High temp mutual solubilities for some 2° and 3° aq mixtures containing aromatic and chlorinated hydrocarbons

8/3/2019 High temp mutual solubilities for some 2 and 3 aq mixtures containing aromatic and chlorinated hydrocarbons

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50 2 J. Chem. Eng. Data 1988, 33, 502-505

High-Temperature Mutual Solubilities for Some Binary and TernaryAqueous Mixtures Containing Aromatic and ChlorinatedHydrocarbonsHerbert H. Hooper, Stefan Michel,+and John M. Prausnitz"Materials and Chem ical Sciences Division, Law rence Berke ley Laboratory , and Chemical Engineering Dep artm ent , University ofCalifornia, Berkeley, California 94720

Mutual soluMUtles at the three-phase equlllbrlum pressurehave been measured for blnary mlxtures of water wlth12-dlcMoroethane and chlorobenzene In the temperaturerange 75-200 OC. Llquld-llquld equlllbrla were measuredfor ternary aqueous mlxtures containlng toluene andphenol at 150 and 200 OC and for ternary aqueousmlxtures containing thiophene and pyridine at 100 and 150OC. Results are glven for equUlbrlum compositlons of bothllquld phases and for three-phase equlllbrlum pressures.

IntroductionWater-hydrocarbon phase behavior is of fundamental interest

in the chemical, petroleum, and synthetic-fuels industries.Mutual-solubility data are required for design and operation ofprocesses where there is contact between water and hydro-carbon or petrochemical streams. Often these processes areoperated at elevated temperatures and pressures, where theorganic-rich stream may contain many components, includingwater-soluble hydrocarbon derivatives. Mutual-solubility data areespecially important for design of water-pollution-abatementprocesses.While experimental solubility data are plentiful for binarywater-hydrocarbon systems at near-ambent temperatures, fewhigh-temperature data are available. Experimental data arescarce for aqueous ternary systems at temperatures exceeding60 OC. However, high-temperaturesolubility data are neededto test and extend the temperature range of existing molecu-lar-thermodynamic correlations. Binary data are useful forestablishingthe temperature dependence of water-hydrocarboninteraction parameters, while ternary data are needed to testthe accuracy of solubility predictions based on binary data al-one.

We report here mutual solubilities for binary aqueous mix-tures containing chlorobenzene and 1,2dichloroethane, forternary mixtures containing water, toluene, and phenol, and forternary mixtures of water, thiophene, and pyridine. Al l mea-surements were taken in the temperature range 75-200 O C .Low-temperature solubility data have previously been reportedfor chlorobenzene/water and for 1 2dichioroethane/watermixtures ( 7 , 2). Our measurements extend the temperaturerange of solubility data for both of these systems and allow usto compare our results with published data at lower tempera-tures.

No previous measurements have been reported for the twoternary mixtures studied here. However, phaseeguilibrium dataare available for each of the binary pairs in the two systems.The ternary data can thus be used to test predictions based onbinary data alone.

To whom c orresponden ce should be addressed.Germany.Present address: Lehrstuhl fu r Thermodynamik, U niversu t Dortmund, West

Experlmental SectlonEquilibrium measurements were made in a recirculating staticapparatus: details of the equipment and of the sampling pro-

cedure are give elsewhere (3). The upper temperature limit ofthe apparatus is 250 O C (corresponding to the maximum ratingof the sampling values). Room conditions fix the lower tem-perature limit.

Accurate sampling of water and hydrocarbon iquid phasesis difficult because of low mutual solubilities. Trace contami-nation of one phase with small droplets or dispersions of theother phase can cause large errors (4). High-temperaturemeasurements are especially prone to error because smallperturbations during sampling (e.g., temperature or pressuredrops) can cause phase separation and significantly alter sam-ple compositions (3). Our apparatus is designed to minimizetemperature and pressure gradients during sampling.

To measure binary mutual solubilities, approximately equalvolumes of water and hydrocarbon are charged to the equilib-rium cell and heated. The liquids are degassed by repeatedlyventingthe cell to low pressure untilthemixture vapor pressureremains unchanged: the vapor in the cell occupies less than5 % of the 140 mL cell volume. Thorough mixing is accom-plished by recirculating he upper liquid throughthe ower phase.At a fixed temperature, both liquid phases are sampled andanalyzed at least three times. After obtaining consistent resultsfor a given temperature, the cell is heated further and thesampling process is repeated.For ternary mixtures, a range of overall cell compositionsmust be prepared at each temperature to study the entire liq-uid-liquid immiscibility region. Because the withdrawal of liq-uid-phase samples alters the overall cell composition, ternarytie lines are measured only once.Chemicals

Water was filtered and purified through a Millipore systembefore use, and spectral-grade-purity toluene was purchasedfrom Mallinkrodt Co. Al l other chemicals were purchased fromAldrich Chemical Co. wlth specified purities of 99+ % .Analysis

Water-rich and hydrocarbon-rich samples were both analyzedon a Varian Model 3700 gas chromatograph with a thermal-conductivity detector. Binary mixtures containing water withchlorobenzene or 1,2dichloroethane were separated on aChromosorb 104 packed column. Water/toluene/phenol mix-tures were separated on a Chromosorb 105 column, andChromosorb 103 provided the best separation for water/thiophene/pyridine mixtures. Al l columns are 1/8-in.X 6-ftstainless steel, and Chromosorb packing material is 801100mesh.Relative responsesof the mixture components are calibratedagainst samples of known composition for each system studied.Details of the calibration procedure are given by Anderson (3).

0021-9568/88/1733-0502$01.50/0 0 988 American Chemical Society


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Journal of Chemical and Engineering Data , Vol. 33, No. 4, 1988 50 3Table I . Water ( l ) /Chlorobenzene (2) Mutual-Solubi l i ty Data in Mole Percent

water-r ich phase organic-ric hphaseno . of replicated T, p,measurements O C bar (2 ) in (1) std dev (1 ) in (2) std dev5 99.8 1.64 0.040 0.0019 (4.7%) 2.51 0.061 (2.4%)6 124.8 3.60 0.059 0.0017 (2.9 %) 4.10 0.077 (1.9% )5 150.1 6.69 0.088 0.0053 (6.0 %) 6.56 0.404 (6.2% )3 174.9 12.2 0.132 0.0016 (1.2 %) 10.0 0.088 (0.9% )3 199.8 21.4 0.239 0.0004 (0.2% ) 15.2 0.056 (0.4% )

Table 11. Water (1)/1,2-Dichloroethane (2) Mutual-Solubility Data in M ole Percentwater-r ich phase organic-rich phaseno . of replicated T, p,measurements OC bar (2 ) in (1) std dev (1) n (2) std dev

4 74.9 a 0.272 0.0030 (1.1% ) 3.21 0.168 (5.2 %)1 124.8 5.62 0.8043 100.0 2.55 0.419 0.0068 (1.9% ) 5.89 0.152 (2.6% )11.0

Pressure too low fo r accurate measurement (essentially atmospheric).

0 50 100 150 200Temperoture, 'C

Figure 1. Mutual solubilities of water and chlorobenzene.Samples to be analyzed (whether from the cell or for calibra-tion) are vaporized into evacuated 1-L stainless-steel cylinders.The cylinders are heated (in the sampling oven) above the at-mospheric boiling point of the least volatile component. Eachsample is analyzed at least three times.For the binary systems, relative responses on the chroma-tograph are reproducible to better than 1 2% . Responses forall components in the water/thiophene/pyridine ternary can bereplicated to f %. Resuits for water/toluene/phenol mixturesare less precise. Inthe nonaqueous phase, relative responsesfor all components are reproducible o better than f 2 % . Inthe aqueous phase, analyses for phenol and toluene are re-producible to f5 %, while water response can be replicated tof % . Calibration accuracy is closely related to reproducibilityof relative responses. I n all cases (except the aqueous phaseof the water/toluene/phenol ternary) mole percents can bedetermined from relative responses with better than f2% er-ror. Concentrations of phenol and toluene in water can becalculated from their relative responses with less than f5%error.Results

Tables I nd I 1 present mutual-solubility data and vaporpressures for water/chlorobenzene and water/ 1,2dichloro-ethane mixtures. The standard deviation for repeated solubilitymeasurements generally decreases with increasing tempera-ture, except for the water/chlorobenzene solubility measure-ments at 150 OC which were only reproducible o f6%. Re-ported vapor pressures were reproducible to better than f3 %.The vapor pressure for water/l,2dlchloroethane at 75 OC wasonly slightly above atmospheric and could not be determinedto better than f10% with our apparatus. Thus, this pressureis not reported here. Measurements for water/ 1,2-dichloro-

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Flgure 2. Mutual solubilities of water and 1,2dichloroethane.Table 111. Water ( l ) /Toluene ( t ) /Phenol (3 ) MutualSolubilities in Mole Percent

T, C P , bar149.9 7.05149.9 6.89149.8 6.74150.0 6.68150.0 6.59149.7 6.53150.0 6.50200.0 22.1200.4 21.9199.4 21.8200.0 21.7199.7 21.6199.8 21.5200.4 21.4200.3 21.4

water-rich phase(1) (2) (3)

99.22 0.09 0.6998.68 0.12 1.2097.75 0.15 2.0997.22 0.20 2.5896.09 0.28 3.6395.21 0.37 4.4294.56 0.44 5.0099.05 0.33 0.6298.26 0.62 1.1297.93 0.56 1.5196.96 0.69 2.3596.02 0.71 3.2795.02 0.92 4.0692.76 1.36 5.8891.82 1.61 6.57

organic-richphase(1) (2) (3)7.39 84.67 7.9411.78 72.39 15.8220.83 53.48 25.6928.43 41.99 29.5841.75 26.08 32.1650.62 18.08 31.3054.88 15.13 29.9917.22 76.86 5.9220.27 70.07 9.6622.32 64.77 12.9128.76 53.55 17.69

35.59 43.30 21.1240.16 37.25 22.5952.92 23.94 23.1455.14 21.84 23.01ethane were discontinued at 125 OC due to an apparentchemical reaction. After equilibrating the mixture overnight at125 OC, green color was observed in the aqueous phase: thiseffect was reproduced with fresh liquid samples.Figure 1 shows water/chlorobenzene mutual solubility datafrom this work along with earlier published measurements attemperatures below 100 OC (5, ). The new data agree wellwith the lower temperature data for both water-rich and chlo-robenzene-richphases. Figure 2 compares new mutual sob-bility data for water and 1,2-dichIoroethane with previous


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50 4 Journal of Chemical and Engineering Data , Vol. 33, No. 4, 1988o Th is WorkA Mu t u a l s o lu b t l ! t i e s for waterand to luene a t 150'C(Anderson 8 Prausn i tz , (311

rar 0 3 0 -n

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Water TolueneFigure 3. Liquid-liquid equilibria for water/toluene/phenol mixtures at15 0 OC (compositions in mole percent).

0 This WorkA M u tu a l s o lu b l l ht l e s f o r wa t e rand to luene a t 200'C(Anderson 8 Prausn i tz , (31)

Pheno l50 50

\74100 " " " . "

0 10 20 30 40 50 60 70 80 90 100Water TolueneFigure 4. Liquid-liquid equilibria for water/toluene/phenol mixtures at200 ' (compositions in mole percent).

10%Phenol

91A9A s A alubil i ty of to luene in walera t 150 and 200T(Anderson B Prousn i tz , I311

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97P98) . 1 2gk: 4

Figure 5. Water-rich compositions for water/toluene/phenol mixturesat 150 and 20 0 OC (compositions n mole percent).measurements below 75 'C (7, 8). Again, the data from thiswork appear to extrapolate well to the lower temperature re-sults.Tables 111 and I V present mutual solubilities for water/toluene/phenol mixtures at 150 and 200 OC, and mutual soh-bilities for water/thiophene/pyridine mixtures at 100 and 150OC. Three-phase equilibrium pressures are also reported. I na ternary mixture, this pressure depends not only on tempera-ture, but also on liquid-phase compositions. We control theoverall cell composition which, at a given temperature, fixes theliquid-phase compositions and the three-phase pressure. Sincethe experimental apparatus does not permit us to repeatmeasurements at individual ie lines, the measured ternary va-por pressures were not a smooth function of composition atfixed temperature. However, the pressures showed the proper

Table IV . Water ( l ) /Thiophene ( t ) /Pyridine (3) MutualSolubilities in Mole Percentwater-rich phase organic-rich phase

T, C P, bar (1) (2) (3) (1) (2) (3)100.2 3.0299.6 2.8899.8 2.77100.2 2.66100.0 2.59100.3 2.45149.7 9.98149.9 9.53149.7 9.31150.0 9.03150.1 8.90150.0 8.74

98.9598.3397.4496.0994.5589.7798.9597.7996.4993.4691.0486.04

0.21 0.840.22 1.450.25 2.310.33 3.580.45 5.000.98 9.250.43 0.620.51 1.700.64 2.870.98 5.561.32 7.642.33 11.63

5.9310.5120.5830.1240.5456.5511.7820.8732.5349.1356.4469.41

77.8366.4049.6437.2426.9415.2177.1957.8442.1524.1217.9910.30

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00 0.02 0.04 0.06 0.08

Mole Frac t ion Pheno l in Water-Rich PhaseFigure 6. Distribution of phenol between water-rich phase and or-ganic-rich phase at 150and 200 'C.

0 T h i s WorkPy r i d i n e50 50

60 40

90IDOoxO 20 30 4 0 50 60 70 SO 90 100

Water Th iopheneFigure 7. Liquid-liquid equilibriafor water/thiophene/pyridine mixturesat 100 O C (compositions n mole percent).

0 This WorkAM u tu a l s o lu b i l i t i e a f o r w ate rand thiophene a t 150OC

(Anderson 8 Prausn i tz , I311Pyr id ine5Op

70J8ow// "I00

Figure 8. Liquid-liquid equilibria for water/thiophene/pyridine mixturesat 150 'C (compositions in mole percent).


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Journal of Chemical and Engineering Data, Vol. 33 , No.4, 1988 50 5Figures 3 and 4 show ternary phase diagrams for water,

toluene, and phenol at 150and 200 OC. Tie lines were mea-sured over the entire two-phase region, coming as close to theplait point as possible. While no ternary data are available forcomparison, our results approach the correct limit at low phenolconcentrations as determined by the mutual solubilities of tol-uene and water. The water-rich region of the ternary diagramsis expanded in Figure 5. Again, the correct boundary conditionappears to be met at low phenol concentrations.Figure 6 presents the distribution of phenol between water-rich and organic-rich phases for the two temperatures studied.At all concentrations, phenol partitions more heavily into theorganic-rich phase at 150 O C han at 200 OC.

Figures 7 and 8 show ternary diagrams for water/thiophene/pyridine mixtures at 100 and 150 O C ; the aqueousregion of these diagrams is expanded in Figure 9. No ternarydata are available for comparison with our results. Mutualsolubiliities for water and thiophene have been measured at 150OC (3),but not at 100 OC. The measured binodal curve at 150OC appears to approach the boundary conditions given by thebinary mutual solubility data.

Figure 10 illustrates the temperature dependence of pyridinedistribution between the water-rich and the organic-rich phases.As the temperature rises from 100 to 150 O C , he liquid-liquidimmiscibility region decreases, and the tie-line slopes becomeless steep. Thus, pyridine partitions less into the organic-richphase at 150 OC than at 100 O C .

Registry No. 1,2Dichloroethane, 107-062 chlorobenzene, 108-90-7;toluene, 108-88-3; phenol, 108-95-2; thiophene, 110-02-1; pyridine, 110-

Llterature Cited86-1.

(1) Horvath. A. L.; Getzen, F. W. Halog enated Benz enes, Toluenes andphenols with Water; IUPAC Solubility Data Series, Vol. 20; Pergamon:New York, 1985; pp 153-182.(2) Sorensen, J. M.; Arit, W. Liquid-Liquid Equilibrium Data Collection;DECHEMA Chemistry Data Series, Vol. 5, Part 1; Deutsche Qesells-chaft fur Chemlsches Apparatewesen: Frankfu rtlMain. West Ger-many, 1979; pp 120-123.(3) Anderson, F. E.; Prausnitz. J. M. HUM Phase Equilib. 1986, 32, 3.(4) Tsonopoulos, C.; Wilson, W. A I C h E J . 1983, 29 ( l l ) , 990.(5) Filippov, T. S.; urman. A. A. Zh. Prikl. Khim. 1952, 25, 95.(6) isarov, V. M. Zh. Prikl. Khim. 1962, 35, 347.(7) Udovenko, V. V.; Fatkullna, L. G. Zh . Fiz. Khim. 1952, 26 , 892.(8 ) Van Arkel, A. E.; Vies, S. E. R e d . Trav. Chim. Pays-Bas. 1938, 55 ,407.

20% PyridineATh i r Workwater at 150-C(Anderson B Prausni lz, 13))A Solubility of thiophene in9 51k' \V V VI O 0 00 5 10 I 5water Thiophene

Figure9. Water-rich composit ions for water/ thiophene/pyri ine mix-tures at 100 and 150 O C (composit ions in mole percent).

6 l o I02 0

P: 1.00 0.05 0 io 0 15Mole F rac t ion Pyr id ine in Water-Rich Phase

Flgure 10. Distribution of pyridine between water-rich phase andorganic-rich phase at 100 an d 150 O C .composition dependence, approaching the vapor pressure ofthe insoluble water/hydrocarbon binary pair at low concentra-tions of phenol or pyridine, and decreasing modestly as themutual solubilities increased on addition of phenol or pyridine.The pressures reported in Tables I 1 1 and I V have beensmoothed over the measured composition ranges. Tie-linecompositions are reported as measured.

Received for review February 17, 1988. Accep ted June 20, 1988. Thiswork was supported by the Director, Office of Energy Research, Office ofBasic Energy Sciences, Chemical Sclences Division of the US. Departmentof Energy, under Con tract DE-AC03-76S F00098. Addltional support wasprovided by the donors of the P etroleum Research Fund, administered by theAmerican Chemical Society. S.M. gratefully acknowledges the Henrlch-Hertz-Foundation (West Germany) for the grant of a fellowship.

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High temp mutual solubilities for some 2° and 3° aq mixtures containing aromatic and chlorinated hydrocarbons