Vapor-Liquid Equilibria of the Binary Systems: Benzene-Ethylene

Home , Ethyl acetate

VAPOR-LIQUID EQ.UI.LlBRIA OF TilE BINARY SYSTEMS! BEIZENE-ETHYLENE DIOHLORIDE ETHYL AC:Jb'TATE·BEHZENE ETHYL AOE'JATE-ETHYLE.NE DICHLORIDE

JAMES CARL JOHNS.ON

A THESIS aubmitted to

OREGON S~ATE COLLEGE

in partial tul!illment of the ~equirement. a . tor the de.gree of MASTER OF SCIENCE June 1956 Redacted for Privacy

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Historical Int~oduction. • • • • • • • • • • • • • • It l Introduction • • • • • • • • • • • • • • • • • • • • • 3 Theoretical Considerations • • • • • • • • • • • • • • 5 Experimental Eq~1pment • • • • • • • • • ~ • • • • • .14 Equilibrium Stills. • • • • • • • • • • • • • • .14 Pressure Control. • ...... • • • • .. . .. • • .18 Temperature Measurement • • • • • • • • ..20 eaaurement of Refractive Irldex • • • • •• •• ••21

reasurement of Dens1 tv~~ • • 1 • • • .. •· • • • • • .21 I Sample Tubes. • • • • • • • ! • • • • .. • • • • .. .22 Chemicals and Pur1£1oation • • • • • • • • • • • • • .23 Experimental Procedure • • • • • . .. • • • • • • • .27 Operation of Stille • • • • • • • • • • • • • • .27 Calibration of Thermocouples...... 31 Determination of Calibration Curves • • • •. • • • .32 Accuracy of Analysis • ., ...... 33

Tbermod~namic Analysis ot Data • • • • • • • • • • • .35 Evaluation of Experimental Data. • • • • • • • • • • .38 Ethyl Acetate-Ethylene Dichloride • • • • • .. • .38 Ethyl Acetate-Benzene .• • • • • • • • • .. • • • .46 Benzene.-Ethylene Dichloride ••• • •••••• •53

Discussion of Expe~imental Results • • • • • • • • • .63 Summary •• ...... ,. . . . • • • . . .. • • .72 ------~------

TABLE OF CONTENTS ( Cont• d.)

Nomenclature • • • • • • • • • • .. • • • • • .. • • • ·74 Bibliography • • • • • • • ., • • • .. • • • • • • • • ·15 Appendix • • • • • • • • • • • • • • • • • • • • • • ·11 VAPOR·LI~UID EQUILIBRIA OF THE BINARY SYSTEMS; BENZENE-ETHYLENE DICHLORIDE ETHYL ACETATE·BENZENE ETHYL ACETATE-ETHYLENE DIOHLORIDE

HISTORICAL INTRODUCTION

Through the years much time and effort have been ex• pended 1n an effort to better understand the conditions of equilibrium between a liquid and its vapor. An early literature classic was •on the Distillation of Binary 1xturea" by Lord Rayleigh (11• pp.531-537). In this paper he described a atlll tor determining the equilibri• um ~elat1onsh1p and presented data tor several eyatema. ince thia time the experimental methods have been greatly improved with the result that his data have been super seded by more recent worka. Lord Rayleigh's still haa been replaced by more modern deaigna which have been developed to correct tor the errors inherent in that type ot apparatus. Paralleling the improvement in experimental methods haa been an effort to better correlate and uee the data Obtained trom equilibrium stills. The use ot fUgacity and activity coetf1c1ents to correct tar the non-ideal behavior ot the vapor and liquid haa permitted an ex tension of the data tar beJond the ideal relationshipa caloulated by a combination ot the lawa of Raoult and Dalton. By ua1ng these correction factors, data taken a under the most ideal conditiona in the laboratory may be uaed under the far different condition• of 1~duatry. Likewise, data from binarr systems may now be used to pre dict the equilibrium relat1onah1pa for multicomponent

collection ot these coefficients p~ovidea the key to a more efficient and widespread uae ot equilibrium data 1n the tuture.

'• 3 INTRODUCTIO

The dat ot many investigators .for the equ1l1bl'1um ~ela.tionahip betweetn liquid ~d ita... vapot- may bo tound in the lit ratur • The collection of thia literature apans more than hal! a centuey ot work . Tlll-ough this period the quality ot the dat presented has been greatly improved . Many changes have been made in the type of equilibrium stills; new methods ot preparation have pro vided chemicals of greater purity; and the development of better analytical equipment have resulted in an increase in the accuracy of the data. A study or the d ta publish• ed on identical systems by different investigators often indicates large differences in the repo~ted values. The possible causes tor these differences are widespread. By using activity coefficients and the Duhem eque.tion, Red lich and Kister (12. pp . 341·34~) 13, PP•34~ - 348) have

~rovided a method of analysis which indicates the thermo dynamic consistency or inooneiatency ot the data and m y also point to the cause ot any inconsistencies present. A study has been made of two of the types ot equi• librium atilla used by previous investigators in an etfox-t to understand the inherent diacrepencies in the particular apparatus . These at1lla are basically ditt rent in their method of operation. The first, as designed by Otbmer

(101 pp . 764•76$), provides for the recirculation of a 4 v•por formed from a boiling liquid; while the second, described by Jones, Schoenborn and Colburn (6, pp .666-669i reelrculates the vapor through the liquid until .a steady condition ia reached. Three binary systems have been studied in these stills. Th&ae systems are: benzene..etb.ylene dichloride, eteyl acetate-benzene an4 ethyl acetate-ethylene di.. chloride. The data obtained were eOrl'elated and examined by the methods or Redlich and Kister to provide a com• parison of the results to be expected from the operation Of theae two Stille. THEORETICAL CONSIDERATIONS •I

Fo, the cases of ideal solutions and vapo:rs it is possible to calculate vapo:r•llqutd equilibl'i\.Ull data through the combination of the laws ot Raoult and Dalton Hence, (1) Howeve,, .the oases in wbieh th1s relationship ifJ obeyed are rare. For thi.s reason 1t 1s quite often nf3ceasaey to correct ro:r the dev1at1ona from ideal behavior. The deviations ot the \fapor from a per·t ·aot gaa may be corttectEJd by using the .f'tlgaoity of the plU'e vapor at the total pveasu.re in place ot the pressure on the vapol". Thus. Equation 1 would be written: (2) At atmospheric pressure the terms !'or the fugacity 1n Equation a and fop the total pressure 1n Equation 1 are nearly equal foP moat substances and the use ot either is· accep·table. A$ th& pre.asure .1n(freaaes it beoomea in creasingly n•aease~y to make the fugacity correction. . '.t'h'$ causes ot the deviations 1n the l1qu!d phase are man,y fold. Unfortunately, even at low pressures few liqu1ds are t:ruly ideal and it is necessary to make eot'* rections tor their non•ideal behavio~ ln nearly all eases. All or the deviations or the 11quid phase are combined intQ one cot-reotlon tao'tor1 the activity coeff'ie1ent. The equation tor the equilibrium between a liquid and 1ta 6 vapor is then written as:

Ylf'J:ii : ~ 1xlP~ • (3) The activity coefficients are different for each component, but in a binary system they are related by the Duhem equationt

d ln 1(. .. d ln '6z. xl( d x1 >.:u ,t- x2( d x2 >...-,t <4> Several e.mp1:rioal and sem1theoret1cal solutions of the Duhem equation have been made . Best known of' these are the Margulea and Van Laar equatione. 'l'he Margulea equations are empirical expressions 1n series form, When rearranged in form as done by C~lson and Colburn (2, p.l89) they may be written aa: log ¥ l c• (2B•A)x22 + 2(A•B)xa.3 (5) log ~ 2 : (2A•B)x12 + 2(B- A}x1l • Van Laar attempted to follow a theoretical approach to the solution ·of the Dubem equation. He uaed the thermodynamic changes which oooured when pure liquids are mixed as his basis. Ce.rtain assumptions were made by Van Laar· which influence the reliability of the equations • .. He assumed that the change in entropy ~ is equal to that of an ideal solution, that no volume change· takes) p_l._ace upon mixing and that the van der Waals equation applies to each of the ·.components and to the. 1n;ixtures , both &ill liquids and aa vapors. One ot the fo~s of his equation& is: 7 A log'6 1 : ( l .. ~~~>a (6) B l.og ~ 2 = ( 1 t- !ii )2

As writte~, the eo~tanta A and B are identical in the two pairs of equations• Their values may be readily obtained t:rom experimental data by plotting the logarithm ot the activity ooetticient against the molar composition ot the liquid. On tbia graph the intersection of the curve log '6 1 • t(x) and x1 : 0 is A and ·similarly the intersection or log ~ 2 : g(x) and ~2 : 0 ia B. Alterna tivelr, the slope or the curve representing log ~ 1 : f(x) at x1 : 0 1a ·2A2/B and the slope of the c1.1rve log ~ 2 =g(x) at x2 =0 is •2B~/A. The a ement or the Margnlea and Van Laar equations with experimental data is dependent upon th agreemont ot the characteristics of the system with the aaaumpt1ona m de in the derivation ot the equations. As the ratio or the two constants used in the Van Laar and argulea eql;tat1ons approaohea l, the ()urves defined by the•• equationa become similar and the uae ot either is aat!a tactory. Carlson and Colburn (2. p.58~) have stated that in genttral t~e Van L ar equations have been found to 1'1t the data well. The7 have p~oposed the use or th argulea equations when the ratio or the molar volum e of thi components is approx~ately 1 and the constants A and B 8 differ considerably. The use of the Van Laar equations is recottm1$nded when the ratio ot the molar volumes i aomewhat larger the.n 1. Several methods have been proposed and used for the emoothing or experilru~ntal data" However, unless due care 1s given to the election ot the points through which the curve is drawn the result• are erroneous and the data . oar tully oollecttld in the laboratocy is not ut111~ed to its fullest possible degree~ One method of smoothing the data ia to plot the composition of the vapor against that or the liquid and to draw the best line through the experimental points. Vhile the data may be smoothed in this manner, the final result is not necessarily correct. Another altet-nat1ve would be to plot the coznpoa:ttions of the liquid and v por against the temperature and to draw the be$t line through th data. The correctness of the data moothed in this ma.nnel' is still doubtful and is dependent on the pitopel9

• ~uat1on of which points $hou1d be adjusted, Some uthor have propoaed that the activity ooef• f1o1ent be calculated and their logarithms plotted against the liquid. composition.. The activity aoetticients are veey eentitive to experimental errors and hence provide an exeellent method ot emphasizing the experi• ment ~ data which are inoorreot., Th best line may then be dr wn through the po1nta and the smoothing accomplished. 9 n alternative method would be to calculate the constants for the Van Laar and Margules equations from the experi• mental data d to draw the best curves using these equations as references. The equilibrium data is then calculated from the smoothed activity coefficient plot. Even with this method of smoothing the data the final results are nott necessarily correct or thermo• dynamically consistent. It is desireable, therefore, to develop some method ot smoothing the data which would also indicate its thermo dynamic consistency. Redlich and Kister have proposed such a method for a bin rr system (13,pp . J45-348) . A function which is related to Soatchard1 s "excea free energy" equation (16, p.l805) by the factor 2. 303 RT is used as the starting point .

~ =x1 log ¥1 + xz log ¥2. • {7) A more useful form of the equation is obtained by taking the deriv1t1ves or both sides with respect to xl• .. ~ • log ~ ~ (8)

This equation is related to the relative volatility term used in distillation ealeulationa which is defined aat (9)

Equation 9 may also be written in a tor.m containing 10 the ctivity coefficients.

log o< : log ~ +- log ~~ (10) Thus an expression tor the ratio or the activity coefficients may be used directly in d1st11lation calou lat1ona. Equation 8 1a alao Important tram the standpoint or the examination ot eJtl)erim.ental data. It may be written

1n the integral form and evaluated ut111~1ng the bo~ndttry conditions which require the function Q to be zero when xl : 0 or x1 • l.. J Q.• xl •1 ... 1 dQ. • j log .;1 dx1 • 0 , ' (11) Q, xl =o 0 IJ 2 Equation 11 provides a quick and simple test tor dete%'mining the thermodynamic cons1ateno'1 or 1ncons1&tenoy or expel"imental data. This relationship is strictly true only at constant temperature and pressure. However, 1t ia suff1e1ently 1nsena1t1ve to changea in temperature to be valid tor a amall temperature range. The activity ooef1'1o1ents ot the two components are calculated and the logarithms of their ratioa determined. The logarithms ot these ratios are plotted against the mole traction or the more volatile component 1n th liquid. It the area bounded by the curves x~ • o, log f~ : o and log~ : t(x) is not equal in size and oppoaite in sign to that bounded by xl : 1, log t~ : 0 and log ~ : r(x) the data 1a not thermodynamically consistent. ll A further insight aa to the souree· ot the systematic experimental errors; it present, may be obtained from this sam$ plot. F:rOltl Equation 3 which mathematically det_in.es the activity coeff1o1ent the following relationship mar be obtainedJ

U~ 2 • Zl.!*Yzxl .· (12)

From Equation 12 tt uy be oe)ncluded that it the net uea under the curve detined by Equation ll is not equal to ze~o, but is positive•. the ratio of' y/x is high. It the net area ia negative the reverse is tJ~ue .and the ratio ot y:/x ia low. In this mannex- $l'2:'ors 1n e:&p.&~t· imental d ta ma7 be pointed ou~. Unfortunately, this method of analysis ot the data does not give a further clue as to the ·ource of the error. That 1s1 1t doe• ·not tell whether 1t is the vapov or liquid composition wb1oh ia in errol-.

Redlich and lU.fJter have prEtsented anoth l' method ot analyzing the data which may a1( in finding the anawer to th!a problem (12. pp • .34l-345). In t.hia method~ Eq,u•tion 3 1a logarithmically ditrerentlat•d. and aubat1• tuted into the Duhem equation (Equation 4J to obta1nc

ii • I • . . . • . 7"1 • I:J. . . . w ' I • • ( 1.3 ) dyl 2 • .303(x1 d log PI dt + x2 d log P~~dtlt 1r2 ·

This equation may be used to calculate the slope or the dew point ourve at. any point. Unless the data !a 12 thermodynamically consistent the calculated slopea will fail to ~1e tangent to the curve drawn through the e.x• pertmental data ~ This calculation is very sensitive to the difference in the oompos1t1ons of the liquid and vapor, If the vapor composition is high or the liquid composition low the slope calculated will be too great.

Thi3 equation~ having been obtained through the use or the Duhem equatio~is aubjeQt to its limitations or constant temperature and pressure . It is auf.f1eiently accurate for the analysis or the data even with small changes 1n either the temperature or pressure. The authors suggest that t he data which fail to atisfy this criteri may be adjusted slightly by increasing or decreasing either the x or y values until the proper slope is obt ined. This adjustment may be made even t a csacrifice to agreement with the· experi mental d ta. After this smoothing process, the end points should agree with the boiling points of the pure com ponents. If the indicated temperatures at the end points are equally high or low the entire curve may then be adjusted to the proper temperature . The solution to the problam of locating the source• or experimental errors may or may not be aided t~ough the use of th1 typ ot analysis. It the data are greatly in error the extrapolation of the dew and bubble point curves to the end points may indicate boiling temperatures tor l) the pure components which are too high or too low . A slight adjuettttei'l;'b or either the & or "' values suf'f'icient to obtain the correct slope 11nes and temper• ature endpoints may be used to smooth the data and at trur same t~e indicate the $OUPOe ot a ay•temat1c series of errors.

The authors have alAe proposed the use ot the "slo~e teat" to differentiate between two sets or data whioh are different and yet appear to satisfy the "area" criteria. In such a caae, the oorttect data will provide alope' linea which tall tangent to the dew point curve. EXPERIMENTAL EQUIPMENT

E UILIBRIU 'riLLS

Two types of qu111brium stills were used 1n this work. The Otbxnt:tr still, illustrated in Figure 1 1 was purchased from the Emil Greiner Company. It 1a composed easent1 lly of a body containing the .liquid., a pail' of external heating legs, a condenser. a trap tor the con• densed vapor, and a connection to return the overflow of condensed vapor from the t~ap to the body of the still.

He t to boil the, liquid was ..supplied by a nichrome heating element wrapped around one of the external heating legs. ixing of the liquid within the still body was accomplish ed s th liqu1d .ciroulated through the heating legs. A hose connection for the attachment or a pressure con trolling apparatus was provided at the top of t he· con denser. The temperature ot the vapor was mea~tured. by a multiple junction theirmocouple located at point (A), The liquid and vapor samples were· withdrawn thl'ough stopcocks

( } and (C), ~e•peotivaly.

Heat loss f~om the body of the still to the aurround•

.ings was reduced bJ coverJ.ng 1t w!th one•fourtb. and three• eights !ncb l&Jers Of magnea1a 1naUlation separated b7 a nichrome h at1ng element. The aecorxl atill, ba•ed upon tbe drawing of Jone•. Schoenborn and Colburn (7, p.669) and 1llu•trated in 15

PRESSURE TAP

CONDENSER

CONDENSED VAPOR TRAP

BODY

OVERFLOW RETURN

HEATING LEGS

FIGURE I OTHMER STILL 16 F1g'IU'e 2, consists ot a residue chamber, a vapor line, a condenser, a condensate chamber, and a flash boiler. Liquid and vapor samples were taken at etopcocka (A) and

(B) respectively. Tempe~ature measurements were ~ade at 1 point (0) by a multiple junction thermocouple. 'l'he three•, way stopcock (D), deaigned tot' equ111zing the pressure /

between the two legs of tbe condensate ch~ber during snmpling, was used to control the rate of flow of the oondenoed vapor to the tlash boiler. Presaure controlling equipment waa connected to the still at point (E). · · Three alight modifications made to the still de scribed by Jonee were: the elimination of' the section or capillary tubing between stopcock (D) and the !'lash bo1le1J the covering o!' the residue ohamber w1 th three.-eights or an inch of magnea1a .insulation and the covering of the vapor line with a amall amount of asbestos paper. 'rhe aection of captllaey tubing waa eliminated aa suitable control of the flow rates ae well as the :elimi• nation of the fluctuation of flow into the tlaah bo1le~

•eemed possible bJ partia~lJ closing the stopcock. In

thie manne:r a greater variation of t~ flow through this part of the apparatus could be obtained. The residue

ohamber and the vapor line were insulated in an etto~t to make this portion or the still lesa sensitive to changes in the temperature or the surroundings. It alao made possible the uae or lower temperatures in the 17

CONDENSER

VAPOR LINE

FLASH BOILER

c RESIDUE CONDENSATE CHAMBER CHAMBER

FIGURE 2 JONES STILL 18

PRESSURE CONTROL

During the experim ntal runs it was deaired to con• trol the pressure at 760 millimeters. For this purpose a "Cartesian Diver" type manostat as manufactured by the Emil Greiner Company was used. A diagram or the ar rangement tor preaaure control is shown in Figure ). Compreaaed air wa1 passed succeaeively through a water trap, pressure regulator. needle valve, the manostat and

a one gallon reservoir. A water !'1llec1 u-tube ma.4~o:ne~er;, uaed for determining the pressure within the reservoir and hence w1 thin the stills, waa connected to the reservoir. small tub or calcium chloride for the TO AIR ~--~ WATER ~--~ PRESSURE SUPPLY TRAP REGULATOR r--

- ~ AIR BUBBLER TO ASPIRATOR

MANOSTAT ll r------.

MANOMETER RESER VACUUM VOIR SURGE :...:: ~

STILL I I I I STILL CoCI 2 TUBE

FIGURE 3 PRESSURE CONTROL ARRANGEMENT ao removal of water vapor in the air was located in the linea betw•en the re&el-vo1l' and the •t11la. A. ;pot"t1on of the air leaving the ptteseure regulator was bubbled through a liquid chamber or variable depth whien was constructed to reduce the effect• of changes in atmoapherie and in the $upply line pressure upo.n the pressure of the ail supplied to tho manoste.t .• Aa atmospheric pressure altettnated between values above and below 760 m1ll.imeters, it wa neoeatary to impose .a alight partial vacuum upon the exb4ust connection of the manostat. The pal"t1a~ vacuum was obtained through the use, ot an a.sp1P•tor oonneoted to the manoJltat through a surge tank. A Slnall bubbler with a liquid seal was used to prevent the build.-up ot a lu-ge pa.-t1al vacuum which would decrease the sens~t.ivlt7 or tho nr..anoatat.

l • .'.;'· TEMPERATURE MEASUBEMENT

Meaeurement or the temperature of" the vapor w1thin · each ot thB at1llll wae done through the use of a fot..:tr" junet1on o .oppe~-aonstantan. thermocouple. ~he hot junetiona we're spttead outward in order to make ·good contact with the walla of the tharmowells. '!'be oold junctlons were placed directly into a distilled water, iee bath oontained 1n a thermos bottle. The· theNa'l eleotltomotive to~oe was measured by a Lteda and J.~orthrup No . 8662 pot&ntiometel'•

The potentiometer ~eading could easil;y be est!tnatefl to 21 o.oo2 millivolt which was equivRlent to o.o2oc . Taking

into account ~light variations in pressur~ trom 760 millimeters and other experimental errors related to the meaaurement of temperature, the reported readings should

be accurate to with1n ~ 0 . 04°0 .

ME SUB ,~ NT OF REFR CTiVE INDEX

The re~active indices of the samples withdrawn trom the stills were measured using a Bausch and Lamb Pre cision Refractometer. The instrument is reported by the manuf cturer to hav an accuracy within ~ 0.00003 .

'l'emp~Patutte control fott the :ttetractom tel' was provided by the circulation or water maintained t a temperature of 20°C . by eircul t1ng water bath manufacturad by the

Precision e1ent1fto omp~J • Maximum fluctuation of th$ temperature of the bath was about o.o,3°C.

SUREMENT OF DENSI'l'I

The den 1t1es or the samples withdrawn from th& stills were measured using 25 m111111ter covered, weld-type pycnometer& . Temperature control was obtained through the uae ot a large water bath wbicb waa maintained at 20

~ o . o4°C . through the use of a Mere to Mere Thermoregu lator. Heat waa supplied to the bath by a 125 watt knife

heater. Cool water was circulated t~ough a small copper tube cooling coil to prevent overheating of the 22 bath. G1~culat1on of the water within the bath was provided by small immersion pump . A cha.1namat1c balance and a set ot weights which had been calibrated against themselves were used to obtain the weights of the pycnometors. It waa found possible to reproduce the weight of the loaded pycnometer& to within ±0. 001 gram when sufficient oare was xero1sed in obtaining thermal equilibrium and in wiping the pleoe.

The maximum expected d vi tion in the 4ena1ty mea~ementa is therefore ~ o. oooo4 srams per milliliter.

SAl PLE 'l'UBES

All samples were withdrawn from the st1lls into glaas sample bottles of approxtmately 50 milliliters. The a pl bottles were about l inoh in diameter and 6 1nches long. One ot the two stopcocks located at one end was tightly fitted into a piece of polyetb1lene tubing which wa connected to a sampling. stopcock on the atill during the aampling process.. 'l'he sample bottles were vaouated using an asp1r tor prior to sampling. Any vapor for.med due to the flashing of t~ liquid during eampling w a r&cove~ed in the sample bottle with the liquid and was condensed upon cooling thUs p~ov!ding a eample of the aama composition as the liquid within the atill. 23 CHEMICALS AND PURIFICATION

Three organic olvents we~e selected for use 1n this wo:rk. They were: enzene. ethylene dichloride and thyl acetate. The.ae three components were sel•oted because their mixtures could be easily analyzed bf either r•• tractive index or dens1t,r1 because they poss sa boiling points which ar only slightly different making possible a nearly exact the odynamio treatment of the data ool• leoted an because theJ repr sent three dissimilar mol oular structures. rther,. it was ex:pected that they would be reason bly easily purlf1ed and that the amount ot decomposition and interaction of the components during the collection of the ·qu1l1brium data would be small. Literary reference has been found for only one of the systems, that or benzene and et~y lene dichloride (6) . Therefore• this study should produce not only a oompar1· aon of the two stills 1tith existing data, but al o equilibrium d t on previously unreported aystems . Th& purification of th$ components was accomplished in the following manne~. Ethylene D1chlor1dea Th$ Purified" grade or eth7lene dichloride was obtained from the Amend Cnem1oal Company. It was dried over calcium chloride with occasional shaking for a period of about six weeke . The dried material wa then distilled 1n a 2 inch diameter column packed with broken glaaa tubing to a height of 2 feet 24 . ua1ng a high reflux ratio (approximately lO to l.) , 'lb.& flJ1st pol:"tton wae dilcavded until a eo.ns.tant) re:f'raet.ive index waa obtained. Thi• representated lO to 15 pel' cent of th& material. The last 10 per oent waa also

discarded. The ps-op$:¥-ti~es of' the purified ma.te~1al $Pfi pre$ented in '!'able 1. Eth:t:l Acetate: The etllJl acetate used was ptWohastd 1'ttom

the Fish&~ Chemical Company as their troertit'1edn grade•

It was dried ovex- anhydrous potassium c~bonate tor a period ot about six ~eeka with occasional shaking. It was d:tstille.d in the previously described packed column at. a . hl.gh reflux :ratio (about ·10 to l), The 1n1 tial 41st1llate was diaoaJ"ded until ·materiaJ. ot au1table. rett"aetive index was obtained. The initial d;!.sca:rd a ... mo'tUlted to about 10 pel' cent of the charge . The last 10 per cent wfla also d:iscardect. The propertieIJ or the pur1t'1e4 ethyl aaebate are shown in Table 1.. Ea.nzeQ!J 4n 1ni'tt1al attempt to puriff the Fiaher .

Chemical Compa:nr"• "C.~t. 1t1ed". thiophene--tree grado o£ t>enzene in the same manner as th41l ethylene dichloride and ethyl acetate was unsuoce&stul as both the retra.etive index and density of the product were tound .to be low. The material was r•d1at11le

Baker Companies we~e distilled in the Oldersbaw column and each wu found tQ be low 1n refractive 1n

A 99 per eent b~ene produced fro• coal tar waa obtained and tt-eated in t:be following manner . One g llon of the benzene was m1~$d with 500 milliliters of 10 pe~ \. Gent aod1WI1 hydroxide. The l)enzene w s decanted orr and

W$8 successively mixed with three 250 milliliter portione or.eoncentrated aulfurio acid. Each mixing period was approximately one hour. '!'his treated material was then distilled in thf, Oldershaw column at a 10 to 1 r flux r t!o. The propertiea of the product wore found to be eatieraeto17 and are presented in T.able 1 . , Anderson and Engelder (1. P•)l$) atud1 d the impuri• t1es in J.'4eagent grade benzene and were able to isolate e.nd identify cyclohexa.ne, methyloy-olopentane, 3-methyl• hexane or 3• etbylpentane or both, heptane or 2, 2,4-tri methyl pentane or both and toluene. They estimated the non~benzo1d 1mpur1tie$ to represent o . 6~v, the toluene o . oo~v and the unidentified materi la O . l~v . Thei~ d~ta is now about 10 year old and due to the recent ohangea

in the manufacture of benzene their ~esult may no longer be applicable to the reagent grade or benzene . However, they do indicate tome of the possible 1mpur1tiea and the 26 problema wbich may have been encounte~$d itt the initial attempt to p'llt'if:1 the re-.gent grade of benz$n& .. 27 EXPERIMENTAL PROCEDURE

OPERATION OF STILLS

Othmer Still .

Approximately 300 milliliters of liquid were ~harged to the body of the Othmer still and su£t1o1ent heat applied to produce about 100 milliliters of vapor per hour. This resulted in the complete recirculation ot the ~ondensate in the vapor trap about 2 times each hour~ Any air trapped within the atill waa vented about 30 minutes after the initial. charging. It ia believed that even if a small amount or air was 1n1tiall'f present it would soon be carried by the vapor to the condenser and released fram the still. After charging. the still waa allowed to re• main undisturbed (with the exception ot slight changes in the pressure control) to~ a pe~iod ot 12 hours although on a f'ew occasions it was round more convenient to sample attel' 10 hours . A check made to dete~ine the time re.:. qu1red to reach equilibrium based upon temperature measurements indicated steady state was reached after about five houra·.. 'One-halt to one full hour before sampling the pressure waa carefully adjusted to exactly 760 millimeters aa over a period ot time the pressure had a tendency to become greater or less than this amount by up to tour millimeters. During thi$ last period before sampling . everal checks wer" made of the temperature in ordet' to obtain the correct value.- '.t'his Yalue was generally :round to be reproduaeable to within ~ o.oa0 c. Just before the time of sampling two of the s.ample bottles were evacuated using an aspirator and connected to the $ampling stop• cocks. The liquid. •ample was eolleeted a$ long as tlle material readily ! 'lowed 1nto the sample bottle. This uaually amounted to about 35 ~llil1ters, ~e vapor sample was collected 1n the aame manner except that 1t was g$nerally found poe.aible to completely Q.rain the q.a m111111ters of liquid ·from the trap. The stopcocks on the sample bottles were closect and the bottles placed in the water bath to cool to about 20°0. before they were reopened and analy·zed.. In this manner t he flashing of the samples was minimized and it was eltJ)eoted that the ohange 1n sample oompoait1on between sampling and ana lyzing was negligible. At the beginning of" the next run, 75 to 80 millt

11ters ot a xn~ture of tbe dea1rod proportion were mix&d and dded to the 11qu1·d in the still. When the vapol!' trap had beco.tliS filled with oondensed vapor. about 2.$0 milliliters of liquid remained in the body of the still. The entire operational procedure was then repeated for e·aoh run. After 4 to 5 days ot operation the oont nta. wer• completely emptied fi'om the still and dis.ce.J-dedi! F;r.e6lh 29 mate:r14ls •ere added and the work continued. In this manner· an ex.oeseiv& build up· of :reaction plJaduots., it pr~sent, was avoided•

.Jon•• s.tj,;J.l. The opeJOation of th$ Jones still was alight:ty mot'e ·d1£t1cult than that Gf the Otbmer still. It was neces• sary to f ·ollow a stri.ot heat balance on ~he heating elements i.n order to obtain the eorreot operation ot the etill. It too little heat had bean supplied to· tht reeidue chamber, the flashed vapor would grac:luallJ be condensed and the operati·on would cease.. on the other• hand• too much heat at tbia point would l'e&.ult in the vapox-1~at1on of an excess of material and a. tlooding of the fl&4h boi~er . foo much heat to the flash boile~ would l'esult in a superheat1ns of th& vapo:r and a.n eventu.• al flooding of thia ohambex-. In accordance nth the literary desat-ipt.ion of the still (7. pp.666...669). ope:ration waa maintained au.ch that a •mall dl"op ot liquid remained at the end ot the tl.ash boiler.. Thi drop ~Jerved as an 1nd1oa.t.1on or little or no superheating;

Fo~tunately, it was found that once a ec~ect heat ba.lanoe had been obtained, the still eoul·d be operated ov$l'" a w1de vart,ance of eompoaittons wlth no ohange 1n heat input. Operation of tb.e Jones lt1ll 1taa aa. 4$acr1bed bel.ow. Current waa applied to the heating coila or the t"'esidue chambel- and the vapor line several hours betore 30 beg1l",l.tling the aotua,l ·operation of' the $t-1~1. In this manner' a large portion of the still and insulation w·aa

~ho# d. . The line t-o the manostca;1; wq disconnected trom the atill and. about .55 m1ll111tera ot a mixture of the desired ootnpoait1on were poured into the #ltUl through this Clpen!ng. The three-way etope.ock: was ad

justed to allow a ~eatPict4d !'low from the condensate ehambe'l' to the .fl-esh boiler~ The current wa$ then applied to the £lai!lh bo1lot- heater and another .20 m1ll1l!teJta or the mixture were s.lowly pou:red into the condensate chamber.

1£· the three.,..way stopcoek W'a$ prope~ly adjusted the mate'Pi..,, al within the still began tQ circulate l:rJ' the t .ime· the last two or thrae m1111l1te;rs we.re added. A final ad justment o:f .the stopcock •as then made to obtain the desired flow into the tl·aah bo1le~. Th.e line to the mano"'" stat was Peeonnected And the still lett in an undisturbed position (exc.ept fol' alight preasure adjustments) tor l2 hoUl'a. The boiling J:~ate generally resulted 1n a complete replaeament of the liquid i:n ·the condensate chamber about etgbt times an hour.. Oon.stant temperature, a sign of steady state, was obtained atte.P about three houPs of· ope.ration., Sampling was done in a manner similar to that fol" the Othmer atill.. In this ease all of the mate:r-1al was withdr·awn trom b~th the oondenaate and l'esidue

ohGmbers. ~1.ng the sampling period it waa found necea aar-y to close th.e three--way s'bopcoc'k to prevent a tnixing 31 ot the vapor and liquid samples . It was not neoeas~ to use the thl"ee•way stopoook to equilize the pressure when the evacuated sample bottles were used.

C LIBRATION OF THE OCOUPLES

The thermocouples were cal1brated ·under conditions as close as possible to their actual use . A water bath with good circulation as he ted to a temperature slightly below 80°0. A Beckman differential thermometer and a Bureau ot Standards calibrated thermometer were inserted into the water bath. The temperature was adjusted until cycling about a control point gave a reading on one of the major calibration l1nes ot the standard thermometer·. Temperatures or 79. 80• or 81°0. were used tor this purpose. The reading ot the Beckman thermometer was recorded. The cycling range was found to be ! o.o2°C. aroou.nd the control point, A!'ter the necessary stem and accuracy corrections had be n applied to the standard thermometer, the Beckman thermometer was considered to be cal1br ted. The two thermometers were removed trom the bath. The Beckman thermometer was reinserted with two thef$lllo wells which extended to the same depth a the thermometel"'a mercury reservoir. The thermowells were made of glaaa or the same diameter as the wells on the equilibrium at.ills. The tour junctions ot the thermocouples, spread outward .32 to make good eontaot with th.a wall• of the thermowells• were .inserted to the bottom or til$ wella:. The cold junetiona we:re placed directly into an ice and wate~ bath ot distilled w•ter. The thei'ltlooouples were calibrated toJt each one•half d.egee inte.rval ove:r the vange f:rom about 78 to $3 .$0 0. It •as •lao found neoesaar, to •pply a stem ooweot1on to tne Beekman "thermometer readings.

The literature values f~ the boiling points ot the pure omnponent·s being studied W$re considered as secondary stand.aztds and were found to agree w1 th the prepal'ed oalibration ourV'e~ The · oal1bration data foJJ the thelnllo eouples are presented in Table 2.

DETERMINATION OF CALIBRATION CURVES

The · oalibrration ot.Wves for each of the ayetems wal"e made in the tol1ow1ng manner. A preliminary calculation was made showing the relationship between the volume of .e,a.eh component and its mole traotion in a mixture.. A predetermined potttion of one component was run from a buret into a clean• weighed,, $0 m11lilitep• glaas• stoppered bottle. The weight ot the bottle and this 11qu1d was accurately determined using a chatnamatic balance. A suttio1ent amount of the second liquid was added to bring the total volume to .30 milliliters and th.fl weight ot the 'bottle ana its contents detex-m1n-.d,. ~he bottle was well shaken, taking care to avoid splashing the 33 materials onto the ground glaaa portion until the contenta wer well mixed. A 2$ milliliter portion w s used to determine the density. of the mixture and the remainder to obtain the refractive index. Wh$n measuring the re• fraotive index it was found best to adJust the temperature ot the bottle and its oont .nts to 20°0. in the water bath before inserting the sample into the refractometer. In this me.nne~ it was ,poasible to quickly obtain sharp dividing line and the possibility of any change in the composition of the sample during analysis was decreased. The calibration curves for the three binaJ7 systems are presented in Tables 3~ 4 and 5·

ACCURACY OF THE NALYSIS

All o£ the samples in each of the three systems were analyzed by both refractive index and density. In all oases it wa possible to measure the refractive index to within -!0.00003. Th!e t\egree or accuracy was round to be sufficient 1n the oaae of the ethyl acetate-ethylene di chloride system to provide an accuracy of analyaia ot

~ 0.0004 mole traction. In the case of benzene-ethylene dichloride the analysis by refractive ind x w a within

~ 0.0005 mole fraction and for the ethyl acetate-benzene system this method of analysis was withtn ~ o.oooa. '.t'brough the use of an lysis by denaity measurement it waa possible to obtain aeouraoy w1th1nt0.0005 mole .34 :traction toto the eth:yl acetate-ethylene dichloride eystem •. The analysis ot the et.hyl acetate-benzene .system by density meastirement was muah poorer and accurate to with• in only t 0.003 mole traction. It 1 believed, therefore. that th%"ough a con6Jider•

ation o:f both the anaJ:ys1a by rttfraet1ve index and dens!ty ths.t the results tor each .system lhould be accurate t«>

!.0,.000$ mole r~act1on. 35 THEBMODYN IO A ALY IS OF THE DATA

The activity coefficients tor each of the binary systems were calculated £~om the experimental data through the use of Equation 3 a suming the fugacity of the vapor waa equal to the total pressure.

~ 1 · : (3) ¥1xl The vapor pressures of the pure components were calculated from the following formulas. 0 Benzene, (3): loglO P • 6.89745 .... 1206.3~ • t .... 220. Ethylene 4$ohloride, (3)2 0 loglO P =7.18431 • . 13~8~ (1.5) t ~ ~ . .

Ethyl acetate, <4, p.22l): J\ loglO P0 c 7.30692 - 13$9,48 • (16) t +- 230 The ratio of the activity coeffi.c1ents were calou• lated and their logarithms plotted againat the liquid campositiona. The net area under eaoh curve was determined aa an indication of th thermodynamic oon aistenoy or inconaiatenoy of the data. Redlich has auggested that in analyzing the data the equation for the curve log ~~: t{x) should be written in a atandard series form with as tew constants aa poaaible. ith such an expression it is possible to store a large amount of information for thermodynamic use in the future. The: following series (J.4, p._50) has been suggested for use.. 36 log ~~ = B( -xl + xa) +- 0(·1 + 6x1x2) + D(xl • x2) ( ..1+8x1x2) (17) Using the same oonatants which appear 1n Equation 17 as determined from the experimental dat , two more important equations may be written- 2 log"i 1 : x ~ + O(Jx -xa) + D(x1-x2)(Sx1•z2)J 2 1 (18)

However, not only do s th& u e or a standard aeries such as thi provide a convenient method of storing data, it also offer$ the advantage ot being able to classify the binary systems into types. The simplest case (Type 1) is the perfect solution for which log i1 • 0 for all values of ~ • '12 . 1 Type 2 1a characterized by B ; 0; C : D • o. This equation is represented by a straight line passing through a value ot 0 at x1 : o.s. Type 2 clo ely approximates systems whose components are not associated, interact only moderately and have approximately equal molal volumes.

Type 3 is eharaoterized by B 1 0, C I 0 1 and D : 0. Binary systems which tail to tall into Type 2 due to unequal molal volumes are otten found in this claaa. The D term 1n the aeries expression is apparently charac teristic of the association of one or the components. However. highly aasoo1at1ng substances often 1nterassoeiate 37 the effect of which ia to diminish the influence of the D term. As a result, highly associating substances are often found in this class. Type 4 is characterized by B j o, D ~ 0, C =0. Th1e curve has an "S" shape and passes through 0 at x1 • 0.,5. Type 5 is characterized by B -1 o, C ;. 0, and D 1 o. Types 4 and 5 are repreaented by systems which will aasociate, but not with each other. The exiatance of the D term can be determined only from data of high accuracy. If the data is not or aufficient accuracy a curve of Type 3 which servea as an approximation will be obtained. The three binarr SJatems being studied were analyzed in this manner to determine the type classifications and to obtain the constants for use in the serlea expreas.ion.

Equations 141 15~ and 16 were also used 1n the calculation of the "slope linea". In thia case it was necessary to differentiate the equations with respect to temperature to obtain the terms for d log P0 /dt. No attempt waa Rade to correct the 1noonaiatenc1es in the slopes determined which were due to the systematic errors in part of the data collected. .38 EVALUATION OF EXPERIMENTAL DATA

ETHYL ACETAT ;ETHYLENE DICHLORIDE

Tbe experimental data obtained r~om the two ·atills are contained in Tables 6 and 7. The calcu.1ated slop.es ot the .dew point ourve. the aet1v1tr eoeffioients and the .ratios of the aet1v1ty ooeft'1eients are contained 1n Tables 8 and 9. Figure 4 shows the x-y data obtained t'rom the two stills. Thta f1gu:re not only graphically illutrbr-ates the data obtained trom each of the stills, but also permits a rap.id eo.mpa.rison or the l\"&sults ·of the two.. Unfortu nately tho g:ra.ph 1 ·too amall to provide a sat1sfG.ctory realization of the magnitude of d1ffe:renoes involved. It is observed,. however, that the data obtained from the Othmer still tall to the outside of those from the Jonee still. It ts ob\r1ous that at lea·st one of' the sets ot data mu•t be 1noorreo1h Aleo indicated on this graph are data obtained tor this system with a larg$r amount of

liquid 1n the attll ,. It is noted that no s. igntfi~ant trend ie seen in this data d1t.fettent from. the Naults obtained. using a amallel' amount of l1«att14• The two s.ets or data were analyzed by the method ot

Redlich by plotting the loga~ithms of' the ratios ot the aotiv1ty .coeffic1ent against the composition of the liquid., The data :tor the Othm&l" still are plotted in 39

0.9 r--+---+--+--+----+-----+----+--+ cr 0 ~ 0.8 t----t----+--+----+---+--+----+ > z - 0.7 t---+---+--+--+---+---+ w ~ ~ ~ 0.6 r---r------t---+--+--+ <{

_J ~ 0.5t----t----+--+---+ w~ 0 0.4 5 c? 0.3 1----4----+- l..a... VAPOR- LIQUID EQUILIBRIUM w ~ 0.2 FOR ETHYL ACETATE- ETHYLENE Dla-iLORIDE • JONES STILL DATA o OTHMER STILL DATA Q OTHMER STILL DATA, EXCESS LIQUID

0.1 0 .2 0.3 MOLE IN LIQUID FIGURE 4 40 Figure S and those of the Jones still in Figure 6. It is readily noted that the data from the Otbmer still fail to meet the Redlich uarea" eriteria. The data from the Jones still were found to tulfill these requirements. Figures 7 and 8 show the dew and bubble point curves tor the· Othmer and Jones stills respectively. Short straight lines hav• been drawn through each of the points on the vapor composition versus temperature curves. These lines have the slope predicted for the tangent to the curve at their respective locations by the use or Equation 13.. It is seen that the sloping linea drawn on the plot of the data from the Othmer still do not fall tangent to the curve drawn through the data, but rather that they are too steep. This was to have been expected as it is an indication that the ratio r/x was too high which was deduced .from the "area" test. The slope lines drawn through the data rrom the Jones still are seen to .fall tangent to the dew point curve over the whole range. Since both or the criteria sug• gested by Redlich are fUlfilled it may be concluded that this data 1a thermodynamically consistent. Several points on the dew and bubble point curves from each of the stills are seen to be low in temperature in both sets of data. The temperature measurements for several pairs or these points were made at the same ttme and it ia believed that they represent errors in 1.6 I I I 0 lA I I 0 I • i I ·- 1.2 - ! I I LOG-J!- VS MOLE FRACTION I I 1.0 I I ETHYL ACETATE- ETHYLENE DICHLORIDE . I 0.8 - 0 I OTHMER STILL DATA 0 I 0 .6 I I ~0.4 0

(.!) 9 0.2 t9n. ' 0 0 -0.2 -0.4 -0.6 oo -0.8 - 1.0 0 OJ 0 .2 0 .3 0.4 0 .5 0.6 0.7 0 .8 0.9 MOLE FRACTION ETHYL ACETATE IN LIQUID FIGURE 5 • 1.6 L4

1.2 ~ LOGL VS MOLE FRACTION 1.0 ~. ETHYL ACETATE ETHYLENE DICHLORIDE o _ OB ~ ' JONES STILL DATA 0.6

,oj,o'0.4

(.!) g 02 0 0 -0.2

-0.4 ~ -0.6 Q)l"\ -o.a I----w - 1.0 0 0.1 02 Q3 04 05 06 07 OB 0 .9 MOLE FRACTION ETHYL ACETATE IN LIQUID FIGURE 6 d 81 ~----~---4----~-----+-----T----- 0 w 0::: :::> ~ 80 0::: LLI TEMPERATURE VS MOLE FRACTION Q. :E ETHYL ACETATE- ETHYLENE DICHLORIDE ~ 79 OTHMER STILL DATA

0 VAPOR 78 e LIQUID

770~--~----~----~--~~--~~--~~--~--~~--~~---- 0.1 0.3 0.7 0.8 0.9 MOLE FRACTION ETHYL ACETATE FIGURE 7 TEMPERATURE VS MOLE FRACTION ETHYL ACETATE.- ETHYLENE DICHLORIDE JONES STILL DATA

0 VAPOR e UQUIO

MOLE FRACTK)N ETHYL ACETATE FIGURE 8 t$mperature measurement. the error probably resulting from insufficient ice in the bath for th& cold junction ot the thermocouple. These points have been indicated as b -ing low in Tables 4 and 5. The dew and bubbl point curves trom the two systems have been compared on carefully drawn plots. It has been found that the dew point curves for the two systems eaaentially coincide when compared at the same temperature. However, the bubble point curves were found to be slightly different. At identical temperature and vapor compo aitiona the composit1o~of the liquid predicted by the Ot:t:uner still are found to be O.OOS to 0.009 mole fraction lower than the d.at from the Jones still over the ttange from o.~ to 0.9 mole traction. Below 0.4 mole fraction the curves become sufficiently flat that it is impo sible to derive &QY quantitative relationship from the data. The constants tor the expression relating the loga• rithms of the ratio of the activity coefficients to the liquid composition were oalcul.ated only foX' the data from the Jones still as the data from the Othmer still were not considered to be as thermodynamicall7 consistent. It was tQl.Uld that three constants were neoeasa17 to deacr1be these data, using Equation 17. For this aystem, the following equation may be used& log ~ =-0.102(-xl+ xz)-0.015(-1 -+ 6xlx2) +O.Ol3Cx1-x2 H·l +- 8xlxz} • '.

The subscripts 1 and 2 refer to ethyl acetate an4 46 $thylene dichloride respeoti'tely. The thl'e finite coef• t1e1ents are oharaote~istio o:f the Type 5 solution which inoludes components whieh w1ll aasoeiate., but not \T1 th each other-.

ETHYL AOETATE-BENZENE

'rhe eJtperimental data obtained fr-om th• two at1ll.s for this system are pre&ented in Tables 10 and 11. The o1!1.loulateCl slopes ot the dew point curves, the activity coefficients and theit- ratios are contained 1n fablers 12 and 1)" Fro:m the x•y ·data shown 1n Figure 9 it 1s seen that the data from . the Otbmer still fall to the outside of those .f'rom the Jones atil.l~ The difference between the two curves is ~411, but definitely exists. In order to find 'Which. if either of the two seta, o.f data was. therm.odynam..teally consistent, the data wer& analyzed. by th(t "area" method or Redlich. ~ graphs of the data analyzed in thia mannel' are prt)sented in FigUres 10 and 11. In each oa.se the ·data may be t-epreeented bf a straight line. Only th$ data from the Jones still are seen to fulfill the req;v.i~e.tnents of the "~ea" test. Th& data fl'om the Othme" still are seen to enclose an area •hich is pos1t1ve !ndioat1ng that the ratios ot the eompo" a1tion ·of the vapo;rt to that of the l1qu1.d are too large. 47

1 09

~ 0 .8 > z -0.7 w ~ ~ ~ 0.6

gQ.5 ...... w z 0.4 0 b ~ 0.3 ~- LL w VAPOR- LIQUID EQUILIBRIUM d 0.2 FOR ~ ETHYL ACETATE - BENZENE 0 .1 1--- • JONES STILL DATA 0 OTHMER STILL DATA

I I I I I 0 0 Ql 0 .2 0.3 0.4 0.5 0.6 07 0.8 0 .9 MOLE FRACTION ETHYL ACETATE IN UQLI) FIGURE 9 o.os

006 LOG 0 .L. VS MOLE FRACTION ~>' ~.. ETHYL ACETATE - BENZENE 0.04 0 0 o- OTHMER STILL DATA _, ... 0 )O)a ~ 0.02

0 0 0 0

0 -0.02 0 0 0

0 -0.04

0 0.1 0.2 0.3 0 .4 0.5 0.6 0.7 0.8 0.9 MOLE FRACTION ETHYL ACETATE IN LIQUID FIGURE 10 008

0.06 LOG fa VS MOLE FRACTION ~ ETHYL ACETATE- BENZENE 0.04 0 0 JONES STILL DATA ~ 0.02 0

0 0 n 0 "' 0

-0.02 0 so

-0.04 0

0 0.1 0.2 0 .3 0.4 0.5 0.6 0.7 0.8 0.9 MOLE . FRACTION ETHYL ACETATE IN UQUID FIGURE II 50 Figures 12 and 13 show the dew and bubble point curves for the Otbmer and Jones s,tills respect!vely. The calculated slopes of the dew point curve have been drawn through the points of experimental data. As was to be expected from the results of the area test, the slop$ lines drawn for the data from the Othmer still are not tangent to the curve representing the data, but are slightly to~ steep . The slopes calculated for the data from the Jones still are seen to fall tangent to the dew point curve , Since the data from the Jones still fulfill the requirements of both the "eea" and "slope" tests it may be concluded that they are thermodynamically consistent. A comparison of the dew and bubble point curves from the two stills was made in an attempt to evaluate the data from the Othmer still. It was found that the curves from both stills essentially coincided and no clue was found to indicate whether the liquid or the vapor measure ment was 1n error. This was not altogether unexpected as the differences between the compositions of the liquid and vapor were small. Because these differenoe are small, a slight error in the data reaulta in a considerable error in the calculated ratios of the activity ooeft1cienta and yet remains undetected in a comparison of the dew and bubble point curves . The conatants for the equation relating the 81

80 TEMPERATURE VS MOLE FRACTION ETHYL ACETATE- BENZENE d OTHMER STILL DATA 0 .. 79 0 VAPOR LLJ ~... a: • -. LIQUID :::> • ~ a: ~ ~ 78 ·~ ~ ~ ' LLJ ~ ...... - 77 --

76 0 0.1 0.2 0.3 0 .4 0.5 06 0 .7 0.8 0.9. MOLE FRACTION ETHYL ACETATE FIGURE 12 • 81

80 TEMPERATURE VS MOLE FRACTION ETHYL ACETATE- BENZENE JONES STILL DATA

0 VAPOR • LIQUID ~ I -~ ~ _.... U'-.

- ~ ..... ~ ~ 77 ~

76 0 0 .1 0 .2 0.3 0 .4 0.5 0.6 07 0.8 0 .9 MOLE FRACTION ETHYL ACETATE FIGURE 13 $3 loga.rithiiUJ ot the :r t1oa of the ct1v1ty coef'i'icients and the compo 1t1on of the liquid ere calculated only for

the data from t Jones still as these data ere con ider . ed to e more aonsietent than those from the Othmer still. Only one constant was necessary to represent this da.t using quation 17 . The data tor tnis system may be expressed as: log l 1 • 0. 037 (•xl+x2) • ~ 2 The subscripts 1 and 2 refer to the ethyl ao t te and benzene respectively. The single finite coefficient is charact riatic of those solutions whose components are

not associ ted- interact only mode~ately and have approxi mately equal molal volumes .

B ZENE· ETHYLENE DICHLORIDE

The e.xper1m•ntal data obtained fro the two stills for this system are preetented in ablea 14 end 15. The

calculated slopes or the dew point curves, th~ activity coefficients and their ratios are cont ined in Tabl s

Included with the x-y data from the two stills in 1gu.re lh ts the data for this system obtain d by Horni. Canjar, and Rothtus (6) using a slightly different model Otbmer still. Very little difference is se n in the three sets or data. The curve drawn through the OthmeJ at1ll data is seen to tall very slightly outside of that 54

I 0.9 a:: 0.8 ~ :::> 0.7 z

IJJ z 0.6 IJJ Nz IJJ m 0.5 z I 0 ~ 0.4 a:: IJ.. IJJ 03 _J 0 VAPOR- LIQUID EQUIUBRIUM ~ 0.2 FOR BENZENE- ETHYLENE DICHLORI~ 0 .1 • JONES STILL DATA 0 OTHMER STILL DATA g CANJAR, HORNI, ROTHFUS [7 I I I I I 0 0 0.1 0 .2 0.3 0.4 0.5 0.6 0.7 0.8 0 .9 MOLE FRACTION BENZENE IN LIQUID FIGURE 14 55 from the Jones still, The data of Horni, et al are seen to fall between the two curves for the low benzene reg1on and to ne~ly follow tho Othmer still dat for the re m inder of the curve. The · two sets of experimental data were analyzed by the "areau method or Redlich to determine their thermo dynamic consistency or inconsistency, The graphs obtained are presented 1n Figures 15 and 16. The data obtained may be represented in each qa~e by curved lines which are s1mil~ in shape but which are displaced on the vertical axis, Only the Jones still data are seen to nearly fulfill the criteria of this me tho~ of testing, It. appears that the data from the Jones still intercept an are which is slightly negative. Beoause of the small di!'ferenoe exist ing between the compositions or the liquid and the v par. a large change in the ratio of the activity coefficients results from a very $mall change in one of the measure• menta or compos!tion. A 8111&11 change in the data1 much les than the acauracy or the analysis, would be suf ficient to correct the alight !noon istenoy indicated. The data from the Otbmer still definitely enolo .e an area which ia positive indicating that the rati~of the composition of the vapor to that of the 11qu1d are too large. A very 1ntereat1ng shape is obtained for the curve representing the logarithms ot the ratios of the activity 0.04 I ' I I I ' 0.03 ,__0 LOG .:1.!.. ll, VS MOLE FRACTION 00 BENZENE- ETHYLENE DICHLORIDE 0 .02 I OTHMER STILL DATA 10 I I I )Q~ 0.01 0 l 00 J-~----f------/ C) I g 0 0 I 0 ~ - 0 .., ~ ----- 0 -0.01

-0.02

0 0.1 02 0.3 0.4 0.5 0.6 0.7 0.8 0.9 MOLE FRACTION BENZENE IN LIQUID FIGURE 15 0.04

- -- 0.03 0 LOG.!!. VS MOLE FRACTION ~~ BENZENE- ETHYLENE DICHLORIDE 0.02 - JONES STILL DATA

0 0 ,.,,: 0 0.01

(!) g 0 0 0

0 0 - 0.01 ~ u ~ u ~

- 0.02 - - r--

0 0. I 02 o:3 04 o.5 os o.7 o.a 0.9 MOLE FRACTION BENZENE IN LIQUID FIGURE 16 68 coetficients ae a function of the liquid. composition. The peculiar upward turn or the curve in the high benzene region seems strange. Fo~ seve~al reasons, however, this curve seems correct. The experience on the other systems studied has shown the data from the Jones still to be thermodynamically consistent, Unless the curve does turn upward as found. the data would definitely be indicated thermodynamically inconsistent. This 1n 1tsel.f is not a proof that the curve should follow this path as it is one of the things being sought in the results of this study. However, the results obtained from both stills show this same trend. The possibility ot contaminants 1n the solutions and their possible •f'fects upon the anal'yaia were considered, Toluene and water are the most probable contaminants in this benzene, The presence of either ot these substances would not have turned the curve upwa~d. but downward due to their effect upon the methods or the analysis. Considering this fact and that the use or this benzene in the previou system studied resulted in no inconsistency it would seem that these possible contami• nates present no proplem. A careful study of' the dew point curves in Figures 17 and 18 indicates that in the region of veey high benzene concentrations an unusual curvature 1s found . This curvature, although slight, is consistent with the result which would be predicted by the slopes calculated 84

TEMPERATURE VS MOLE FRACTION

83 BENZENE- ETHYLE NE DICHLORIDE OTH MER STILL DATA

(.) 0 VAPOR 0 ~ 8 2 e L I QUID w a: ~ 1

SOI----~~--~-----4-----+-----+-----+-----+-----+-----+----~

79----~~--~----~----~----~----~----~----~----~------o O. I 0.2 03 0.4 0.5 0.6 0 .7 0.8 0 .9 MOLE FRACTION BENZENE FIGURE 17 •

84 ~--~-----r- ---~----r-----+---~-----+----~----~-----,

TEMPERATURE VS MOLE FRACTION

BENZENE- ETHYLENE DICHLORIDE JONES STILL Ot\TA o I 0 VAPOR ~ 82 t------r----1 e LIQUID a:: :::> t <(a:: ~ 81 ~ w t

0 0 . 1 0.2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0.9 MOLE FRACTION BENZENE FIGURE 18 61 fltom the experimental data and by the boiling point data

obtained for pure benzem;~ . 'l'htt summation of all of this information seems to indicate that the clll"'ve obtained

for the logarit hms ot the ratios of the activity coet~ f'1c1ents ver us the liquid OOltlPOSition is possible and probable in the light of' the analysis ot the experimental data. A curve of similar shape was obtained tor the

system of chlorofo~ and ethyl alcohol by Scatohard and

Raymond and discussed b7 Carlson and Oolburn (3 1 p.$83) . The dew and bubble point cuttves for this ystem are· presented in Figure.s 17 and 18. The oaloulated slopes of

the dew point ou~ve have been drawn through the polnts of the experimental data. The elope lines drawn through the d ta tor the tbmer still are almost tangent to th cu~ve. but are slightly too steep. The slope lines fall tangent to the curve drawn through the data from the Jones still. A comparison of the dew and bubble point om-ves from the two systems yield$ no turthe&- lnfol'mation as to whioh measwement in the Otbmelt still data 1$ in error. The constants tor the equation relating the loga• ritbm or tho ratios of the activity ooe!f1a1ente and the oompo~ition of the l1qu1d. were calculated only tor the data from the Jones etill as they were considered to be more consistent than the measurements obtained from the OtbmeJ:t still. Three constants are necessary to :represent the data uaing Equation 17 . 'The data tor thia system mq 62 be expressed s: log t~ :: 0.013l(-Xl~ X2} - 0 . 0152 (• l + 6x1~) +0.0022(x1 - x2 )(-1 +- 8a1x2 ) • The subscripts 1 and 2 refer to the benzene and ethylene dichloride respectively. The three finite coefficients

are characteristic of the Type , solution ~ bieh th~ components associate, but not with each other. Horn!. et ,.!! reported that their data tor this system could he represented by a straight line hich would reqUire only one coefficient 1n the above expression. The value for the coefficient was not given. They reported that the 11 area" test indicated that their data were thermodynamically consistent . To obtain a comparison of the thermodynamic analysis of these data and those produced by this study, the data of Horn! were r calculated and the logarithms or the ratios of the ac.t1v1ty coefficients wer plotted against the liquid composition. As reported by Horni, th data could be represented by a straight lin through the se ttered points. However, the d t appeared to be better ·

f"itted by a curve of the approximate shape found in this study. ith either type or curve the net area as

approximate~y zero, indicating the oona1steney or the data. DISCUSSION OF EXPERIMENTAL RESULTS

The oompal'ison ot the data plotted as the logarithm of the ratios of the ac'b1v1ty eoeff'ioients versu the liquid composition in Figures 5 and 6, 10 and 11, and 15 and 16 has already indicated that the data obtained t~om the Jones still were more thermodynamically con sistent than those :from the Othmer still. In order to find a method of eliminating these exper1• mental erro~ in the data from the Otbmer still it is neoeaaary to ftnd their source. It has already been indicated that in the dat rrom this still the ratios of the composition ot the vapor to th t of the liquid are too large. Ther are aeve~al possible areas which may act as the source of the e 1nconsiateno1es. In a discussion ot this type an aaauranoe of steady state eonciit1ons is a neoesa&.X7 starting point. It has already been stated that although steady state conditions as indicated by constant te.mpex-ature measurements were apparently attained within $ hours, the length or. each run was approximately 12 hours. Hence- steady state was believed to, have been attained. How vex-, if a vapor is oollected which is not in equ1l1b~1um with the liquid due tQ inherent diffioulties tn the equipment or in the method of operation. no amount of r~oiroulation will produce equilibrium oond1t1ona even though steady state !a, rEJached. An 1n1tial asaurnpt1on made 1n the use of a still of 64 th Othmer type is that the vapor formed from a boiling liquid is 1n equilibrium with the liquid. As yet, this has neither been totally proved or disproved. Robinson and Gilliland (15. p . 9) have stated that while theoretical considerations would indicate that a vapor in equilibrium with the liquid should not b obtained from a boiling solution, the few exper,imental data which have been obtained indicate that the difference in composition of the v por obtained in this manner and the true equi librium 1 not great in moat c sea . The vapor after leaving the surface of the liquid must pass into the body o~ the still. If a large amount of heat is lost from the wall of this seotion condensation 111 occur on these surfaces and the contacting ot the rising vapors with this condensed liquid will result in enrichment of the vapors. The walls of the still may be insulated and some compensating heat applied as done in this work . Othmer (10, p. 765) states that for tempera~ tures below 100°0. insulation alone is probably sufficient.

There is danger in the p~aotice of providing compensating heat for if the walls ar-e above the temperature of the liquid within the still the vapors will be superheated which results in incorrect temperature measurements and &n1 vapor splashing onto the overheated walls will be totally vaporized and a higher concentration of the leas volatile oompon nt 1n the vapor will result. This same 65 result may also be obtained if a sufficiently high vapo_. velocity i .e ·employed to \lntl*ain small dl'opl~ts of liquid and carry them to the vapor rese.rvo1r. After the liquid leaves the body of the still, it passes lnto an area in which condensation occurs. This condensation takes plae.e in the section lmmediately above the still body, 1n the arm between the still body and the vapor trap and in a conden.,er directly above the trap in which the condensation or the vapo~ is completed (see Figure 1). At each of these, sttes a partial condensation oco.urs and the liquid fox-m.ed from each ~ns to the con• dens.ed vapor trap. The possibility of th$ anPichmont oi' the condensed vapor as 1t contacts the vapor in thes.e areas should not be overlooked although it would seem that a.s steady state iffJ ·reaohed the effect of this enrichment should become negligible. The vapor after bt)ing condensed and held in the vapor trap for a pe~iod of time 1s returned to the body of liquid in the still. When the condensed vapor returns : to the still several actions ma,- take. place. Being of a composition he>.ving a boiling point . lower than the tempera ttl.re ot the liquid 1n the still 1t may .flash vapo·rize as. suggested by Jones, Schoenborn and Colburn (7, p.666). lf 1t does not vaporize ilnmed1ately, mixing with the liquid present to ,form a hete:rogeneous or homogeneous solution will take place depending upon the degre• ot 66 ' mixing. The vapozt which is then formed will have a eompo ait1on whieh is related to the liquid composition.'" If the liquid 1s uniformly mixed and boiling produces an equi l _1brium vapcw as, &aewned, tht relationship between the liquid and vapor oompo&ttio.ns is simply written as in

Equation 3. Howeve~. it the liquid is not uniformly mixed, the composition ot the vapOJ' to-rtned w1ll b$ X'&l&bed to the liquid oonoentration b7 an intricate au.mmation of the equilibrium oompoa1t1ons of eaoh ot the small volumes of liquid making up the total volume. The pr oblem -ot aampling the l1q;u.1<1 in a heterogeneous solution is great. Xt 1o small aample 1s taken- it will probably be taken at onQ looation and will have only the eomposit:ton of the liquid 1n that attea. A total l1q~1d eample may be taken. but even so no guarantee is p~ovided that an average or th~ compositions ot the l1qu1d 1n the still will be tl.le sqe &~a the avet*age Qf the aolli>os1tions, £'J9om wfiioh the v-apor- is foJJmed .

In thia p~tioulfU' atudJ only a small sample ot liquid •as withdrawn from the still at a location directly oppo .... site the connection tor th~ :'r'eturn line tor condensed vapor. While the removal of a total liqu14 sample tnay seem desireable it would h.ave been dif:fioult to do in the particular still used due ~o the large '9'olume of liqu.id hold up below the sampling stopcock. The removal ot this liquid WQuld have reaulted in considerable flaehing and the reoove:ry or a liquid of slightly different compo s1t1on. In test to de,termin$ the pre enoo of a concen• tr tion gradient, samples were tmultaneously withdrawn from the sampl stopcock and from a probe pl oed directly in the middle ot the still. A a11ght deere se (0. 0005 mole traction) in the concentration or the more volatile component wa.s observed :!'rom the center to the sampling stopcock. While the concentration ~ d1ent indicated by this crude test was small it was sufficient to how that the liquid in the till was not uniform.J.y mixed.

The possible ourc a ot error and their effect~ may now be discussed with rasp et to the re ults obt ined from this still. The thermodynamic analysis or the data haa indicated in e eh oase that the ratios of the v por to the liquid oompositiona ar too large. From this 1t may 1mmed1 tely be concluded that the possible sources of error which would result in an opposite ffect do not haV$ a controlling influ nee upon the quality of tb4 data obt ined. Thus, the effeot$ of entrainment and total vapor1z tion of any liquid droplets $pl shed onto the w lls of the still are not problem 1n the operation of this still.

For the purpose$ of oompariso~ the data obtained trom the Jones still wbieh ere found to b thermo• 4ynam1c lly consistent ar , assumed to be correet. The comparison of the dew nd bubble point ourves from the 68 two at1ll.s has indicated that the compositions or the vapor samples from the Otbmer still are correct when compared with the Jones still data using temperature as the basis of comparison and that the liquid compositions are too low when compared . in this manner . Therefore, the heat loss from the still with the l'eaulting condensation and refluxing of the vapors must have been negligible. These actions would have resulted in the enrichment of the vapol' and caused the vapor composition to be high when compared in this manner . It does not seem that the returning condensed vapors should flash immediately upon their return to the still if good mixing of the still contents takes pl ce .. ·These condensed vapors are returned to the still body at room temperature which is 50 to 6o0 c. below the temperature of the liquid within the still. Othm r (10, pp . 764~765) bas suggested the inclusion of a water cooling condenser to further oool the returned condensate and allow ore ttm. for mixing. However', 11.' good mixing is present thl8 modification should not represent a great advantage in the results obtained. / Several authors (5, p.576) 7, p.666) 15, p.ll) have discussed thb mixing problem associated with this type or apparatus. Langdon and Keyes (8, p.939) stated that in their particular typ& ot apparatus stirring of the liquid was a neceasity as the therm~l agitation was insufficient. 69 No modification ot the Otbmer still used in this stud7 was attempted 1n an effort to cause better mixing and hence more consistent results. Two changes in the method of operation of this equipment were considered, One was to operate with more liquid 1n the still body to p~ov1de a greater depth of liquid between the return line tor the condensed vapor and the liquid sur.race.. Aa previ ously mentioned and shown 1n F1gux>e 4., the rgaults obtained with this operation ehow no charaoter1at1c trend different than that obtained throughout the remainder of the study using a smaller volume ot liquid. A second change was to increase the heat input to the still which resulted in an increased boiling rate and possibility better agitation. It was observed that this

~thod of operation resulted 1n a heating ot the entire still by conduction through the glass $nd a slight super heating ot the vapor. No trend in the data which 1nd1• oated more consistent results was obtained wben using the increased boiling rate. Thus it aeema that the Otbmer still as constructed in 1t$ present rol'm 1s not capable of providing theJ:lmodyn.amicaJ.ly consistent results. The operation of the Jones still is not without cr1tic1am. Many investigators attempting to use this still have found it difficult to operate. Others hav• found dlfflaulty with entrainment (10, p. 763) . Gillespie ($, p.576) has questioned the results obtained from this 70 till Q.u to the retuttri ot the vapor 1n a somewhat super• heatod condition. In reference to this tJPe of an equi librium still, Rob1nll¢n and Gilliland (15, p.l3) have stated that this type or apparatus is believed to be a definite improvement over the regular continuous d1at1l• lation system of which the Othmer st1ll is a m&mber. In the present stuCly the Jones still was not found to be partioularly dittieult to operate. This may have been due in part to the mcd1t1cat1ons made to Jones' original design. Neither modification was great, just sufficient to make 'the control less sensitive to the conditions of the surroundings, Entrainment while very definitely a poss1b1l1ty due to the :relatively small surta.ce on whioh the flash boiling occurs and the high vapor velocitt tlwough the l1qllid in the r'es;tdue ohambez. watJ not eons1dered to be a major problem. No test was· made to determine the amount of entrainment w1th th1a st111, but considering the the:rmodynamic oonsistenor ot the data, the entrainment if present must have had a negligible ttesult on the e:y-Gtems studied. It is dift1oult .to dr.a.w a quant1tativ$. oonelus·ion 1W'1 th J-egfiiid to the amount ot superheating of the vapo:r.

Qerta1nly it could not havE;~ be~n greatly $Uperheated fo~ if this Wel'e 'true an excess of material. would have been vaporized from the· res1du~ ehamber wit1;l. the eventual tloodlng of the tlash boiler. Another ind1eat1on of a 71 negligible supa.Pheating of the vapor is that the tempera

tUll$ obt.ained in th& Jones still was the santE!) as that obtained from the Othmer still for 1dent1oal. vapo:r compo•

sitiona~ ~ rtnal check on the ove~all ~perat1on of

the· Jones still ia ah~ by the thermodynamic consistency or the data. 72

SUMMARY

A comparison ot the results obtained in the use of the Jones ana Othmer types of vapor-liquid equilibrium stills,wbile making equilibrium measurements on three

· binary system~ has indicated that the data obtained were

in sli~t disagreement. The data obtained from each still were analyzed by two tests in an attempt to determine whether either set of data was thermodynamically con sistent. In all cases the data from the Otbmer still were found to be less consistent than those from the Jones still. ln each ease the thermodyn ic tests applied to the Oth.-ner still data indicated that the ratios of the vapor to liquid compos!tiona were too large. study was made of the possible causes of this systematic inconsistency. The data from the two stills were com pared assuming those from the Jones still to be correct. It was concluded from this study that the primary error was related to poor mixing of the liquid within the still which resulted in the formation of a heterogenous so lution. No change in the construction of the still was attempted in an effort to overcome this difficulty. Two changes in the ·operational procedure were considered and found to have little or no influence on the character of the data collected. The data obtained using the Jones still were 73 analyzed by the thermodynamic tests and were found to be essentially

Data were collected on the three binary ~stems: ethyl acetate-ethylene dichloride, ethyl acetate-benzene and benzene-ethylene dichloride. The data from the Jones still which were considered to be the mGre consistent ere e.xlpressed in the form of a series equation. The general form of t he equation is;

log 'l1 : B(-x +x ) + C(•l + 6i x ) -t- D(x -x ) (-l ...- 8x x ). ~ 2 1 2 1 2 1 2. 1 2 This equation was found to fit the data ror the various I I systems when the £ollowing oonstrots were. used: ethyl ·aeetate-ethylene dichloride, B :Lo.l02, c =-0.015, D : 0.013; ethyl acetate-benzene, B : 0.037, C: D =0; benzene-ethylene. diohloride, B: 0.0131, C =-0.0152, D : 0.0022. 74 NOMENCLATURE

A,B,C,D ~ constants

t~ =fugacity of pure vapor at pressure, ~ 0 P : vapor pressur~ o£ pure component Q : excess free energy function t =temperature x =mole traction 1n liquid 1 : mole fraction 1n vapor

~ =relative volatility ~ =activity aoefficient q : total pressure

Subscripts 1 =more volatile component 2 : less volatile component 75 BIBLIOGRAPHY

1. Anderson, J., R. and c. J, Engelder ~ Impurities in benzene.. In Organic solvents; physical pr"Oper·tles and methods of pur11'1cat1on.. 2d ed.. New York, Interscienee, 1955. p .• 315. 2. Garlson, HaM-ison c.. and Allan P.. Colburn. Vapor liquid equ1libr1a of nonidea.l .sol.utions-.. Industrial engineering chemistry 34:58~-589, 1942. 3. Dre.isbaah, Robert R., Physical properties of chemical su'bat~cEu1. Midland,. Dow llh.emi.cal* 19$3, 4. Dreisbach, flober't R. Pr-essure-volume-temperature relationships of organic compounds . 3d ed,. Sanduslq~ Handbook, 19$Z. 30.3 p.

5. Gillespie, Donald T~ c. Vapor...liquid equilibrium still tor miscible liquids. Industri~l eng!... nearing chemistry, analytieal edition 18:575-577.. 1946. 6. Horn!, Edward CIP Vapor-liquid equilibrium in the acetone•benz·en.e•ethylene dichloride system. Thesis ~ Pittsburgh,. Carnegie institute of tech nology, 1954~ 7• Jones. c. A•• E. M. Schoenborn and A., P. Colburn. Equilibrium sti~l .for miacib~e liquid~h Industrial engineering chemistry .35-:666-672. 19lt,.3. 8. Langdo-n, w.. .M., and. ]),. B-. Keyes., Vapor..liquid equilibrium da.t-a on ethyl al.cohol..wa:ter and on isopl-opyl al·eohol...watezw. Industrial eng1neetting chemist-ry .31p9)8-942· 1942. Olderahaw, c. F, Ftar.forated plate columns for ana...., lytical batch distillations. Industrial engi neering chemistry, analytical edition 13:26,5-268. 1941· 10. Othlner, Donald F. Composition of vapors from bQiling . solutions. Analytical chemistry 20t76.3-766. 1948. ll. Rayleigh, Lord.- On the distillation of binary mix tures. Philosophical magazine and journal or· science 4: 52l•S)7,. 3.902., 12. Redlich, Otto and A. T. Kister. Thermodynamics of nonelectrolyte solutions. Industrial engi nee~ing chemistry 40:341· 345• 1948. 13 . Redlich, Otto and • T. Kister. lgebraic represent ation of thermodynamic properties and the classi fication of solutions. Industrial engine-ering che~stry 40:345-348. 1948 .

J.4 , ~edl1ch. Otto.- A. T. Kister and c. E. Turnquist. . Thermody-namics of solutions. Chemical engi neering progress symposium no . 2 (phase• equilibria) ~8:49-61 . 1952 . Robinson, Clark . • and Edwin R. Gilliland. Elements of fractional distillation. 4th ed,. ew York, cGraw -H~ll , 1950. 492 P• 16 . catchard, George and alter J . HliUller . pp11oation of equations for the chem.1cal potentials to partially miscible solutions. Journal of the American chemical society 57:1805-1809 .. 1935. · Tyrer, Dan . Boiling point ot ethy.l acetate. In International critical tables, vol. 3. New York, L.cGraw-Hill~ 1928. p . 2J.9 . 77

I I I • I

I I TABLE 1

Physical Prope~t1es ot Purified Components Normal Bolling Point ( 0 c .,) ~ . . Oba'g Ref . CJl Ob:s'd Ref. {J) Obs1 d Ref~• (J)

Benzene 80.11 80 . 10 1.50102 l.$011.0 o.87865 0. 87903 1 Ethyl Acetate 77.15 77 .1$ 1.372)6 1~372.3'9 0. 90038 0. 90063 Ethylene Dlohlorid& 83.47 8J•.47 1..,44478 11'44476 1.25313 1 .,2$309

l Re-.feren~"Gt 17, p.219 79 TABLE 2 The:rmoeouple Oe.l1brat1on Data

TemperatUPe 1 MeasUI'ed emf •• deg. a• ... millivolts Thermocouple # l u. 8J.4l 1.4-127 14"133 82.48 l.:h96l 13.961 81 .79 1,3.8.3$ 13.8.35 81.42 13.762 1.3.763 8G.7J. 13.634 1,3.635 79·78 1.3.460 13,460 79-00 13.33.2 1.3 •.31a 78,40 1.3.206 13.206 80

Calibration Curve Data Ethyl Acetate•Ethylene D1ehlo~ld6

Refra~tive Den$1ty (g./ml.) Mole Fraction Index .. 0 Ap$ta11& a.t 20 0 0 , i\hzl np at 69dt'P• ~ - 1 . 1 o.oooo l.4Ji478 1,2$.31.3 o.o987 l.~3SQ.S 1.21004 0.1443 1.4.3108 1.18976 0,200.$ 1.4,2656 1 .16791 0.,)001 1.41842 1.12881 0 • .3966 1,4llll 1.09241 0.49$0 1,40397 l.0$778 0.5976 1.39692 1.02.307 0.7023 1.)9014 0 . 9891.3 0.7949 1;384.36 0.96109 0.8578 1;.-.38060 Of94215 0.9111 l,J77q_6 0 ,92689 1.0000 1.)12)6 0.900.38 81 TABLE 4. Calibration Qurve Data Ethyl Acetate-Benzene

M'ole Fraction Refractive. . lndex0 . Density (g~/llll . )

Ethi;\; Acetate !loI t h at ! gg.o. t . ,o. . . at ao.ooo• . o.oooo l;$0102 0 . 8786.5 0. 0489 1.49364 o.a796o 0 . 107.$ 1 , 48502 0. 88085 o. J.492 1. 47905 a.88l31 o• .aQ4o 1. • 47096 (),.,88252 0 . 2978 l -45830 0'.. 88432 0-4011 1 . 4444,8 0.8860$ 0. 4991 1.4.3215 0. 88847 0. 5979 1. 41929 0# ·89075

0~6973 1~40717 Oo.89306 0 . 7992 l -39.506 0 , 89529 o. 8.5l7 1 .,.38906 0 .• 89658 0 . 9030 1.38.314 0 . 89774 0. 94.79 1. 3760} 0 . 89884 l. .. oooo 1 . 372)6 0. 900)8 82 TABLE $ Calibration Ourve Data Ben~ene•Ethylene D1chlo~ide

Mole Fl*act1on Retractiv Index Density (g'./ml.) Ben~ene. ·20 0°0·. at go.o 0 c, no.at 1.! ! o.oooo 1·44478 1~2$.31) 0.0474 1.44733 1.232$5 0.100, 1.45017 1~20974 0.1531 1~4.5291 1.18783

0 .. 1990 1.45$~ 1.16902 0 .. )004 l.-46097 l,l28Z6

o:.3995 1.46637 1~08959 0.4.966 l-47165 1 .053.34 0.5<;64 1~47732 1!101·631 o.6983 1.48311 0.98006 0.7958 1.48865 0.94676 0.8479 1.4.9181 ' 0.92.867 0.8988 lt:lt9483 0.91165 1,0000 l,..$0102 0.8786$ TABLE6 Vapor-Liquid Equilibrium Data for Ethyl cetat -Ethylene Dichloride Othmer Still Data

Run Temp . Retract~ve Index Density, (§a/m1.) ole Fraetlon Bo . deg. c. rJ at 20.o0 c. at 20.0 c. Ethzl Ae;tate - tq\ild Vapor Liquid Vapor Liquid apor 23 83.#-6 ~.44269 lphlt2~ l.243o6 1.2l,.268 0.0220 0.0230 22 83. ft% 1.wl1 l.W,.j. 1.2376~ 1.237lt% o.~o o.o~so 24 83 .ij. 1.~0 5 1.44051 1.2338 1.2334 o. 5 o.o 30 83 .ijJ 1.ij4023 1.4J,i.Ol0 l.2320b 1.23146 O.g%60 0.0~75 ~~ 83 .Wf. 1.43600 l.ij.)881 1.2263 1.2w1 o. 00 o.o 20 83 ..41 1.. 43l~ 1.43652 1.21589 1.2 8~ 0.08%5 0.0870 ~A 83 .2~ 1.ij.27 1.ij.2678 1 .17275 1.16 56 0 .. 18 5 0.1985 29 8).2 . l-!i.271~ l.lj.2628 1.11f:Rl 1.16600 o.1~ij.o 0.2045 ,30 83.03 1.ij.1A6 l.lj.l.787 1.13 1 .. 12592 0.2 35 0.3070 31 82.39 1.ij.l 96 1.lj.l.712 1.13108 1.122~ 0.. 2930 0.,3170 32 82. 3 l.li-1.573 l.ij.l339 1.115~6 1.10ij.2 o.3~go o.l65o 82 .63 l.ij.!J.30 l.ij.1070 1..100 0 1.09111 0~, 5 o. 020 5~ 82.SO 1.4.1oz2 1.4077i 1.-09181 1.gz1o~ o. 015 0.~30 35 82.23 l.ij.07 1 l.ij.04.3 1.076~2 1. 02 o.ij. 85 1.8 82 .35 l.lj.0737 1.40394. 1.075 6 1.058i7 o.o.mo 5 0.4950 21 82.20 1.4ozo1 l.ij.0290 1.gzos9 1.052 0 0.~30 0.~100 19 82. 22 1.lj.o 21 1.ij.o~l2 1. 984 1.05728 o.. 35 o. 985 17 81.66 1.~0087 1.39 6 1.. 04323 1.022~0 o •.$390 o.. 015 15 81 .~~ l.ij.0002 1.3956 1.03888 1~017 8 0.5515 0.6160 20 81 . 1-39986 1.3955l 1.03865 1.017~ 0.5~40 0. 6185 81.252 1.39938 1.3951 1.03560 l.OJ.48ij. 0.5 10 0.6240 il 81.00 1.395~ 1.3~088 1.0~? 0.93371 0.6215 0.6910 12 80 .~~ 1.393 1.3 927 1.0 0 0.9 53~ o.65oo 0.7155 80 . 1 • ():) J.4. .391 8 1.38721 0.99706 0.9757 0.6790 0.7470 \...)

2 Data .from both at111s indicate temperature measurements .for run are low. TABLE 6 (Cont•d.)

9 79.61 1.38621 1.38261 0.9z043 0-9~245 0.764-0 0.8235 10 79.30 1.. 3840J 1.3608~ . 0.9 001 0.9 359 0.7960 0.8530 11 78.8~ 1.3818 1.3789 0.94838 0-9~79 0.8,3 5 0.88~5 5 78.4 1.37936 1.3770 .. 0.93686 0.9 52 0.8770 0.91 0 8 78.17 1.37785 1 •.37594 0.92827 0.91635 0-90~0 0.9r5 4 78.05 1.37721 1.37~0 0.92479 0.91! 11 0.91 0 0.9 55 .3 77-70 1.37,2~- 1.37 2 0.91491 0.90~ii 0.94~5 0.9 80 7 77-~ 1.37 7 1.37377 0.91326 0.90 9 0.95 0 0.9z45 2 11· 1.37375 ·1.37315 0.90798 0.90~9z 0.9750 0.9 55 1 77.22 1.37291 1 .37266 0.90355 0.9020 0-.9900 0.9950 TABLE 7 Vapw-Liquid Eq.u1librium Data ror Ethyl. Aoetat•-Eteyle:ne D1ehlor1d• Jones St.ill Data

RUl'l Temp. R$£~aet1ve I~ex Density, '§•/ml.) Mole Fraction No.•. d&St c. . ~ at 20(l·c, .. at go,o c.. . .· Etf5tl Acetat:t - L quid .apo-r -Liquid .VapoJ' Liquid Vapor' 26 8.3.49 1~4#470 1.4#462 .l..Z$260 1.2.$258 o.oo15 o.oo2o ~~ 83.4.6 1-44378 1.#4371 1.24823 O.{llOO 0.0110 8).~3 :t.4Ji2:4s 1 •.hlj23a l-- 2~35 l.2ij.202 o~o2lto 0#>02$0 n 83.-$0 ~-lj.4a~ 1.,k42oo 1.~034 1.23996 o.oztlo 0.0290 22 8.3.47 1.ij.39.·.~s.. 1.4393s.. 1.22786 o. •o530 .o.osso 21 8).~ 1.~7 5 1-43732 ) l-24434 0.0760 0-.-0115 29 8j.!iJ> 1.4J6 7 1.43675 1 •.21645 . 1 • .21555 0.0815 ,o.o835 30 8).ij.O 1.#.3288 'l.lj.J24.2 1,.1972.4 l..l953o 0.128!) 0.,1)30 31 8).-37 l.ij.)067 l+!f.JOijJ. 1 . ~18775 l- .. 18$68 0-15.15 .O.l$65 18 8).,.21 l.l.i.2WJli. .l-4234.3 1._15319 0.225'0 0.2370 20 83.07 1.#2i28 l~H-1993 1.~85 1.1.3679 0.2635 0.2805 28 8).17 l .t!'lj.2105 1.~970 l.iliJ.2$ 1.13497 0.2660 0 • .2835 32 1 •.41659 1.~472 1.11963 l.llOS2 0~.3235 0-3415 :t-5 ~~:~i l.ljJ.$02 l.J.i.l297 3 1.10239 0.3440 . o.~oo 3.3 82.67 1.41~7 l ...ij.0902 l-~94.79 1.08295 0~ · :3915 .34 82 .3~4 1.~oaze 1~~o~hk 3 l.o6576 Oto:!t-355 ~=*-1~g 82.].4: l.lj.07l$ 1_..4042~ 1.074.03 1 o~45oo 0.-~95 l4 ·. 3 le'0$. 996 35 8.2-0.. Zr .· l ..!.f-0350 1.40031 1.04022 0.$010 . o . ~~15 13 81.-6 . 1.~0297 l.J9968 l.0.$)17 1.03705 0.5090 .o..-5 ·570 .!7 ai.s 1.39909 1.395)6 J 1.0159.3 0.56,55 .0;.,6!05 12 81 .11 l .•J

9 81.42 1.3983~ 1,.3~472 s 1.01277 0.~765 o.6.305 11 80..72 1.3~33 l .. 3ggtt 5 0.98722 o. 52G 0·.7105 l.O 80.28 1.,3 979 1.3 5 0.~048 0.7075 0.7650 5 79.·95 . ~.38772 1.38419 0.96836 .o. 106 0.7380 0.7965 8 79-52 ~.38495 1.38179 0.-9 4-00 0-94853 0.7850 0·.8375 73·-0l 1 .• 382.08 1.37934 0.. 95001 0.9.3662 0.8)20 0.8770 b 7 ,.1 1-.37672 1,.37751 0.93772 0.92693 0.8720 0.9090 4 77.-~9 1;.37 23 1 ,.37~03 5 0---91413 0.9325 0.9535 2 77.- 2 1 .• 37493 1 .. 37 02 5 0.90921 0.95~0 o.9Aoo 1 77,.36 1~37372 1.37315 5 0.90510 0.97 0 0.9 55

5 Sample contained lesa than 25 ml. l.1qu1d. Density was not measured~ \. TABLE 8 Cal cul ated Data: Ethyl Ac e t ate•Ethyl ene Di chloride Othmer St1l~ Data Run liole Fraction -dt· Activity Coeffioienta Ratio No .. Etpyl Ac~tate · ·, - Ac•tate - Dichloride Act . Co!t .. I ~;_ ..· - ,Liquid apor · ~. '¥,_ . 'll,/1-z. Z3 0 . 0220 0 . 0230 1.4? 0.852 0. 999 . 0 . 853 22 0 . 0,40 o . o~5o 0 . 9~ o . 8l9 1 . 000 . 0 . 8~9 24 o. o 1.5 o . o 30 1 . 1 o . B 3 0. 998 · o. B 5 o. gt6o 0 . 0~7.5 l .. o6 o. a42 1. 000 · o . a ~ ~~ o . 00 o . o 20 1.. 09 o. aij2 0. 998 . 0. 844 27 0 . 08~.5 0 ~ 0870 1 . 00 o . a~o 0. 999 0 . 8~1 28 0. 18 5 0 "1985 1 . 99 o. 8 H. 0 . 994 o. a 9 29 o. 1 4o 0.2045 2.. 04 o. B64 0.9~3 0 . 870 30 0. 26 3.5 0 . 3070 3 . 50 0. 894 0. 9 0 0. 912 31 . 0 . 2930 0 . 3170 ,.51 0. 89.5 0. 981 0 . 912 32 0 · 3~.50 0 . ~6.50 .24 0 . 905 0 . 9l4 0 . 922 0. 3 6.5 o . 020 4, . 65 0 . 917 0. 9 9 0 - 9~ 0 . 4015 o. ifu30 5 - ~2 0 . 927 0 . 956 0 . 9 7 5'3.5 o. mo 0. 4 85 .5 . 0 0 .. 932 0 . 9~ 0. 975 18 o . ~ 5 o . ij.9.50 ~ - 84 0 . 931 0. 9 8 0,982 19 o . ~ 35 o. ij.985 . 39 0 . 911 0. 972 0 . 937 21 o . 453o 0 . 5100 7·17 0.9~.5 0. 932 1.02.5 17 0.5390 o. bo15 8.14 0 . 9 ~ 0.. 91.5 1 . og2 15 0 • .5515 0 .. 6160 8 . 50 0 . 96 0 . 908 1 . 0 4 20 0 . 5540 o . 6185 8 . 53 0 . 969 0. 911 1 . 064 o . golo o. 624o 8 . )6 0 . 973 0 . ~20 1 . 0.59 i6 o. 215 o. 6910 10 . 11 0. 980 o. 83 1.110 12 o . 6soo 0. 7155 0 . 988 0. 896 1 . 103 9 · 94 a> 14 0,6790 0,.7470 11 . 11 0. 993 0. 872 1 . 139 -.J TABLE 8 (Gont'd.) 9 0. 7640 0 . 8235 12.52 0. 996 041845 1 . 179 10 0 . 7960 0 . 8530 1~ . 20 0 . 995 0 ,. 835 1 .192 11 o. 83 5 0 . 8855 1 ·65 1 . 000 0 . 811 1 . 233 5 0.8770 0.9180 1 • 0 1 . 002 0 . 782 1., 281 8 0 . 9050 16 ,85 1.001 o. A79 1 . 285 4 0. 9160 0 . 9r59 55 17 . 33 1 , 002 o •. 2.3 1 ·. 300 3 0.9465 0. 9 80 18 ~t 07 1,001 0.762 1 . 3~ 7 0. 95 0 0~9745 20 . 01 1 . 003 0~736 2 0 . 97.50 0.9855 22 . 18 1 . 001 o.lo3 1l . t24 3 l 0 . 9900 0 ~ 99.50 30 . 30 1.003 o . 10 1. 40 TABLE 9 Calculated Data: Eth11 Acetate Etb1lene Dichloride Jones Still Data Run Mole Fraction _dt Activity Coefficients Ratio ...... 2..!. Etb.y1 Acetate _

5 Oca7)80 0"7965 ll..l! 0*984 0.968 1.,1.34 ' 8 0.,78SG o.8375 11.8) 0.987 0 .. 857 l .. l$2 o.B)ao 0.8770 12~87 0·991 0.8)6 1~185 z 0.872;0 0.9090 l ..) . •.65 0.<)93 0 . 830 1.-190 4 0.9325 0.9535 14.35 0.998 0"82.<3 2 0.,9550 0·9700 l5,bO 1.ooo 0~804 i:~r.?. l o.97bo o~.CJBs5 20.04 1.00'2 o · ~ 135 l-361

'8 TABLE 10 Vap

Run Temp . Rit£ract1ve ~dex Dena-ity, . (~. /ml . ) Mole Fraction N'oi deg . ·· c. · n~ a:tc ~0 ! 0 ·C. . at z,o.oc. Et!§:l Ageta:t.! Liquid' Vapor · Ii1quid Vapor ~1qu1d Vapor

22 80.11 1 . ~0090 1 . ~0086 0. 87860 ().87828 0.0010 o. ool4 80.. 00 l . 9894 1 . 9842 0_.87876 0 . 87881 0 . 0138 O. OllO ~ 79-88 1. 49657 l . H-9$52 0 .. 8790~ 0.. 8791! 0 .• 0295 O. OJ i 25 79.82 J..ij.9362 1 --ti-6233 o..87

77 - ~0 1 .. 41038 1 .40847 0 . 89247 0 . 89~0 0 . 6700 0. 6856 71 · 0 1. 40401 l . lj.0~9 0 . 89~90 0 . 89 0 0 . 72l~ '6].2 77. 36 1. ij._a272 1 . 40 3 0.89 05 0 . 89~6 0. 73 . 0.1r0 . 7 50 10 77 . 31 1 . ~0035 1. 39912 0 . 894~ 0. 89480 0.7548 0. 7 ~ 77 . 31 1. 39536 1 . 39442 0 . 895 . 0 . 89 46 0 . 7972 0. 80 il 77 . 2.7 1 • .39224 1 • .36156 o. 8961 o. a9l2l 0 . 8236 0 . 8~00 77 . 24. l -36031 1.3 ,670 0.89655 0. 89670 o.a~o5 .o.a 62 ~ 77. 22 1-.3 725 1 . 38 83 0.89715 0.89721 o. a · 10 o •.a7o5 77 . 22 l.J85l2 1 • .38465 0. 89757 o.89A55 0 . 8605 0. 8876 l 77-23 1.382 0 1.38232 o. 8981l o. 89 o8 0.9075 0.9100 77.21 1 . )8100 1.)8083 0 . 8983 04898~ 0.92~$ 0 . 9228 77.19 1.379ll 1 . 37602 0.89884 0.898 2 0.~88 0 - 9~93 3 77-17 1 . 37819 1. 37 09 0 . 89912 0 .. 8989l o. 68 0 . 9 75 2 77.18 1 • .37548 1.315~5 0 . 89955 0. 8992 0.9~1,3 0-9~15 '1 11·14 1.37.370 1 . 373 8 0.90003 0.89995 0.9 78 0 . 9 80

....0 1\) TABLE 11 Vapor- Liquid Equilibrium Data for Ethyl Acetate-Benzene . .. Jones St1~l. Data Run Temp. Ref'raot1ve Index Dens1tr. ts-/ml . } Kola Fraction No . deg . c. ' FD - -.at 20. o0 c. at 20 . 0 c. Et!!;I1 Acetat! - Liqul.d Vapor Liquid Vapo~ ' 22 80. 09 1. ,oozs 1 . ~oo55 0 . 87870 0 . 87866 ' 0 . 0022 0 . 0034 80. 01 1 . 99 2 1 . 9932 0 . 87873 0. 87%58 0 . 009~ 0 •.0115 79-· 72 1 . 49774 1. 49708 o.szses 0. 87 30 0 . 021 o.o,Q~ ~ 79 . 87 1 -49532 1 . 46i30 . 0 . 8792~ o.~75 o. o 27 79 -71 l . lj.9074 J. . lj. 93 0.87963 0 . 8801 . o. 82 o. o oij. 79·56 1. ij.880l 1. 48,90 0 . 88027 0 . 88045 . 0. 0866 0. 1112 ~~ 79 - ~1 1 . ~6%l 1 . 48 24 0 . 880~ 0. 88071 0 . 097~ 0.-.1126 38 79 · 0 l . ij.84J . l . ij.8101 . 0. 880 4 0. 88101 0 . 102 0 . 116i 20 79.12 l . ij.6ij.64 1 . 4604-5 0 . 88334 0 . 8839~ 0.1558 0 . 17 ' 39 7~ - 05 1 . ij.b~o 1 . 4l112 0 . 8821.3 0 . 8825 0 . 1810 0.2040 37 1 . 88 1~4 947 1 . w 598 0 . 88292 0.08333 0 . 2150 0. 2394 31 78.~ 1 . 4670~ 1 . 46350 0 . 88309 0 . 88~59 0 . 2322 0 . 25bO 32 78 . l . ij.6J.6 1 . 45799 0 . 88~90 0 . 88 55 0 . 2700 0.29 8 78.50 l.ij.58~ l·tfg32 0. 88 3.3 0.88~81 0. 2902 0.. 3178 ~~ 78 . 2z 0 . 88571 0 . 88 17 0 . ~556 o . ~o 19 78 . 0 1.1 - fr~g,, . 3 l. 1 . 4ij.105• 94 o. 88b5o o . 88709 o. 022 o. 8 30 77 - ~3 1 . 441~ l . t.i-3772 0.887~ 0. 88782 o. lj.26o o . lj.$48 21 77 - 0 1 . 43l 1 . 43454 o. 887 o.aaA~ o. H-5 e 33 77 -92 l . ij..) 79 1 . 43.370 0 . 88789 0. 88 o. ij.618 o.ij.o.ij.A6 . 4o 18 77. 73 1 . 42952 1 . 42697 6 0 . 88998 0. $186 0. 5383 16 77 . 60 1 . 42319 l . l.;2083 0 " 889~4 0. 89043 0.$67~ 0 . ~860 35 77 . 61 l . ij2005 1 . 41782 0.890 5 0. 89119 0 . 592 ' o. 096 6 Sample contained leas than 25 ml. llquid.. Dens!ty was not. measured . ....0w TABLE ll (Conttd.)

40 77 .62 1.41875 1 , 416~ 0. 89122 0.89146 o . 6o24 0. 6196 17 77 .47 1. 4.1219 1.410 . 0.89214 0 . 89~ . 0 . 6~2 0.669~ 11 77 .38 l . l;.o~lo 1.402 0.89375 0. 89402 0. 7 3 0 . 73~ 10 77 . 33 1.39 .. 0 1 .. 39603- o. 895J$ 0.89$41 0. 784' 0.7910 12 77 .28 1.39260 1-.3~200 o. 89o02 o.89b1.3 0 . 820 0 . 8258 77 . 24 1.)8850 1.. 3 807 · 0. 89686 0 . 896~2 o.8565 o. 86oo ~ 77·24 1.384.07 1 . 38378 · 0;89771 0 . 897 0 0-, 8945 0,;8972 6 11 ·1l 1 . 38234 1 .-38212 1 0. 89810 0 ,~ 9098 0~9117 77 . 1 l-379b7 1.37945 7 0 . 89890 o;9335 . 0; 9354 f 77.16 1.)7967 1.379t5 7 0.89875 . o;9335 o~ 9355 1$ 77 . 13 1.37778 1~377 0 7 0. 89918 . 0~9502 . o;9518 3 77 -.17 1. 37746 1 . 37736 . 0.89960 0 . 8991~ 0.9535 0 ~9g42 2 77 -18 1 . 37[19 1 . 375b9 7 0. 8996 o~9o86 o . ~9 95 l 77 -19 1 . 37 02 1 . 37397 0. 9000.3 0 . 8999 o . 98~ . o;9852 77 . 17 1. 372.58 1 . 3725~ 0. 90026 0 . 90017 0.·99 2 0~9985 M 77 .1.5 1 • .37236 1.3723 0 . 90034 0. 90037 1.0000 1~0000

7 Sample contained leas than 2.5 ml . liquid. Densi.ty was not meaaared .

$ T..tBLE 12: Oalcula.ted Data: Ethyl Acetate...Benzene Othmexr sti.ll Data Bun Mole Fract ,ion dt Activity Coef:fieiehts Rat.io No •. Etl}.yl Acetate. _gz Ae·e.tat! aenzene Act~ ..QotfA -- . . . '?5, - Liquid Vapor 'lS'z.. ¥,I 'If}.. 22 0.0010 o.<>ollt- 2.·96 1.270 o• .999 1 •.271 0.0138 o.olzo 6.25 1.122 1.000 1;.122 ~ 0 .. 0295 0.03 ~ 6,)7 1.128 1.000 1.128 25 0.0~70 o-.057 · 6if.31 1.122 0.999 1~123 26 o.o 90 0.0832 6 01- 1.110 0.996 1~122 27 0.0904 o •.1076 . 1.099 0.997 1.102 28 0.103~ 0,1.220 ~:~6 1.094 0~999 1,.o9g Z9 0.113 ~-77 llll03 0·99l 1.1.0 31 0.1176 g:i~~ •.34. l.l2l 0•99 11!126 30 o.l3S2 O.,l$88 5.52 1.096 0·999 1~09~ 32 0.1956 0,2234 5.10 1.079 1 .. 003 1~07 3.3 0.2126 1.0r1 1*001 o.ili~2 f·16 1.ul • . a5 o.~2 0 .. 7 ·. . 83 1.0 l 1.002 i~ o. 6 0.27)0 4-87 1.0~ 0.970 20 o.24 8 0•2788 ij..73 1~0 . 7 1.004 l.oz1~0 i 21 0.2$22 0.28.30 ~-81 1•066 1.003 l.o6 17 o.2t>o5 0.2922 H--85 1.06 0.999 l~ . O~ .34 0.3160 0.~20 4-66 l .•o6o l.OO~ 1.0 .. 35 o.~ 6 o • .·· 96 3.9 l-044 0.95' 1~0§2 16 o• .ot o.ij.710 ).7l 1.037 l .. Oo6 1.0 1 1~016 .36 o.~7o o.4976 3·3 1.0.32 1.016 t 31 o. 3~6 0 .~36 1.1, 0.996 1.046 0.;9$2 0.~9 0 o. 17~ a.s 1.017 1.029 0•988 ~~ o. 438 o.66o . 2 • .31 l.013 1.0,32 . 0.982 \R TABLE 12 (Cont•d.)

0.6700 o.6856 2.22 1.011 1.032 0.980 0.72~4 0.7!56 1.92 1.008 1.0,3 0~9g7 '162 0.73 3 0.7 50 1.~2 1.008 1.0 5 0.9 g 10 o. 7548 0.7 1.oo 1.008 1.04.3 0.96 0.7972 0. 80'5 8 o.~6 1.004 1.050 0.956 ~ 0.82)6 0.8)00 o. 0 1.ooij. l.0$2 0.954. o.8io5 0.84-62 ).15 1.003 1.054 0.9~ ~ 0.8 70 o.87og l.$8 1.002 l.Ob5 0·. 9 0.8805 o·.aa7 2.15 1.006. 1.029 0.978 l 0 ..9075 0.9100 0.92 1.000 1.06~ 0,940 0.9215 0.9228 0.55 1.000 1·.07 0.929 ~ 0.9~88 0.9~93 0.26 ·0·999 1.086 0.920 3 0.9 68 0.9 15 ·o.42 1.000 1.081 0.925 2 0.9713 0.9715 0.21 0.999 1.087 0.619 l 0.9878 0.9880 0.56 1~001 0.180 5·. 10 TABLE 13 Calculated Dat : Ethyl Aoetate·Benzene Jones Still Data

Run Mole F~aot1on .dt Activity Coeff'icients Ratio o. thi;l ,Acetate dy Acetate . Benzene Act . Coef. - Liquid · Vij.por .)f. '6z.. "t{,jy.,__ 22 0.0022 0,0034 1,52 1.404 0.998 1.406 0.009~ 0.011.5 5.81 1.11 1.001 1.113 0.021 o.o~t~ 5t~ 1.090 1.001 1.089 ~ 0.0~75 o.o 5.2 l.o8~ 1,000 1.083 27 o.o 82 o~o o4 5-33 1.08 0.9?9 1.085 o.o866 0.1112 8 .02 1.18 0.9 9 1.169 ~~ 0~097t 0.1126 4·89 1.070 1.001 1.0 ~ 38 0.102 0.116~ ~·13 1.080 1.002 1.07 20 0.1558 0.17 .61 1.063 l.OO~ 1.058 39 0.1810 0.2040 ij..52 1.059 1.00 1.oKg 37 0.2150 0.2394 ~-27 1.052 1,.00 1.0 31 0.2322 o.25zo ij..12 1.0.50 1,009 l.Oij.l 32 0.2700 0.29 8 4-07 1.0,0 1.011 1.039 0.2902 0.3178 ij..03 1.0 7 1.010 1.03A ~~ 0 .~556 o.lB30 1.037 1,.029 1.00 19 o. 022 o. 288 3·~3. 1.034 1.017 1.017 30 0.4260 o.l.i-548 3.36 1.033 1.021 1.012 21 o.45 a 0.4764 2.89 l.02l 1.029 0.998 33 0.4618 o.ij.a o 1.02 1.022 1,00~ 18 0 • .5186 o.$,383 23·. ~ 1.018 1.033 0-9~ 16 0.567~ o.g86o 1. 1.017 1.011 1.0 o.692 o. 096 2.2% 1.013 1.035 0.979 o. o2:4 o.6196 2.2 1.01.3 1.032 0.982 'g17 0.6694 1.98 1.011 1.008 1.00) -.!) 0.6552 -.J TABLE l.3 (Conttd.) ll 0.7?43 0.7348 1~16 1,007 1.047 0.962 10 o.~84~ 0.~910 0.52 1.002 1.057 0.948 12 o. 20 o . 258 0.35 1.002 1.056 0.94-6 0.8565 o.s6oo 1.73 1.ooo 1.06 . 0.938 A 0. 8945 0. 8972 0.93 '1.000 1.065 . 0.939' 6 0.9098 0.9117 0.72 1.001 1.062 0,9.34 0.9335 0.9.354 0.9.5 1.002 1.0 4 0.9~ 0.9335 0 .. 9355 1.00 1.002 1.062 0.944 1~ 0.9502 0.9518 o.~ 1.002 l.o6l. P·944 3 0.9535 ().9542 o.~ 1.000 1.079 2 2 0.9b8~ 0.9695 o. 9 0.999 l.l2b o.P·6 8l 1 0.98~ 0.9852 0 . 83 0. 999 1.06 ·0..937 0.9l) 2 0.9985 0.17 1.000 0.913 ;t.095 i' 1.0000 1.0000 o.oo 1.000 ..... ifABLE 14

V,ap()r...L1qu1-d Equ111b~1um Date. toll" Beneene- Ethyl.ene D1ch:Lo:P14a Otbm$r StUl Data

' ' ' Run Temp. netraetiv• Index D&na1ty. (g./ml.) &tole Fttaetion 0 No. deg• .a. ~at ao.o c. · at 20.0 ·c. _ Bvnzell! - .. Litud Vapol' ·. Liquid - Vapor Liquid Vapor l 8341'36 i ..~566 1-.44576 1.~03 1.24452 o . o~6i 0 . 0202 2 83.,28 l . hl4,66 . 1.4#.687 1~23827 1 .. 23554 0.034 0 . 0410 83 . 24 J,.ID39 1.44.774 1.232$5 _1 . 2_2.892. 010·gt78 o.o564 83 ..15 1,. . .31 l.lj487t 1~22$91 1.221~~ Q;._ ' .32 · a~o7Jli ~ 8)..06 .l.4Ji917 l-449l · .1.21818 1 ...2:12 . 0 ..0810 0 .. 09.)2 6 82 ., ~9 ~ - 45001 l . ij.50 1 •.21.170 1~20561 0 . 0960 0 .•1102 7 82. 9 l ,. ,ij.$107 l.ij.$188 1.20323 1.19646 0 .1160 0 .1.320 8 82 .82 l.ij.$228 1.45.317 . l - .1637~ 1.18599 0 .1386 ·o.l574 9 82 .48 1,.~5599 1.~5705 1.1 ~3 1.~:621 0 . 2082 0.2310 1.0 82. 27 l . ij.574E_ l.ij.t824 1.15 79 l • . 733 0.2292. 0.2532 l4 82.32 1.~~9 . l.ij: 102 1.13975 l..l265l 0 .. 2716 0.2076 11 82.19 1.~ 105 1.-46240 1.12728 1.11 94 O.)O.JO '0.3290 l2 82.12 1.#.6207 l.ij;6~1}4 1.11990 1.10911 o •..;z16 0.3i60 ll 82.02 1.46.311 l.ij..6 $.2 1.11256 1 .. 1023.3 o.34e2 o.~ 2 32 81.87 l.lj.660l 1.46731 1.0~211 1.08161 ·o. 212 .31 81.80 1.4,6768 l.,ij.6869· .1.0 040 1.~052 oo~~kl~• .·.. · o.~goa 30 81.l4 l.ij.6831 1.469 1 1.07692 l.- ·625 o~.ij.J.So ·o .. .!~ 22 81 . l.lj.7ll2 1-47~9 l.05l09 1.0463.8 04864 0.5130 ~~ 81.61 1.47126 l.!f-72 9 1.05 50 1. 04J 33 o_.ij.882 0..51'6 27 81 .-42 1.47i6 l-47592 1.03323 1 .02~70 0.5495 ·o.57 o 81.33 1.47 .31 l-47776 1.02276 l.Ol.ij.09 o.g798 o.oo26 ~g 81.18 1.479~1 l.li.8110 0.9~955 0.99141 o. 4?8 81 .04 l.lj.82 8 l-hli399 0 . 9 · 100 0.97l92 0.6960 . g.:~~~~ 80 . 81 l.ij.8764 1.48853 ....0 ~ 0. 95244 Q.914J 55 0.7790 0.79$8 ...0 TABLE l.4. (Cont t d . )

22 80 . 81 1. 48765 1 . 48862 0 . 95~3 0. 94644 0 .. 7790 0. 7962 20 80 . 66 1.49073 l-49159 0. 93 0 0 . 92979 0. 8,300 o.am 21 80. 64 1 . 49082 1 . 49159 0. 934ll 0 . 92938 0 . 8320 0 . 8~~ 19 80 . ~ 1 -49348 1 . 49410 0. 9195 0 . 91576 0 . 87~ 0..8 0 18 80. 1-49531 1 . 49579 0. 9093, ·0. 90633 0 . 905 0. 9150 80. 44 1 . 49555 1. 49604 0 . ~079 0. 90.511 0 . 9100 0 . 9~88 il 80~32 1.49785 1 . 49813 o. 9555 0 . 89~78 0 ·. 9ft80 0. 9534 1.5 80 •.19 1 .. 49985 1• .49995 0.88517 0 . 88 26 0 . '9 04 0 . 98.'30

- -·---- 0 TABLE 15 Vapor-Liquid Equilibrium Data tor Benzene-Ethy;tene Dichloride Jones Stil l Data Run Temp . Ret"ractive Index :Density, <§ •/ml . ) Mole Fraction No . deg . c . n~ a.t 2o .ooc . _at 20 , 0 c ! Begzene - •Liquid Vapor Liqu1d · Vapor Liquid Vapor

a 83 .4l 1.44532 1 . 44632 1. 4t880 l -.24787 0 .. 0120 0 .. ~122 3 83 . 3 l . ij4567 1 . 44 oh 1. 24245 0.0212 0. 0250 83 . 29 l .W+b 3 1. 4467 . 1 . 23918 1. 23746 o . o~66 ~ 83 . 29 1.4ij.?ll 1 . 44739 1 . 23503 1 . 23206 . o . omo o. o 0 83 .. 21 1 . 44.791 1 . 44831 1. 22807 1 . 22466 0 . 0582 o.• o 62 l 83 . 19 1 . 447~8 1 . 44829 1 . 22807 1 . 22446 . o . os~ o. o664 8).08 l . lj.49 0 1. H.5024 1 . 214-0b 1.20919 o . o9 0 . 1020 li 83 , 00 l . ij.$015 l . ij.5l09 1 . 2102 1~20484 0.0994 0 . 1122 9 82 .67 l . lj.5408 1.~5~91 1. 17961 1.17210 0. 1732 0. 1920 10 82 . 29 1,4~724 1. 45 28 . 1 . 15~10 1 . J.466o 0 . 23~8 0. 2548 11 82,19 1. 4 oocj 1 . 4.o119 1.. 1,3 64. 1 . 12$88 0 , 2.8 0 0 , 30~0 12 82,10 1 . 46279 1~46397 1 . 1~7.3 1 . 1 05~8 0 . 33~8 0 . 35 0 26 82. 04 1 . 46403 1 ~ 4651, 1 . 10 26 1 . 0~b 1 0 • .352 0 . ~790 28 81 . 95 1 . 46569 1 ~ 4668 ~. l . 09ft9 1. 0 +4 0 , ~858 o. 096 13 81. 79 1 . 46802 l . l.j.69~ 1 . 07~1 1. 06962 o. 300 o . #.S3~ 25 81 . 80 1 . ~824 1 . 469 1. 0l 0 1.06794 o . ~J~ 0. 457 29 81. 4 1 . 4.695.3 1 ~ 4.70 9 1 . 0 z12 1 . 0~~37 0. 45 0.4804 27 81 .b1 1.47113 1. 472li .1 . 05 86 1 , 0 7~ 0 . 4812 0. 5090 81 . 42 1 . 47530 1 . 476 1.02908 1 . 0211 0. 5618 o.g838 ~l 81 . 35 1.47684 1 . 47799 1 . 01206 1.01149 0 . 589~ o. , 096 22 81 . 15 1 . ij.ao4~ 1 . ~145 0 , 99 2 0,98932 0 . 6$1 o . 6716 21 80 . 98 1 . ij.842 1 . 48512 0. 97304 0. 96715 0. 7190 0. 7360 ..., 0 8 Rampl.e-.contained ~.sa th~5-m-l-.-l-1qu14-.- -Den41-t~-no.t-me.aa~e~ · ~ ~LE 15 {aont'd.)

.30 80 . 96 1. 48524 1.~8 611 o. 96727 o.961h.o 0.. 7358 o·,,7530 20 80 .71 L.~89 22 1.ij.9000 o.-94349 o,. 938g1 o~8o4B 0,.8184 18 80 .6$ 1.49047 1 . 49111 0 . 9j6J.i,O 0. 93211 0 . 8254. 0 '. 8380 31 1 . 49329 1.49383 0,<)200J. .. 0 . 916?3 0.8732 o.aa;a 19 ~g ;, ~ 1. L~9!J. 78 1.49$23 0.91227 0 . 90~0 0.8968 0 · 9056 32 80 .39 1.49467 1.49527 0 .• 91167 0.90903 ·0,8988 0 . ~9o68 8\h 37 1.49643 1.49679 0,.90~· 08 0 . 90091 0.9249 0•9314 tl 80 .30 1.49797 1.49819 o. a 68 o.a 334 0•9504 0•9550 15 ao.al 1.49960 1.49972 o.,a~37 o.8~554 0.-9764 0*·9794 TABLE 16 Calculated Data: Benzene-Ethylene Dichloride Othmer Still Data Run .Mole Fraction _dt . Activity Coefficients Ratio No . Benzene cry : Benzene D1chlorid& Aot • .coer. - L1quid Vapor ~. "L '1,)'6 ..,__ l 0 .016~ 0 . 0202 6 •.12 1.115 0.999 1.116 2 o.o~~ o,o4J.o 5 .19 1.076 0.996 1.077 o.o 78 o . o,564 ,.15 1.072 0. 99 l.Ob4 o.o 32 0 . 07.34 1.058 1.0 2 ze <- 0·996 ~ 0.0810 0.:0932 4: l 1.051 0.999 1.052 b 0.0960 0.1102 ij. .62 1.0~1 0.999 1.0~2 0. 1160 0.1320 4-45 1.0 5 1.000 1.0 5 ~ 0.1386 0.1574- 4 ·53 1.045 0.998 1.047 9 0 .2082 0.2310 4.10 1.032 1.002 1.031 10 0.2292 0.2.532 4,02 1.ou_ 1.006 1.027 14 0.2716 0.2.076 3.98 1.0 1.000 1.024 11 0,3030 0,,3290 3·1l 1.019 1.002 1.017 12 0.3216 0.3i60 ).8 1,020 1.001 1.019 13 0.,3402 o~, 2 ).59 1 •.015 1.00~ 1.010 32 o. 212 3.bo 1.013 1.00 1.009 31 o.o.illf! o.ij.$o8 3-42 . 1.008 1.00 1.002 30 0.43.50 b.4622 ).~ 1.006 1.00~ 1.0o6 o.ij.Bo4 0.5130 3. 1.00 1.00 1.002 ~·~ o.ij.882 0.5lf6 ).52 1 •.008 1.004 1.004 27 0.5495 0. 57 0 ).22 1.003 1.009 0.994 0.~798 o.6oa6 3.06 1.001 1.012 0.986 o. 4-?8 3.30 1.002 1.006 0 . 99 ~~ 0•66~6 1-' 0.6960 0.71 6 3.27 1.000 1.007 0.99~ 0 JL _ a.779-0 ---0-.1-958 3.-34------0~99- - --J...-005 - 0~-99 ~ .w- TABLE l6 (Cont•d.) az o.~7790 0-&962 ).43 1,000 1.003 0.997 20 . 0 ..8300 3- · ~ 1,.000 1.000 ' • 1 .. 000 21 0.8320 oo:aft5-· m 3. 1.,ooq lo~OOk 0.996 1~ . 0 . 87~ Ol8 oO 3·72 1.ooo 0.99 ' 1.004 l . 0,905 0. 9150 1.ooo 0.991 _~ 0.9100 0.9188 0-999 0.993 . 1.00.. ooz il 0.9~80 0.95.34 t63.9! 0.999 0.960 1.009 15 0.9 04 0.98.30 5.05 1.000 0 ..9 2 ·-· l.O~O

1-' 0 -F'"' TABLE 17 Galeu.lated Data: Benzene•Etb3l$n.& Dichlo.:r1de Jones Still. Data Run Mole Fraction ....dt Activity Coeff1a1ents Ratio No. ]21ghlor~g.e. · l3tnzj&n& ...

a 0,0120 o ,~~o1.a2 0·,00 0;.919 1·,.001 0.918 0.0212 o.ozso. 4.·97 1,068 0 .. 999 1;.069 4 o.olis . 1.012 1.002 l..OlQ 5 o.o 2 o.!Mo.a o 4·~• 5 l.05i 0-998 1. 056 0~0$32 o• ....•6f #.1.3 .1,03 o.•999 1.0,36 b o.o5~ o•.o66 Ji.,l2 l.OJS l.ooo 1.•0)5 0.090 o.1020 1.028 0-999 1.• 028 ~ 0.0994 0.11.22 ~:i6 1..0.3) 1.ooo l.-0.3.3 9 0.17':32 o.192o .3-87 1,02$ 1.002 1.023 10 0.23l8 0,-2548 ).$2 1.01~ 1.006 1.010 ll 0.28 0 0.30~0 ).62 1 .. 01 · 1.00 1.012 12 0 .. ;3$' 0 ).23 :1.0o6 1.008 0.998 . 26 0·33~6 0~35 2 o.l790 3.10 ~.00.3 1.oo~ 0.994 28 o.l858 o. 096 ).15 1.003 1.00· 0-995 1.3 o. 300 o.•.!i,$.;~ 3~02 1.001 1.011 0.9~0 29 o.~586 o.480ij. 2.81 0.996 1.013 0.9 3 27 0,4.812 0.$:90 2.80 o.99A l .•Ol5 0.982 o.$618 0·& ·3.6 2.91 o•.99 1.013 0.985 & o.589i o. 0'}6 2--74 0 ..995· 1.016 0.975 22 o.b51 o.6716 2.90 0.996 1.0~8 0.980 21 0.7190 0:.7)60 2~1~ 0,996 1·.. 016 0.•980 .30 o.A;~a o.~$30 z.,9 0.997 1.012 0,985 ao o. 0 8 0·• ·184 2w96 0.998 l..Ol 0~ 98 ...... 18 0.8254 0~8 )80 3.01 o. 98 1.01 o. 8 0 TABLE 17 (Cont•d . _)

31 o.87J~ · o... 88.38 J-;35 0.999 1~: 00.3 0,996 19 0.8<)68 0.9056 ).)0 ·0•999 1.007 0.992 .32 0.8988 0.90b8 l-07 1.ooo J.. Ol;$ · 0.985 17 ' 0.9249 0.9314 l.· ~a> 0.999 . 0.-992 '16 0•9504 0.9$$0 .).h.7