INDUSTRIAL A N D ENGINEERING CHEMISTRY
854
Vol. 17, No. 8
Formula Weights of Low-Temperature Phenols' By Jerome J. Morgan a n d Mer1 H. Meighan COLUMBIA UNIVSSSITY,
for this purpose and some valuable information gain&.' It was thought that further information be Obby determining the aver&@formula weights of various fractions of Carbocoal and Hydrogas tar acids.
NEW Y O R K , N. Y.
r
The d e t e r m i n a t i o n of average f o r m u l a weights of fractions of the phenols f r o m b o t h Hydrogas and Carbocoal tar oils shows that the average formula weights of the Hydrogas phenols range f r o m 110 in the lower fractions to 212 in the fraction, w i t h average boiling p o i n t of 290' C. The r a n g e of the Carbocoal phenols is f r o m 109 in the lower fraction to 163 in the fraction, w i t h average boiling point of 270' c. These results are f u r t h e r proof of t h e m o r e complex s t r u c t u r e of the Hydrogas phenols and of the cracking of the phenols in the tar formed by t h e Carbocoal process.
and o-cresol 197.4' to 211' C. for cresols 211' to 232' C. for cresols andxylenols and 232' higher t o 266' phenols C. for xylenols
266' t o 305.8' C. for higher phenols
The distillation was con1ducted in an liter distilling flask, resting on a pieceof transite board Previous Work which had a 9-cm. (3.5-inch) hole cut in it. The flask I n studying the phenolic was surrounded with an ascoinwounds vresent in lowbestos shield extending to temperature-tar oils the tar acids have been carefully fractionated and the physical and the side-neck and the shield was covered with a piece of heavy chemical properties of the fractions determined.s The de- asbestos paper. This arrangement was used so that the discrease in the specific gravity as the boiling point increases, of t h e first fractions, has been attributed to the presence of ali- tillation could be carried on with the least possible amount of phatic side chains attached to the phenol nucleus-e. g., cresols cracking of the phenols. There was no visible evidence of and xylenols. In the higher fractions a sharp rise in the density cracking until 240" to 250" C. was reached. About 65 per cent and a notable increase in the viscosity of the fractions mark the by volume of the tar acids distilled below 315' C. (Figure 1). appearance of alpha- and beta-naphthols in the high-temperature This series of phenol fractions was refractionated twice phenols' and bicyclic compounds, a t least, in the low-temperawith a 25.4-cm. (10-inch) Vigreux column. Further fracture phenols.a I n an investigation of the alkali-soluble compounds of high tionation was not attempted, as it would only lead to cracking boiling point in low-temperature coal tax, Bogert and Caplan5 of the phenols without much improvement in the separation prepared a series of the higher Carbocoal phenols. After examining the fractions boiling between 292' and 373" C., they con- of the compounds. Curves of the second fractionation with the column were plotted and the average boiling points of cluded that these consisted in part, a t least, of dimethyldihydronaphthols. the fractions taken as the mean ordinates of these curves. An attempt was made by Weindele to identify the phenols The average boiling points and specific gravities of the fracfrom low-temperature tar produced by the Dellwik-Fleischer tions are given in Table I. "Trigas" process. The tar acids were separated and fractionated
within close limits and the carbon and hydrogen contents of these fractions determined and compared with figures for known phenols. It was decided, however, that the method of elementary analysis does not permit conclusions concerning the individual phenols present in the fractions above 215' C. The analyses of the hipher fractions indicate the presence of unsaturated polyhydric phenols. As an alternative method for the identification of the phenols, the molecular weights were determined by the esterification method of Verley and Bolsing, which gave results confirming the above conclusion. It is further claimed that betanaphthol has been isolated from fraction 280' to 290" C., and that probably other naphthol derivatives are present. Materials
HYDROGAS TARPHEivoLs-The total tar acids were extracted from a quantity of Hydrogas tar oil by repeated shaking with 23.5 per cent sodium hydroxide solution. The 1 Received January 13, 1825. Presented as a part of a paper entitled *'An Investigation of the Caustic Soda Process of Extracting Low-Temperature Phenols" before the Section of Gas and Fuel Chemistry at the 69th Meeting of the American Chemical Society, Baltimore, Md , April 6 to 10, 1925. Abstracted from the doctorate dissertation of the junior author in $he DeDartment of Chemical Engineering at Columbia University. Numbers in text refer to bibliography at end of article.
*
Table I-Hydrogas
Fraction 1 2 3 4 5 ~~
Distillation Per cent range of total O C. fcorr.) tar acids 2.7 Up io 1 9 8 . 3 7.8 1 9 7 . 4 to 211 17.0 211 to 232 to 266 12.0 232 to 3 0 5 . 8 11.5 266 Pitch and loss.. . 49.0 Total.. . . . . 100.0 ~
.. .. . .. . .
Phenols Average boiling Average Sp. 5'. formula point C. 25'/4 C . weip.ht 196.0 1:034 IYO 204.0 1.022 114 216.0 1,009 127 242.0 1.015 167 290.0 1.063 212
CARBOCOAL PHmoLs-In order to determine the average formula weights of phenols which had been examined by Morgan and Soulea a series of Carbocoal phenol fractions was prepared according to their method. The distillation curve for these phenols is shown in Figure 1. It is evident from a comparison of the distillation curves of the Hydrogas and Carbocoal phenols that the former are higher boiling. The Hydrogas process produces a tar which is more truly primary or low-temperature tar than that from the Carbocoal process. I n the latter process the products have an opportunity to come into contact with surfaces heated to 600' C. and they undergo decomposition to some e ~ t e n t . In ~ the Hydrogas
INDUSTRIAL A X D ENGINEERING C H E * I S T R Y
August, 192.3
process,8 however, the distillation is carried on by hot gases and the products are swept out through the cooler upper zones of fuel and are not decomposed by hot retort walls. The average boiling points and specific gravities of the fractions are given in Table 11. 320 I
,
,
I
I
Percent of Tofa/ Volume Disfi/led
855
Discussion of Results
The formula weights given in the tables are calculated on the basis of one hydroxyl radical per molecule. It is believed, therefore, that the results are additional proof of the absence of any considerable quantity of dihydroxy phenols in these tar acids. If appreciable amounts of dihydroxy phenols were present the formula weights would have been much lower. The average formula weights of the Carbocoal fractions, as here determined, yield further light on the composition of the Carbocoal phenols. It was formerly thought3 that Fractions 1, 2, 3, and 4 were mainly mixtures of phenol and the cresols, and that Fractions 5, 6, and 7 were mainly mixtures of cresols and xylenols. The average formula weights show, however, that even Fractions 1 and 2 contain compounds of higher formula weight than the cresols, formula weight 108. If much phenol, formula weight 94, is present a considerable amount of xylenols must also be present. In Fractions 3 and 4 the average formula weight is slightly higher than that of the xylenols, 122. Hence Fractions 3 and 4 must contain, in addition to phenols and cresols, large amounts of xylenols and considerable quantities of compounds of higher molecular weight. Further, in Fractions 5, 6, and 7 boiling from 203.7' to 231.5' C., the average formula weights found show that these fractions, instead of being mainly xylenols, must contain large amounts of phenols of higher formula weight. The average formula weights obtained for Fractions 8 and 9 tend to substantiate the conclusion of Bogert and CapIan6 that the higher boiling fractions of Carbocoal phenols consist in part of dimethyldihydronaphthols. The formula weight of naphthol is 144 and that of dimethyldihydronaphthol is 174. The formula weights found, 150 and 163, respectively, might readily allow the presence of considerable of the latter compounds.
of Phenols
Figure I-Distillation
Procedure
The average formula weights of the various Hydrogas and Carbocoal phenol fractions were determined by means of the sodium method described in another paper.l Samples of 0.25 to 0.80 gram were used in the determinations. In the analysis of Fractions 8 and 9 of the Carbocoal phenols an interesting indication of the presence of naphthol derivatives was obtained. -4s soon as the phenol came into contact with sodium a violet-blue to bluish green color appeared. The phenolate residues from these fractions were always dark blue or olive-green. A methodQwas recently proposed for the detection of alpha- and beta-naphthol by the bluish green color developed when a small quantity of the substance, in absolute alcohol, is treated with metallic sodium. It is quite possible, therefore, that the color noted above may be due to a similar reaction. The formula weights of the Hydrogas phenols, as obtained by the sodium method, are given in Table I, and are plotted against the average boiling points of the fractions in Figure 2. The formula weights of the Carbocoal phenols are given in Table I1 and Figure 2. Table 11-Carbocoal Phenols
Praction 1 2 3 4 5 6 7 8 .9
Distillation Per cent of total range O C. (corr.) tar acids 174.9 to 194.5 2.7 184.9 to 1 9 7 . 0 7.8 192.4 to 203.5 8.9 198.4 to 212.0 13.0 2 0 3 . 7 to 2 1 6 . 9 10.3 210.0 to 222.7 7.6 216.6 to 231.5 5.7 2 2 7 . 3 t o 260 5 18.7 2 6 0 . 8 t o 302 0 10.1 Pitch and loss.. Total . . . . . . . . . 100.00
.
. . . 16.2
Average boiling point O C. 186.5 188.2 196.5 201.5 208.5 214.5 221.0 235.0 271 0
S p 5'. 25 /4 C. 1.049 1.049 1.036 1,026 1.018 1,013 1.006 1.012 1.060
Average formula weight 109 110 124 124 135 137 150 150 163
Averuge BoihngPoint offruct/ons, "C. Figure 2-Molecular
Weight
VS.
Boiling Point of Phenol Fractions
The curve showing the boiling point-specific gravity relation has been used in studying the phenol fractions of Carbocoal tar.3 Curves are therefore given in Figure 3 showing this relation for the fractions of both Carbocoal and Hydrogas phenols. For comparison the curve for hightemperature phenols is reproduced from the above reference.
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
Vol. 17, No. 8
A Clearing House for Chemical Manufacturers' B y A. INTERNATIONAL
S. Behrman FILTERCO., CHICAGO, ILL.
MANY fields of chemical industry large quantities of ItoNsolid and liquid by-products and waste products are sent the dump heap or the sewer. Often these materials are
Figure &Boiling
P o i n t v8. Specific Gravity of Phenols
These curves indicate a close similarity in the constitution of the lower boiling phenols from all three tars. As the boiling points increase the curves for the two low-temperature tars, owing to the presence of aliphatic side chains, drop below the curve for high-temperature tar. Upon further increase in boiling point the curve for the Carbocoal phenols bends back toward that for the high-temperature tar phenols while the curve for the Hydrogas phenols continues t o diverge. This indicates that the Hydrogas tar is a very primary tar, as has been previously explained, and that the Carbocoal tar is an intermediate step between the primary or low-temperature tar and the coke-oven or high-temperature tar. The difference in the constitution of the phenols of Hydrogas and Carbocoal tars is brought out still more strongly in Figure 2, which gives the boiling point-formula weight relationship of the fractions of the two tars. The formula weights of the higher fractions of Hydrogas phenols are considerably above those for the corresponding Carbocoal phenols. This is further proof that Carbocoal tar is not a true primary tar, but has been subjected to considerable cracking. Bibliography I-Ind Eng. Chem., 17, 626 (1925). 2-Ibid., 17, 696 (1925). 3-Morgan and Soule, Chem. Met. Eng., 28, 923 (1922). 4 S c h u l z e , A n n . , 327, 143 (1885). 5-Bogert and Caplan, unpublished investigation. G W e i n d e l , Brennstof-Chem., 3, 245 (1922). 7-Verley and Bolsing, Ber., 34, 3354 (1901). 8-Report of the Carbonization Committee, American Gas Association, 1822 Convention, p. 116. 9-Kunz-Krause, Chcm. Ztg., 47, 646 (1923).
Argentina Requires Chemical Analysis on Imported Foodstuffs-In order that adulterated foodstuffs or those containing any substance injurious t o health may not be allowed to enter the country, a chemical analysis of all foodstuffs imported into Argentina has been declared obligatory.
potentially of real value-not necessarily to the plant in which they are produced, but to some other branch of chemical industry. There seems to be no adequate means of contact between the manufacturer who has such waste products and the manufacturer who might use them. Occasionally one sees in the classified advertisement section of one of the technical journals notice of some material which, by its description, might be a waste product or by-product, but this can hardly be considered as satisfactory means to the end desired. I n the Chicago manufacturing district a plant has been daily turning into the sewer a large quantity of almost chemically pure sodium sulfate. Less than five miles away another plant-there may be more-has been purchasing considerable quantities of sodium sulfate. Yet only by accident did the possibility of mutual benefit become known. What was true of sodium sulfate, which happens to be quite cheap, might just as well have been true-and undoubtedly is true-of more costly materials. Another case is that of a plant producing crushed limestone, which threw away all screenings smalley than one inch in diameter. Again by accident, a lime burner found that this limestone, when calcined, slaked so rapidly with water that the screenings were almost ideal for certain types of lime-feeding equipment for water purification and similar processes. The object of this paper is to suggest that some adequate means of contact be provided for the mutual benefit of those who might be interested-some agency that would receive and disseminate information regarding the available waste materials . Several forms which such an agency might take suggest themselves. One is a sort of chemical industrial trade association, to which manufacturers would submit lists of their waste materials, to be broadcast in turn to the members of the association. The same functions might be exercised by an appropriate branch of the Government, presumably the Department of Commerce, with the activities of which this new service might dovetail. A third form this agency might take would be that of a private organization of industrial chemists and chemical engineers. Whatever the particular form of agency, it might well do more than merely publish information. It might give technical service and cooperate in making the waste products of one plant more suitable for utilization by another. It might actually develop new outlets for such materials. It might furnish data on costs and methods of transportation, and such other information that the individual manufacturer might find difficult or expensive to secure promptly and accurately. It would, in short, act as a clearing house for information relating to waste products of chemical manufacture. Such an arrangement would result, not only in greater effectiveness and economy in the industries concerned, but likewise in a conservation of resources, in which chemists and chemica1 engineers have a very definite responsibility. 1 Received July 8, 1925. Presented before the Division of Industrial and Engineering Chemistry at the 70th Meeting of the American Chemical Society, Los Angeles, Calif., August 3 to 8, 1926.
