Oct., 1921
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERfNG CHEMISTRY
SUMMARY The relation between the oxidation of petroleum oils and the formation of deposits in internal combustion engines to the sludging of transformer oils and to the deterioration of turbine oils is briefly discussed. The acceleration of the rate of oxidation by the presence of catalysts is then taken up. Finally, data which show the effect of several metals and
903
metal oxides upon the carbonization values of two typical oils are given in tabular form and discussed. Zinc and aluminium caused no increase in the quantity of precipitate. Steel, cast iron, nickel, and cobalt caused a slight acceleration, and phosphor bronze, brass, and copper a considerable acceleration of the rate of oxidation. All of the oxides showed marked effects. The highest values of all were obtained ‘with oil which had been exposed to sunlight and air for 20 hrs. before heating.
The Action of Anhydrous Stannic Chloride on Petroleum and Its Distillates’ By Gregory Torossian IDEAL PASTE & CHEMICAL WORKS, 1497 COUTANT AvE., CLEVELAND, OHIO
When crude petroleum or crude petroleum distillates are shaken with concentrated sulfuric acid, the acid gradually attacks the resinous, tarry, and oxygenated bituminous bodies found in petroleum, partly decomposing them, pa:tly absorbing them in a complex mixture which, on standing, separates as a dark lower layer below the unaffected hydrocarbons. By this process practically all of the main impurities of petroleum distillates are removed, and by subsequent washings with alkali solutions, filtration, etc., the final refining is completed. Although special methods of refining are employed for special petroleums, especially those containing a large amount of sulfur compounds, sulfuric acid is the primary reagent which e!iminates most of the tarry, resinous, oxygenated bituminous bodies. No. PRODUCT 1 Gasoline distillate
2
Kerosene distillate
3
Kerosene distillate
4
Fraction from 300’ C. up .to Machine 011: “Solar Oi!,” “Vaseline Oil,” etc. S a m e a s No.4
5
6
SOURCE
AVERAGE SP.GR.
filter press, while small amounts can easily be filtered through a wad of cotton. Several gallons of “Machine Oil” distillate treated with the tetrachloride and passed through a small experimental filter press packed with paper and cloth filtering mediums came out as a clear yellow oil. In all cases, and especially with petroleum distillates containing sulfur compounds, distinct improvement in the color and odor of the oils was observed. A kerosene distillate obtained from a sample of Baku petroleum showing a color test of 50 mm. (chromometer similar to Stammer’s) gave a color test of 138 mm. when treated with about 0.35 per cent SnCla and filtered through paper. After washing with a dilute alkali solution, the color rose to 178 mm., which is the nearest to Mark 2, or what is known in the oil market
BOILINGRANGE O
c.
APPROXIMATE AXOTJNT Per cent S n C t
PRSCIPITATE 1
Petroleum in general
0.750
Up t o 150
0.10-0.15
Reddish
Any petroleum not containing much S Sulfur-containing petroleums
0.820
150-300
0.3-0.6
Blood-red when settled
......
0.3-0.5 or more
Light yellow to bright orange; also red
Russian petroleum
0.885-0.890
......
1 .O-1.5
Gray t o brown
dark
Small amounts t o none if carefully distilled: com;act film formed on vessel Sticky’ compact transparent film’formed on vessel; acid t o litmus paper Red ppt.: sticky; filmforming; yellow and orange ppts.: loose particles containing sulfur compoudds Gray ppt.: loose partlcles, easily stirred; brown ppt.: partly plastic, partly por-
ous
......
Yellow t o orange; Appears t o contain most of brown sulfurcompounds.dark ppt.: plastic as usual; ;ellow and orange ppts. are of particles loosely held together, easily stirred Machine Oil Cvl- Petroleum in gen0.895-0.911 1.5-2 or mo.e Dark brown t o Plastic, tenacious, forms soft inder Oil Distileral black wax when worked up in the lates hand: melts and solidifies into a lustrous product; becomes brittle and porous on continued heating 1All these ppts. are decomposed when treated with concentrated sulfuric acid, anhydrous stannic chloride being set free. Ohio and Canada petroleums
0.886
1.0-1.6
......
When anhydrous stannic chloride, SnC14, is poured into a crude sample of petroleum or any of its distillates, a precipitate is instantly formed. Its color, quantity, and physical and chemical properties depend upon the character of the petroleum and the particular fraction a t hand. Red, orange, yellow, gray, brown, dark brown, and black precipitates are produced from various distillates. These precipitates are formed whether the samples contain moisture or not, the water combining with SnClr to form the hydrated chloride, which is incorporated with the precipitate. Table 1 shows some of the results thus far obtained.2 REMOVALOF COLOR The distillates treated with tin tetrachloride are easily filtered through ordinary filter paper on cloth in a suitable 1
*
Received April 11,1921. These d a t a are not complete, as work has not yet been finished.
as “superfine white.”’ The so-called sulfuric acid test showed the absence of tarry, resinous, and oxygenated bituminous bodies, and it passed the “soda” test, the odor being that of the best refined kerosene. A sample of “Machine Oil” distillate was treated with about 1 . 5 per cent of tin tetrachloride, the resulting precipitate freed from the oil, and the latter washed with caustic soda solution. It now gave a color test of 21 mm., the color being crystalline, bright, and light brown (Russian specifications, somewhat different from American). The action of tin tetrachloride upon various crude distillates of petroleum is so characteristic that it is not difficult to tell offhand, from the color, bulk, and physical properties of the precipitate, which of a given series of crude distillates 1 According to Redwood, 11, 214, “superfine white” corresponds to 190 mm. on Stammer’s chromometer. There is no explicitness on this
point of specifying the color of kerosene.
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THE JO bTRATALOF INDUSTRIAL AND ENGINEERING CHEMISTRY
a certain fraction is, and from what kind of petroleum the distillates are derived. An excess of tetrachloride has no action upon the hydrocarbons of the petroleum, once the impurities have been eliminated. The end of the reaction is easily seen by the characteristic fuming of the tin tetrachloride when the latter has been added in excess. That the chloride has no action on the saturated hydrocarbons is evident chiefly from the fact that it gives no precipitate with the purified petroleum products. White paraffin wax and white vaseline remain absolutely unaffected when treated with the chloride, while the yellow vaseline gives a slight reaction, indicating incomplete refining or oxygenation of the original pure product. A few drops of tin tetrachloride added to a sample of petroleum product will show instantly whether the sample is a crude product or refined, and, if refined, how far the refining has been carried.
NATUREOF ACTIONOF TETRACHLORIDE The action of tin tetrachloride upon the impurities of petroleum is chiefly chemical, although some physical phenomena seem also to be involved in the process of precipitation. It forms compounds with various impurities of the petroleum without itself undergoing decomposition. This is shown by the fact that when concentrated sulfuric acid is added to the precipitates, the anhydrous tetrachloride is liberated, as shown by the characteristic fuming, and by testing the regenerated liquid with a sample of crude distillate. When burned, the compounds leave an ash containing stannic oxide, although on careful burning the tin appears in the metallic state as a gray spongy mass. The tetrachloride also polymerizes the oxygenated bituminous bodies of petroleum. This is seen from the fact that a very small quantity of SnC14is necessary in order to produce a bulky precipitate from a heavy crude distillate and also from the action of the chloride directly upon tars, which are converted into solid asphaltum or pitch-like products. Pine tar, for instance, is converted into a solid, lustrous, pitch-like body on treatment with 10 or 15 per cent of SnCL. The reaction is very vigorous and is accompanied with liberation of much heat. Felix C. Thielel mentions the action of tin tetrachloride briefly in connection with the terpinenes, Cla&e, and polyfound in petroleum. While it is true terpinenes, (CIOHlB)+, that certain hydrocarbons classed as terpinenes do combine with tin tetrachloride, the action of this reagent on crude petroleum products cannot be explained on the assumption that it is solely chemical in nature. To be sure, chemical compounds are formed when petroleum impurities come in contact with SnC14, and polymerization also takes place, but it seems that some physical factors must enter into the process of precipitation of bulky, tenacious, or plastic bituminous bodies from the crude petroleum or its heavier .distillates. The fact that such small quantities ol tetrachloride are required to bring down bulky precipitates from the heavier distillates, combined with the fact that although in adding the reagent to a heavy sample all particles of reagent and oil are not brought into close contact a t once, the precipitation is almost instantaneous, indicates that the process is physical as well as chemical. It appears that, once the tetrachloride has brought down part of the impurities, the rest will follow as a result of disturbed equilibrium. The tetrachloride seems to react primarily with the oxygenated bituminous bodies, sulfur compounds, unsaturated organic acids, and terpinenes, found in petroleum. Terpinenes, especially, enter into a violent reaction, forming yellow or brown precipitates. Thus, spirit of turpentine 1
A m . Chcm. J . . 22 (18991,490.
Vol. 13, No. 10
reacts with stannic chloride with almost explosive violence, with the liberation of much heat, and the formation of a brown precipitate, consisting of loose particles which can be separated by filtration from the unaffected portion. Incidentally, this reaction shows that turpentine contains hydrocarbons, some of which are reactive and some not reactive with stannic chloride. The unsaturated organic acids, such as are found in drying oils, are also attacked with great violence. Linseed oil, for example, is bodily converted into a brown, viscous product when treated with tin tetrachloride. The tetrachloride, however, does not eliminate all the so-called naphthenic acids found in petroleum. Thus, a sample of kerosene distillate which had been treated with SnC14, filtered, and washed with distilled water, showed 0.10 per cent acidity in terms of SOs, while a sample of lubricating distillate, also treated with the chloride, filtered, washed, etc., gave an acidity of 0.20 per cent. It is interesting to note here that while tin tetrachloride destroys practically all the unpleasant odors from the crude petroleum products, it does not eliminate the last traces of “raw” odor, and only after washing with an alkali solution does the odor become “sweet.” This is explained by the fact that SnC14 does not completely remove the naphthenic acids, to which the odor is due. SU~CIMARY 1-Tin tetrachloride precipitates the tarry, resinous, oxygenated bituminous bodies, and also sulfur-containing compounds from crude petroleum and its crude distillates, by forming compounds with them, and also by polymerizing action upon them. 2-Tin tetrachloride has no effect on the saturated hydrocarbons of petroleum. It combines violently with unsaturated organic acids and hydrocarbons of the terpinene series with liberation of heat, and also polymerizes the tars. 3-The tin tetrachloride reaction affords a means for qualitative and quantitative tests for petroleum products. 4-Tin tetrachloride performs all the functions of sulfuric acid in the process of refining oils, and in addition it eliminates the sulfur compounds, thus serving as a reagent for the purification of all kinds of petroleum products.
The Societ.6 de Chimie Industrielle The Annual Meeting of the French SociCtC de Chimie Industrielle to be held a t the Conservatoire National des Arts et MCtiers, October 9 to 12, 1921, will bring together its home and foreign members. The meeting will constitute a true congress of industrial chemistry, embracing thirty-four technical sections, as follows : analytical chemistry; factory equipment; laboratory equipment; gas and coke-oven industries; hydrocarbons and petroleum; distillation of wood and its derivatives; refrigerating industries; water; metallurgy and electrometallurgy ; precious metals ; electrochemistry ; lime, cement and building materials ; glass, ceramics, and enamels; rare earths and radioactive substances; dyes; pharmaceuticals; photographic products; powders and explosives ; essences, natural and synthetic perfumes ; resins, pigments, lacs, varnishes, and waxes; rubber and rubber substitutes; fats, soaps, candles, and glycerol; cellulose and paper; plastic materials, and artificial textiles; bleaching, dyeing, printing and sizing; dyeing and tanning extracts; tannery industries; fermentation, wine, cider, brewery and distillery industries; sugar; starch and glucose industries; dairy industries; food materials; agricultural chemistry, soils, fertilizers. In connection with this meeting, the society has arranged a cheniical exposition, under the patronage of the Minister of Commerce. This Exposition, which is t o be held a t the Conservatoire National des Arts et Metiers, October 7 to 16, 1921, will consist of two sections: laboratory equipment and factory control, and dyes. Already a majority of French manufacturers have enrolled as exhibitors. The novelty and diversity of apparatus and products which are to be exhibited cannot fail to attract a large number o€ visitors interested in the development of the different branches of chemistry.
