Nov., 1920
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
IIOD
NOTE ON CATALYSIS IN THE MANUFACTURE OF When ethylene was led into a carbon tetrachloride ETHER1 solution of selenium monochloride or into the attempted selenium dichloride, the same product was obtained, By Hugo Schlatter HERCULES POWDER Co.,WILMINGTON, DELAWARE but in smaller yields. Received August 18, 1 9 2 0 To establish the structural formula of C4H6C14Se1 Senderens,* discussing the action of aluminium we may reason by analogy from the sulfur compounds. I n the following equations may be found a brief resum6 sulfate as a catalyst in the manufacture of ether, of the work done by Guthrie,' as interpreted in the states t h a t the addition of about j per cent of t h e anhydrous sulfate t o t h e usual mixture of sulfuric light of our modern knowledge of chemistry. acid and alcohol lowers the temperature a t which S regular and rapid evolution of ether takes place from I1 11 140' C. t o 130' C. He explains this action by assumCaHio SzClz C1- C6Hio - S - CsHio - C1 (I) ing the formation of a double aluminium ethyl hySClz --f C1- CbHin - S - C1 C6Hio (2) drogen sulfate (Alz(S04)3.S04HCzHh), which breaks S up a t a lower temperature than ethyl sulfuric acid. il Although in plant operation the temperature of the C Z H ~ SzClz C1- CzH4 - S - C2H4 - C1 (3) still a t which regular and rapid evolution of ether CzH4 SzClz S takes place is about 1 2 j o .i t was thought of interest I/ t o determine whether the addition of aluminium Clz - CH - CH2 - S - CHz - CH -Clz (4) sulfate would result in lowering this temperature CzH4 SClz --f C1- CzH4 - S - C1 (5) still further, or in increasing the capacity of the still. C11.- CzHs - S - CzHs - Clz Clz + During the war any increase in the capacity of existing 'I apparatus was of supreme importance. S C1BC - CHz - S - CHz - CC13 ( 6 ) A small, glass, ether still with the necessary column I/ and condensers was charged with a mixture of sulS furic acid and alcohol. After the evolution of s ether had started, alcohol was fed into t h e still below I CzHs - S - C2H5 Cli ----f S the surface of the liquid a t a rate corresponding t o t h e It ether produced. Senderens' statement, t h a t evoluC13C - CHz - S - CHz - CCls (7) tion does not become regular until a temperature of Further work by Frederick Kont-Norwal12 shows 140O is reached, was confirmed. Amounts of alut h a t one selenium from selenium monochloride may minium s t lfate varying from 3 t o I O per cent by weight readily be split off from its compounds, as is sulfur in were introduced into the still in subsequent runs, and the manufacture of mustard gas. Equations 3 and 4 i t was found t h a t with 5 or I O per cent of aluminium show how the reaction between ethylene and selenium sulfate the temperature was lowered t o 130'. A somewhat larger still of 1.5-gal. capacity was then monochloride may quite probably run. Althou'gh we have no evidence of the existence of the compounds constructed of lead and equipped with a steam heating C1- C2H4 Se - CzH4 - C1 and CLCH CHZSe - CHZ- CHClz coil, so as t o approach factory conditions as closely as possible. Two runs of about jo hrs. duration were I1 1; Se Se made, one with and one without the addition of j per cent by weight of aluminium sulfate. The temi t is quite probable t h a t they may be formed and the peratures throughout the two runs were the same a s final product be C12CH.CH2.Se.CHz.CHClZ. Equations 6 and 7 show the symmetry of the atom, and by in factory operation, i. e . , from 1 2 0 ' t o 1 2 j " , and there analogy the selenium compound is assumed to be like- was no difference in the net yield of the two runs. When the still was opened after the completion mise symmetrical. of t h e run, it was found that severe pitting of the coils PHYSIOLOGICAL E F F E C T S had occurred when aluminium sulfate was present, Although the physiological effects of this compound possibly owing t o electrolytic action between the lead have not been studied, the experimenter has been con- of the coils and the aluminium sulfate. I n both tinually troubled with water blisters on his hands cases there was a sludge of sulfates. A short test was also made in t h e original glass while doing this work. A person working with this compound is also liable t o be overcome with a sense still with broken porcelain. I n this case the temof drowsiness. Whether this be due t o the compound perature a t which regular evolution occurred was lowered t o the same temperature (130') as with or t o some by-product is not known. aluminium sulfate in the glass still. CONCLUSIONS It is apparent, therefore, t h a t aluminium sulfate offers no advantages over the lead sulfate which is I-A simple method for the preparation of selenium normally present in lead ether stills, b u t is actually monochloride has been described. harmful, since i t causes pitting and rapid failure of the P - C C ~ H ~ C ~has ~ S ~been prepared and it has been coils. The action of lead sulfate could be explained shown t o be symmetrical tetrachlorodiethyl selenide.
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J Chem SOC.,12, 109, 13, 35, 135 Chem -Ztg , 16, 288,
* Oesterr
1 Presented a t the 60th Meeting of the American Chemical Society, Chicago, I11 , September 6 to 10, 1 9 2 0 2 C o n p t r e n d , 1 5 1 (1910), 3 9 2
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T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol.
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b y the formation of a double salt (PbS04.S04HCzH6), 3 4 . 7 8 per cent was reached in 1 7 days, which he states b u t the action of broken porcelain rather seems t o dis- was not the maximum. prove this theory and inclines us t o the view t h a t the S I G N I F I C A N C E O F MOISTURE CONTENT O F F L O U R rapid and regular evolution is due t o physical or I t seemed desirable t o ascertain the moisture consurface action. This view is strengthened by the ’tent of flour in atmospheres of differing but constant fact t h a t irregular evolution of ether actually com- humidity, after a period of exposure sufficiently long mences at the lower temperature, even if no lead sul- t o permit the hygroscopic moisture of the flour t o fate is present. reach equilibrium with the atmosphere. Such d a t a The observations recorded are interesting, also, would be of service in a number of ways. Shippers, because the choice of lead for the construction of a purchasers, and food control officials dealing with manufacturing still, which was made necessary by t h e flour need more precise information concerning changes character of the reagents, resulted in an improvement in moisture content, and consequently in the net weight in the process t h a t could not have been foreseen from of flour packages. The baker and storekeeper need laboratory experiments in glassware, and in fact such d a t a for the same reason, and, in addition, are had heretofore been largely overlooked. concerned with the indirect effect of changing moisture Credit is due t o Mr. W. M. Billing for carrying out content upon the keeping qualities of flour on prolonged storage. Flour which reaches a high moisture the laboratory work. content is quite likely, if kept moderately warm, t o become unsound through t h e activity either of its own T H E HYGROSCOPIC MOISTURE O F FLOUR EXPOSED T O enzymes, or those of fungi, and especially molds and ATMOSPHERES O F DIFFERENT RELATIVE related forms, which develop on the moist flour. HUMIDITY’,’ Millers may find such d a t a of service in developing By C. H. Bailey8 methods of controlling the atmospheric humidity in DIVISION OF AGRICULTURAL BIOCHEMISTRY, MINNESOTAAGRICULTURAL mills and certain milling machines. Milling operaEXPERIMENT S T A T I O N , ST. PAUL, MI“. tions of the future will doubtless include more a t Received July 30, 1920 tention t o the moisture content of the streams a t It has long been known t h a t cereals and cereal prod- each stage of the process, and such control will be esucts are hygroscopic, and t h a t their moisture content tablished in large part by maintaining the proper may be altered by varying the conditions of exposure. humidity in the air in the various machines. Brewer (1883) details certain experiments which esMETHOD OF P R O C E D U R E tablish this property. Other investigators, i h l u d i n g The humidity of t h e atmosphere t o which flour was Willard ( I 9 I I), Neumann ( I 9 I I ) , Guthrie and Norris exposed was controlled b y contact with the surface of (I 9 I 2), Sanderson ( T 9 14), Swanson, Willard and Fit2 (1915), and Stockham (1917),have studied the sulfuric acid solutions. These solutions were prepared changes in weight and moisture content of stored after the Reynault tables in Landolt, Bornstein and flour. I n none of these experimentb, save those of Roth’s “Tabellen.”’ Four solutions were prepared, Stockham, have the atmospheric conditions apparently which were intended t o afford humidities of 30, 50, 70, been controlled throughout the period of exposure. and 80 per cent, respectively. I t was not deemed adGuthrie and Norris (1912) recorded the atmospheric visable t o attempt t o maintain the humidity above humidity each day during the period t h a t the flour 80 per cent because: (a) The flour is apt to mold in very damp atmospheres. was under observation, but their readings were ap(b) In most parts of the United States an atmospheric huparently taken a t one particular time each day, and hence do not represent the mean humidity for the midity in excess of 80 per cent is not likely t o be maintained several 24-hr. periods. Even had the latter been for a prolonged period. (c) It becomes more difficult to maintain the humidity at determined, it is doubtful if the hygroscopic moisture a constant level when in excess of 80 per cent. of the flour could be regarded as in equilibrium with Two samples of flour were used in these studiest h e mean humidity of the atmosphere, when the a patent and a second clear flour. Their chemical humidity fluctuated as suddenly and violently as apcomposition is shown in Table I. pears t o have been the case. TABLEI-COMPOSITION OF &OURS USED I N HYGROSCOPIC MOISTURE STUDIES Stockham (1917) reports the moisture content of -CALCULATED TO DRY BASISwheat, bran, shorts, and flour exposed in a “saturated” Crude Protein Acidity MOISTURE (N X 5.7) Ash (as Lactic) and “ d r y ” atmosphere, but did not employ any degrees SAMPLE Per cent Per cent Per cent Per cent of atmospheric humidity between these extremes. Patent.. . . . . . . 8.71 0.47 0.159 12.44 2.38 0.781 16.46 He found t h a t a comoosite samole of flour exoosed in a Second clear.. . 9.92 Five grams of each of these flours were placed in “still, saturated” atmosphere a t a temperature of 2 3 O C. (see p. 109) reached a maximum moisture content of tared, flat-bottomed, aluminium drying dishes, having 28.74 per cent in 9.12 days, a t which time it was moldy. a diameter of 50 mm. This quantity of flour filled I n a saturated atmosphere a t o 0 a moisture content of the dishes t o a depth of 5 t o 6 mm. The dishes were placed in desiccators, the lower part Of which was 1 Published with the approval of the Director as Paper No. 214, Journal filled with t h e appropriate sulfuric acid solution. The Series, Minnesota Agricultural Experiment Station. * Presented a t the 60th Meeting of the American Chemical Society, several desiccators were set in a thermostat having a Chicago, Ill., September 6 to 10, 1920. d
a With the cooperation of Miss Isabel Everts.
1
4th Edition, 1912. p 426.
