1 THE STUDY OF ASPHALTENE IN GILSONITE BY ERROL BATHURST MIDDLETON B. A. University of Illinois 1919 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE IN CHEMISTRY IN THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS 1921 ' % m\ UNIVERSITY OF ILLINOIS THE GRADUATE SCHOOL June 2, 192 1 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY . Srrol Bathurst ki &dleton ENTITLED Study of Asphaltene in Gilson ite . ” BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THF npr.RFF OT 7 Master of Science in Chemistry u y. ^ / In Charge of Thesis Head of Department Recommendation concurred in* Committee on Final Examination* Required for doctor’s degree but not for master’s Digitized by the Internet Archive in 2015 https://archive.org/details/studyofasphaltenOOmidd ACM OWLED G-MEN 2 I take this opportunity to thank Professor S. W. Parr for the valuable assistance and kindly suggestions , which he so freely gave at all times during this investigation. I am also indebted to the American Asphalt Association who furnished the materials used in this research. . TABLE OE COL LEFTS IF PRODUCTION Geology of Gilsonite Composition of Gilsonite Mining Uses of Gilsonite HISTORICAL PART SOLVENTS AND SOLUBILITY GG1 4* and its Use as a Solvent for Different iat- ing Bitumens G3 2 as a Solvent in the Analysis of Bitumens Solubility in 88° D aphtha or Hexane Other Solvents EXPERIMED TAD PART ■ Methods of Examination of Asphalts Methods of Analysis of Gilsonite by Hexane Centrifugal Method of Analysis of Gilsonite Discussion of Methods Method of Determining Sulfur Fit no gen 0 RIGID OE ASPHALTEDES , THEIR PROPERTIES ADD COMPOSITION SUMMARY Page 1 1 2 2 4 6 6 7 7 8 9 13 15 17 17 19 23 BIBLIOGRAPHY ACKNOWLEDGMENT 25 ' , 1 - THE STUDY CD ASPHATENE IE GIL SOU ITE INTRODUCTION Geology of Gilsonite . Gilsonite is a solid natural bitumen not distributed very widely in nature. It is the result of metamorphism of petroleum under pressure , and is found in fissure veins which approach the vertical and afford the conditions which are favorable for the metamorphosis of petroleum into those materials. Grahamite, another solid native bitumen is also found in nature. The change has gone on under a varying time factor, to an extent that has resulted in substances presenting different degrees of condensation , from one which flows softly in the sun, as is the case with our softest .Gilsonite, to one of the hardness of the brittlest Grahamite, which does not melt at even the highest temperatures . Composition of Gilsonite . xhis mineral is a hydrocarbon and is found in commercial quantities in the immediate vicinity of Dragon , Utah. It is shipp- ed in two grades, select Gilsonite, and Gilsonite. The grading is done at the mines and by appearance only, but this is sufficient for the appearance of each grade is so characteristic that there is a small chance for error. Occasionally a melting point is taken to check up on the ore. The selects are taken from the center of the vein and are characterized by a conchoidal and lustrous fracture* The seconds occur near the edge, and have a semi-conchoidal and semi-lustrous fracture. In other respects they are alike. Of the two grades of Gilsonite, the select is in much more demand, because it is more suitable to use in paints and varnishes. * 2 - Very few paint and varnish makers can use Gilsonite at all. Gil- sonite is used in the manufacture of roofing compounds, and this use distinguishes it from the higher grade select Gilsonite. Mining. The methods of mining Gilsonite are very crude. It is done with a pick and shovel, together with some sort of simple hoisting apparatus. Very little timber is required, as the veins are nearly vertical, and the surrounding rock is firm and self-support- ing. Prom this Utah source, 20,000 tons of Gilsonite are mined and shipped annually , -value approximately §65,000. There are 52,000,000 tons of Gilsonite left in the region, according to Abraham, "Asphalts and Allied Substances", page 155. Uses of Gilsonite . The general method for making permanent coverings using Gil- sonite Selects is to melt the selects down to a flux, usually rosin and then the mixture is thinned d own with benzine and an oil, usually chinawood oil or linseed oil. Every varnish and paint maker has his own formula. Select Gilsonite has a lower melting point, and is more soluble than Gilsonite. For these reasons it is in demand by the paint or varnish maker. Since Gilsonite is more easily mined than Select Gilsonite and is lower priced it would greatly benefit the entire paint industry, if a method could be obtained whereby Gilsonite could be changed to select Gilsonite. Besides its use in paint and varnishes, and roofing, Gilsonite has successfully been used in the paving industry, and it is well to note its use here, because of the number of road treatment preparations which use it as a binding base. It can "be used with- 3 - out refining for this purpose. It is also used in the manufacture of electric insulators, for acid proofing, and in instances where we want a smooth, elastic resistant and weatherable coating. Its physical and chemical properties are on the average: Table I. Analysis and Examination of Gilsonite. Sp. Gr. 1.04 Softens 127-149 Plows 134-164 loss at 63°G . ( 7 hrs . ) .4$-6.5 $ loss at 205°0 . ( 7 hrs.) 1.0$-2.0$ Character of residue at 65°G and 205°C. Smooth Bitumen (90 $ Soluble in CS£ ( 7 $ Organi c Hat ter Inorganic Matter 3 $ Percent Bitumen Insoluble in CC1 Z . 0-0. 4$ Pixed Carbon 14$ Sulfur .66$ According to G. C. Austin, General Manager of the American Asphalt Association, the chief difference between the two grades of Gilsonite is in the percentage of "malt^enes" or "petrolenes” present. These materials are soluble in hexane. The Gilsonite selects are supposed to have a higher percentage of "malt/enes" than the lower grade. If this be the case, certain steps or measures might be taken to remedy this. Maltha may be added, if need be, or a heavy as -o halt oil. . - < 4 - HISTORICJAL PART In 1837, Boussingault , a Frenchman, published a memoir of the composition of bitumens. He discovered that certain bitumens yielded a portion of their constituent hydrocarbons to one class of solvents, and another portion to another class. He called one portion "asphaltene" , and the other portion "petrolene " . The conclusions that he drew from his work was that these two substances were simple, and also that they were identical from whatever source obtained. However, indications pointed that "petrolene" is but a name that covers a multitude of substances, decidedly unlike, which exist in different forms of bitumen, and are only related in this instance, as being held in solution by a limited number of solvents, and it includes the whole list of paraffins, iso-paraffins, ben- zenes, olefines, and additive benzenes , with many other less abundant and well known substances. The solvents for petrolene are ethyl ether, petroleum, naphtha. Petrolene is nothing but a name . In 1827, LeBel and Muntz went over the same ground, a nd in $ 1883, LeBel went over it again, added a few facts in relation to other bitumens than those which had been examined. He left the two substances asphaltene and petrolene practically where he found them. Laura A. Linton showed later that asphaltene is little more definite than petrolene, and that no certainty attaches itself to the identity of asphaltene from different sources or of asphaltene dissolved by different solvents. The bitumens examined by these French chemists, LeBel and Boussingault never assumed any commercial importance. This re- 5 - search was purely scientific and little was thought that the chemi- cal examination of asphalts would ever assume any great importance. Since asphalt paving has "become economically important, technolo- gists have "begun to seriously consider the question of a chemical examination of asphaltic material, and the problem has been carried outside the laboratory. By 1894, large numbers of so-called analyses had appeared, which represent various attempts to determine and set forth the values of many kinds, and samples of asphaltum, that may or may not be suitable for different uses. Since asphalts are mixtures there is a great danger that the product could be adulterated, and the chemical examination of asphalts has proved an obstacle for adulterators. These mixtures are usually based on the fact that they must contain Trinidad Asphalt. The substitutes for Trinidad Asphalt usually contain Gilsonite tempered with petroleum residues, and are only suited for a certain class of work. Before chemical an lysis began to play such an important role in the asphalt game, a lew physical tests on mixtures were sufficient, The first avenue of approach, as to the chemistry of asphalt mix- tures was to turn the attention toward organic solvents that would indicate the chemical nature of the asphalt mixture. Up to the present time, the methods employed are not satisfactory methods of chemical analysis, so improvements must be made on the older ones, or new ones devised. 6 - 3 OL VENTS AND SOLUBILITY CGI , and its Use as a Solv ent for Differentiating 4 Bitumens . CGl^ is used as a substitute for GSg in the dete rmina.t ion of bitumens. It is non-inflammable, non-explosive, has an aromatic odor, low vapor tension, and no toxic effect, while GSg is very inflammable, explosive, has a high vapor tension, and is poisonous. CCl^ boils at 46°G. and GSg at 76.6°G. Considered as a standard for extraction on a commercial scale it is the equal in solvent power of almost all other solvents, exceeding them with certain substances . The value of CCI 4 as a solvent in the case of bitumens lies in the fact that it possesses a selective action on hydrocarbons. CCl^ will dissolve the ma Irenes or petrolene in bitumen, but will have no effect on the carbenes . The expression, "carbenes" , has been applied to that portion of bituminous substances soluble in C3g and insoluble in GC1 Z . They are the result of over heating or over blowing. When the solvent power was tried on Gilsonite , the result was practically the same as with GSp . So the Gilsonite contains very little of the carbenes, if any at all. Garbon Bisulfide as a Solvent in the Analysis of Bitumens . The percentage of bitumens soluble in GSg is useful for pur- poses of identification, for ascertaining the adaptability of a bituminous substance for certain purposes, for a gauge as to its uniformity of supply, and as a means of judging its quality. Crude bituminous materials are purchased sometimes upon the basis of CS 9 soluble bitumens. In the case of certain natural asphalts, the greater the percentage solubility in G3g , the greater their intrin- , 7 - sic value. Gilsonite is a solid natural "bitumen approximately 99 70 soluble in CSg. CSg may exclude mineral matter in asphalts, so the Gilsonite is practically free from mineral matter. Solubility in GSg is a measure of purity of an asphaltic cement. The cementing value, other things being equal is propor- tional to the GSg solubility. Any carbonaceous material such as coal tar or pitch is detected by the GSg solubility test. Solubility in 88 ° K aphtha or Hexane . The solubility of asphats in 88° petroleum naphtha is a cri- terion of the percentage of malthenes in an asphalt. Asphaltites are relatively insoluble in this solvent. The portion of asphalts insoluble are the asphaltenes. Other Solv ent s . ( Solubility) Other solvents, than those just mentioned, as turpentine, toluol, benzol, mixtures of benzol and toluol, and acetone are sometimes used for the identification of certain bitumens, but are not as successful as C3 r . 8 - EKPEHIMEN PAL ( DI SCU3SI OF ) Methods of Examination of Asphalts . The presnet chemical knowledge of bituminous substances is very limited. Their practical chemistry is confined to the most rudimentary of tests , based on rule of thumb methods rather than on an accurate scheme of chemical analysis. There is a woeful lack of scientific analytical methods. In the determination of asphalts, the term percentage of asphalt has not as yet been defined in chemical terns. It, there- fore, cannot be determined like other chemical individuals. The presnet means of determining asphalts is as follows: (a) Precipitation with petroleum ether. (b) Precipitation with alcohol-ether. (c) In case of soft materials evaporation until a certain consistency is reached. The methods "a" and "b n tend to determine the percentage of asphalt by a chemical reaction, precipitating a part of the same, while the last method tends to define the percentage by reducing the bitumen to a certain fixed physical consistency, calling any- thing asphalt which has that consistency or harder. By the first method, we make use of the fact that the so-called "asphaltenes" are insoluble in petroleum ether, and therefore, are precipitated by it, v/hereas the petrolenes are soluble. This method is of course, not a direct measure for the real composition or content of the asphalts, as it permits only of an approximate estimation of the same by the percentages of asphaltenes, unless we previously know the nature of the bitumen. If the asphaltic material to be be examined, contains some light petroleum distillates, then a ' - . r 9 - distillate of 86 ° to 88 ° Be' shows less asphaltenes present. Methods of Analysis of Gil son it e by Hexane Iletho d . After considerable experimentation with different solvents such as CS £ , GgHg , CCI 4 , CHClg , and toluene, it was found advisable to use GS £ (sulfur free), and the proper condition for the solvent action of 0S £ and the precipitation with hexane was at room tem- perature. She following plan of analysis was suggested from the pamphlet "The Chemical Examination of Asphaltic Material", by Prof. 3. W. Parr, B. Mears , and D. 1. Weatherhead. Half gram samples of powdered Gilsonite was placed in separatory funnels of a50 cc. capacity, and 5 cc. CS £ was added. When the solution is complete, ICO cc . hexane, sp. gr. .66 (Westphal balance) are added. The mixture is allowed to stand for two hours and a precipitate is formed, which corresponds to the asphaltenes of the usual methods. This precipitate is next thoroughtly washed with hexane and filter- ed on a specially prepared Gooch crucible, described on page (16), which is dried in an electric oven at 105°G. to constant weight. This is possible because no oxidation or chemical action has taken place. This precipitate calculated in terms of the sample was precipitate # 1 . , corresponding to the asphaltenes mentioned above. Hexane can be recovered by condensation from the filtrate ob- tained from precipitate ,1 where CS £ is used, much easier than the other solvents , and the recovered hexane can be used again very satisfactorily. Recovery yields of from 60-70$ of the amount of hexane used can be obtained. Since both hexane and CS £ are highly inflarama ole , the source of heat for d 1 st ills, t ion is from an electi*ic hot plate about 4" in diameter, and the distilling flask a 250 cc. Erlenmeyer flagk. The distillation can be made to dryness. 10 - To obtain precipitate # 2 , the filtrate from the preceding determination can be evaporated to dryness. The residue is next taken up in the Erie nmeyer flask with 10 cc . of hexane, while the flask is warm and poured back into the original separatory- funnel. A complete transfer can be made with no loss of material or solvent . This hexane solution while still warm is allowed to run slowly into 500 cc. of methyl alcohol, in a glass crystalliz ing dish, previously tared , the alcohol having been cooled below the freezing point of water. The alcohol must be constantly agitated and stirred. A sticky, gummy, black precipitate is obtained which collects on the sides of the dish. After complete precipitation and standing for two hours, the al- cohol is decanted through a weighed Gooch crucible of the type used for precipitate #1. Both the dish and crucible are dried at 1C5° and weighed. The gain in weight of the dish and crucible repre- sents the secnnd precipitate ..corresponding to the mslthenes. Precipitate #3 was obtained by evaporating the methyl alcohol from the second determination and weighing the residue in a glass dish ,and contains the tarry residues of the Gilsonite. Table # 2 . Solubility of Gilsonite. Insoluble in GSg Insoluble in CCI 4 Insoluble in CHOI 9 . 4 $ . 4 $ .3 .5 .35 .17 Chloroform: Takes Gilsonite CS 2 : Takes Gilsonite •16 .25 .2 .3 into solution very rapidly. i-ho solution, but not quite so rapidly as 11 - CHClg, in its solvent power. Benzene : Dissolves Gilson ite more slowly than GSg or CHClg. Acetone : Acetone has only a small noticeable effect. CC1 4 : Similar to chloroform in its behavior. Ether: Little noticeable effect. Samples of Gilsonite from the museum were analyzed according to the method of analysis as used in "The Chemical Examination of Asphaltic Material", by Prof. 3. 17. Parr, Barinerd Hears, and D. L. beatherhead . Table III. Gilsonite. Sample Do . Ppt . trl Ppt. #2 Ppt . #3 Total 1 Asphaltenes 48 • 01% Malthenes 40.71% Tarry -e 7 . 28% sidues 96.00% 2 44.38 43.63 12.99 100.00 3 43.27 42.25 8.35 93.87 Average of each 45.22 42.19 9.54 96.62 An analysis of Gilsonite for precipitate {=1 using special care for the determinat ion of this following results were obtained: Table IV. Gilsonite. Sample II o. Ppt . #1 1 2 3 Asphsltene s 45.95% 46.83 45.23 alone was made , precipitate and the average 46.00 12 - Analyses were made on samples of Gilsonite and Gilsonite select and the following results obtained; Table V. Gilsonite Select Ppt. #1 Asphaltenes 11.2 $ Ppt. #2 Malthenes 66.84 % Ppt. #2 Tarry Residues 16.24 % Total 96.28 % 12.2 % 67.4 15.04 95.64 io 11.46 70.84 15.16 97 .46 Average 11.95 69.02 15.48 96.67 Another analysis using CCl^ in place of CS^ was made, and tl following result s obtained: Table VI. Gilsonite Ppt. #1 Asphaltenes 46.50 % Ppt. #2 Malthene s 42.06 % Ppt. #2 Tarry Residues 9.52 % Total 99.09 $ 47.75 42.25 9.58 99.59 45.56 42 .66 10.45 99.67 Average 16.60 42.79 9.54 99.78 Table Vll. Gilsonite 45.20 fo 44.66 % 9.22 °]o 99.19 45.94 44.24 6.45 98.62 45.84 42.72 9.67 98.24 Average 45.69 42.88 9.12 98.68 The above results appear to bear the assumption of Mr. C.C. Walker of the American Asphalt Co., which is that the difference between the two grades of Gilsonite is due to the percentage of the malthenes or Petrolemes. Numerous runs were made on the analysis of Gilsonite and Gilsonite select with varying results. Those just mentioned above being the best - . 13 - fable VIII. Gilsonite . Sample 1 Bo . Ppt . #1 Asphaltenes, Ppt . # 2 Ppt . # 3 Malthenes Tarry "Residues 47.20# 7.60 fo Total 87.05# 2 36.85 38.03 12.3 87.05 3 27.25 49.06 6.2 82.51 4 45.00 39.25 4.6 88.85 5 39.20 37.73 11.45 CO to • CO CO 6 28.03 47.03 12.36 88.42 7 51.36 27.00 10.06 88.32 8 42.48 15.00 57.48 9 37.39 5.20 42.59 10 44.74 56.14 8.66 109.54 11 52.06 32.59 16.77 101.41 1 Table IX. Asphaltene s 5.25 Gilsonite Malthene s 76.93 Select Tarry Residues 25.26 91.27 2 6.34 82.04 12.36 100.74 3 9.68 53.38 18.84 81.90 Centrifugal Method of Analysis of Gilsonite . After making these analyses, a new method for making the r re- e ci; it at ion 01 the naphthalnefi more complete suggested itself. JProm observing the lormaticn and precipitation of the asphaltenes, and novv quickly they settled out, it seemed possible that the re- precipitation might still further be hastened if they were centri- fuged . A few Qualitative runs were made, using a high powered centrifuge, -nd it was found that a very clean cut precipitate would quickly lorm, and that the natant liquid above them could practically 14 - be decanted. The asphaltenes thus obtained could be easily dried in an electric oven at 100°C. The occluded or adsorbed solvent present in the precipitate made it very bulky, and it was observed that the drying at 100°3 would cause a noticeable shrinkage. A very pure product may be obtained this way, very quickly. This centrifuge method worked very satisfactorily, quantita- tively, with Gilsoriite as the results will show. An analysis for asphaltenes alone by this method was nn.de. Table X. Asphaltenes in Gilsonite. Sample Mo. Ppt. $ 1 ASp ^?f es £ 46.73 3 44.31 Avera ge 45. 4£ The precipitation of an asphaltene can be easily made in the glass centrifuge cups, the precipitate centrifuged out, and the hexane easily recovered as in the preceding method. Precipitate vf3 was obtained in the usual manner. Results on Gilsonite by this method: Table XI. Gilson ite Select. Ppt. #1 Ppt . #2 Ppt. ''-3 Total Asphaltenes 11.33$ Malthenes 70.00$ Tarry Residues 15.43$ 96.76 $ 10.56 72.00 14.73 97.29 11.05 73.00 15.28 99.33 Average 10.98 71.66 15.14 . 97.13 15 - Discussion of Ifethods . In the analysis of asphalts by the method of selective organic solvents, quite a number of difficulties have to be contended with. For example, in the precipitation of asphaltenes from a C3g solu- tion by means of petroleum ether or hexane, sp. gr. .66, the pre- cipitate obtained is colloidal in nature , and ver difficult, to remove, usually part of the precipitate pas.es through the Gooch filtering crucible. (This would be a source of considerable error if it could not be remedied. It may be remedied in this way. The reduced pressure creates a freezing of the hexane in the filter flask, and the asphaltene precipitate going through comes in con- tact with this freezing mixture, and separates out, and can be refiltered through the same filtering medium. The only danger here is that the asphaltene has a tendency to stick to the filter flask. Pre.ctically all of the asphaltene can be removed by this refiltering process. If allowed to stand for any length of time in contact with gla^s, the asphaltenes adhere very closely, and are very difficult to remove so the quicker they can be filtered, after having been formed, the better. However, at best, the filtering of asphaltic precipitates suspended in organic solvents is a slow, tedious and unsat is fact ory process. The following simple deviation from the ordinary method oi preparing Gooch crucibles was used. Ordinarj ily the Gooch crucibles are prepared as shown in the accompanying illustration. ' * ■ . t 16 - ^his slight change. Pig. 2, was made, and proved satisfactory in the laboratory. A thimble cone of Gu gauze is placed in the bottom of a Gooch crucible and the asbestos sucked dry over it as shown in the figure. In cases where ignition is not necessary, as in our case, the copper gauze is satisfactory. Where ignition is necessary, the cone should be made of Pt. In actual practise, the cone not only gives us an increased surface for filtering, but also allows the heavier and denser portion of the precipitate to settle in a ring at the bottom of the crucible, leaving the asbestos on the apex of the filter, in such a condition that the filtrate and washing liquids can be quickly removed. It might be called a fractional f ilt er . It is very difficult to obtain duplicate results on accout of the fact that it is very hard to obtain a uniform homogeneous sample of such a mixture as Gilsonite or Gilsonite mixtures; and hard to obtain solvents of uniform specific gravity and composition. Table XII. Sulfur analyses were made on Gilsonite, Gilsonite Select, and the Asphaltenes , and the following results obtained: Gilsonite Gilsonite Select Asphal tene . 674# Sulfur .637# Sulfur .9605# ; . 666 .680 .972 .655 .656 .954 .671 .643 .936 17 - Method of Determining Sul fur . The sulfur on these samples was determined as follower: .2 grams samples of material were weighed, and fused in a peroxide fusion bomb with 1 gram KCICg , and 10-12 grams of Ba^Gc. The fused mass was dissolved in about 2C0 go. of distilled water, fil- tered to remove any insoluble matter, treated with 10-20 cc. sat- urated bromine water, and made slightly acid with HC1 , and the sulfate precipitated out with 10 cc. of a hot 10 $ BaClg solution. Bitrogen . Analyses for nitrogen were made on Gilsonite Select, and as- phaltene by the Xjeldahl- Gunning Method, using 1 gram of material, 30 cc. concentrated HgS0 A , . 6-. 8 grams of CuSO^. in the digestion, and KMhC '4 crystals were added after the digestion to insure com- plete oxidation. The following results' were obtained: Tabl e XIII. H it rog en . Gilsonite Select Asphaltene 2.51$ 1.48$ 2.49 1.53 Carbon , Hydrogen , and Oxygen Analysis . An analysis for 0, II, and 0 was made on a sample of asphaltenes , and the following result obtained on a .5 gram sample of the materia Carbon Hydrogen Oxygen 44,87$ 5.25 $ 47.39$ A sample ultimate analysis of the asphaltene would be: ”fc Carbon Hydrogen Oxygen Biro gen Sulfur 44 . 87 $ 5.25$ 47.39$ 1.53$ .96$ - * 18 - This -ultimate analysis shows that asphaltenes to be the result of continued action of oxygen on petroleum resins, because of the high percentage of oxygen present. It shows them to contain 3 and H in appreciable quantities. lliscellaneous Tests t The asphaltene will reduce aqueous EMhO^ on continued boiling and standing for several hours. They have no diazo reaction, or anthraquinone reaction. They have a trace of saponifiable natter. . 19 - ORIGrlM OP ASPHALTEIES, THEIR PROPERTII AID COMPOSITE 01 Asphaltenes may be formed by continued action of oxygen or sulfur on petroleum resins, or by atomic rearrangement. The resins formed on heating heavy mineral oils in air are gradually trans- formed into asphaltenes by continued heating. Properties of Asphaltenes . Externally, the asphaltenes are a brownish-black pov/der, do not melt , but swell up on heating , decomposing and leaving a coke that ; is very difficultly combustible. They yield no distillate on heat- ing. They are almost insoluble in alcohol and benzine, slightly soluble in ether and acetone, but are complete!;, soluble in C^Hg, CHGlg , and CSg. The asphaltenes of natural asphalts are character- ized by their high sulfur content. The sulfur compounds are very sensitive to light, being transformed into an insoluble modification Chemistry . On being treated with fuming nitric acid at -1C°C., the as- phaltene may be converted into nitro compounds wh' ch dissolves in alcoholic KOH. On heating, we have nitrous acid split off. HgSO A and HCHO form insoluble salts. The iodine number of asphaltene is very high, 52.6. The Br substitution number is 4.8. It is not to be concluded however, that we have unsaturated bodies in the asphaltenes, as the HgpBiv test shows that they contain sulfides which may take up Br. ( 2Br = 13) format! on and Composition of Asphal t Constituent 3 . 1. Oily constituents. 2. Petroleum resins. 3. Asphaltenes. 4. Asphaltous acids. The oily portions separated from natural asphalts resemble 20 - viscous fluorescent mineral oils. They show optical activity. Concentrated H 0 SO 4 . takes asphaltenes in solution at 1G0°C. , providing all solvents are absent , then the solution becomes black, and pasty, with the evolution of SOg. On pouring into water, black products sparingly soluble in pyridine form; heating with dilute HC1 splits off HgSQ^. The products of H^SO^ and asphaltenes in the cold probably indicate the formation of an oxonium or sulfonium compound. On treating a benzene solution of asphaltene with concent rated sulfuric acid at room temperature , the precipitation was almost quantitative , the precipitate having the appearance of the original asphaltene, with the exception that the precipitate was flocculent in appearance. The precipitate was washed out with HgSO^ , and v/as found to be almost insoluble in benzene. Heating had no effect on the solubility for asphaltenes are freely soluble in cold benzene. This indicates the formation of double compounds. Polymerisation has taken place, and an HgSO^ compound was probably formed, for on heating with dilute HOI, HgSO^. was given off. When testing the solubilities of the compound it was found to be insoluble in ITH^OH, alcoholic KOH, but soluble in pyridine. The pyridine solu- tion mixed freely with water, arid on, shaking yields a foam similar to soap solution. On the addition of water, a precipitate of the original asphaltenes was obtained. Sulfuric acid, in the cold, as we have seen before, indicates the production with asphaltenes 0 f an oxonium or sulfonium compound The corresponding ether compound shows the property of a salt, and is a weak acid, due to the OH group, and is analogous to the - p * . • * • * 21 - asphalt sulfur compound. The ether has the following formula: sulfate, so the action of sulfuric acid on asphaltene at 1C0°G., except that there might he a possibility for the formation of a new closed ring due to the union of the free OH of the primarily formed H 2 S0 4 compound with a nuclear H atom yielding water. Asphaltenes are polycyclic compounds, which contain G, H, S, and 0 in the ring form or as sulfides or ether; 3 and 0 may re- place one another. A. sphaltene is higher in S and 0 than the resins. Asphalts may he formed from unsaturated or saturated compounds; the former are mainly naphthalenes and terpenes, since aliphatic hydrocarbons occur only to a small extent in petroleum. The reaction between unsaturated hydrocarbons and 3 and 0 takes place according to the Engl er Aut oxidation Theory. A Bakelite condensation was tried on a sample of asphaltenes obtained from G-ilsonite. The procedure was as follows: the as- phaltenes were shaken up in an alcoholic KOH solution. Hexamethy- lene tetramine was added and the mixture refluxed on an electric hot plate for 8 hours. The apparatus used was one as described in the accompanying figure, (JFig. 3). Just as ether, HgBO^ at 100°C., forms small amounts of diethyl 22 - fhe substance after refluxing, was neutr lized with HgSO^. Ifore hexamethylene tetramine was added, and the product salted out with UH4CI. The results were negative. Ho condensation product was formed, and according to Baekeland, this condensation will not work where the OH is in the ring, it must he in the sice chain for the condensation to take place. SUMMARY 23 - 1. The percentage of asphaltenes in certain "bitumens is sig- nificant because it helps determine the nature of the asphalt. In general, it might be said, that the higher the percentage of as- phaltene present in a petroleum product, in Gilsonite, in coal, or any other bituminous material, the more asphaltic is its character, and specifications sometimes make use of this test in order to se- cure a highly asphaltic content. 2. That the differences between Gilsonite and Gilsonite Select is in the difference betwe n the percentages of asphaltenes. Gil- sonite containing approximately 45$, Gilsonite Select 11.2$. 3. The analysis of asphalts by the Selective Solvent Method has its disadvantages because the composition of asphalts is not uniform and the composition of the solvents does not remain constant, 4. Asphaltenes may be found in petroleum residues, pitch from coke ovens, and natural asphalts. This may give us a clue or an insight into the common properties which certain bituminous materials possess. it may oring to light , the fact that these bituminous materials are all of a common origin representing different stages in car oonizat ion or condensation. Asphaltenes may be a connecting link between coal, asphalt, and petroleum. The asphaltenes of crude oil and native asphalts are closely related to coal. A transformation theory for bituminous or asphaltic material may throw some ligit on this relation. Goal;- Peat Lignite Bituminous Anthracite Petroleum;- Petroleum R esins Asphaltenes Oarbenes Garbo ids . 5. uinoe asphaltenes take up 5 so readily it might be concluded *8 . . 24 - that the sulfur and oxygen are present in a ring structure rather than if the form of ether or sulfides. 6. Since the uses of asphalt, asphalt residues, flukes and binders both natur 1 and artificial has increased tremendously in the last few years, a chemical examination is almost imperative. 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