INDUSTRIAL AND ENGINEERING CHEMISTRY
October 1949
CAR C 10 I COMPRESSION RATIO
I
s
l
l
100
CAR D I 2 5 I COMPRESSION RATIO
2365
the knock characteristics of various motor fuels in high conipression engines has been completed, it is believed that these limited data will contribute to the knowledge required for the economical production of satisfactory fuels for engines of advanced design. I t appears certain that fuel development programs should be carried out in engines of the specific design expected on the road, as antiknock ratings in stepped-up, conventional engines do not appear to be comparable. The road octane number of the motor fuels tested to date appears to incre:ise with in( compression ratio. This is particularly true a t high speeds, with the result that the octane number Lig:iinst spwtl curve for sensitive fuels tends to bcconic Hatter :IS compression ratio is increnscd. Several relations were similar to ttiosc. already noted froin previous octane number d:it:i obtained in prtwnt-clay cngiriw [ i f lower compression ratio. However, the corre1:ition b c t w w n research mcthocl octane numbers and loir- sped i,o:itl oc.t:uic, numbers in high compression c:ii's :ippenrq to I)e sigiiific*;iiitIy better than the correlation usu:ill>. detcrmincd using p r t w n t - ( h ~ ~ engines. ACKNOBLEDG3IEhT
0 FUEL 31
COMMERCIAL
GASOLINE
A
X FUEL 32
COMMERCIAL
GASOLINE
A CUT AT
800
1200
1600
2000
ENGINE SPEED
Figure 6.
325 OF
2400
2800
R PM
The authors are indehted t o the GcncrcLl 11otor.q Corpor:irion for making availnhle esperinient:il engine. of 8 t o 1 , 10 t o 1, and 12.3 to 1 compression ratio, for their kind c>oopcwtionn.hile rating the fuels, and for their consent to relts in their esperimental engines.
Road Octane >umber us. Engine Speed
Effect on road ratings of i n c r e u 4 n g volatilit? by u n d e r c u t t i n g
The only fuel which was completely different from the others in over-all composition was fuel 28, n n aviation stock consisting almost entirely of isop:ir:tffins. The road octane number-speed curve slopes upn-nrd rather than donnivard as for all of the other fuels. This type of rating would be expected from all previous work in lower compression engines. Although only a small portion of the program for evaluating
L1TER:ATURE CITED
(1) Am. Soc. Testing Materials, test proceduie D 484-40. ( 2 ) Francis, -4. IT..ISD.ESG. CHEM.,18, 821 (1926). (3) Groase, h. v , , and ivackher, I(. u., Isi). 1:s~.C H E M . , z'.s.\r.. ED., 11, 614 (1939). (4) Kettering, C . I?., S . A . E . Joicrnai, Qicavierly Trans., 1, GG9 (1947). (5) Petroleum Industry War C'ouncil. Tech. ;Idviaory Cornni., R e p t . HcAC-6. (6) Kagner, C. R.. lloss. IY.B., Henderson, I,. l l . , and Risk, T. f1.. Refiner .Vatzcral Gasolinf .l[.fr., 20, 436 f 1941). R E C E I V E )[arch D 8 . 1949.
Ternary System Diisopropyl Ether-Isopropyl Alcohol-Water at 25"C. F. J. FRERE I'ziblicker Industries, Znc., Z'hiladelphiu, P a . 3 f u t u a l sol~ihilityand tie line data on the s!stem diisopropyl ether-isoprop?l alcohol-water, determined during a general inicstigatioll of liquid-liquid extraction, are reported i n this paper.
I
x i t h freshly c:tlcincd lime, :tlttbr ivliich it was fraction:ttcd on :t Podbielni:tk colunin; the ccJntcli,c u t \v:i* *eltIcted. Re:igcnt-gratle diisopropyl ethcr w ~ i hir:ictiori:itcd on :t l'ocibiclniak column; the centclr cut W:M w l w t c c l . 0rdin:iry distilled water x i s used.
S THE course of a rather general investigation on liquitl-
liquid estraction, mutual solubility and tie line data were required on the system diisopropl-l ether-isopropyl alcohol-water. .As far a s can be ascertained, this system has not been reported in the literature. Therefore these data were determined and arc reported in this paper. Re:tgent-grade isopropyl alcohol \vas reflusetl for several hours
3IUTUAL SOLUBILITY DATA
Known amounts of two components, isopropyl alcohol :ind diisopropyl ether or isopropJ-l alcohol and water, contained in a 100-ml. glass-stoppered volumetric flask, were mixed; quantities of the third component, water or diisopropyl ether, were ntldcd dropwise from a buret until the misturc became turbid :md re-
INDUSTRIAL AND ENGINEERING CHEMISTRY
2366
ISCPXOPYL A L C O H O L
5 0 r
p c l ~ i ~ ~t h t ie
flasks r w r p :illowed
tu
, r,eni:iin i n t h e b a t h u n t il the
DIISOPROPYL ETHER
Figure 1.
Vol. 41, No. 10
phabea had completely separated: then samples of the separated layers were n-ithdrawn and their specific gravities were measured. The coin. positions of the equilibrium layer:. were determined by rcferencc to i 8 large scale plot of specific gravit! against isopropyl alcohol c o ~ i ( ~ i i t r : ~ tion for s:iturated solution.*. Tht. circles near the centers of the represent the over-all conipu the tn-o-liquid-phase mixtures in d t terniining the individual tie lines. 11, all cases t h e tie lines prtsstvl througl these and the corresponding t l c a t ~ r miried points on the binodal rurv+ t withii-i 0.2y0. Table I1 show< t h w d:it :i\vhicah :ire plotted in Figiiw 1
WATER
S y s t e m Diisopropyl Ether-1soprop)l ilcohol-Water at 23" C.
T I E LINE COKRELATIOSS
Xatcr ( b ) .
S?
99.3 93.4 89.0 84.4
79.0 74.4 22.8 (0.3 68.7 65 3 64.0
61.: 58.3 56.4 50.8 47.6 42.6 38.6 35.7 31.5
18.3 24.8 22.6 18.9 16.3 14.5 12.6 12.2 10.6
8.6 6ti 5.9 5.2 4.7 3.4 2 2 1.6 1.3 1.2 1 0 0 0
Weight % 0.5 1.1 1.5 2.2 3.2 4.: + . I
0.2 5 8 6.7
7 1 7.8 8.9 9.6 11.6 13.0 15.5 17.8
-~ 5.5 9.5 13.4 I D '3 21 0 22 j 24.3 2.5 , 3 28.0 28.9 30.7 31' 8 34.0 37 6
19.7 23.0
39.4 41.9 43 0 44 6 4.3 5
26.0
4.5. i
2!1,7
43.5 45.0 43.5 41.8
32.4 37.6 41.9 45.0 48.4 49.0 52.1 55,6 60.2 61.8 63.6 65.0 $9.6
,4.8 78.3 53.3 89.4 93 8 9'3 1
Tre>-b:iI ct ul. ( 5 ) developed a himple method fur astirnatiil:: the plait point which, in part,, ie basal on the correlation suggestrc by Hand ( 2 ~ ) .Csing the same symlmls of not:\tion? t h e methoc is briefly outlined here to illu3trate thcs :ipplic:itJility of the presem data. .it the plait point the t w o corijugnte I n ~ ~convwgr. rs int(
iJ . 8
96 1 !I3 0 $10 1 80 1 82 8 76 3 72 I ii4 2 54 2
IIJ 2
Id 1
11 ( I
36 9 31.5 2.5 3
18 7 21 0 1'9 0
14.3 19 i 2 1 , !i 58.h 35 t i 40 6 44.4 4.5 .5
1 2 I ' I ,2 I ' 1 3 I 4 1.2 1.i 2 3 2 , !I 3.7
45.7
4 7
8.4 11 ! I
P i I.0 i Cl i.0
'12. 1 e.!).0 86 , !I 85.4 8.3.8 82.4 81.6
I 0
2.h 3 8
1 2 1.5 2 ,0
50.3 ,? 8 74 1 71.2 fi8.3 64.6
40,s
39.0 38.8 37.3 32.8 33.2 35.3 31 5 3u 3 27.0 23.0 20.1 1.5 4 ?.4 .a 2
i
1.0
45 3 L 0.4 XII 0.3 mained so for several srcond,. Thr H:i>l; \\-a* t11c311 s t o p p e r ~ ~ d and placed in a con+t:int ti1mper:iture bath n1aint:tiriecl a t 25' = 0.051~C. .ifter reac'hing constant tcmpernture, tlw fl:isk wx renioved arid more of the third corriponciit W:IS adcled until the mixture became permanently turbid. I n g e n ( d . the end point could be detected within one or trvo drops. Table I shoivs t h i w data, which are plotted in Figure 1. TIE LINE DATA
To determine the tie lines, known amourits of the t h ~ e cconiponents (corresponding t o points ithin the binodal curve), contained in stoppered flasks, n ere agitated in the constant temprrahire bath over a period of about 8 ~ o u I ~ At ; . the end of thi-
1
0.01
I
Figure 2.
I
I
i
I
I
I
1
I
1
1
)
)
3 5 03 0.5 ID 0.l Tie Line Correlation and Determination I'lsit I'oini
OD3 os6
IO I I ~
INDUSTRIAL AND ENGINEERING CHEMISTRY
October 1949
,
,
10
"
Othmer and Tobias (4)showed that a straight, line is usuallv obtained when log (1 - ai):ul is plotted agninst log (1 - b l ) / b , . In thi. rase too. the correl:ition ronqiPts o f three straight-linr. sepmclntq (Figure 3).
1
0.9
Figure 3. Log Plot of (1 against (1 - bg)/bl
I
al)!al
Figure 1. Effect Concentrations in the System I)iisoprop!l Ether-Isoprop>l ilcohol-Water
one, and hence the distinction betn.een them vanishes. 'As result the following conditions must be satisfied:
il
C)thmer et ai. (3)pointed out that in extmction processes i t is important t h a t the relative, inimiwilrilitj- of .solvent :tnd w t v r be maint:iined at high solute e~)nc~c~ntr:itions. They shon.ed I h:i t t h cfficicric?~ of a solvent ma)- I w dr~tnrniir~etl by n plot ( ! t c1 (h, c I ) 2's. c a / ( O , cg). The prvsrnt d a t s :ire plotttid i i i t h i q nianntlr on Figure 4; the curve wtnaiiis high over wide ratipt,. of isopropyl alcohol coneeritr:itions, :iiid at 1 (.;il point of v i e n . cliisoprc)Li>-lc~tlit~r i* :in rffective solvent.
-
where s u b x r i p t p represents the plait poiut. Bec:ru.se the p h i 1 point avtu:rlly rPprr?ents a tie lie. the point reprcwnttvl I ) > tlic iwordinatrs
(z:',, (2) aiicl
2367
iiuisr :iIso f:ill on the tit,
+
liiir>
I1
. Therefore, ivlieii the limiting solubility (*urvi, is plotted :is X , / X , u s . &-Y1 (Figuw 2 ) on the same plot the tie line correlation, a Continuous curve of two branchc> ic obtained. S o w , the plait poilit niny bti found simply by extrapolating the tic line correlation curve until it interserts thtz limiting solubility curve. Tahlti I1 gives the estimiitrd plait point Figure 2 s h o w t h a t the correlation is not liriear but rather is mad? up of three straight-line segments. This variance from linearit! can be attributed t o the large deviations of the system from customary behavior, as evidenced by the f w t that the tie lirir,. show a reversal of slope. In spite of this, the correlation still V ; I I I serve a useful purpose. Campbell ( 1 pointed out this f a c t . I n this connection i t might be mentiorid t h a t the estimated plait point appears to be somewhat too far on the water side of the binodal curve. Hoivever, it must be remembered that thc. estimation is semiquantitative, based on ari e u r t mnthenintic:il correlation which does not take into account tht, deviations of *nliitioiis from idpnlitv.
s o ~ l E ~ c I H' E~ l ~
\\-eight fraction of solvciit (cther) h = \wight fraction of diluent (ivitter) r = weight fraction of solute (alcohol) S = liquid concentration, weight fraction Suhseripts 1, 2, 3 = components o , h, e, respectivclJ-; first S U I > script rcsfers t o compont'nt n.hoscx property is intlicsted, the second to predominant conipoiit'nt of soliltion ; thus Sal= weight fraction of c i n a-rich layw p = plaitpoint (I
=
LITEK.ATt'KE CITED ( 1 ) Campbell, J. A , . ISD. ESG. CHEir., 36, 115s (1944). (2) Hand. D. B., J . Phys. Chem., 34, 19til (1930). (31 Othmer, D. F., Bergen, It-. S., Schlechter, S . . and Bruins, E'
F
EX. G H E X . , 37, 890 (1945). (4) Othmer, D. F., and Tobias, P. E.. I b i d . , 34, 093 i1042). ( 5 ) Treyhal, R. E.. ITebrr. 1,. D.. anti Daly, J . F,,I h i d . . 38. i l ; IND.
(19461.
