alcoho]s and chemiYOUR ALCOHOL DOLLAR BUYS: cals, write to Enjay, 1952 1956 1961 15 West 51st Street, ~ ~ ~ ~ ~ ~3.6s ~4.8~ b5,6s New York 19, N. Y, rRlDECYL (Ibs.) 3.1 4.2 5.0

EXCITING N E W P R O D U C T S T H R O U G H P E T R O - C H E M I S T R Y

ENJAY CHEMICAL COMPANY A DIVISION OF H U M B L E OIL & R E F I N I N G COMPANY Circle No. 16 on Readers' Service Card

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Activating Uranium Dioxide Low reactivity UOz can be readily converted to a very reactive form by successive oxidation to UIOs and reduction again to UOz. The mechanism of activation by this method was studied on aggregates of microcrystalline UOz. Physical changes resulting from activation were correlated with changes in reactivity toward HF gas and oxygen. Surface area, pore size, and x-ray measurements showed that activation resulted from separation, but not reduction in size, of primary crystallites, Hydrofluorination of U02to UF, was found to be sensitive to changes i n porosity of the UOz during the course of the reaction. Repeated successive oxidation and reduction of the UOz produced first an increase i n surface area at constant crystallite size, because of separation of adhering microcrystals, and then a decrease in loose bulk density with both crystallite size and surface area constant, because of further separation of the detached microcrystals.

Unit Processes Reviews Halogenation

L. R. Belohlav and E. T. McBee

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Combustion Raymond Friedman and J.

H. Grover

R. J. BARD, J. P. BERTINO, and D. L. BUNKER Los Alamos Scientific Laboratory, University of California, Loa Alarnos, N. M. Ind. Eng. Chem 53, 1003-6 (196:)

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Chemical Engineering Fundamentals Review Heat Transfer

Crystallization of the Rare-Gas Clathrates

J. K. Ferrell and T. M. Godbold

Experimental studies were made of variables affecting concentration of the rare gases in clathrate compounds. Twenty two organic compounds were screened as possible matrix materials, but only p-quinol and p-fluorophenol were found to trap substantial quantities of gas. Solute concentration, type of solvent, and gas pressure were also varied. Concentrations of argon, krypton, and xenon i n crystals of p-quinol ranged up to the stoichiometric proportion of 1 molecule of rare gas for 3 molecules of solid matrix material. In addition to formation by crystallization from solution, clathrates containing high gas concentrations can be crystallized by solventless methods. J. E. MOCK, J. E. MYERS, and E. A. TRABANT Department of Nuclear Engineering, Purdue University, Lafayette, Ind. Ind. Eng. Chem. 53, 1007-10 (1961)

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AWTHOR INDEX

SUBJECT INDEX Poisoning in Fixed Beds of Catalysts The effect of distribution of poison i n a fixed bed of catalyst on activity has not been considered i n detail previously. Thus the average relative activity was evaluated as a function of average poison concentration for combinations of four equations relating activity to poison concentration i n an increment of the bed and three equations describing the distribution of poison with respect to bed length for two limiting conditions: ( y ) The distribution remains the same and the concentration is increased by a constant factor along the bed; and (2) the concentration at the inlet of the bed remains constant, and average concentration is increased by changing the parameter of the distribution equation. For condition ( z ) , which most closely approximates poisoning by impurities i n the feed, accumulation of the poison near the inlet of the bed usually decreases the effectiveness of the poison. R. E. ANDERSON and A. M. WHITEHOUSE Pitlsburgh Coal Research Center, Bureau of Mines, Pitlsburgh, Pa.

nd. Eng. Ghem. 53, 1011-14 (1961)

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