1911
V O L U M E 2 4 , NO. 12, D E C E M B E R 1 9 5 2 dimethylpentane for the 3-methylhexane. For 2,3-dimethylpentape Z43/P = 74.4 and sensitivity of P = 2.31 divisions per micron.
Pi Pn Pi
+ P,
-
3695 = 21.6 171.3
~
Pi - 21.6 - 13.3 47.6
148.2 23.1 171.3
-
kn-i
p*
Dim.
1975 1720 3G95
10 p nC7 10 p 2,3M&s Totals observed in mixture spectrum
loo),
P ( w e =
243, Divs.
- 21.6
E = 0.319 26.0
= 171.3
Sensitivity, Dirs./r
Partial Press.,
11.82 4.39
8.76 9 43 __ 18 19
= 129.9 = 41.4
Mole % 48.2 51.8
P
CHECK:243 = 3605 divisions. Sensitivity 243 = 202 divisions per micron. 3695 Total paraffin partial pressure = __ = 18.30 (good agree202 ment) Example 111. Isoparaffin Values in Extreme Error. Consider the same case once more with 3,3-dimethylpentane as the isoparaffin. I n this case 213/P = m and sensitivity of P = 0.
10 10
nCi p 3,3M*C5 Totals observed in mixture spectrum
243, Dirs.
P ( m / e = 1001,
197.5 2673 4650
148.2 0 148.2
Dim.
-
p
k,+i = 4650 148.2 ~
=
31.4
Pi
31.4 = 47.6
Pi
+ P,
- 13.3 = - 31.4
=
Pi = 7 8 . 2
-
1.118
148.2
Sensitivity, Divs./M 14.82 4.39
Pn = 7 0 . 0
18.1 _ 16.2
P a r t i a l Press., P 4.73 17.80 22.53
-
Mole % 21 0 79.0
CHECK:243 = 4650 divisions. Sensitivity 243 = 202 divisions per micron. Total paraffin partial pressure = 23.03 microns. The discrepancy in this case, while larger than for the others, vould not in itself indicate the large error in the result. However, it is seen that even for the case of an unusual compound comprising 100% of the isoparaffin portion of a mixture, the analytical error that results is very much smaller t,han the error in the assumed isoparaffin coefficients would infer. ACKNOWLEDGMENT
The author is appreciative of helpful consultations with F. P. Hochgesang and the assistance of Mrs. B. L. Brown in compiling the reported data. LITERATURE CITED
(1) Am. Petroleum Inst., “Catalog of Mass Spectral Data,” A.P.I. Research Project 44. 1 2 ) I m . SOC.Testine Materials. Method D 1019. (3) Brown, R. d., AkS4L.CHERI., 23,430 (1951). (4) Leithe, IT., IbLd., 23,493 (1951). (5) Reese, R. 11, Dibeler, V. H , and Xfohler, F. L., J . Research ,VatZ. Bur. Standards, 46, 79 (1951). (6) Rossini, F. D., and h‘fair, B. J., A.P.I. Research Project 6, Report, June 1951. RECEIVED for review April 29, 1932. Accepted August 15, 1952. Presented I
before t h e Pittsburgh Conference o n Analytical Chemistry a n d Applied Spectroscopy, U a r c h 1952.
Determination of Individual Alkyl Aromatic Hydrocarbons From Benzene through the CloAromatics by Infrared Spectrometry R . B. WILLIA3IS, S. H. HASTINGS, AND J. A. AKDERSON, Humble Oil and ReJining Co., Baytown, Tex.
JR.
As a result of process research studies on segregating aromatic hydrocarbon fractions for possible use as chemical raw materials, it became necessary to determine many individual aromaticg over a wide molecular weight range. Procedures involving distillation plus infrared spectrometric analysis have been developed for determining essentially all of the individual alkyl benzene hydrocarbons through the Clo’s. Techniques are presented for achieving the infrared analysis, including a simple method for linearizing aromatic absorptivities that is an improvement over previous methods. Composition data of particular interest to the petroleum technologist are given which cover in great detail a few typical refinery aromatic stocks of Cs, CS, and CIOmolecular weight range.
H E trend during the past few years toward the use of individual aromatics derived from petroleum sources as chemical rat\ materials has prompted the extension of existing techniques and the development of new techniques for determining these constituents. The infrared analytical method described here has been used both in exploratory characterization studies of the higher boiling aromatic stocks and in routine determinations of the Cg and lower boiling aromatics in connection with the various phases of process research dealing m-ith these compounds. This method now largely supersedes formerly employed routine ultraviolet procedures for benzene and toluene and for the CSaromatics.
Except for certain modifications in measuring absorption, the infrared method is based on commonly known multicomponent techniques. Fractional distillation, and sometimes other separations, are generally required for the higher boiling ranges. AlthouKh determinations of the various compounds are relatively straightforward in most cases, there are situations in higher boiling ranges in which the infrared method alone is inadequate for distinguishing between a few compounds, even in 17-ell separated fractions, and in these cases auxiliary analytical tools are required both for supplementary analyses and for cross checking. .1 discussion of the infrared method and the presentation of analyses of aromatics in virgin naphthas and of aromatics derived
1912
ANALYTICAL CHEMISTRY
from hydroforming operations are presented in the following sections. DESCRIPTION OF METHOD
The major differences between this method and the usual liquid multicomponent scheme are in the necessity for making corrections for apparent Beer’s law deviations and for eliminating wave-length shifts of the absorption bands. Kaye and Otis (IO) mention the first difficulty but not the second. The apparent Beer’s law deviations occur because the absorption bands used are very sharp and are situated in the 11.5- to 15.0-micron region where spectrometer resolution is poor. The wave-length shifts occur when the aromatics exist in different relative concentrations or in different solvents. This phenomenon evidently is due t3 molecular association. The difficulty of the shifting absorption bands is eliminated if the samples are diluted in the same solvent each time prior to analysis to a concentration of total aromatics of less than about 10%. I n any event it is necessary to dilute the sample, as these aromatic bands are intense. The authors therefore, as did Kaye and Otis (IO), blend all samples in carbon disulfide, which is transparent in the spectral region of interest. The wave-length shifts for toluene in various solvents are shown in Table I. Other aromatics behave in a qualitatively similar fashion.
Table I.
Peak Shift of 13.7-Micron Toluene Band in Different Solvents Solvent None n-Heptane Methylcyolohexane Benzene m-Xylene p-Xylene Carbon disulfide
Shift, Microns (Relative to P u r e Toluene)
0.00 +0.05 +0.02 -0.04
-0.02 -0.02 +0.02
the corrections thereto sufficiently linear, all absorbance measurements are restricted to the range 0.3 to 0.5. All absorptivities are then corrected to a 0.400 absorbance basis-Le., all absorptivities are corrected to those values which would have been obtained had the absorbance been exactly 0.400 I n the case of toluene and several of the other aromatics, the absorptivity deviation is about 2% for 0.100 change in absorbance from the 0.400 level, the higher absorbances giving negative deviations, and vice versa. For benzene, n-hose band appears a t the longest wave length of all, the comparable deviation is about 4%. The various corrections are slightly different for each compound, depending upon the spectrometer resolution (aave-length location and slit size) and the sharpness of the absorption band. The actual corrections can be made by means of the simple relation, a, = a,, [ l
+ ( A - 0.400)J]
u here ac is the corrected absorptivity au is the uncorrected absorptivity
A is the absorbance of sample in carbon disulfide f is the correction factor-0.2 for toluene and 0.4 for benzene, for example The separation requirements prior to analysis depend upon the boiling range of the sample and the magnitude and types of compounds other than the aromatics in the sample. Because the absorptivities of the aromatic compounds are so much greater than those of other hydrocarbons, and the interference betxeen aromatics is generally lom even for relatively wide boiling ranges, it is evident that the separation requirements usually are not too stringent. For samples containing high concentrations of nonaromatic hydrocarbons, silica gel percolation or other similar separation is sometimes necessary to remove these otherwise minor interferers and to improve analytical accuracy. For very wide boiling ranges, distillations are required. Occasionally both types of separations are needed. Such requirements, especially of distillation, naturally become more severe for the higher boiling ranges where the number of aromatic isomers is great.
The correction for the apparent Beer’s law deviation is straightforward and simple. It is based on the conclusion that the deviation is due principally to inadequate resolution and to a lesser extent to uncompensated stray radiation. Observations EQUIPMENT AND EXPERIMENTAL TECHNIQUE show the absorptivity deviates only as a function of the abAll absorption measurements were made on a Perkin-Elmer sorbance level and not of the concentration of aromatic in Model 12-B infrared spectrometer having rock salt optics, opersolvent a t the low concentrations employed. For example, if ated a t an amplifier gain equivalent to a full-scale recorder deboth the concentration of aromatic in solvent and the length ~ - of samole cell are varied in such a w a as 6 a h ays to maintain the absorbance a t the same level, the absorptivity of the aromatic does not change. 4 If, however, either the concentration or the cell -w 2 length is varied while the other is maintained fixed, the absorptivity also varies. This is shown in Fig0 ure 1 for the case of toluene. If the deviation were :p LZ due to any significant factor other than spectrometer -2 limitations, such as, for example, molecular associa-0 -4 tion (which depends on concentration), the two sets of data would not be adequately represented by a -6 single curve. The observed effect appears to be that 5 ; a-hich one would predict from resolution limitations 2 e -8 ( 3 , 12, I S ) . It is thus permissible to make a correct-m tion t o absorptivity deviation based on absorbance sg-Io alone and to employ whatever concentrations of sam2; -, c ple in solvent and whatever cell lengths are chosen. :-I4 The process of calibration thereby becomes much simpler and the method more versatile; the method pre-16 sented thus seems to be a significant improvement over -18 that of Kaye and Otis (IO) from these standpoints. 00 01 0 2 03 04 0 5 06 0 7 0 0 ABSORBANCE I n order to achieve the optimum in photometric accuracy and to keep the Beer’s law deviations small and Figure 1. Deviation of Toluene Absorptivity with Absorbance
,: I-=
i5 i:
0::
2
1913
V O L U M E 2 4 , NO. 12, D E C E M B E R 1 9 5 2 Table 11.
Compound
Boiling Point,
F.
Benzene Toluene Ethylbenzene
176.19 231.12 277.14
1,4-Dimethylbenaene l,3-Dimethylbenzene 1,Z-Dimethylbenaene Isopropylbenzene n-Propylbenzene 1-Methyl-3-ethylbenzene 1-Methyl-4-ethylbenzene 1,3-5-Trimeth lbenzene 1-Meth yl-2-etgylbenzene tert-Butylbenzene 1,2,4-Trirnethylbenzene Isobutylbenzene 8-Butylbenzene 1-Methyl-3-isopropylbenaene 1,2,3-Trimethylbenzene
281.03 282.38 291.95 306.31 318.59 322,34 323,57 328.48 329.27 336.40 336.82 342.96 343.94 347.4 348.94
1-Methyl-4-isopropylhenaene
350.78 3 52 352.9 358.03 360 361.88
Hydrindene 1-Methyl-2-isopropylhenene 1,3-Diethylbenzene 1-Methyl-3-n-propglbenzene n-Butylbenzene
Calibration Data on Pure Compounds
Source
Purity, Mole
Phillips Petroleum Co. Phillips Petroleum Co. Phillips Petroleum Co.
99.93 99,89 99.82 99.94 99.94 99.99 99,93 99.75 99.57 99.87 99.95 99.33 99.94 99.67 99.87 99,88 99.936 99.982
XBS KBS Republic Chem. Co. KBS Penn S t a t e College NBS
1-Methyl-4-n-propylbenzene 362.21 Penn S t a t e College 362.26 NBS 12-Diethylbenzene 362 75 1,3-Dimethyl-5-ethylbenzene NBS 362 80 NBS 1,4-Diethylbenaene Penn S t a t e College 363 1-Methyl-2-n-propylbenaene hTone 367 2-Methylhydrindene h-one 368 1-Methylhydrindene Penn S t a t e College 1.4-Dimethvl-2-ethvlbenaene 368.44 Penn S t a t e College 1,3- I)irnerhj~l-4-er hf.1Senzene 371,14 Penn S t a t e College 1.2-~irnerhyl-4-erhylhenzerie 373.55 Penn S t a t e College 1,3-l)iruerhgl-l-ethylbenzcne 374.02 Penn S t a t e College 1,2-Dir11ethyl-3-eth?.lbenzene 381.04 Humble 1,2-4,5-Tetramethylbenaene 385 NBS 388.27 1,2,3,5-Tetramethylhenzene 5-Methylhydrindene Humble 395 Humble 4-Methylhydrindene 396 (est.) Humble 101.07 1,2,3,4-Tetramethylbenzene 1,2,3,4-Tetrahydronaphthalene Penn S t a t e College 402,2 Naphthalene NBS 424.33 a Alternate. b Estimated approximately f r o m spectra given in (9),a n d more precisely from measurements
flection for about 1-microvolt input signal. The precision of measuring absorbances was such that the standard deviation a t the 0.400 absorbance level was about 0.002 absorbance unit, or 0.5%, when tested over a period of several days and about 0.004 absorbance unit, or 1%, when tested over a period of several months. Samples generally were weighed and diluted to the proper volume with carbon disulfide, the concentrations being expressed in grams per milliliter. Occasionally blends were made volumetrically. Because of the necessity for dilute solutions, the sample cell has to be fairly thick. lllmost all sample measurements, and all calibration measurements, were made with the same sample cell, which was about 1.0 mm. in thickness. The thickness, or length, was measured by the method of interference fringes. At frequent intervals this was checked for possible changes, but there never was a change greater than about 1% over several months. ilbsorp tion measurements were made from short scans, only a few hundredths of a micron in width, recorded across the desired spectral positions of the various absorption bands. The scans were kept short to reduce errors from zero drift. A lithium fluoride shutter was used for zero deflection measurements. A scan of a rock salt plate “reference” always was made along with the sample scan, either immediately before or immediately after, to avoid errors from long period changes in deflection sensitivity. Either a t the beginning or end of a series of measurements on a sample, similar scans of the salt plate and of the sample cell filled with pure carbon disulfide were made to provide a more accurate correction for the sample cell absorption. The absorbance of the pure carbon disulfide with respect to the salt plate was subtracted from the absorbance of the sample diluted in carbon disulfide with respect to the salt plate. This effectively gives the absorbance of the sample with respect to carbon disulfide. The use of the rock salt reference as an intermediate step in the absorbance determination is important in two ways. First, it saves time, allowing one to move to another analytical wave length and to change the slit without having to empty the sample cell alternately of sample and of carbon disulfide between set-
99.95 99.94 95 (est.) 99.93 98. 99.88 99.6 99.95 99.89 99.93 99.4
...
... 99.8 99.9 99.6 99.8 99.6 99.8 99.92 50 (est.) 50 (est.) 95 95 99.96
Anal tical Wave xength P
14.86 13.74 14.37 14.05= 12,58 13.02 13.51 13.15 13,47 12.80 12.28 11.96 13.27 13.12 12.40 13.58 13.18 12.78 13.04 14.05a 12.28 13,33 13.21 12.56 12.83 13,44 14,3W 12.46 13.28 11.83 12.07 13.44 13.55b 13.55a 12.38 12,21 12.20 13.05 13,84 11.54 11.78 12.34 13.05 12.44 13.39 12.78
Actual Slit Width, Mm. 1.19u 0.670 0.940 0.990 0.460 0.520 0.590 0.520 0.590 0.490 0.425 0,428
0.520 0.520
0,425 0.615
0.520
0.490 0.520 0.690 0.425
0.520 0,520 0.460 0,490 0.590 0.840 0,490
0,520
0.455 0.425 0.590 0.590 0.590 0.490 0.460
0.460
0.570 0.765 0.350 0.360 0.490 0.490 0.490 0.590 0.510
Corrected Absorptivity a t Analytical Wave Length, Ml./G. M m . 500.3 300.1 108.1 22.7 209.1 190.3 299.8 121.0 87.2 51.9 98.7 130.7 108.0 118.7 127.6 125.6 85.5 113.6 152.8 23.2 140.9 128.7 89.0 47.3 103.0 61.5 98.8 76.0 137.0 100.2 116.9 109.3
... ...
95.0 82.2 77.9 136.4 38.0 70.2 90.2
... ...
96.4 160 477.8
on samples containing these substances.
tings. It would not be good practice to try t o obtain several measurements of the sample (PIS or 1 ’ s ) a t various slit settings and wave lengths and then replace the sample with carbon disulfide and try to determine the correct corresponding reference intensity measurements (Po’s or 1o)s), without some intermediate absorption reference. Second, because the pure carbon disulfide is the ultimate absorption reference, the accuracy of calibration of the various pure compounds does not depend upon changes betn-een the relative absorption of the salt plate and sample cell over extended periods so long as there is no change during a single analysis. CALIBRATION
rlll compounds used in calibration were of the highest purity available in the laboratories. Of the 39 compounds employed, 35 had purities of better than 99.5 mole % and 37 had purities of better than 99.0%. Fortunately, neither of the two compounds of lowest purity has been present in very large concentrations (above 10%) in any fraction yet analyzed. All absorptivities were corrected to a constant absorbance level basis (0.400, as already mentioned) and the absorptivities a t the peaks of the major absorption bands were further corrected for purity of the spectroscopic standards by dividing the absorptivities obtained by the mole fraction purity of the respective standards. The latter correction was not applied to interference absorptivities, as the absorptivities of the impurities a t these interference positions many times are of about the same level as of the standards; a t a position of strong absorption, however, the probability is that the absorptivities of these impurities are far less than that of the standard, and in this case one is justified in applying a correction. It is sometimes possible to determine individual impurities if they are known, and correct for their specific con-
ANALYTICAL CHEMISTRY
1914
Table 111. Relative Absorptivities, or Compound Benzene Toluene E BzC 1,4-DM Bz 1,3-DM BE
14.86 100.0 1.0
1,3,5-TM Bz 1-M-2-E BE iert-C, BE 1 2 4-TM Bz I&, BE
100.0
0.3 0,l
1.4 1.0
26.4 8.8
0.3
0.0 18.4
1.8 12.8
0.1
...
0.0
...
a-C, BE
I
1-M-3-iCa Bz 1,2,3-TM BE 1-M-4-isoCa Bz Hydrindene
14.37 21.6 37.9
8.9 0.2 0.6
0.6 0.0 0.3
1,2-DM Bz IsoCt Bz nCa BE 1-M-3-E Bz 1-M-4-E BE
13.74 0.9
100.0
.
.
0.1 0.1
.0.1 ..
2.2
6.6
Analytical Wave Length, Microns 14.05 12.58 13.02 13.51 13.15 11.2 0.4 0.8 0.e 1.1 454 0.7 1.2 4.6 2.6 100.0 4.2 8.6 15.6 110 0 . 5 10 0.9 10.7 ?.: 100.0 1;:
.
52.5 0.8
10.5 5.1
3.0 1.1
0.7 6.0 0.7 3.1
.0...0
...
...
...
...
...
...
*..
,..
... 4.3
30.4
11.8 1.1
...
9.3
1.2
9 . .
0.4 0.4
4.4
...
1.3
...
2.7
1.0
...
g::
11.7 2.9
2.0 0.7
15.5 0.4
11.3 4.4
12.80
12.28
11.96
13.27
2.0 16.6 53.7 0.7 2.6
0.8 4.0 26.0 13.5 21.6
1.3 1.4 2 2 5.1 1.4
2.6 1.9 2.1 3 0 0 5
1.3 6.0 22.8 0.5 5.5
6.8
100.0
2.9 12.11100.0
0.8
11.6 3.2
2.3
43.7
.
2.2 68.1
0'3 0.9
5.7
13.12
...
..., ...
0.8
16.6
I
11.9 4.5
100.0
0.2 12.9
... ...
13.47
27.4
3.2
4.6 176.5
18.3
0 1 0.3
0.9
1.5
53.1 7.2 5.3 16.9
2 0
0.8
I-M-2-isoCa Bz 1,3-DE Bz I-M-3-nCa Bz n-C, Bz l-M-4-n-Ca Bz
2.0
1.1
4.6
2.6 1.6 12.9
1,2-DE Be 13-DM-5-E BE 14-DE Bz I:M-2-n-CI Be 2-M Hydrindene
0.9 7.2 28.8 1.4
6.3
124.9 0.6 2.0 24.1
55.3 7.9
,..
... ... ...
0.9
2.5 .,.
1-M Hydrindene 1,4-DM-Z-E Bz 13-DM-4-E Bz 1.2-DM-4-E Bz 1.3-DM-2-E Bz 1,2-DM-3-E BE 1.2,4,5-Thf Bs 1,2,3,5-TM Bz
Compound 1 2 3-TM BE 1:Mjl-4-isocaBZ Hydrindene
13.44 3.1 0.6 72.4
I-M-2-isoG Bz 13-DE Be lLM-3-nCs Bz nCc Bz 1-M-4-n-CI BE
26.1 4.1 8.7 56.3 4.9
12-DE Br 1:3-DM-5-E Bz 1&DE BE 1:M-2-n-Ca BE 2-M Hydrindene 1-M Hydrindene 1.4-DM-2-E Bz 13-DM-4-E Bz 1'2-DM-4-E Bz 1:3-DM-2-E Bz
'E)
$'
.f Y
C
2
12-DM-3-E BE 1'2 4 5-TM Bz 1:2:3:5-TM BE 5-M Hydrindene C M Hydrindene 1,2,3.4-TM Br 1 2 3 4-Tetrahydronaph. Na'phthalene
18.7 0.6 1.7
100.0 xx xx
13.55
13.55
x xx x x
x x x x
100.0
11.8
xxx xxx x x x
5.4
x
1.0
0.3
1.6
0.0
0.5
x x
Analytical Ware Length, hlicrons 12.20 13.05 13.84 11.54 11.78
12.38
12.24
xx x x
2.5 30.4
3.0 19.6
3.3 17.5
2.4
5.5
1.3
1.3
x x x x xxx
6.0 1.3 8.5 1.3
5.3 2.0 21.3 1.8
8.6 0.9 2.6 10.9
25.3 3.4 4.2 32.1
3.0 4.4
0.5
X
X
4.4 2.3 27.9 2.2 x
xx
xx
100.0
x
x
xx
xx
12.34
13.05
12.44
13.39
12.78
X
18x9
15.3 99.2
xxx x x
100.0
100.0
x
11.6 9.7 1.5
80.8 1.2
100.0
x x x
7.3 0.6 0.7
4.6 0.9 0.8
4.1
xxx
?
xx
?
xx
4.2 28.1 5.2
8.0
...
4.7
tributions. This has been done for o-cymene where the major impurities were m-cymene and p-cymene, for which accurate calibration data were available, and similarly for 1-methylS-npropylbenzene where the impurities were I-methyl-2-n-propyl benzene and 1-methyl-4-n-propylbenzene. A listing of the compounds used in the infrared calibration, their source, and their purity, and a tabulation of the analytical wave lengths and key corrected absorptivities are shown in Table 11. Four compounds found in the CMrange, the methyl hydrindenes, were not available for calibration except in very impure form in the case of 4- and 5-m-hydrindene. These can be identified and semiquantitatively determined by means of their tabulated infrared spectra ( 9 ) , by mass spectrometer analysis, and by other analytical methods. These supplementary methods are referred to again in a later section. Table I11 lists the relative absorptivities, or absorption coefficients, on a percentage basis a t each analytical wave length. The boxes shown are intended to indicate, by the data they en-
1.2
0.8
0.7
0.5 0.6 1.
4.6 1.2
4.1
1.0
35.4 6.4 1.4
X
X
1x2
OXO
4.
1
4.9
0.t
E
xxx x
9.3100.0 0.3 0.2 0.8100.0 0.2 1.7 2 3
0.0 3.7
x x x
100.:
:.;
1
.
6.0
X
X
X
?
?
?
?
5.0 4.3 5.5
0.6 7.8 7.0
1.6
1.3 4.3 2.5
14.2 6.3
100.0
:
x
lO0;O
0.5 2.8 1.8
xxx x x
?
.
x x
46.0 6.1
x x
0.2 0.3
x x x
12.5 0.5 0.5
x x x
5.7 0.1 0.1
X
X
;:; :
x:
? 100.0
x
xx
?
100.0
xx x
4.2 6.7
? x 100.0 x
::: ?
0.3 0.8
100.0
close, which compounds generally can be allowed in any single fraction for the attainment of highest accuracy. They do not necessarily restrict the analysis of more complex mixtures as particular situations may warrant. The last column of Table I1 plus the figures in Table 111 constitute the complete calibration data, I t can be seen from Table I11 that, except for a few scattered compounds, the general level of interference is low. It is essentially this factor Tvhich accounts for the relatively high accuracies obtainable with the infrared method for determination of individual aromatics. ANALYTICAL APPLICATIONS
The infrared method has been applied to a wide variety of samples, derived both from virgin naphthas and from hydroformates. Since the composition of these types of stocks might be of as much general interest as the analytical method itself, the analytical results on the aromatic portions of a virgin naphtha, covering the boiling range from about 200" to 880' I?., and of
V O L U M E 2 4 , NO. 12, D E C E M B E R 1 9 5 2
1915
Absorption Coefficients, Expressed i n Per Cent' 12.40 0.7
1.1
2 8 8.8 1.3
13.58
. . . .
. . . .
13.18
. . . .
. . . .
. . . . . . . .
12.78 0.4 1.9 11.9 6.2 9 9
13.04 0.9 1.6 9 1 1.0
-23.7 -30.2 0.0 -2.6
2.3 11.5 3 0 11.8 3. 5
-1.3 -23.7 -23.3 -19.0
0.1
-0.9 -7.3
......
... 4.5
0.9 0 8 2.2 4 7 28.3
42.2 1.2 0.8
lOb'3 12.9 17.0 5.6
1.8 2.5 1.8 43.1 5.6
0.7 2.2 0.8
0.2 46.5 6.6
03 51.1 595
0.2 6.0 1.9
lo::!
4 4 18
.a
3":;
10:;;
100.0 16 27 3 1 2 329
6 6
10
136 1 3
3 4 1 7 0 9 596
1.5 11.1 3 2 2 0
13.0 1.1 10.2 35.3
96.4 10.5
4.8 1.0 5.4 1.1
9.1 0.6 1.4 39.9
585 1.1 3.0 30.5
10 6
9 6
6 1
1 2 2 4
0.0
103.4
1
X
xx xxx
,.. ,.. ,.. 1.1 1.6 0.8
I
14 1 2.0 1100.0 0 5 5 8
100.0 -17
7.7
2.2 10.7
0.2 46.2 4.0
17.2 0 7 4 8 0 5 100.0
... ...
15.5 5.3 4.4
... ... ,.. ...
4.2 0.9 8.9 1.0
73.7 0.5 1.6 36.4
... ...
...
... ...
12.07
0.3 69.9 26.2 0.9 4.0
1.8 22.2 3.0 18.5 3.8
85.8 1 4 18 2 10 450
8.3 1141 4 2 8 9 3 6
1.4 2.9
31.7
1.1
1.6 100.0
4 2 62.6 10 7 13 2 9
25.7 1.5 5.5 1.0 128 6
13.0 1.2 0.5 1.3
100.0 6.41 3 . 0 1 46.3 9 , 8 1 1 0 0. O 15.6 7.3 8 . 4 1 1 1 . 0 ' 100.0 15.5 11. .5 5. 100.0
3.7 36.3 53.6
87.4' 1.0 2.8 28.0
1.8 11.1 2.1
6.9 0.5 74.2
0.2 1.9 2.5
0.7 6.5 2.1
4-C4 Bz 1-M-3-iC; Ba 1.2.3-TMBz l-M-4-iaoCsBz Hydrindene
4.6
43.4 5.8 4.2 1 .
0.8
1.1
100.0
32.9 8.9 3
1.5 1.6 1.0 1.5
1-M-2-isbC; Bz 1,3-DEBz l-M-3-nCiBs n-CIBz
1.5 40.6
9.0 1.5
100.0 0.5
0.9 100.0
1.3 3.1
1,Z-DEBz 1.3-DM-5-EBe 14-DE Br 1:M-Z-n-CIBz 2-M Hydrindene
I
32.0 2 5 135
8.7 1.5 4.5 3.2
6 0 x
xx
x
xx
0.8 0.7 1.4 4.7
1.0 0.9 2.1 14.5
20.4 7.6 7.6 8.5
4 9 1.3 2.9 11.7
3.1
10.6
14.8 0.3 0.5
25.4
37.2
1.1
0.5
1.1
...
0.6
33.2 1.1 3.1 177.7 xx
xx
1.8 0.5 2.8 21.0 9.6
0.0 0.7
i:; x
1::; X
1.4
t:;
xx
17.1 0.7 0.7
1 0
'2:':
X
x
0.5 1.0 1.0 5.3
0.8 1x3 2.0 0.0
2 6 10.3 7.9 0.8
*S 1,4-DM-2-EBs
12.7
0.9 2.7 43.4
1.4 0.7 0.7
l,O-DM-3-E Bs 1.2,4,5-TMBz 1,2,3,6TMBz
xx
1.3 39.2 1 x 4 1 6.6 1.4 6.3 0.4 3.3 1.3 0.5 1.8
1 0
l!':
x
0.1
0.3
x
E.
b Baseline measurements; base end points a t 13.92 and 14.18~.
BE. DM. TM. DE.
Toluene E Bz 1,4-DX2 Bz 1,3-D.11 Bz 1,2-DXl Bz Iso-Ca Bz n-Ca Bz 1-Xf-3-E Bz 1-XI-4-E Bz 1,3,5-TM Bz 1-M-2-E B e tert-Ca Bz 1,2,4-ThI Bz Iso-Ca Bz 8 - G Bz l-hf-3-iso-Ca Bz 1,2,3-TMBe l-hl-4-lso-Ca Bz Hydrindene l-M-2-1so-Ca B e 1,3-DE Bz 1-M-3-nC3 Bz n-Ca Bz 1-M-4-n-Cs Bz 1 2 - D E Bz 1:3-DRf-5E Bz 1,4-DE Bz 1-RI-2-n-Ca Bz 2-M Hydrindene 1-M Hydrindene} 1,4-DM-2-E Bz 1 3 - D M - 4 - E Bz 1:2-DXZ-4-E Bz} 1,3-DlI-Z-E Bz 1,2-DlI-3-E Ba 1,2,4,5-TM Bz 1,2,3,5-TM Be 5-hf Hydrindene' 4-iV Hydrindene) 1,2,3,4-TA\I B e 1.2.3 4-Tetrahvdronaoh. C,! aromatics
i
1-M Hydrindene
e13-DM-4-EBz $l:O-DM-CEBz 1,3-DM-2-EBz
Ethyl Benzene Dirnethvl Trimethyl Diethyl
Analysis of Aromatic Portion of Virgin Naphtha (Volume Per Cent) Boiling R a n g e of Fraction,
Compound
Compound Benzene Toluene E BzC 1,4-DM Bz 1,3-DM Bz
1,3,5-TMBe 1-M-2-E Bz Lert-C, Bz 1 2 4-TM Bz lAo%' Bz
Medium,estimat,ed interferdnce. High estimated Interference.
204-257
a
11.83
Low eRtimated interference
Table IV.
Total
13.28
1.2-DM Be h0C1 BE nCa Be 1-M-3-E Bz 1-M-4-E BE
15.3 45.1 1.7 0.9
Data not obtained. No means for estimating interference.
12.46
3.4
1.4 3.3 1.4 1.
...
0 8
1.8
0 9 100.0 1 1
14.36
22.7 9 2 30.7 7 8 2.1
I
,..
1.4 20.9 14.8 6.4 37.6 1 6 . 2 4.2
I
13.44
0.3
::; g:!
.6I0
8.3
...
,,.
-
0.5 0.6 1.8 89.3
0
... ...
...
7:;
9.0 1.5 4.5 2.9
Analytical Wave Length, Microns 12.28 13.33 13.21 12.56 12.83 ... 1.2 ... 5.8 ... 29.3
-3 . 0 1 . . .
6.4 24.8
i.8 3 1 100.0
14.056
257-272
272-277
277-289 11.83
21.12
8.06
14.88
100.0 0 0
0.0 79.1 8.4 12.5 0.0
0.0 19.7 21.0 59.2 0.1
1.7 9.3 31.6 55.4 2.0
0.0
289-301
301-306
306-315
315-326
F. 326-334
Vol. % Fraction, Based on T o t a l Aromatics 0.54 3.95 9.97 10.45
1.51
0.0 0.0 20.8 79.2 0.0
0.0 23.4 76.6 0.0
1.7 25.9 51.9 18.6 1.9 0.0
0.0 3.3 23.3 16.1 29.3 2oao
334-345
345-361
361-380
6.64
5.66
5.39
0.0 0.0
0.4
13.7
5 6
8.0 0.0
74.0 2 5 (i
3a3
0.5
0.0 0.0 0.0 9.5 5.2 8.7 17.8 35.6 9.9 3.0 6.3 3.2 0.8
{ [
0.0 0.0 0.0 8.7 8.1 1.6 0.0 1.6 8.4 9.7 19.5 6.7 3.6 14.0 4.3 6.5 1.4 5.2 0.0
{
8.2 5.7
114.4
i 1,5a
Possible trace present.
- 100.0 - 100.0 100.0
100.0
~
100.0
-
100.0
0.7 100.0 ~
100.0 21 12 9.52 4.90 13.56 6.88 1.63 1.77 4.37 2.38 4.43
2
