May, 1913
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERI-VG CHE-IIIITTRY
of the free bromine according t o their equation is not required, (6) I t has been shown t h a t not more than 50 per cent excess potassium bromide over t h a t called for by the equation at the top of p. 392 need be used in making the standqrd bromide-bromate solution. The U. S. P. recommends a n excess of 340 per cent. 3. Complete liberation of the iodine by the free bromine may be effected in one minute, if thorough diffusion be obtained by sufficient shaking. 4. The acidity of the solution in which the tribromphenol is precipitated must not fall below 0.48 r\i if the bromination is t o be complete in one minute. An acidity of 0.5-1.0 i V is recommended. 5 . Low temperatures have a retarding influence on the rapid formation of tribromphenol: 20-30’ C. is recommended. DEPARTMENT O F INDUSTRI.4L RESEARCH UNIVERSITY OF KANSAS I..4WRENCE
PETROLEUM ANALYTICAL METHODS’ B y S. I?. SADTLER
~
The object of this paper is t o discuss the following: Can the presence of oxygen in petroleum and asphalts be established by a direct method of ultimate analysis? To get the full import of this question, a few words of introduction are needed, bearing upon the subject of what those interested in the chemistry of petroleum and asphalt know with regard t o this matter of the presence of oxygen in substances of these two classes. Hoefer2 gives a list of 59 ultimate analyses of petroleums from all countries. I t is true t h a t more than half of these are the earlier analysesof St. Claire Deville and Boussingault in which only carbon and hydrogen were determined and the balance needed t o make I O O was assumed t o be oxygen, but in a large number of more recent analyses both the sulfur and the nitrogen when present have been directly determined and the balance then ascribed to oxygen. Notably in Russian oils and Japanese oils, both analyzed in recent years and noting the sulfur a n d nitrogen, has this presence of oxygen been recorded. Rakusins also quotes more recent analyses of Russian petroleums b y Charitschkoff and by Nastjukoff, who find from 0.4 t o 2.5 per cent of oxygen and what is of interest, note t h a t the percentage of oxygen increases in the heavy petroleums and residues with the specific gravity. But we are not obliged t o base our belief on the presence of oxygen in petroleums on calculations made from ultimate analyses. The discovery of the petroleum acids b y Hell and Medinger in Roumanian oils and phenols and of the naphthene-carboxylic acids by Markownikoff and Oglobin has given us a n explanation of the presence of oxygen and justified the assumptions made from the ultimate analyses. With the natural asphalts, the case is different from t h a t of petroleums. Although earlier ultimate analyses of asphalts gave large percentages of oxygen, Paper presented a t the Eighth International Congress of Applied Chemistry, before the Section on Fuels and Asphalt, Sept. 6, 1912. 2 Das Erdoel und seine v e r z ~ a ~ d t e 2te n , Auf., Seiten 55 und 56. 3 Die Untersuchung d e s Erdoels una! seine Producte, 1906, 7 7 . 1
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i t was because the presence of sulfur in them had not been recognized and the oxygen was supposed, with the carbon and hydrogen, t o make up the ash-free bitumen. However, Kohlerr gives several analyses of natural asphalts by Day and Bryant and by Kayser, in which a small percentage of oxygen is given a s present along with a larger percentage of sulfur. Both Clifford Richardson and Prof. S. F. Peckham, eminent American authorities on asphalt, have taken the position t h a t not only is sulfur a distinctive element for natural asphalts, but equally that oxygen is t o be considered as foreign t o natural asphalts. Besides the natural asphalts, we have also t o note the artificial asphalts, obtained from ‘ petroleum, either by simple removal of the volatile portions o r by some form of treatment with oxygen or sulfur at high temperatures. To the first class belong such products as “ D grade asphalt,”2 made from California asphaltic petroleum, and “ Baku Pitah”3 and to the second class Ventura Flux, Byerlite and Sarco asphalt. Of these last mentioned products, Byerlite and Sarco asphalt have been made irom liquid petroleum-residuums b y the action of a current of air, either drawn through or forced through a t temperatures ranging from 380‘ F. (193.3’ C.) to 500’ F. (287.70C.). The action of the heated air may have two different effects4 according t o temperature and rapidity or quantity of air passed through. The oxygen may cause splitting off of hydrogen in the form of water, with condensation of the hydrocarbons affected, or the oxygen may be fixed, forming products of oxidation which remain, in either case resulting in thick semi-solid or solid products. Not only would it be very desirable from a scientific point of view t o determine which of these reactions has taken place, or whether both have united in the formation of the solid asphalt-like products obtained, but the matter has been the subject of investigation in connection with patent litigation over rival processes. Of course, direct determinations of carbon, hydrogen, sulfur and nitrogen may and (do leave varying deficiencies t o be charged up t o oxygen, but it would be desirable to be able t o confirm these calculations by a direct determination of the oxygen in the product. No such method has thus far come into common use. The method of Baumhauer, either in its earlier form or in its later form, using a weighed quantity of dry silver iodate and requiring first a current of hydrogen, then of nitrogen and finally of hydrogen again, has not been favorably commented Ion by those who have tried it. The method of Mitscherlich of burning with mercuric oxide is also intended. t o give the oxygen a t the same time t h a t the carbon and hydrogen are obtained, but this method does not seem t o have worked satisfactorily in the hands of those who have referred to i t and has not been adopted by chemists. The process which I desire t o present t o those in1 Chemie u n d Technologie der .\’atiirlichen uttd Kiirtstlichen Asfihalte, 1904, 81. Clifford Richardson, “The Modern Asphalt Pavement,” [2] 1908, 263. 3 Ibid., 271. 4 Hofer, p. 85.
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T H E J O U R N A L OF I N D U S T R I A L AND EiVGIiVEERIlVG C H E M I S T R Y
terested in this subject is very simple in theory, although its execution is not free from difficulties and requires time for its proper completion. I t is primarily the invention of Dr. Wm. M.Cross, City Chemist of Kansas City, Mo., with whose permission I have worked upon i t with a view to making i t applicable to this class of products, and to whose courtesy I am also indebted for the permission t o give publicity to these results. I t consists in a combustion carried on in a current of dried and purified hydrogen gas, the front of the combustion tube being filled with iron wool, which, brought up t o a bright glow and thoroughly reduced by the hydrogen, then acts as contact-substance and brings about complete reaction between the hydrogen and the vapors given off from the decomposing petrbleum or asphalt, whereby any oxygen present is taken up in the form of water vapor, passing on to be absorbed ultimately in a weighed chloride of calcium tube. I n making the determination, hydrogen is passed very slowly through strong sulfuric acid, calcium chloride and over phosphorus pentoxide into the end of the combustion tube containing the boat sample, beyond which is a with the weighed sufficiently long layer of iron wool, The combustion tube a t the farther end is connected with a good-sized U-tube containing purified asbestos wool or preferably spun glass and this to a weighed chloride of calcium tube for absorbing water. When the combustion furnace is first lighted, only that part of the tube containing the iron wool is strongly heated, the part containing the asphalt being kept cool. Hydrogen is then passed very slowly through the apparatus until the chloride of calcium tube used for and so collecting water has to constant time. The part of the tube conremained for taining the asphalt is then increased in temperature very gradually until ultimately the boat and its contents are heated to the maximum temperature attainable and so held for a time. 1f the large ~ containing the asbestos or glass-wool is kept cool, no condensable vapors pass beyond, and if the current of hydrogen be continued a sufficient length of time after the full heat has been applied, it will take all water through as vapor into the Reighed &loride of calcium tube. Xo trouble need be anticipated from the small amount of sulfur contained in the asphalt or petroleum product, because the heated iron wool is capable of taking it up, in whatever form it is liberated. After beginning my trial of the process with ordinary combustion tubing, 1 was led by reason of the necessity of keeping the portion of the tube containing the boat with the Tveighed asphalt cool, while the portion ‘ containing the iron wool had to be heated to a bright red heat, to try a tube of fused silica and have found this to possess great advantages, With a tube of transparent fused silica, Some 30 inches in length, which I obtained from the Silicate syndicate, Ltd. of London, Eng., the iron wool can be brought to the desired heat, while the end of the tube contairljng - the boat can be kept perfectly cool by water trickliiig upon it. By this means the rubber corks, with wl-iich the
Vol. 5 , No. 5
ends of the combustion tubes are fitted, can also be kept cool so that no overheating can take place. I have not yet completed my analytical work upon the material taken to try out the method and prefer to reserve a complete illustration of the applicability of the method to both petroleums, and asphaltic substances for a fuller paper. I will, however, give two oxygen determinations in a blown petroleum-residuum, or so-called artificial asphalt. Determination oE oxygen Weight of material taken,. , , , Water absorbed in CaC12 tube
.
I
11
,oo65 gram 0.0440 gram
0.9767 gram 0.0394 gram 0.0350 g r a m ~ ~ : ~ e , s , p , ~ ~ i ~ ~ , ~ ~ ~ ~ , ~ ~ o x y g e n 3.58 , per cent. ,,
..
(‘:‘389ieyc::t:t.
39
SOUTH TENTHSTREET PHILADELPHIA, PA.
EVAPORATION TEST FOR MINERAL LUBRICATING AND TRANSFORMER OILS’ BY ‘2. E. WATERS Received March 17, 1913
A Year ago the difficulty in obtaining concordant duplicate determinations of the percentage of loss by evaporation when certain mineral oils were heated was forcibly impressed upon the writer. I t was not until quite recently, however, that any attempt was made to determine t o what extent the amount. and rate of evaporation are influenced by conditions to be described The results obtained with a typewriter oil and with two transformer oils finally led to the present work being done. The results lead to the conclusion that the factor of Prime importance is, for a given temperature, the area of oil surface exposed to the atmosphere. Even when quite different weights of oil are heated in vessels of the same size, the actual losses are nearly equal, SO that when the results are figured as percentages they are f a r from concordant. As far as we have been able to find from the literature, comparatively little paid to this factor and, in~ attention ~ bhas been ~ deed, to the whole subject of the evaporation of oil. Gillz uses filter Paper, 1 5 / 8 inches in diameter with a five-eighths inch hole in the center. The paper is dried in a desiccator over sulfuric acid, weighed on a watch glass and then “about 0.2 gram” of oil is dropped upon it. We have found that eight drops Of a certain Oil was sufficient to saturate the paper. This amount Of Oil weighed from 0.1401to o . r 5 0 6 gram. Holdes uses the inner chp of the Pensky flashPoint apparatus. The CUP is filled to the mark and mreighing. With the amount O f Oil determined this cup, heated in the bath devised by Holde, i t should be easy to duplicate results very exactly with a given oil. Since the loss in weight of oil depends so largely on the surface, i t might seem that duplicate determinations Of the percentage loss TVould not agree exactly if great ‘are were not taken to the CUP to the mark. As a matter of fact a variation of I mm. in the depth of the oil makes a difference of a little more than 2 . 0 cc. and, therefore, of rather less than 2 . 0 grams. The 1 2
Published by permission of the Director of the Bureau of Standards. “Oil Analysis.” 6th ed., p. 35. Mitth. fechn. Vers.-Anstalt,Berhn, 20, 67-70 (1902).
