October 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
2347
if sensitivity were limiting, i t would be necessary to resort t o TABLESI. LABORATORY OCTAYESZ.\IBT,R I~EQT.IREIIESTmore costly and restrictive refinery processes than those currently available in order to produce adequate quantities of high antiC‘oinpreq-Research 0 . 3 . M o t o r IIPthod 0.S. FlOIl Detroit Sea nrtroit Sra Liniitinr knock quality fuels of low sensitivity. However, the conclusion Ratio (*ar area If,vel 3rt-a level Sensitivity
that fuels of high sensitivity are limiting only in research octancx numbcr is tcntative since it involvcs the following basic assuniptioris:
1. T h a t the cars tested are representative of high coinpressii~i :tutoinotivc equipment which may be produced in the future 2. T h a t the method of Borderline test technique employwl gives a reasonably accuratc indication of relativc fuel performaiiri. as evcntual1.y evaluated by customer acceptance
Thc relation bcttvc~c~li ci~niprc~ssion ratio arid the octalic* rcquirenient a t sea level is presented in Figure 0 which sk1on.s that the generalization probably holds for engincs of present-day as n-cll as future design. I t will be noted from Figure 9 t h a t as compression ratio is raised, both research and motor method octane requirements increase, but this increase becomes sina1lt.r for a given increasc. in conipressiou ratio as the higlivr comprcxsIs are rcached. Furtliclrmore, i t appears that tliv tiiotcir mcthod rrquireiiient is increasing a t a slightly lower r;ttcx n i t h compression ratio than is the requirement in terms of rcscwch ortanc’ number. This implies t h a t as compression ratio is incrixascxd, thc motor octarics number b(!comw leis important with t h o wsult that fucals having higher sc~1isitivitiwcan bc tolerated hcfori. high specxd knock beconies limiting. This observation is iri agreenient with experimental results recently reported by Holaday ( 3 ) . Additional evidence t h a t in these high compression ratio engines, fuels of high sensitivity are limiting in research octane number only is presented in Figurc 10 from n-hich i t is indicated t h a t in car C a fuel of slightly higher rescxarch octane number similar t o the highly olefinic fuel 11 lvith a scnsitivity of about 16 units would be satisfactory over thv ontirr speed range once t h r rcse3rcIi octane number requirement was satisficd. Such a conclusion is extremely important to thrl petroleum refiner since the processes t h a t could be utilized for the productiori of high octane gasolincs, such as catalytic cracking and polymerization, are those which give high sensitivity. On the other hand,
( : o . Y c L L ~ s I o Ys
As compression ratio is increased, the research and iiiotoi’ tncthod octane number requirements increase in a n orderly fashion but this increase becomes smaller as the compression ratio increases. In high compression ratio engines the research octane numtic~r rcquirement is limiting and fuels of greater scnsitivity can he tolcsratrd with increasing conipressioii r:rt io. 4CKYOW LEDGMEYT
The authors wish to acknowledge the assistance of thc General Motors Corporation in providing road antiknock evaluations of the sixteen fuels in the engines specificallv designed to operatt a t high comprt,ssion ratio. LITERiTURE CITEI)
-4nierican Society for Testing Materials, “.I.S.T.II. Manual of Engine Test llethods for Rating Fuels,” 193’3. Coordinating Research Council, Inc., “CRC Handbook,’’ 1946. Holaday, presented before the meeting of the NP.1, Cleveland, Ohio (April 1948). (4) Kettering, presented before tho tnerting of tlie Society of Automotive Engineers, Frenrh Lick, Ind. (June 1947). RECEIVEII October 7 , 1948. Presented as a p a r t of the Syriiyosiurn on Relationship of Fuel Properties t o Engine Design and F u t u r e of EIigh Octane Fuels before t h e Division of I’etroleum Chemistry a t tlie 114th SIeeting of the : ~ > l E R I C A S C H I U I C A L S O C I E T P , St. Louis, 110.
Senaration of Svnthesis Mixtures J
VAPOR-LIQUID EQUILIBRIA OF ACETONE-METHANOL-WATER JOHW GRISTVOLD’ ASD C. B. BUFORD2 T h e Cnicersity of Texas, Austin, Tex.
\*apor-liquid equilibria and boiling points of the acetone-methanol-water ternary are presented. The acetonemethanol binary has been redetermined to resolbe discrepancies in the literature data. .tccurate densities and refractive indexes of the ternary and all binaries are determined for use in analysis. The binary density data are in good agreement with the values in the International Critical Tables, but the present refractive indexes are appreciably lower than the literature at high water concentrations. 1
1
Present address. Illinois I n s t i t u t e of Technology, Chicago 16. Ill. Present addrrss, box 1391, Parkcrsburg, IT. Va.
A
CETOSE and methanol arc. major components of the wrtcr
product obtained from hytlrorarlmn synthesis i ~ yt t i c s Fischer-Tropsch-type process (through cnrbou moiiositle : ~ i i ( i hydrogen). Vapor-liquid equilibria of the binaries ant1 tlic ternary are needed in fractionation calculations for sep:wation and rerovery of the organic compounds. Vapor-liquid equi1ihri:r of the binaries have been reported by numerous m r k e r s ( 2 , 10, 11) and fragmentary data on the ternary have :tlso appr:irod (IS). The present data rcsolvc discrepancies in the acetone-mt,th:triol syst,eni, and complPtP the ternary system. Densities, rcfmctivc indeses, and boiling points of improved acciurary arc givcn for the ternary and for :ill hinarirs.
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
Vol. 41, No. 10
1.33881 1:34721i I , X4GR8 1 ,35281 1 ,3.5357 1 ,3383Ii 1 .30l!ll;
1.36227 1 36322 1 ,36290 1.30271
1.3iii4: 1 . :3r;03s 1 . :1.788i bore
5
0
Figure 1.
2
3Ioclified Colbiirii E ~ ~ r r i I i b ~ . i iStill itl~
_*
~
EXPERiMENTAL
I370
CALCLLITED FROM
I'milirig poitits \vi!ri! i l i ! t i ~ i , i i i i i i i , i l *o.oj" 1))' 2. (~lJttl't?1l-t~~l! boiling point :L~J~):LI~:L~LIS (.Y) with a t hermonic, t e r graduated i i i 0.2" C. divisions. I t was chrrlccd against a Bureau of Stanihrils certified thermometer and s t o m corrections were applied. Sligli t air pressure was maintained on 1 he apparatus, so t h a t the absolute pressure>K:LS 760 * 0.5 mm. :it all times, The t)oiIiIig points lif pure \v:ttc.r, n-heptane, benzene, and m e t h y l c y c l o h e x a n e vhecketi the literature values as closely R S the thermometer rould Iir. r r x i . tlJ
0 95
:*
1360
I350
0 90
-0
I_j-C
c I 340
0 85 I330
0 80 I320
0
20
40
60
BO
100
MOLE % OF MORE VOLATILE COMPONENT
Figure 2.
Rinarj Specifir Gravity C i i n e*
0
MOLE %
20
40
60
80
100
OF MORE VOLATILE COMPONENT
c.
.
2349
INDUSTRIAL AND ENGINEERING CHEMISTRY'
October 1949
I
r 1
v:Lpor-litlui~lcquilibi,i:t \\ I'IY~ t i .toi,iiiiiieili i i ;L glass Coll)iii,ii n i c i t l i f i c d as to climerisiolis :tiid by the inclusion IJI :IIC ( 1 1 1 i r i r l : i l c,olnpeiis:iting hc,:iters. Tllr design cirtails are shown iir 1;igiiw 1. Pressure \vas mairitainrd :it 760 =t0.3 mm. by Inearis 111. : i t 1 :iir supply and pressure regulator. Thr regulator is essen1 i : i l i > , the niercur;- t):ilance typc (leveloped 1-, Bailey ( 1 ) with the c,:ii)illnryleak installed on t h c oppoyitr 5ide of the pivot so t h a t a p i ~ ~ s usonieivhat rc :tl,ovr Il:ri.omrtiic,i h maintaiiiid. .Iniiniature 1):iIl-bc:iring race was used f i ) r thc pivot bearing : t i l t 1 i h c control prnved entirely ,satisfactory. The air supplies i o lioth hoilingI i o i r i t and vapor-liquid :ippu'~ttusiverc dried by p :I c,:d~~iiim chloride tutje. The 1ir:tter windings of t h r equilibrium hl i l l \ v i ~ i i ! cncrgized 1))- svpnrate variable-voltagt tr:tiirformt~rs ~IYIIII:I 1 IO-volt a1tcrn:tting current power s u p p l ~ttii,uugh . :I coini i i o i ) l-k\v. con.qtnnt volt:tgc tr.:tirsformc-r. T h c c - r l u i l i l ) i ~ i u nstill i iCI ill (;),
I,i
