THE SEPARATION AND IDENTIFICATION OF 
 ACIDS IN LOW TEMPERATURE TAR 
 
 BY 
 
 DELLA DARLE JUNKIN 
 B. A. University of Michigan 
 
 1912 
 
 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 
 
Digitized by the Internet Archive 
 in 2015 
 
 https://archive.org/details/separationidentiOOjunk 
 

 UNIVERSITY OF ILLINOIS 
 
 THE GRADUATE SCHOOL 
 
 June 2 192.1- 
 
 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY 
 SUPERVISION BY JQella.Darle Junitin 
 
 ENTITLED The Separation and Ident.i fin n.t.i on of Acids 
 
 in Low Temperature Tar. 
 
 BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR 
 THE DEGREE OF _ 
 
 
 I n Charge of Thesis 
 
 Head of Department 
 
 Recommendation concurred in* 
 
 Committee 
 
 on 
 
 Final Examination* 
 
 *Required for doctor’s degree but not for master’; 
 

 
 i 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TABLE OF CONTENTS 
 
 Acknowledgment Page 
 
 I, Introduction 1 
 
 Purpose of investigation 1 
 
 Historical 2 
 
 II* Experimental 
 
 1, Fractionation of tar ^ 
 
 a. Extraction and purification of acids 6 
 
 b. Fractionation of acids 7 
 
 c. Physical nature of acids 10 
 
 2. Extraction of acids without 
 
 fractionation 10 
 
 a. Dehydration of acids 11 
 
 b. Effect of steam distillation 11 
 
 c* Effect of vacuum distillation 11 
 
 d. Use of solvents 11 
 
 e. Choice of fractional extraction 
 
 solvent 12 
 
 f. Choice of precipitation solvent 12 
 
 g; Purification of solid acids 13 
 
 3. Tests to determine nature of acids 14 
 
 III. Summary and Conclusion 20 
 
 IV. Bibliography 21 
 

 
 
 
 
 
 
 
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ACKNOWLEDGMENT 
 
 This investigation was carried out in the Chemical 
 Laboratory of the University of Illinois 1920-21 under 
 the direction of Dr. Layng. The writer takes this opport- 
 unity to express appreciation for the assistance given by 
 various numbers of the department, but more especially to 
 Dr. Layng for his cooperation and timely assistance which 
 has meant so much to the progress and development of this 
 work. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE SEPARATION AND IDENTIFICATION OF ACIDS 
 
 IN LOW TEMPERATURE TARS. 
 
 I, Introduction 
 
 The purpose of this investigation is to secure, if 
 possible, the acids in low temperature tar in their original 
 form or as nearly so as possible, and thereby gain some 
 knowledge of the mature of the constituents of the tar and 
 perhaps of the original coal. In the process of low temper- 
 ature carbonization, there is some decomposition of the 
 higher boiling consti tuents , but the amount of this is 
 small in comparison to that produced by high temperatures. 
 Because of this there should be found in tar some of the 
 constituents of the coal not wholly decomposed among which 
 many acids undoubtably occur. The percentage of these acidic 
 bodies known to be high in low temperature tar, their separ- 
 ation and identification may give some idea of the nature of 
 those compounds which decompose on application of heat to 
 give bodies having lower boiling points and some which later 
 polymerize to give the higher boiling liquids and solids in 
 tar. 
 
 By the low temperature carbonization^^ is meant the 
 
 maintenance of such temperature that the formation of 
 
 naphthalene and fuel oils is not begun, as a result of the 
 
 decomposition of the higher boiling substances, 
 
 ( 2) 
 
 This transition temperature v ' occurs between 530 de- 
 grees and 560 degrees but by careful distillation a very 
 slight decomposition can be made to occur which increases 
 

 
 
 
 . 
 
 * 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 ' 
 
 
 
- 2 - 
 
 with rapid, rise in temperature resulting in a thickening 
 
 (3) 
 
 which Schneider' ' attributed to be due to polymerization! 
 and thus was he able to conclude from his work that the high 
 boiling substances passed off undecomposed ^ 4 ^ from the coal 
 in the coking process. 
 
 Professor Parr (5) says that this secondary decomposition 
 must be prevented, and may be, by maintaining a temperature 
 of less than 750 degrees, otherwise the "oxygenated constitu- 
 ents of the coal" will react with the phenol soluble substances 
 whicn form the binder for the coke, 
 
 ( 6 ) 
 
 Already there have been found over three hundred 
 substances in tar, of which about one hundred fifty have been 
 estimated and over ninety separated and purified. Among these 
 are. neutral basic, and acidic classes, containing oxygen, 
 nitrogen, or sulphur, either in the ring or in the side chain 
 and comprising five and six membered rings exemplied by 
 benzene, phenol, pyridine, thiophen, and coumarone. Of all 
 compounds contained, tar yields but few in large quantities, 
 
 such as benzene, phenol, and naphthalene. 
 
 (7) 
 
 The higher homologues of phenol occur in large 
 quantities in low temperature tar both as polyhydric phenol 
 and their esters which form resins. The latter remaining 
 undistilled if a fractionation is made at 240 degrees and form 
 a perfect material for road making. 
 
 Various methods have been employed for the purification 
 of the constituents v ' of tar among which are the formation 
 of salts of organic and inorganic reagents, with their sub- 
 

 
 
 ■ 
 
 . 
 
 
 
 
 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 •'■i ‘<n£^L 
 
 - 
 
 
 
 
 
 . 
 
- 3 ' 
 
 sequent decomposition, and the use of organic solvents* 
 
 ( 9 ) 
 
 Maclaurin removes bases by K 2 S 04 , acids by NaOH , 
 
 and the resins by means of hydrocarbon oils. 
 
 In the ordinary method of separation of tar acids, an 
 
 aqueous solution of sodium hydroxide is employed, resulting 
 in a water soluble salt of the acid which may be liberated on 
 
 addition of sulphuric acid. If the specific gravity of the 
 alkaline solution be increased, in each successive extraction, 
 afract.ional separation results, v/ith phenol and the lower 
 boiling horaologues appearing in the first extract. 
 
 The percent of acids in low temperature tar is high, 
 
 (fifty percent a maximum) but shows a great variation with 
 
 different tars , ( ^ ) because different coals produce different 
 types of tars; the younger the coal, the greater the yield of 
 
 acids, in any given tar.^- 1,c ^ 
 
 When however, the acids are removed from low temperature 
 tar there remain behind hydrocarbons which are not character- 
 istic of any definite tar, in decided contrast to tars produced 
 at high temperatures. These residues resemble more 
 
 closely petroleum products. 
 
 (14) 
 
 Heating of these petroleums like paraffin hydrocarbons 
 causes decomposition followed by polymerization to substances 
 of aromatic nature. 
 
 Identification of phenol and its homologues has consisted 
 (15) 
 
 of color reactions and the formation of derivatives • 
 
 hot the least among these derivatives is the condensation 
 with formaldehyde or with hexame thylene tetramine giving 
 

 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 * 
 
 . 
 
 
 
 
 
 
 
 
 
 
-4- 
 
 -d *1 n ^ 4 . (17) -r, , n (18). Dr. Baekeland defines a 
 
 Baekelite v ' or Reamanol v 
 
 "phenolic tody" as one having & benzene neucleus with the 
 
 hydroxyl attached to the ring either in a free or substituted 
 
 (19) 
 
 form. Moreover, anhydrides of the side chain hydroxyls 
 
 will, if produced by very careful heating, condense to give 
 an infusible product with formaldehyde but, if no such anhyd- 
 ride be present, there must be a substance of phenolic nature* 
 ( 21 ) 
 
 Sage has observed that an aqueous solution of NaOK 
 
 does not remove all of the acidic substances from tar and 
 
 that there remains behind dissolved in the sodium phenolate 
 and higher homologues a large percent of the acids. 
 
 These insoluble compounds are of asphaltic type and 
 ( 22 ) 
 
 Schneider v ' has reduced the percent of these compounds 
 by heat and pressure to one half their original amount and 
 
 secured a corresponding increase of low boiling phenols. 
 
 Marcus son ( 23) found ths-t by blowing air through heated 
 tar there were produced substances which were asphaltic in 
 nature . 
 
 To these substances does Hubbard (24) attribute the 
 superiority of low temperature tar to the process of road 
 building. In the determination of the percent of "soluble 
 bitumen" he suggests the use of carbon disulphide ( 25 ) and 
 subsequent precipitation in hydrocarbon oil. 
 
 Robertson^ 6 ) finds pyridine a suitable solvent for the 
 extraction of resinic and cellulosic bodies from low temper- 
 ature tar. 
 
-5- 
 
 Me thod and M anipulatio n 
 
 The method of securing the acids as nearly like those 
 in the crude tars as possible was two fold (a) distilling the 
 
 tar and extracting the acids and their subsequent fractionation 
 and (b) fractional extraction by means of organic solvents 
 
 and prec lotion reagents. 
 
 The tar was dried and distilled according to the method 
 suggested by Church. (2 1 ?) There was a very large amount of 
 foaming due to the high pyridine content and decreased but 
 little until the last traces of water had passed over. At 
 a temperature of 300 degrees heavy decomposition occurred and 
 the residue in the still began to increase in volume and 
 viscosity, finally resulting in a coke that was porous but 
 hard and having a volume of twice that of the residue in the 
 still at the beginning of heaviest decomposition. 
 
 TABLE I. 
 
 Crude Tar Frac tionation 
 
 f,H 2 0 
 
 .81 
 
 .72 
 
 % to 170 
 
 13.2 
 
 120 
 
 % to 230 
 
 25.9 
 
 26.9 
 
 ( 
 
 fo to 320 
 
 7.6 
 
 8.1 
 
 % to 360 
 
 8.4 
 
 9.2 
 
 % pitch 
 
 27.6 
 
 25.4 
 
 % decomposi- 
 
 
 
 tion 
 
 15.49 
 
 17.68 
 
r 
 
 - 6 - 
 
 Each fraction as above made was treated with an aqueous 
 
 solution of sodium hydroxide and the hydrocarbon removed from 
 
 the alkaline solution by means of steam distillation. The 
 acids were then liberated by the addition of sulphuric acid 
 
 and a second steam distillation gave a very pure acid. 
 
 This method was successful for all low boiling phenols, 
 
 but, with increase in boiling points the amount of steam 
 
 needed to distill a given Volume of acid rapidly increased. 
 
 Moreover, there remained in the still at the end of purifi- 
 cation of the 270 degree fraction a black viscous mass which 
 could not be distilled with steam. 
 
 The futility of this met nod in securing the high boil- 
 ing acids v/as avoided in the highest fraction by heating the 
 alkaline solution in anopen vessel thus removing any hydro- 
 carbon and then neutralizing "by the use of H^SO^ The 
 
 resulting phenols were darker in color and more viscous than 
 those secured by the previous method. 
 
 A sample of the acids thus purified was subjected to a 
 time temperature distillation with a view of determining- 
 points for fractionation. The results of this process, how- 
 ever, snowed no marked points of increase in volume for any 
 set temperature and the amount of distillate steadily decrea.sed 
 with a rise in temperature. The distillate at first was 
 
 \ 
 
 water-white but on standing assumed honey yellow color. The 
 succeeding distillates increased in depth of color and 
 viscosity and difficulty wa.s encountered toward the end of 
 

 
 
 
 
 
 '\ I,} - * ' 12 ' • 
 
 
 
 
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- 8 - 
 
-9 
 
 the process in the chokin , of the condenser* 
 
 Another sample of the purified acids subjected to 
 
 repeated distillation and the physical nature 'and yields 
 noted with the following results: 
 
 TABLE IX 
 
 Repeated distillation of Pure Acids 
 Distillation flo. 1 2 3 
 
 of Distillate 
 
 
 
 
 to 170 
 
 0 
 
 0 
 
 0 
 
 '•50 
 
 45 . 6 
 
 46.3 
 
 60.3 
 
 270 
 
 23.1 
 
 15.5 
 
 11.7 
 
 520 
 
 6.1 
 
 7.7 
 
 7.4 
 
 340 
 
 4.6 
 
 4.4 
 
 2,2 
 
 Prom the foregoing data the amount of decomposition in 
 the higher boiling fractions gradually increases giving 
 bodies having lower boiling point* 
 
 The higher boiling constituents grew darker in color 
 with each successive distillation and became so viscous as 
 to be poured with difficulty after several such heatings* 
 (iluud^*^ has sao ./n that if the high boiling tar 
 acids are h ated, their decompostition results in an increase 
 in the yielu of phenol w iich probable explains why the per- 
 centage of phenol is so much lower in the tar produced by 
 the low temperature coking process than that of ordinary tars. 
 
 (2i>) 
 
 Fischer elso maintains that the percent of phenols 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 10 - 
 
 can "be doubled by cracking tars at high temperatures. 
 
 Having found no satisfactory temperature for taking 
 fractions the cuts were made at those temperatures known to 
 be about the boiling points of several substances previously 
 found intars, ie, phenol 186 degrees, cresols 200 degrees, 
 xylenols 210 degrees and 225 degrees. 
 
 Color tests with FeCl-z were made on these members and 
 
 £ 
 
 positive results were secured but in no case was an individual 
 member isolated. 
 
 Comparative tests of the members of the liquid acids were 
 made with those of the solid acids secured by the second method 
 of extraction. This consisted in treating the crude tar with 
 a 50% solution of potassium hydroxide. Successive extractions 
 with the alkali finally gave an aqueous extract that contained 
 but a small part of the acids, but still was not colored on 
 further admixture with the tar. It was observed at the same 
 time that all of the alkali being used was not recovered from 
 the tar and upon examination it was found held in a black 
 viscous emulsion below the remaining hydrocarbon layer. 
 
 Because of the extreme viscosity of tnis product, removal 
 of hydrocarbon by use of a separatory funnel was impossible. 
 
 To remove hydrocarbon, suction was applied and from the remain- 
 ing alkaline solution the acids were liberated by means of 
 sulphuric acid. Having washed out any potassium sulphate re- 
 maining, the acids were subjected to a combination of steam 
 and vacuum for drying. Drying by the usual process was avoided 
 because the viscosity of a.cids caused local superheating and 
 
• ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 - i }tf , ■ i. 
 
 
 
 
 - 
 
 ■ 
 
 
 
 
 
 
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- 11 - 
 
 resulting d'-composti on . To avoid this the acids were warmed 
 on a steam bath and transferred to a three liter flask having 
 a long neck. Dry steam was passed into the war m acids and 
 at the same time a vacuum of 600 ram. was maintained. After 
 about 300 cc. of distillate had been collected the steam 
 supply was shut off and the vacuum simultaneously increased 
 to 200 mm. By this method complete dehydration was accomp- 
 lished in a short time. The small amount of acids appearing 
 in the distillate were low boiling. The yield of acids thus 
 obtained was 36$. 
 
 A sample of the dried acid was subjected to steam vacuum 
 distillation as applied to the drying process with the same 
 results, ie, any acid appearing in the distillate was of the 
 lowest boiling fraction and a yield of a few cc. per liter 
 of steam. This low yield of acids which were transferred in the 
 steam showed that the percent of phenol in this sample of tar 
 was very low. 
 
 Extraction With Solvents. 
 
 If the acids in the tar are to be separated and examined 
 as they are in their original form, these methods are useless. 
 
 By the time a sufficiently large yield could be obtained for 
 satisfactory observation, the nature would be so changed that 
 their resemblance to high temperature tan acids would be 
 closer. 
 
 Ligroin and petroleum ether were tested out as precipit- 
 ating agents. Petroleum ether is more satisfactory, there 
 being a heavy loss of all the low melting solids in the 
 

 
 
 
 
 
 
 
 
 
 
 
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 ♦ 
 
 
 
 
 
 
 
 
 
— 1 £— 
 
 ligroin, whereas, it was from the cold petroleum ether solu- 
 tion that these could he obtained and resulted in giving the 
 nearest pure of any of the extracted products. Moreover, the 
 high boiling point of the ligroin made sufficiently rapid 
 evaporation by vacuum an impossibility. In no case, could 
 there be produced a coat of ice on the outside of the filter 
 flask and this was essential to securing the last traces of 
 the dissolved solid, acids* 
 
 The solvents tested for their extracting ability are the 
 following, given in the order of their decreasing power to 
 dissolve the acids: phenol, sodium phenolate, alcoholic KOH, 
 
 CS 2 » CHCI3, ether, benzene, ligroin, alcohol, and petroleum 
 ether, of which the fractional extraction solvents chosen 
 were phenol, carbon disulphide, chloroform, and ether. 
 
 A sample of the crude acids was extracted with ether and 
 any undissolved residue was filtered and later treated success- 
 ively with CHCl^, CS2» and phenol until none remained. The 
 ether solution was poured slowly and with constant stirring 
 into about ten times its volume of petroleum ether and a fine- 
 ly divided light brown precipitate formed which filtered readily 
 into a suction flask containing more petroleum ether previous- 
 ly cooled by rapid evaporation. In the filter flask another 
 precipitate appared and this being filtered and the filtrate 
 as above gave second precipitate. This process was followed 
 until no more precipitate could be secured even by using a 
 large excess of petroleum ether at zero degrees, giving in 
 each tr ial a precipita.te lighter in color and more readily 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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- 13 - 
 
 soluble in petroleum ether on warming. 
 
 The chloroform, carbon disulphide, and phenol extracts 
 were likewise treated with petroleum ether as previously, the 
 resulting precipitation in each case darker than the preceed- 
 ing and much less soluble in the petroleum ether. 
 
 Difficulties in Extraction ar d Precipitation. 
 
 Carbon disulphide is a better solvent than ether, but 
 for the separation of those acids which are soluble in petrol- 
 eum ether at room temperature and precipitate on cooling, CSg 
 is a failure. It can not be as readily evaporated as ether 
 by vacuum and holds all of the more soluble bodies in solution. 
 
 If the CS^ extracted be poured rapidly into the petroleum 
 ether, the very rapid precipitation of the solute occluded 
 liquid acids resulting in a tarry mass. This difficulty is 
 greatly lessened if the petroleum ether is stirred rapidly 
 and the CS£ solution added slowly. This trouble is not en- 
 countered in the ca.se of the ether extract because the sub- 
 stances dissolved by ether are more readily soluble in petrol- 
 eum ether. 
 
 If a filter paper is used for two or more filtrations 
 there appears a resinous mass on the paper which causes very 
 slow filtration. This is coused by the high boiling acids 
 clogging the filter and then dissolving any solids to be 
 filtered. 
 
 A purification of the precipitated acids was made in the 
 same manner as that previously done in the extraction and 
 

 
 
 
 
 
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-14- 
 
 this resulted in the removal of all viscous liquid acids 
 
 and a very readily filtration. 
 
 The residue that was soluble in phenol only, presented 
 difficulties due to the fact that when the phenol solution 
 was poured into the petroleum ether it formed a viscous mass 
 adhearing firmly to the walls of the beaker and giving no 
 precipitate in the petroleum ether. When a small amount of 
 ethyl ether is added to the solution, it reduces the solvent 
 action of the phenol, and then a fine black precipitate is 
 liberated which is readily filtered. 
 
 Appearance of the Purified Products. 
 
 A gradual darkening in color occurrs with the rise in 
 melting point and decreases in solubility of the solid acids 
 separated by means of organic solvents. But one slight var- 
 iation occurred in this generalization: those solid acids 
 
 insoluble in the cold petroleum ether solution and having a 
 melting point between 80-85 degrees were more distinctly 
 orange in color than either the preceeding or following 
 members. This characteristic became even more pronounced 
 on repurifi cation. 
 
 The lowest melting point of any solid obtained was 
 60 degrees and each succeeding sample gave a rise of from 
 three to five degrees until that of six members wa,s taken. 
 
 It was in these latter samples that the presence of mixtures 
 could be observed, by the transition temperature occurring 
 

 
 
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 if . jH 
 
 
 
 
 
 
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 I m\u ' 
 
 
 
 
 
 
- 15 - 
 
 on application of heat. This became more pronounced on using 
 those sa pies most easily precipitated in petroleum ether. 
 
 The darker colored samples showed several transition points 
 but no definite melting point. The phenol soluble extract 
 had a melting point of 111 degrees and was the highest obtained. 
 
 In every case there occurred a decided change at the 
 melting temperature. The lightest colored products became 
 dark and viscous did not return to their former color or 
 powdered condition on cooling. At a few degrees above the 
 melting point decomposition set in and the product began to 
 increase in size. 
 
 After the filtration of the acids the petroleum ether was 
 allowed to evaporate and tne resulting precipitate was powder- 
 ed. All of the lower melting solids were powdered with, con- 
 siderable ease and had a tendency to adhere strongly to the 
 spatula giving an easily compressed cake. Those having 
 higher melting points possessed this property to a small 
 extent there being a considerable decrease with increase of 
 melting point and increase in hardness. The phenol soluble 
 product wae very compact and was reduced to a powder only 
 after considerable pressure had been applied. 
 

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- 16 - 
 
 Teste on Extracted Solid and Liquid Acids. 
 
 Numerous tests were applied to the extracted acids to 
 determine their chemical nature, among which were solubilities, 
 ignition, combustion, nitrogen and sulphur determination, and 
 condensation with hexame thylene tetramine. 
 
 The solvents used were alcohol, turpentine, benzene, ether, 
 chloroform, carbon disulphide, phenol alconolic KOH, and 
 pyridine . 
 
 All light colored acids precipitated by the cold petrol- 
 eum ether were soluble to a greater or less extent in all 
 solvents. Turpentine and alcohol showed the poorest solvent 
 power. 
 
 The light brown products were soluble in all reagents with 
 the exception of turpentine a no. alcohol. 
 
 The darA products showed a decided decrease in solubility 
 in all solvents. The last extract was soluble in phenol and 
 alcoholic KOH only. 
 
 The pyridine test was made that the asphaltic character 
 of the products might be observed. Samples were dissolved 
 in pyridine and some water added. On being agitated a soapy 
 foam was produced and this remained for sometime. The addit- 
 ion of K SO4 caused the precipitation of the solute. 
 
 The solubility tests in general show that all of the sub- 
 stances are decidedly acidic in character, and that those 
 lightest in color are more readily soluble in all reagents, 
 and also that an increase in depth of color is accompnied by 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
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 ♦ 
 
 . 
 
 . 
 
 
 
-17- 
 
 a decrease in solubility. 
 
 The ignition of the liquid acids showed no characteris- 
 tics other than that they were of the aromatic type. Cn 
 burning all of the solid acids, however, there was a decided 
 change. Shortly after melting they began to increase decid- 
 edly in volume and charred. This volume assumed remained 
 constant until most of the carbon had been burned off. 
 
 To obtain the percentage composition, the determinations 
 of carbon hydrogen and oxygen were made in a combustion 
 furnace, nitrogen was determined by the Kjeldahl method, 
 
 ana sulphur as by the NagOg KCIO 3 fraction ation using 
 
 id 1 • v v ( 30 ) 
 
 a Parr explosion bomb. 
 
 The following gives the results obtained using samples 
 of the lightest and darkest acids: 
 
 TABLE III 
 
 Color 
 
 of Samples 
 
 C 
 
 H 
 
 C 
 
 N 
 
 S 
 
 Dark 
 
 (CSg ext. ) 
 
 78.6 
 
 4.3 
 
 13.6 
 
 1.5 
 
 1.11 
 
 Light. 
 
 (ether ext.) 
 
 78.9 
 
 5.4 
 
 13.5 
 
 1.0 2 
 
 1.04 
 
 From the data thus obtained there was no indication 
 that these acids were of very great difference in molecular 
 structure. Due to the fact, hov/ever, that these are decided 
 mixtures an accurate determination is impossible. 
 
 To determine the position of the hydroxyl group in the 
 molecule, ie, to ascertain if these are either cargoxylic 
 
 " ' ' — 
 

 
 
 
 
 
 
 
 
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-18- 
 
 acids or alcohols, or of true phenolic nature, Redinanol 
 condensations were made using hexamethyline tetraraine in 
 alcoholic KOH solution, with the following results: 
 
 
 
 TABLE IV 
 
 
 
 Sample 
 
 B .P. 
 
 M.P. 
 
 Result 
 
 Residue 
 
 liquid 
 
 • V 
 
 200-10 
 
 
 light brown resin 
 
 none 
 
 liquid 
 
 210-20 
 
 
 light brown resin 
 
 none 
 
 li quid 
 
 220-30 
 
 
 brown resin 
 
 none 
 
 li quid 
 
 230- 60 
 
 
 dark brown resin 
 
 none 
 
 liquid 
 
 260-300 
 
 
 aark brown resin 
 
 none 
 
 li quid 
 
 300-340 
 
 
 black resin 
 
 light yellow 
 
 
 
 
 
 ppt. in water 
 
 solid 
 
 
 65-85 
 
 none 
 
 original 
 
 solid 
 
 
 94-96 
 
 none 
 
 original 
 
 solid 
 
 
 104 
 
 none 
 
 original 
 
 crude tar 
 
 acids 
 
 
 black resin 
 
 asphaltic 
 
 
 
 
 
 powder. 
 
 The 
 
 foregoing 
 
 table shows 
 
 that there are two 
 
 types of 
 
 acidic substances isolated by the two methods used. Those 
 separated by distillation are of phenolic type, and may 
 contain a s mall amount of the lower melting solid acids which 
 precipitate out on condensation of the liquid acids and those 
 bearing decided acidic properties but not of phenolic type. 
 
 The residue left from the crude tar acids after conden- 
 

 
 
 
 
 
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- 19 - 
 
 sation was the same in color and character as that obtained 
 by the extraction methods. In this way hexane thy lene tetra- 
 
 mine may be considered as a satisfactory reagent for extract- 
 ion of the higher acids. 
 
 Tests on Gilsonite. 
 
 Comparative tests on some asphaltene extracted from 
 gilsonite were made, with a view to determine similarity to 
 the solid acids obtained by extraction with one exception 
 that there were no low melting products secured, every test 
 applied was identical in its outcome to those applied to the 
 acids, leading to the conclusion that these solid acids are 
 in reality asphaltenes. (No combustion on asphaltenes from 
 gilsonite was made). 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
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- 20 - 
 
 SUMMARY OF INVESTIGATION 
 
 1. Low temperature tar cannot be fractionated without 
 
 a large amount of decomposition of the higher boiling consti- 
 tuents giving a porous coke having a large volume. 
 
 2. Subsequent fractionation of the tar acids causes a 
 decrease in yields of the higher boiling constituents with 
 a corresponding increase of the low boiling fractions. 
 
 3. No satisfactory cutting temperatures can be select- 
 ed for low temperature tar acids, as there is no decided 
 increase in yield at any one temperature. 
 
 4. Tar acids may be classed as to liquid and solids: 
 those soluble in common organic reagents and those insoluble 
 in all save phenol and alkali; those possessing the hydroxyl 
 connected to the ring (truly phenolic), and those of 
 carboxylic or alcoholic natures; and those truly acidic and 
 asphaltic . 
 
 5. Free carbon determination in low temperature tar 
 cannot be made as in high temperature because there is found 
 in low temperature tar an acidic substance insoluble in 
 benzene and CSg. 
 
 6. The asphaltic bodies in low temperature tar decompose 
 on heating giving an increase in the volume. 
 
1. 
 
 Freeman 
 
 -21- 
 
 BIBLIOGRAPHY 
 
 Petroleum Times 3 , 543-4. 
 
 2. 
 
 Fischer and 
 
 Schneider Ges. Abhandl. der Kenntn. Kohle. 
 
 3. 
 
 Schneider 
 
 __3, 36-56. 
 
 Ges. Abhandl. der. Kenntn. Kohle. 2 , 
 
 4. 
 
 Schneider 
 
 133-44. 
 
 Ges. Abhandl. der Kenntn Kohle. 2. 145-50. 
 
 5. 
 
 Parr and Layng Mining and Met., 1920 Bo. 158 Sect. 4. 
 
 6 . 
 
 Spielman 
 
 Gas Journal 143, 65. 
 
 . j 
 
 7. 
 
 Lewes 
 
 The Carbonization of Coal P.192. 
 
 8. 
 
 Loco Git. 
 
 
 9. 
 
 Maclaurin 
 
 Gas Journal 139 , 143 
 
 • 
 
 o 
 
 i — 1 
 
 Lunge 
 
 Coal Tar and Ammonia 1_, 577. 
 
 11. 
 
 Fischer and 
 
 Schneider Ges. Abhandl. der -^enntn. Kohle. 
 
 18. 
 
 Ibid 
 
 3_, 200-12. 
 
 3 ., 1-38. 
 
 13. 
 
 Benson and 
 
 Canfield J. Ind. Eng. Chem. 12 , 443, 
 
 14. 
 
 Cooper 
 
 By Product Coking P. 138. 
 
 15. 
 
 Lunge Coal 
 
 Tar and Ammonia 1, 219-20. 
 
 15. 
 
 Mulliken 
 
 Identification of Pure Organic Compounds, 
 
 17. 
 
 Baekland 
 
 _1, 90-106. 
 
 J. Ind. Eng. Chem. 1, 149-61. 
 
 18. 
 
 Redman and 
 
 Wei til J. Ind Eng. Chem., 6 _, 3-15. 
 
 19. 
 
 Baekeland 
 
 J. Ind Eng. Chem.,__5, 506-11. 
 
 20. 
 
 Baekeland 
 
 L. Ind. Eng. Chem.,_l, 545-9. 
 
 21. 
 
 Sage 
 
 J. Soc . Chem. Ind., ^30, 558. 
 
 22. 
 
 Schne ider 
 
 Brennstoff Chemie 1 , 70-72, and 80-85. 
 
- 22 - 
 
 23. 
 
 Marcus son 
 
 Z. Angew. Chem., 32, I 385-6. 
 
 
 24. 
 
 Hubbard 
 
 Dust Prevention Bull. Dept. Ag. 
 
 , Ho. 34, 
 
 
 
 P. 34. 
 
 
 25. 
 
 Hubb ard 
 
 J. Soc. Chem. Ind. 30, 201. 
 
 
 26. 
 
 Robertson 
 
 Chemistry of Coal P.21. 
 
 
 27. 
 
 Church 
 
 J. Ind Eng. Chem., 3 , 227-33* 
 
 
 28. 
 
 Gluud 
 
 Ges. Abhandl. derKenntn. Kohle. 
 
 ,&2 , 236 
 
 
 
 
 56. 
 
 29. 
 
 fischer 
 
 Ges. Abhandl. der Kenntn. Kohle. 
 
 , 2_, 
 
 22-35. 
 
 -30 
 
 White 
 
 Gas and Fuel Analysis 
 
 P. 206