Calculating the Performance of Motor Fuel Blends J. S. BOGEN AND R. M. NICHOLS Universal Oil Products Company, Riverside, I l l .
A method and substantiating data are presented for es-
.
timating the performance characteristics of multicomponent motor fuel blends. The scope of this investigation covers four major components of motor fuel-straightrun, thermally cracked, polymer, and catalytically cracked gasolines from mid-continent crude. Multicomponent blends which covered practical commercial concentrations were made and rated by F-1, F-2, and F-8B (modified borderline procedure) methods, clear and with 1 and 3 ml. tetraethyllead per gallon. A series of curves was obtained from which it is possible to estimate the performance characteristics of multicomponent motor fuel blends. Future work will include stoclrs from other crude sources.
I
N T H E field of motor fuel blending considerable time and
money have been expended in an effort to predict accurately the performance of a finished fuel through a better understanding of the antiknock characteristics of the many components that constitute the high-quality motor gasoline of today. This paper is a progress report on the developmellt of a method for calculating performance characteristics of multicomponent motor fuel blends. There are probably as many methods of estimating performance characteristics of motor fuel blends as there are persons invalved with these problems. The two basic procedures might be expressed as straight-line blending and nonlinear blending. The former method is a simple linear volumet'ric relationship which is
satisfactory for some types of work. 4 recent paper by Heath and Hicks (2) shows that in a large blending program, with various types of commercial stocks having octane numbers between 50 and 90, about 90% of t'he laboratory ratings fall within 3 octane numbers of the estimated linear volumetric values. A nonlinear blending prediction method has been reported by Eastman ( 1 ) wherein the character of the components is used as a function of sensitivity (difference between F-1 and F-2 octane numbers). The method is rather complicated, especially when more than two components are involved. Both of these reported methods are based on laboratory ratings and offer practically no help in estimating road performance characteristics of finished fuels. The problem is so complex that no simple single solution is contemplated; however, the authors present data and a method which they hope will lighten the burden of the motor fuel prognosticator. Those who have made Comprehensive studies of multicomponent blends realize the magnitude of such an undertaking and will appreciate the need for limitations of the range of the work, The authors have limited their work to what they consider the four major Components of motor fuel-straight-run, thermally cracked, polymer, and catalytically cracked gasolines. Although their initial program, as reported herein, centered around mid-continent stock$, they have subsequently studied additional fields; the physical inspection data for the mid-continent base stocks are included in Table 1. PROCEDURES
Crude source Type gasoline
TABLE I. FUEL INSPECTION Mid-continen++ 4 Straightrun
F-1 Clear 4 - 1 . 0 ml. TEL/gal. + 3 . 0 ml. TEL/gal. F-2 Clear f 1 . 0 ml. TEL/gal. + 3 . 0 ml. TEL/gal. Reid vapor pressure, lb./sq. i% Gravity, API at
$!
95% End point
% over % bottoms % loss
E% P + N
46.2 57.0 67.8
68.6 73.8 77.1
75.1 80.0 83.0
5.9
1% 30%
.
77.5 84.0 87.9
61.4 116 152 170 220 262 306 365 385 400 98.0 1.0
Engler, Initial b.p. F,
Bromine No. Dispersion, A20 Refractive index, nso Peroxide No. Sulfur, % .4.S.T.M. gum, mg./ 100 ml. Cu dish gum, mg./100 ml Induction period, mm. Cu strip correction Wt. % aromatics olefins
45.1 54.3 66.5
Catalytically cracked 83.8 89.3 92.4
polymer 96. 99.3 99.9 82,1 85.0 86.3
1.
F.
60'
Thermally cracked
1.0 1
'
74.7 1,40979 0.2 0.06
7.8 60.4 98 126 142 239 192 281 330 345 373 98.0 1.0 1.0 86 87.6 1,41746 1.8 0.10
2.5 51.5 130 174 196 248 285 321 360 376 390 98.0 1,2 0.8 37 96.0 1.43540 0.8 0.02
1
3
2
4
236
12
>2090 Neg. 4
1
95
145 Neg. 9 55 36
>3600. Neg. 26 26 48
12" 68.0 86 118 134 222 192 256 350 422 416 95.5 1.5
a.o
143
.., ..o..,..0 2
14 I . .
710
...
loo'
. ..
With four components, innumerable blends can be made. To keep the test program within reason, certain practical limits were arbitrarily set. For example, the ratio of catalytically cracked t o polymer was maintained a t 9 to 1. This figure was based on preliminary data which showed that at ratios from 4 t o 1to 15 to 1 the blending value of the catalyticall cracked-polymer mixtures in straight-run was practically uncganged. The decision was reached that concentrations of 10, 20, and 30% thermally cracked gasoline in the blends would be sufficient to cover the range of practicability. With these two limits established the outline of blends then resolved to five main groups representing 0, 25, 50, 75, and 100% straight-run, each to contain blends of 0, 10, 20, and 30% thermally cracked gasoline, the balance to be catalytically cracked and polymer in the ratio of 9 to 1. For complete antiknock value information, all blends were run by the F-1 and F-2 laboratory methods and by the F-8B (modified borderline) road test procedure, clear and leaded with 1.0 ml. of tetraethyllead per gallon and 3.0 ml. of tetraethyllead per gallon. All of the road test data was obtained in a Chevrolet station wagon converted to a 1947 model by installing a new engine. The test car was equipped with a special spark-advance cont,rol and recording device of the authors' design. Suitable instrumentation was provided for determining engine operating variables thereby assuring consistent operation. It is generally poor practice to attach much weight to results from a single test car; however, in several cooperative test programs involving a large number of cars and wide range of fuels, it was established that the test car used was consistently close to the average of all cars. The method used in the road test was the F-8B method, a standard procedure whereby engine speed versus borderline-knock spark advance is plotted for a framework of reference fuels of known octane number. By obtaining the spark advance borderlineknock curve in the same manner for any unknown fuel and plotting on this framework, i t is simple to express the performance of the unknown in octane numbers as a function of engine speed by means of a crossplot. Rather than express the
2629
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INDUSTRIAL AND ENGINEERING CHEMISTRY
'0
Vol. 41, No. 11
I
10
20
30
40
50
60
80
70
90
Id0
PER C E N T OLEFIN +AROMATIC
Figure 1
'0 -
,
10
2b
,
30 40 50 60 70 8'0 PER C E N T O L E F I N t AROMATIC
I
SO
ID0
Figure 2
PERCENT
THERMAL
CRACKED
Figure 3
rating of a fuel as a curve, the authors have arbitrarily selected three speeds (1000 r.p.m., 2000 r.p.m., and 3000 r.p.m.) to cover the range in octane number variation on the road. The blend compositions and faired octane number data for the mid-continent stocks are shown in Table 11. I n such a large program i t should be recognized that the chance for experimental error is great and that checking each individual point would be impractical. The fairing that was necessary was quite reasonable, the change in octane number seldom exceeding 0.5 unit. For the road ratings, somewhat greater changes were necessary to bring the points into Iine, but it must be remembered that, whereas the accuracy of the laboratory methods is approximately t0.4 unit, the accuracy on the road is about * 1.5 units. When the data in Table I1 are plotted and cross-plotted in all the combinations possible, a large number of graphs is obtained. These graphs help in the analysis of the results but are of little
November 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
2631
TABLE 111. BLENDINGOCTANENUMBERSOF THERMALLY CRACKED IN STRAIGHT-RUN Clear
F- 1 +1.0 ml. TEL/gal.
4-3.0 ml. TEL/gal.
Clear
F-2 f l . O ml. TEL/gal.
+3.0 ml. TEL/gal.
77.5 82.4 82.6 84.1
84.0 89.0 89.3 91.3
87.9 92.2 92.5 93.5
68.6 73.9 74.7 76.2
73.8 78.7 79.5 81.0
77.1 80.5 81.3 82.8
r
7%
Thermally Cracked 100 30 20 10
TABLE IV.
c
r
-
BLENDING OCTANENUMBERS OF CATALYTICALLY CRACKED-POLYMER GASOLINE
70
Catalytically CrackedPolymer Gasoline 100
75 50 25
F-1
c
80 70
F-2 f 1 . 0 ml. TEL/gal.
+1.0 ml. TEL/gal.
+3.0 ml. TEL/gal.
Clear
85.9 91.0 93.5 95.9
90.6 95.6 98.7 100.7
93 3 96.9 98.9 100.1
76.1 79.9 82.6 83.0
, With Straight-Run 80.4 83.1 84.6 85.8 87.2 87.6 88.6 89.0
8 1 . 0 76.0 8 3 . 0 78.4 85.0 8 2 . 0 89.0 8 7 . 0
72.0 74.2 76.5 79.4
87.0 89.3 92.0 96.0
82.0 83.8 87.5 92.4
78.0 80.2 82.5 87.4
92.0 93.5 95.5 97.4
87.0 89.2 92.5 94.4
83.0 84.0 86.0
76.1 76.6 77.2 78.0
With Thermally Cracked 83.1 80.4 80.8 83.5 81.3 84.0 84.7 82.1
81.0 81.2 80.8 80.9
76.0 75.7 76.0 76.4
72.0 71.9 71.8 71.6
87.0 87.1 86.6 86.7
82.0 82.2 81.9 82.2
78.0 77.8 77.6 77.4
92.0 91.7 92.0 91.6
87.0 86.8 87.3 87.1
83.0 83.0 83.0 83.0
90.6 91.0 91.6 92.3
93.3 93.7 94.0 94.6
value in the final use of the data. For this reason all thejse graphs are not included in this presentation. Plotting tetraethyllead concentration versus octane number for the components shows typical lead susceptibility curves. On the same lead susceptibility basis, the blend data fall into families of curves wherein the slope varies as the concentration of straightrun gasoline is changed. DATA AND DISCUSSION
Considering the four major components, straight-run, thermally cracked, polymer, and catalytically cracked gasolines from mid-continent crude, several things should be noted-namely, in the laboratory the sensitivity (F-1 minus F-2) of the four fuels is markedly different. Sensitivity is a function of the degree of unsaturation (olefin plus aromatic), as shown in Figure 1. The sensitivity of polymer (completely unsaturated) is 14 units, while that of straight-run (nearly saturated) is -1 unit, and for the cracked gasolines (partially unsaturated) it is from 9 to 10 units. This is true regardless of tetraethyllead concentration. Similarly, on the road there is a definite relationship between degree of unsaturation and speed sensitivity of the components. This i s seen in Figure 2 where per cent of olefin plus aromatic is plotted against road speed sensitivity. The latter term is defined herein as the difference in road octane numbers a t 1000 and 3000 r.p.m. (approximately 20 and 60 m.p.h.). The authors have emphasized the sensitivity factor because i t is their contention that
d
f 3 . 0 ml. TEL/gal.
80
70 60 50 40 30 20 PER CENT THERMAL CRACKED
Figure 4
IO
90.0
the blending characteristics of stocks are largely a function of hydrocarbon composition which is reflected in the differences between F-1 and F-2 ratings. However, no single combination of F-1 and F-2 ratings will give a satisfactory indication of road performance for a variety of stoclrs. It is their opinion that assigning blending octane numbers to fuels without qualification is a meaningless gesture; to have utility, an indication of concentration and the antiknock level of the base stock is essential. Throughout their work they adhere to this basic concept. The blend data calculated from Table I1 may be arranged conveniently as follows: blending values of thermally cracked in straight-run gasoline; blending values of catalytically cracked and polymer in straight-run gasoline and in thermally cracked gasoline; and blending values of catalytically cracked, polymer, and thermally cracked in straight-run gasoline. T o calculate blending value i t is assumed first that saturated components (paraffins) have a blending value equal to their actual antiknock rating. For two-component blends the following simple formula is in order:
B = -C
- XA Y
Where x = volume per cent component A; y = volume per cent component B; A = octane number of component A (the satu-
I 90
--.
F-8B Clear +l.O ml. TEL/gal. 4-3.0 ml. TEL/gal. 1000 2000 3000 1000 2000 3000 1000 2000 3000 r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m.
Clear
85.9 86.5 87.3 88.2
100 90
F-8B Clear +1.0 ml. TEL/gal. +3.0 ml. TEL/gal. 1000 2000 3000 1000 2000 3000 1000 2000 3007.r.p.m.r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. r.p.m. 74.5 6 8 . 5 6 3 . 0 81.0 75.0 6 9 . 5 8 4 . 5 78.5 7 3 . 0 83.3 83.3 77.2 95.3 89.2 8 5 . 2 93.8 8 4 . 8 73.0 87.5 8 7 . 5 8 0 . 6 99.5 9 5 . 0 88.5 95.5 89.0 7 3 . 0 90.0 90.0 85.5 107.0 102.5 93.5 100.5 9 1 . 5 73.0
0 CAT. C R K ~ P O L Y .
Figure 5
INDUSTRIAL AND ENGINEERING CHEMISTRY
2632
Vol. 41, No. 11
laboratory result,s as plotted in Figure 3 show regular smooth curves indicating a gradual de0 1 7 . 5 35 52.5 Val. 7 ' " straight-run 0 22.5 45 67.5 0 20 40 60 crease in blending valw of the Val. % ' oatalstioalls 18 63 47.25 31.5 15.75 81 6 0 . 7 5 4 0 . 5 20.25 72 54 36 thermally craclred as its concracked 9 6.75 4.5 2.25 8 6 4 2 7 5.25 3.5 1.75 Tal. 7' polymer c e n t r a t i o n increasrs. These Tal. yo thermally 20 30 30 30 30 10 10 10 10 20 20 20 cracked curves are nearly parallel for Unsaturated compoclear and leaded blends by both 40 100 82.5 65 47.5 100 77.5 55 32.5 100 80 60 nents, t,otal % laboratory methods. The road Catalyticallycracked,% 81 78.4 73.6 62.3 72 6 7 . 5 60 45 63 5 7 . 3 48.5 3 3 . 2 Polymer Yo 9 8.7 8.2 6.9 8 7.5 6.7 5 7 6.3 5.4 3.7 results give the same general 10 12.9 18.2 30.8 20 25 3 3 . 3 50 30 36.4 46.1 63.1 Thermaliycracked, % type of curve, but it may he Clear seen from Figure 4 (at 2000 Calcd. linear octane 8 3 . 6 8 3 . 2 82.6 81.3 82.8 82.3 81.6 80.3 84.3 84.1 83.7 82.8 No. of unsaturates r.p m.) that there is an effect of Calcd. blending octane 85.0 85.6 85.9 85.7 8 5 . 3 87.1 8 8 . 1 88.1 90.6 9 1 . 0 30.of unsaturates 85.6 89.0 tetraethFllead concentration which wab not noted in the + 1 . 0 mi. TEL/gal. Calcd. linear octane laboratory-namely, that the 89.2 88.4 8Y.0 8 8 . 7 8 8 . 2 8 7 . 2 8 8 . 4 8 8 . 0 87.4 8 6 . 3 No. of ~insatiirates 8 9 . 7 89.5 Calcd. blending octane blending values of thermally 90.1 92.7 94.3 94.1 89.8 91.5 92.5 92.0 96.1 96.5 No. of unsaturates 90.3 93.9 cracked a t any given concenf3.0 ml. TEL/gal. Calcd. linear octane tration belon 62% increase 92.2 9 1 . 5 92.1 9 1 . 8 91.4 90.5 91.6 91.2 90.7 89.8 No. of unsaturates 92.6 92.5 and then drop off with conCalcd. blending octane 96 9 9 7 . 3 92.8 94.6 95.7 95.8 92.6 9 3 . 8 9 4 . 7 94.9 No. of unsaturates 93.1 95.5 tinually incieasing lead conc e n t r a t i o n . This is most TABLE 1'1. CATALYTICALLY CRACKED-POLYMER-THERMALLY CRACKED GASOLINE, CALCULATED noticeable at higher speeds LINEAR F-2 OCT.4n-E N U M B E R ASD F-2 BLENDIKG OCTANE KU31BER IN STRAIGHT-RUN where a t concentrations of Vol. % straight-run 0 22.5 45 67.5 0 20 40 GO 0 1 7 . 5 35 62.5 40% or less of thermally Vol. Yo catalytically cracked 81 60.75 4 0 . 5 20.25 72 54 36 18 63 47.25 31.6 15.75 cracked the blending values Vol. % polymer 9 6.75 4.5 2.25 8 6 4 2 7 5.23 3.5 l,75 with 3.0 ml. of tetraethyllead 10 10 10 20 20 20 20 30 30 30 30 1701. 7' thermally cracked 10 per gallon arc lower than wit,h Unsaturated coinponents, total 5% 100 77.5 55 32.5 100 80 60 40 100 82.5 65 47.5 no tetraethvllead (Table 111). 73.6 62.3 72 6 7 . 5 60 45 63 Catalyticallycracked, % 81 78.4 57.3 48.5 33.2 Thus it is seen that even wit,h Polymer 70 9 8.7 8.2 6.9 8 7.5 6.7 J 7 6.3 5.4 3.7 20 25 33.3 50 30 Thermaliycracked, % 10 12.9 18.2 30.8 36.4 46.1 63.1 only t,wo components the blending relationships are not Clear Calcd. linear octane S o . of unsaturates 75.1 7 4 . 8 74.5 73.6 74.4 74 0 7 3 . 4 7 2 . 2 7 3 . 6 73.2 72.4 71.3 simp1e. Calod. blending octane The aecond group of data 75.5 77.3 79.2 80.7 S o . ofunsaturates 75.8 78.6 80.6 81.0 75.2 76.3 77.6 78.0 covering the blending values of + 1.0 nil. TEL/gal catalyt'ically cracked and polyCalcd. !inear octane S o . o f unsaturates 79.8 79.6 79.3 78.4 79.2 7 8 . 8 7 8 . 3 '7.' 78.' 78.1 77.4 76.3 mer in straight-run and in Calcd. blending octane 7 9 . 8 8 2 . 0 82.8 8 2 . 8 S o . of unsaturates 80.1 83.2 84.5 84.7 79.6 81.0 81.6 81.2 t h e r m a l l y cracked gasoline f 3 . 0 ml. TEL/gal. blends is given in Table .'!I Calcd. linear octane 81.5 81.1 8 0 . 5 79.4 Since the catalyt,icallp cracked 82.1 81.8 81.3 80.2 82.7 8 2 . 5 82.2 81.4 No. of unsaturates Calcd. blending octane 83.5 83.2 and polymeT at 8 2 . 6 8 4 . 1 8 4 . 8 8 4 . 3 8 2 . 4 83.2 No. of unsaturates 82.9 8 4 . 8 8 6 . 2 85.6 a constant. ratio of 9 to 1 throughout the program, t,heg have been considered as a rated component); 5 = calculated blending octane number of single component for the purpose of blending value calculations. component B (the unsaturated component); and C = octane In view of this, the simple formula used in the foregoing section is number of the blend. applicable here with the additional assumption that when tho The blending octane numbers for the two-component blends, thermally cracked in straight-run, are shown in Table 111. The
CRACKED-POLYMER-THERMALLY CRACKED GASOLINE,CALCULATED TABLE IT. CATALYTICALLY LINEhR F-1 OCTANE NUMBER AND F-1 BLENDIXG OCTAXE UMBER IN STR.4IGHT-RUN
100
I
I
90
80
I
1
I
I
70 60 50 40 30 PERCENT CAT. CRK./POLY
Figure 6
I
I
I
20
10
0
I J Figure 7
November 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
2633
2
BLENDING
6 IbO
u
PER CENT UNSAlURATES@CbLY/T]
IN STR-RUN
0
I
I
80
80
I
OCT
1
I
I
I
60 50 40 30 Zb PER CENT UNSATURATES (CWPOLYITC]
70
I
I
I0
0
IN STR-RUN
Figure 9
Figure 8
catalytically cracked-polymer component is blended with thercomponent unsaturate computed on a linear basis. These two mally cracked, the blending value of the thermally cracked is values, the calculated linear octane number and the calcuthe same as its actual octane number. Figures 5 and 6 are for lated blending octane number of the catalytically crackedthe laboratory method results wherein it may be seen that the blending value of catalytTABLE VII. CATALYTICALLY CRACKED-POLYMER-THERMALLY CRACKED GASOLINE, CALCULATED ically cracked-polymer gasoLINEARF-8B OCTANENUMBERAND F-8B BLENDING OCTANENUMBERIN STRAIGHT-RUN line is higher when blended with Vol. % straight-run 0 22.5 45 67.5 0 20 40 60 0 17.5 35 52.5 straight-run than when blended Vol. % catalytically cracked 81 6 0 . 7 5 40.5 20.25 72 54 36 1 8 ' 63 47.25 3 1 . 5 15.75 with thermally cracked. This polymer 9 6.75 4.5 8 6 2.25 4 2 7 5.25 3.5 1.75 thermallycracked 10 10 10 10 20 20 20 20 30 30 30 30 is to be expected since the Unsaturated compostraight-run is completely satunents, total % 100 77.5 55 32.5 100 80 60 40 100 82.6 65 47.5 rated whereas the thermally Catalyticallycracked, % 81 78.4 7 3 . 6 62.3 72 6 7 . 5 60 45 63 57.3 48.5 33.2 cracked is partially unsatuPolymer, % 9 8.7 8.2 6.9 8 7.5 6.7 5 7 6.3 5.4 3.7 Thermallycracked, % ' 10 12.9 18.2 3 0 . 8 20 25 3 3 . 3 50 30 36.4 4 6 . 1 63.1 rated and blends more nearly Clear, a t 1000 r.p.m. linearly with the unsaturated Calcd. linear octane No.of unsaturates 80.3 80.1 7 9 . 8 79.0 79.7 7 9 . 3 7 8 . 8 77.7 79.0 78.6 78.0 76.9 catalytically cracked-polymer Calcd. blending octane component. This effect is No.ofunsaturates 80.5 83.1 8 6 . 8 92.7 79.5 81.9 8 4 . 2 8 6 . 3 79.0 8 0 . 8 81.9 82.9 +1.0 ml. TEL/gal., a t more pronounced on the road 1000 r.p.m. Calcd. linear octane as shown in Figure 7 (at 2000 No.ofunsaturates 86.7 8 6 . 5 86.2 85.4 8 6 . 0 85.7 85.2 84.2 85.4 85.0 84.4 8 3 . 3 Calcd. blending octane r.p.m.). This may be due to No.of unsaturates 86.5 8 8 : s 9 3 . 8 99.7 8 5 . 5 87.6 91.2 9 5 . 8 8 5 . 0 86.6 88.9 92.0 the lack of sensitivity to fuel +3.0 ml. TEL/gal., a t 1000 r.p.m. component concentration of Calcd. linear octane No.ofunsaturates 9 1 . 2 90.9 9 0 . 6 89.6 90.4 90.1 8 9 . 4 8 8 . 2 89.7 89.2 8 8 . 5 87.2 the road test engine as comCalcd. blending octane No.ofunsaturates 91.0 92.5 94.6 97.8 9 0 . 5 91.8 9 3 . 8 9 4 . 3 89.5 91.0 91.6 9 2 . 9 pared to that of the laboratory Clear, a t 2000 r.p.m. test engine. Calcd. linear octane The third group of blending No.of unsaturates 7 5 . 1 74.9 74.5 73.6 74.4 7 4 . 0 7 3 . 4 7 2 . 2 7 3 . 7 73.2 72.5 71.2 Calcd. blending octane value data for all four comNo.0funsaturate.e 75.0 78.5 83.2 9 1 . 1 74.5 77.5 80.0 83.8 74.0 76.5 78.8 8 1 . 8 +1.0 ml. TEL/gal., at ponents in the same blend is 2000 r.p.m. Calcd. linear octane covered in Tables V to VII. No.ofunsaturates 81.5 81.3 80.9 80.0 8 0 . 8 80.4 7 9 . 8 78.6 80.0 79.6 78.9 77.7 After considerable thought on Calcd. blending octane No.ofunsaturates 81.5 84.1 88.9 95.6 8 0 . 5 8 3 . 1 86.7 91.3 80.0 8 2 . 2 8 4 . 0 87.2 how best to handle these data +3.0 ml. TEL/gal., at 2000 r.p.m. it was decided to consider as a Calcd. linear octane No. of unsaturates 86.0 85.7. 85.3 8 4 . 2 8 5 . 1 84.7 84.0 8 2 . 7 8 4 . 3 83.8 unit all the components oon8 3 . 0 81.4 Calcd. blending octane taining unsaturates (as deterNo.ofunsaturates 86.0 8 8 . 4 91.0 94.2 85.5 8 7 . 8 89.0 90.3 84.5 87.1 8 7 . 3 87.5 mined b y p a r a f f i n - o l e f i n Clear, a t 3000 r.p.m. Calcd. linear octane naphthene-aromatic analysis). No. of unsaturates 70.9 70.7 70.2 6 9 . 1 70.0 6 9 . 6 68.9 6 7 . 4 6 9 . 2 68.6 67.7 66.3 Calcd. blending octane This unit was blended with the 71.0 73.2 No. of unsaturates 76.4 8 0 . 9 7 0 . 0 72.4 7 6 . 3 8 0 . 5 69.0 71.0 7 4 . 0 78.1 +LO ml. TEL/gal., a t straight-run to compose the 3000 r.p.m. finished blend. The values Calcd. linear octane 7 7 . 3 77.0 76.6 75.5 76.4 7 6 . 0 7 5 . 3 7 3 . 8 74.2 72.7 No. of unsaturates 75.6 7 5 . 0 given in Tables V, VI, and VI1 Calcd. blending octane No. of unsaturates 77.0 7 9 . 9 83.5 8 8 . 9 7 6 . 0 79.1 81.8 8 6 . 0 75.0 77.7 7 9 . 6 81.9 were thus obtained, using the +3.0 ml. TEL/gal., a t 3000 r.p.m. general formula previously Calcd. linear octane Also included in described. 81.8 81.5 8 1 . 0 79.7 No. of unsaturates 8 0 . 8 8 0 . 3 7 9 . 5 77.9 7 9 . 8 79.2 7 8 . 3 76.6 Calcd. blending octane the tables is the calculated No. of unsaturates 82.0 83.5 84.4 8 4 . 9 81.0 83.0 83.0 8 1 . 8 80.0 81.3 81.1 79.6 octane number of the three-
2;:p
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
2634
PER
CENT
UNSATURATES
(CC/FOLYJTC)IN
STR
- RUN
I!.
Vol. 41, No. 11
0
90 80 70 60 50 40 30 20 IO PER CENT UNSATURATES (cc/poLv/rc) IN STR-RUN
ol@J
Figure 10
Figure 13
Figure 11
Figure 14
thermally cracked concentration on delta octane number wyas practically negligible and so single curves have been drawn t o simplify the plots. Thus one has a method for calculating the octane numbers of blends of these components or others of a similar nature. It may be understood best by examdes: Blend Composition, Straight-run 45.0 Catalytically cracked 4 0 . 5 Polymer 4.5 Thermally cracked 10.0
F-2 Clear 46.2 75.1 82.1 68.6
E'-8B a t 2000 R.P.RI. +1.0 Ml. TEL/Gal. 52.5 82.0 84.0 75.0
To find the F-2 clear octane number of the blend, calculate the linear octane number of the unsaturated components: Catalytically cracked, 70 4 40 . 5 (40.5/55.0) 4.5/55.0) X 75.1 82.1 = 55.3 6.7 Polymer, % Thermally cracked, % E (10.0/55.0) x 68.6 = 53.0 74.5 From Figure 11, a t 55.0% unsaturates Aoctane Ho. = 6.3 Calcd. blending octane No. = 80.8 Then, 0 . 5 5 X 8 0 . 8 = 44.4 0.45 X 46.2 Calcd. octane No. of blend = 6 5 . 2 Actual octane No. of blend = 65.1 (Table 11)
12.6
PER CENT UNSATURATES [CC/POLY/TC)
IN STR.-RUN
Figure 12
polymer-thermally cracked component, were plotted against concentration in straight-run for the various test methods, clear and x i t h tetraethyllead. Typical plots are in Figures 8 and 9; Figure 8 is included for F-1 clear determinations, and Figure 9 is included for F-8B a t 2000 r.p.m. with 3.0 ml. of tetraethyllead per gallon. From a complete series of such graphs it was possible to construct crossplots as shown in Figures 10 through 14. These are curves of concentration versus delta (A) octane number of the catalytically cracked-polymer-thermally cracked component in straight-run, where delta octane number is the difference between the calculated blending octane number and the calculated linear octane number of the unsaturated component. The effect of
-_
==
Likewise, to find F-8B at 2000 r.p.m. 4- 1.0 ml. TEL/gal., calculate the linear octane number of the unsaturated components, Catalytically cracked 4 0 . 5 % (40.5/55.0) X 8 2 . 0 = 6 0 . 4 Polymer 4.5% ( 4.5/55.0) X 8 4 . 0 = 6 . 9 Therinally cracked (10.0/55.0) X 7 5 . 0 = 1__ 3.7 55.0 81.0 From Figure 13, a t 55.0% unsaturates 4 octane No. = __ 7.9 Calcd. blending octane No. = 88.9 Then, 0 . 5 5 X 8 8 . 9 = 48.9 0 . 4 5 X 52.5 = 23.6 Calcd. octane No. of blend = 72.j Actual octane 3 0 .of blend = 7 2 . 5 (Table 11)
s?,
November 1949
~
INDUSTRIAL AND ENGINEERING CHEMISTRY
The authors recognize that the agreement in the examples is good because the calculations are all on the same basic data, but as indicated, previously it is apparently satisfactory to use these curves and this procedure for blends with stocks of similar characteristics. It is also realized that the road performance data presented are based upon tests with only one vehicle but as explained previously the authors feel that the results from this car are reasonably close to the average. The factor which cannot be expressed as a table or curve is that of experience. With further refinement of the data presented and accumulative experience in this field, it should be a relatively simple matter to predict accurately the antiknock characteristics of any multicomponent blend either in the laboratory or in the vehicle in which it is to be used. SUMMARY
fied borderline procedure) methods, clear and with 1 and 3 ml. of tetraethyllead per gallon. A series of curves was obtained from which it is possible to estimate the performance characteristics of multicomponent motor fuel blends, Only typical exaniples are included in the paper but the data are given from which the complete series may be drawn. Future work will include stocks from other crude sources. ACKNOWLEDGMENT
The authors express their appreciation for the assistance of the following Universal Oil Products personnel in preparing the samples, obtaining data, and editing this paper: M. Bokholdt, E. Cain, W. J. Faust, C. S. Larsen, F. C. Skach, G. A. Steffens, R. L. Van Ort, R. J. Voris, and D. Votava. The authors wish to thank the Universal Oil Products Company for permission to use these data.
A method and substantiating data are presented for estimating the performance characteristics of multicomponent motor fuel blends. The scope of this investigation covers four major components of motor fuel-straight-run, thermally cracked, polymer, and catalytically cracked gasolines from mid-continent crude. Multicomponent blends which covered practical commercial concentrations were made and rated by F-1, F-2, and F-8B (modi-
2635
LITERATURE CITED
(1) Eastman, IND. ENG.CHEM.,33, 1555 (1941). (2) Heath and Hicks, paper presented before the Division of Petroleum Chemistry at the 113th Meeting of the AM.CHEM.SOC., Chicago, 111. RECEIVED October 8, 1948. Presented before the Division of Petroleum St. Chemistry at the 14th Meeting of the AMERICAN CaEMIcAL Louis, MO.
Solubilitv Characteristics of Sulfones -
TETRAMETHYLENE SULFONE, 3-METHYLTETRAMETHYLENE SULFONE, AND 3,4-DICHLOROTETRAMETHYLENE SULFONE T. EARL JORDAN AND FRANK K I P N I S Publicker Industries Inc., Eddington, Pa. Tetramethylene sulfone is a stable and inert compound with interesting solubility characteristics. It dissolves or is miscible with most types of organic compounds except alkanes and cycloalkanes, and with the commonly available polymers except polymethacrylates, polystyrene, and polymers of vinylidene chloride (saran). A few tests indicate that 3-methyltetramethylene sulfone has similar properties. The solubilities of sulfur in tetramethylene sulfone and of 3,4-dichlorotetramethylene sulfone in lubricating oil are given.
T
ETRAMETHYLENE sulfone (2,3,4,5-tetrahydrothiophene1,l-dioxide, sulfoxaline) has many interesting solubility relationships. Somewhat like liquid sulfur dioxide but less polar, it has great solvency for many classes of organic compounds and yet retains water solubility (6). These properties have been the subject of a number of patents. Morris and co-workers used it for extraction of fatty acids ( I I ) , separation of noncellulosic wood products (I.@, separation of hydrocarbons (IO),and general extraction and separation processes (3, 17). Morris and Snider (15) found it to be a useful azeotroping agent, Hoffman and Mortenson (6)prepared derivatives of polyhydric alcohol, and Merner (9) used it as a spinning medium for po!yacrylonitrile. Other uses for this class of compound comprise hydraulic fluids (Id), tackifiers for synthetic 1
Present address, Oxford Prodiiots. Inc., Cleveland, Ohio.
resins ( I S ) , and corrosion-resistant agents in lubricating oils (16); all depend on the solubility characteristics. This investigation reports certain phases of the stability and solubility characteristics of tetramethylene sulfone, and limited studies with 3-methyltetramethylene sulfone and 3,4:-dichlorotetramethylene sulfone. Tetramethylene sulfone appears quite stable toward many metals and several types of inorganic compounds (Table I). At reflux temperature prolonged heating with aluminum chloride, sulfur, or chlorine causes decomposition. Table I1 illustrates the solvent power of tetramethylene sulfone for a variety of chemicals. Except for the alkanes and c*vcloalkanes, practically all classes of organic compounds of a monomeric nature are soluble in or miscible with tetramethylene sulfone. Of the commonly available polymeric substances, only the polymethacrylates, polystyrenes, and saran showed insolubility or limited solubility (Table 111). A few tests indicated that 3-methyltetramethylene sulfone has solubility properties similar to the unsubstituted derivative (Table IV). Since tetramethylene sulfone showed such remarkable solvent properties, the authors hoped that it would act as a primary solvent for the preparation of sulfur emulsions in water. Table V shows the solubility of sulfur in tetramethylene sulfone a t temperatures up to 150"C. and indicates that it is too limited to be practical. 3,4-Dichlorotetramethylenesulfone was also considered ab an additive for extreme pressure lubricating oils, and a number of types were evaluated for solubility, but even a t 100' C. the solubility WRS too low t o be practical (Table VI).
