Liquid–Liquid Equilibrium for the Ternary Systems Methyl tert-Butyl

Article pubs.acs.org/jced

Liquid−Liquid Equilibrium for the Ternary Systems Methyl tert-Butyl Ketone + o‑, m‑, p‑Cresol + Water at (298.2, 313.2, and 323.2) K Shaoming Zhou,† Mochen Liao,† Dong Liu, Libo Li, and Yun Chen* Department of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, P. R. China ABSTRACT: Liquid−liquid equilibrium (LLE) for the methyl tert-butyl ketone (MTBK) + o-, m-, and p-cresol + water ternary systems, at temperatures of (298.2, 313.2, and 323.2) K and 101 kPa, were determined in this work. High distribution coefficient and selectivity values were calculated from the LLE data, which indicated that MTBK extracted cresols from wastewater with high efficiency. MTBK also has good physical properties (e.g., low solubility in water, suitable boiling point). The experimental results were regressed and correlated by the NRTL and UNIQUAC activity coefficient models, which both predicted LLE data in close agreement with experiments with RMSD below 3.5%. The corresponding binary interaction parameters were also regressed by these two models, which would be useful for separation process designing or optimizing.

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INTRODUCTION Cresols are major pollutants with high toxicity in wastewater from various industrial processes, such as coal gasification, coal liquefaction,1,2 coal pyrolysis,3 petroleum refining, and petrochemical processing.4 They are also widely used as industrial raw materials, antioxidants, herbicides, surfactants, dyes, and pigments.5,6 With high toxicity and carcinogenicity,7,8 cresols are even more toxic than phenol: the LD50 (rats oral) of o-, m-, p-cresol and phenol are 121, 242, 207, and 317 mg·kg−1, respectively.9 Therefore, cresols are listed as priority pollutants by USEPA,7 whose concentrations in industrial stream or surface water are restricted by many regulations or laws in the world.7 There are two broad kinds of methods to remove cresols from wastewater: destructive methods (e.g., incineration, chemical oxidation, photodegradation or biological degradation) and nondestructive methods (e.g., liquid−liquid extraction, membrane separation, absorption, etc.).10 Liquid−liquid extraction has been proven to be an efficient nondestructive method to recover phenolic compounds such as cresols from wastewater, with many advantages such as high throughput, versatility, and commercial efficiency. It is very difficult to separate cresols from water by distillation, during which they form azeotropic mixtures (boiling point is 372.3 K, and the mole fraction of water is 0.954). Liquid−liquid extraction is often performed to treat highly concentrated phenols and reduce the concentration from over 10,000 ppm to below 300 ppm so that the wastewater could be treated by following biological degradation. Extracting cresols or other phenolic compounds from industrial wastewater usually consists of 3 steps: First, the wastewater was pumped into an extraction column and had a countercurrent contact with the extractant at the stage of the extraction column, after which the phenols in the wastewater were reduced to below 300 ppm. Second, the extractant in the extraction phase from the top of the extraction column was recovered by distillation. Last, the residual solvent in the extracted wastewater from the bottom of the © XXXX American Chemical Society

Figure 1. Ternary diagram for experimental LLE data of the ternary system, MTBK (1) + o-cresol (2) + water (3), at (a) 298.2 K, (b) 313.2 K, and (c) 323.2 K; ■■, experimental tie-line; △, calculated data by NRTL model; ×, calculated data by UNIQUAC model.

extraction column was recovered by a stripping column.11 Then, the treated wastewater could be treated by following biological degradation. It is critical to develop an appropriate extractant for recovering cresols from wastewater with both high extraction efficiency and high cost efficiency. The extractant’s distribution coefficient, selectivity of cresols (mainly affecting extraction Received: September 22, 2016 Accepted: June 6, 2017

A

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Figure 2. Ternary diagram for experimental LLE data of the ternary system, MTBK (1) + m-cresol (2) + water (3) at (a) 298.2 K, (b) 313.2 K, and (c) 323.2 K; ■■, experimental tie-line; △, calculated data by NRTL model; ×, calculated data by UNIQUAC model.

Figure 4. Distribution coefficient (D) of cresol versus the mass fraction of cresol in aqueous phase at different temperatures; panels a, b, and c represent o-cresol, m-cresol, and p-cresol, respectively; (■) at 298.2 K, (○) at 313.2 K, and (Δ) at 323.2 K.

Luo et al.14−16 studied the LLE of ternary systems of methyl tert-butyl ether + o-, m-, p-cresol + water, and Martin et al.17 studied the water + o-, m-, or p-cresol + heptane or octane systems. Among these extractants, MIBK has been used in some industrial plants. However, some extractants suffer from various flaws such as low extraction efficiency (e.g., low D and S) and inferior physical properties, (e.g., high boiling point). Thus, MTBK, a solvent with high distribution coefficients for a range of organic solutes18,19 and low water solubility, was studied in this work for extracting cresols from the aqueous solution. The tie lines for the MTBK + o-, m-, and p-cresol + water ternary systems were studied at temperatures of (298.2, 313.2, and 323.2) K under 101 kPa, which have not been reported yet. The extraction efficiencies of MTBK for cresols were assessed by the distribution coefficient and selectivity calculated from the experimental results. The nonrandom two-liquid (NRTL)20 and universal quasi-chemical (UNIQUAC)21 activity coefficient models were used to correlate the LLE data and to calculate binary interaction parameters for the studies of LLE systems.

Figure 3. Ternary diagram for experimental LLE data of the ternary system, MTBK (1) + p-cresol (2) + water (3) at (a) 298.2 K, (b) 313.2 K, and (c) 323.2 K; ■■, experimental tie-line; △, calculated data by NRTL model; ×, calculated data by UNIQUAC model.

efficiency), and its solubility in water and boiling point (mainly affecting extractant recovery and cost efficiency) are the main considerations. Hence, quite a few studies have been performed for such purpose. Lv et al.12 reported the LLE data of ternary systems (methyl butyl ketone (MBK) + cresols + water) at (298.2 and 313.2) K. LLE data for the ternary systems methyl isobutyl ketone (MIBK) + o- or p-cresol + water, butyl acetate + o- or p-cresol + water, and isoamyl acetate + o- or p-cresol + water at 303.2 K were published by Telkikar et al.13 B

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Figure 5. Selectivity (S) of cresol versus the mass fraction of cresol in aqueous phase at different temperatures; panels a, b, and c represent o-cresol, m-cresol, and p-cresol, respectively; (■) at 298.2 K, (○) at 313.2 K, and (Δ) at 323.2 K.

Figure 6. Distribution coefficient (D) of cresol versus the mass fraction of cresol in aqueous phase at different temperatures; panels a, b, and c represent at 298.2 K, 313.2 K, and 323.2 K, respectively; (■) o-cresol, (○) m-cresol, and (Δ) p-cresol.

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EXPERIMENTAL SECTION Materials. The suppliers and the purity of materials used in this paper are listed in Table 1. The purity of these chemical reagents was verified by gas chromatography, and they were then used without further purification. Deionized water was used throughout this work. Experiment Procedure. The experimental tie lines of the MTBK + o-, m-, p-cresol + water ternary systems were studied at (298.2, 313.2, and 323.2) K and 101 kPa. Certain amounts of MTBK, cresol, and water were fed into a customized 100 mL vessel. The temperature of the vessel was controlled by a thermostatic bath, with an accuracy of ±0.1 K. After 2 h intensively agitating, the ternary mixture was settled for at least 20 h, enough to reach full phase separation and form two clear layers (or two phases). A sample of each layer was withdrawn with a syringe differently and accurately weighted, and then analyzed by a gas chromatography (GC6820, Agilent

Technologies), equipped with a flame ionization detector. The compounds were separated by a DB-5MS capillary column (30 m × 0.32 mm × 0.25 μm). The determination of mass fractions of MTBK and cresols was based on an internal standard method, for which n-butyl acetate was chosen as the standard substance for MTBK and 1,3,5-trimethylbenzene for cresols. Methanol was selected as the organic solvent for GC analysis. All samples and internal substances were prepared by mass using an analytical balance (Shimadzu AUW220D) accurate up to ±0.1 mg. The mass fraction of water in all phases was calculated by deducting that of MTBK and cresols from 1. The temperature of the GC oven was held at 313.2 K for 2 min and subsequently rose to 443.2 K at a rate of 30 K/min. High purity nitrogen was adopted as the carrier gas, whose flow rate was 30 mL/min. The temperature of the detector and the injection port was kept at 543.2 K and 523.2 K, respectively. Each sample was analyzed 3−5 times, and the mean value is C

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RESULTS AND DISCUSSION LLE Experimental Data. The tie-line data of the ternary systems MTBK + o-cresol + water, MTBK + m-cresol + water, and MTBK + p-cresol + water at (298.2, 313.2, and 323.2) K, under 101 kPa, are listed in Tables 2−4. All concentrations in Tables 2−4 are expressed in mass fractions (they were converted to mole fractions when we correlated them with the NRTL and UNIQUAC models). The tie lines were also depicted as a cut of triangular diagrams in Figures 1−3. The expression of distribution coefficient (D) and selectivity (S) is shown as follows: D=

S=

Table 1. Sourcea and Purity of the Chemical Reagents Used in This Work mass fraction

CAS number

methyl tert-butyl ketone o-cresol m-cresol p-cresol n-butyl acetate 1,3,5-trimethylbenzene methanol

>0.98 >0.995 >0.995 >0.99 >0.99 >0.99 >0.99

75-97-8 95-48-7 108-39-4 106-44-5 123-86-4 108-67-8 67-56-1

w2W

(1)

(w2 /w3)O (w2 /w3)W

(2)

where w refers to mass fraction, superscripts O and W stand for the organic phase and the aqueous phase, and subscripts 2 and 3 denote cresol and water, respectively. The values of distribution coefficient and selectivity for cresols in each studied system are listed in Tables 2−4 to evaluate the separation ability of MTBK. As shown in these tables, MTBK extracts all three cresols (o-, m-, p-) with D > 119.3 and S > 2455. The distribution coefficient and selectivity of cresols in MTBK are even higher than those of phenol: D of phenol in MTBK is 31.41−91.79, while S is 634.7−4008;19 The higher D and S of cresol than phenol may be attributed to cresol being more hydrophobic than phenol: e.g., the water solubility of cresols ( p-cresol (1.93) > m-cresol (1.90) > phenol (1.77). Taking into account that there have been industrial plants recovering phenol from wastewater with solvent extraction,24 it should be even more feasible to extract cresols from wastewater with MTBK, since higher D and S of cresols would lead to less extractant usage and fewer extraction tower stages when we design an extraction process.25 The values of distribution coefficient (D) and selectivity (S) are also plotted in Figures 4−7 as functions of cresol mass fraction in the aqueous phase. As described, D and S both decline with rising temperature; the reason may be that the hydrogen bonding interaction of water molecule is broken by increasing the temperature, which leads to considerable improvement of cresol solubility in water.26 D and S also decrease with increasing cresol mass fraction in the aqueous phase. However, D and S are still adequately large even for high cresol concentrations at 323.2 K: D > 150 and S > 3000 for cresol mass fractions higher than 0.0012. These results indicate that MTBK should be capable of treating wastewater with highly concentrated cresols, which further strengthens the advantage of LLE in treating phenolic wastewater over other methods, e.g., biological degradation and absorption method, whose treatment capacities are usually under 300 ppm.27 The boiling point of MTBK is 379 K, quite lower than that of other extractants (e.g., MIBK, 389 K; MBK, 403 K). Thus, MTBK could be recovered with less energy consumption after extraction. On the other hand, its boiling point is considerably higher than that of ethers (MTBE, 328 K; diisopropyl ether, 341 K). Thus, a MTBK-based extraction process could be performed at a wider temperature range, a desirable advantage when we extract wastewater with high concentration paraffin

Figure 7. Selectivity (S) of cresol versus the mass fraction of cresols in aqueous phase at different temperatures; panels a, b, and c represent at 298.2 K, 313.2 K, and 323.2 K, respectively; (■) o-cresol, (○) m-cresol, and (Δ) p-cresol.

component

w2O

a

All reagents in this table were obtained from Xiya Reagent Research Center.

reported in the work. The uncertainty of each compound in the aqueous or organic layer was calculated by GUM and NIST guidelines.22 D

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Table 2. Experimental LLE Data (Mass Fraction) for the Ternary System MTBK (1) + o-Cresol (2) + Water (3) at 298.2 K, 313.2 K, and 323.2 K, under 101 kPaa organic phase

aqueous phase

T/K

w1

w2

w3

w1

w2

w3

D

S

298.2

0.63955 0.65644 0.68839 0.69747 0.72506 0.73185 0.73784 0.76239 0.77707 0.98529b 0.62872 0.66312 0.71394 0.73900 0.76582 0.79376 0.81266 0.83382 0.85319 0.98272b 0.67022 0.69726 0.72516 0.74961 0.77159 0.79667 0.81671 0.82964 0.85421 0.98187b

0.31884 0.30303 0.27633 0.26897 0.24350 0.23724 0.23158 0.20855 0.19448 0.00000b 0.32591 0.29379 0.24527 0.22545 0.20211 0.17525 0.15756 0.13753 0.12046 0.00000b 0.28415 0.25782 0.23105 0.20908 0.18826 0.16581 0.14920 0.13697 0.11469 0.00000b

0.04161 0.04053 0.03528 0.03357 0.03144 0.03092 0.03057 0.02906 0.02845 0.01471b 0.04537 0.04308 0.04078 0.03555 0.03208 0.03100 0.02977 0.02865 0.02635 0.01728b 0.04564 0.04492 0.04379 0.04131 0.04015 0.03753 0.03409 0.03339 0.03111 0.01813b

0.00832 0.00872 0.00933 0.00984 0.01094 0.01195 0.01239 0.01355 0.01397 0.01916b 0.00803 0.00895 0.00922 0.01027 0.01047 0.01128 0.01182 0.01213 0.01251 0.01592b 0.00853 0.00875 0.00930 0.00952 0.01050 0.01081 0.01126 0.01167 0.01197 0.01495b

0.00218 0.00179 0.00150 0.00141 0.00107 0.00099 0.00093 0.00077 0.00069 0.00000b 0.00215 0.00190 0.00149 0.00118 0.00100 0.00081 0.00064 0.00049 0.00037 0.00000b 0.00205 0.00158 0.00133 0.00106 0.00087 0.00074 0.00063 0.00053 0.00041 0.00000b

0.98949 0.98948 0.98917 0.98875 0.98799 0.98707 0.98668 0.98568 0.98534 0.98084b 0.98982 0.98915 0.98929 0.98854 0.98854 0.98792 0.98755 0.98738 0.98712 0.98408b 0.98942 0.98967 0.98937 0.98943 0.98863 0.98845 0.98810 0.98780 0.98762 0.98505b

145.9 169.0 183.9 190.4 227.1 240.5 248.8 270.2 280.8

3470 4126 5155 5609 7134 7678 8028 9163 9724

151.6 154.5 165.1 190.8 203.1 217.3 247.1 279.1 324.9

3308 3547 4004 5304 6259 6926 8197 9618 12171

138.6 163.1 173.9 197.7 217.0 223.9 235.4 258.0 280.2

3006 3594 3928 4736 5345 5896 6824 7633 8896

313.2

323.2

a

W W O O Standard uncertainties u are u(T) = 0.1 K, u(P) = 1 kPa, u(wW 1 ) = 0.0049, u(w2 ) = 0.0036, u(w3 ) = 0.0061, u(w1 ) = 0.0085, u(w2 ) = 0.0066, u(wO3 ) = 0.0107. bEnd point data taken from ref 18.

Table 3. Experimental LLE Data (Mass Fraction) for the Ternary System MTBK (1) + m-Cresol (2) + Water (3) at 298.2 K, 313.2 K, and 323.2 K, under 101 kPaa organic phase

aqueous phase

T/K

w1

w2

w3

w1

w2

w3

D

S

298.2

0.64070 0.66131 0.69895 0.72994 0.74793 0.75640 0.76632 0.78234 0.79883 0.98529b 0.63723 0.69689 0.73197 0.76254 0.79610 0.82673 0.83996 0.86896 0.89422 0.98272b

0.31725 0.29944 0.26586 0.23893 0.21731 0.20943 0.20059 0.18639 0.17289 0.00000b 0.31847 0.26174 0.23292 0.20409 0.17222 0.14271 0.12979 0.10216 0.07816 0.00000b

0.04206 0.03925 0.03519 0.03113 0.03476 0.03417 0.03309 0.03127 0.02828 0.01471b 0.04430 0.04138 0.03511 0.03337 0.03168 0.03056 0.03026 0.02888 0.02763 0.01728b

0.00789 0.00843 0.01089 0.01132 0.01196 0.01238 0.01296 0.01330 0.01448 0.01916b 0.00775 0.00749 0.00997 0.01013 0.01045 0.01087 0.01131 0.01157 0.01207 0.01592b

0.00239 0.00199 0.00155 0.00138 0.00110 0.00098 0.00088 0.00077 0.00062 0.00000b 0.00249 0.00185 0.00153 0.00118 0.00097 0.00073 0.00063 0.00048 0.00033 0.00000b

0.98971 0.98958 0.98756 0.98731 0.98694 0.98664 0.98616 0.98593 0.98490 0.98084b 0.98976 0.99065 0.98850 0.98869 0.98858 0.98840 0.98806 0.98795 0.98761 0.98408b

132.6 150.6 171.2 173.2 197.7 213.4 228.2 241.5 277.4

3120 3796 4805 5495 5614 6163 6801 7616 9661

128.0 141.1 152.6 173.1 176.9 195.6 206.7 214.2 240.3

2860 3379 4296 5128 5522 6326 6750 7328 8589

313.2

E

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Table 3. continued organic phase

aqueous phase

T/K

w1

w2

w3

w1

w2

w3

D

S

323.2

0.63517 0.69141 0.73888 0.75313 0.78104 0.80161 0.81719 0.83747 0.85897 0.98187b

0.31672 0.26153 0.21467 0.20093 0.17649 0.15856 0.14726 0.12924 0.10817 0.00000b

0.04812 0.04706 0.04645 0.04594 0.04247 0.03983 0.03554 0.03329 0.03286 0.01813b

0.00707 0.00891 0.00979 0.01024 0.01052 0.01062 0.01076 0.01091 0.01137 0.01495b

0.00266 0.00205 0.00158 0.00128 0.00112 0.00094 0.00080 0.00062 0.00048 0.00000b

0.99027 0.98904 0.98863 0.98848 0.98835 0.98844 0.98844 0.98847 0.98815 0.98505b

119.3 127.5 135.8 157.0 157.1 169.5 183.5 208.2 225.9

2455 2679 2890 3378 3656 4205 5104 6182 6793

a

W W O O Standard uncertainties u are u(T) = 0.1 K, u(P) = 1 kPa, u(wW 1 ) = 0.0049, u(w2 ) = 0.0036, u(w3 ) = 0.0061, u(w1 ) = 0.0085, u(w2 ) = 0.0066, b O u(w3 ) = 0.0107. End point data taken from ref 18.

Table 4. Experimental LLE Data (Mass Fraction) for the Ternary System MTBK (1) + p-Cresol (2) + Water (3) at 298.2 K, 313.2 K, and 323.2 K, under 101 kPaa organic phase

aqueous phase

T/K

w1

w2

w3

w1

w2

w3

D

S

298.2

0.62148 0.66468 0.68920 0.72809 0.74183 0.75516 0.77860 0.79673 0.81229 0.98529b 0.64699 0.68649 0.73148 0.77115 0.79588 0.82844 0.84035 0.87054 0.89481 0.98272b 0.62894 0.67548 0.71809 0.74981 0.78594 0.80636 0.82793 0.85245 0.87527 0.98187b

0.33663 0.29577 0.27373 0.23724 0.22613 0.21546 0.19264 0.17509 0.16018 0.00000b 0.30749 0.27219 0.23134 0.19442 0.17200 0.14358 0.13246 0.10274 0.08013 0.00000b 0.32218 0.27857 0.24176 0.21069 0.17561 0.15596 0.13703 0.11297 0.09437 0.00000b

0.04189 0.03955 0.03707 0.03467 0.03204 0.02938 0.02876 0.02818 0.02754 0.01471b 0.04551 0.04132 0.03718 0.03442 0.03212 0.02798 0.02720 0.02672 0.02505 0.01728b 0.04888 0.04595 0.04015 0.03950 0.03846 0.03768 0.03504 0.03458 0.03036 0.01813b

0.00745 0.00829 0.01029 0.01167 0.01202 0.01253 0.01265 0.01320 0.01446 0.01916b 0.00709 0.00812 0.00875 0.00891 0.01002 0.01035 0.01078 0.01091 0.01175 0.01592b 0.00640 0.00759 0.00851 0.00900 0.00973 0.01040 0.01072 0.01111 0.01152 0.01495b

0.00235 0.00180 0.00161 0.00119 0.00102 0.00085 0.00073 0.00063 0.00052 0.00000b 0.00230 0.00193 0.00142 0.00109 0.00089 0.00070 0.00062 0.00042 0.00029 0.00000b 0.00256 0.00212 0.00151 0.00118 0.00091 0.00083 0.00065 0.00051 0.00036 0.00000b

0.99020 0.98990 0.98809 0.98715 0.98696 0.98662 0.98662 0.98616 0.98502 0.98084b 0.99060 0.98995 0.98983 0.99000 0.98908 0.98895 0.98860 0.98867 0.98795 0.98408b 0.99105 0.99029 0.98998 0.98982 0.98936 0.98877 0.98862 0.98839 0.98812 0.98505b

143.4 164.0 169.5 200.2 221.4 252.2 264.0 276.1 309.4

3390 4105 4519 5700 6818 8469 9055 9661 11068

133.4 141.0 163.4 178.2 192.9 206.4 214.2 244.1 274.6

2904 3379 4350 5125 5939 7294 7786 9032 10829

126.0 131.5 160.1 178.7 193.7 187.2 209.7 223.5 262.2

2555 2833 3948 4478 4983 4913 5917 6387 8535

313.2

323.2

a

W W O O Standard uncertainties u are u(T) = 0.1 K, u(P) = 1 kPa, u(wW 1 ) = 0.0049, u(w2 ) = 0.0036, u(w3 ) = 0.0061, u(w1 ) = 0.0085, u(w2 ) = 0.0066, b O u(w3 ) = 0.0107. End point data taken from ref 18.

Tie-Line Data Correlation. The NRTL20 and UNIQUAC21 models were used to correlate the LLE data of studied ternary systems. The structural parameters, r (volume parameter) and q (surface parameter), of the UNIQUAC model are shown in Table 5 and taken from the literature.28 The non-randomness parameters (αij) for the NRTL model are presented in Table 6. The binary interaction parameters of the NRTL and UNIQUAC

(melting point: 328.15−335.15 K) at higher temperatures to avoid paraffin clogging the extraction installation.11 The water solubility of MTBK is quite small, 2.44 g/(100 g of water), indicating that this extractant can be recovered easily from the solvent stripping column. All these results show promising application potential of MTBK in extracting cresols from wastewater with high extraction efficiency and desirable physical properties. F

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Table 5. UNIQUAC Structural Parameters r and q component

r

q

water MTBK o-cresol m-cresol p-cresol

0.9200 4.5952 4.2867 4.2867 4.2867

1.4000 4.0320 3.2480 3.2480 3.2480

cal where wexp ijk and wijk mean the experimental tie lines and calculated data for the mass fraction of the component i in the phase j for the kth tie line. The RMSD values of the NRTL or UNIQUAC models are all smaller than 3.5%, as shown in Table 6, which further confirms the agreement between these two thermodynamic models and experiments for the studied LLE systems.

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CONCLUSIONS LLE tie lines for the (MTBK + o-, m-, p-cresol + water) ternary systems were determined at (298.2, 313.2, and 323.2) K and 101 kPa. High separation indexes including distribution coefficients and selectivities, were calculated from the LLE data, which manifest that MTBK could efficiently separate cresols from water. MTBK also shows better physical properties (e.g., moderate boiling point, low water solubility) than other extractants. Additionally, the experimental LLE data were compared with the values correlated by using NRTL and UNIQUAC models, which indicate that both thermodynamic models describe the phase behavior of the discussed systems with high accuracy. The determined tie lines and calculated binary interaction parameters in this work should be helpful when an industrial process to extract high concentration cresols from wastewater is designed or optimized.

models were determined by minimizing the objective function (eq 5) and are listed in Table 6. 3

OF =

2

⎡ (x exp − x cal)2 ⎤ ijk ijk ⎥ 2 ⎥⎦ σ w k=1 ⎣ n

∑ ∑ ∑ ⎢⎢ i=1 j=1

(5)

here xijk denote the mole fraction of the component i in the phase j for the kth tie-line, and the superscripts exp and cal represent the experimental data and calculated data, respectively. σw denotes the standard deviation of the mole fraction. The calculated LLE data from the NRTL or UNIQUAC models are compared with experimental data in Figures 1−3, which shows satisfying consistency between them. The consistency of experimental tie lines and calculated data from the NRTL or UNIQUAC models was also assessed by the root-mean-square-deviation (RMSD): ⎡ ∑3 ∑2 ∑n (w exp − w cal)2 ⎤1/2 ijk ijk i=1 j=1 k=1 ⎥ RMSD = ⎢ ⎢ ⎥ 6 n ⎣ ⎦

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AUTHOR INFORMATION

Corresponding Author

*Tel: +8613632384249. E-mail: [email protected].

(6)

Table 6. NRTL and UNIQUAC Binary Interaction Parameters and RMSD Values for the Studied Systems, MTBK (1) + Cresols (2) + Water (3) UNIQUAC T/K

i-j

uij − ujj/J/mol

298.2

1-2 1-3 2-3 1-2 1-3 2-3 1-2 1-3 2-3

19426.43 −4827.33 136.39 −2573.73 −4441.77 888.68 2306.52 −4106.34 936.63

1-2 1-3 2-3 1-2 1-3 2-3 1-2 1-3 2-3

2457.15 −3946.96 92.44 −165.68 −3556.71 81.31 −2423.91 −4034.53 1451.90

1-2 1-3 2-3 1-2 1-3 2-3 1-2 1-3 2-3

19513.96 −4465.04 −8.50 −2297.37 −4055.06 741.56 579.92 −3474.15 548.55

313.2

323.2

298.2

313.2

323.2

298.2

313.2

323.2

uji − uii/J/mol

NRTL RMSD

gij − gjj/J/mol

MTBK (1) + o-Cresol (2) + Water (3) −333.49 0.00222 −20411.80 −604.72 2425.21 14842.09 −610.65 2556.95 0.00347 5357.78 −845.63 2137.24 −3329.56 −3354.20 414.23 0.00135 −9219.24 −1008.2 1822.99 −2234.23 −2596.69 MTBK (1) + m-Cresol (2) + Water (3) 687.61 0.00274 −21796.10 −751.42 7615.35 −837.03 −37792.30 1196.69 0.00210 −2237.55 −1098.01 7708.71 −2335.98 −39220.80 2385.98 0.00272 3911.78 −1045.01 1684.42 −4106.48 −4086.08 MTBK (1) + p-Cresol (2) + Water (3) −1225.13 0.00255 −33901.30 −689.42 8065.54 14664.6 473.81 2297.30 0.00104 6191.17 −1022.24 8169.85 −3166.85 −3317.23 968.68 0.00200 −3440.79 −1209.25 7713.72 −2626.45 −1910.12 G

gji − gii/J/mol

αij

RMSD

−3850.14 12106.17 −4221.57 −5915.38 13532.35 19007.91 −1785.30 14440.53 11925.06

0.3 0.2 0.2 0.3 0.2 0.2 0.3 0.2 0.2

0.00214

−3115.34 −14687.10 −25056.70 −1788.99 −14460.80 −3528.52 −5210.32 14602.28 19896.82

0.3 0.2 0.2 0.3 0.2 0.2 0.3 0.2 0.2

0.00280

−4009.05 −14971.30 −19773.90 −5721.93 −14669.30 18924.17 −1915.32 −14640.30 16062.07

0.3 0.2 0.2 0.3 0.2 0.2 0.3 0.2 0.2

0.00286

0.00133

0.00204

0.00289

0.00261

0.00088

0.00199

DOI: 10.1021/acs.jced.6b00825 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

Article

ORCID

methoxy-2-methylpropane + o-Cresol + Water at 298.15 and 313.15 K. J. Chem. Eng. Data 2015, 60, 1396−1400. (17) Martin, A.; Klauck, M.; Grenner, A.; Meinhardt, R.; Martin, D.; Schmelzer, J. Liquid−Liquid(−Liquid) Equilibria in Ternary Systems of Aliphatic Hydrocarbons (Heptane or Octane) + Phenols + Water. J. Chem. Eng. Data 2011, 56, 741−749. (18) Liu, D.; Luo, L.; Li, L.; Chen, Y. Liquid−Liquid Equilibria for the Methyl Tert-Butyl Ketone + Phenol + Water Ternary System at 298.15, 313.15 and 323.15 K. J. Solution Chem. 2015, 44, 1891−1899. (19) Liu, D.; Li, L.; Luo, L.; Chen, Y. Liquid phase Equilibria of the Water + Propionic or Butyric Acid + Methyl tert-Butyl Ketone Ternary Systems at (298.15 and 323.15) K. J. Chem. Eng. Data 2015, 60, 2612−2617. (20) Renon, H.; Prausnitz, J. M. Local compositions in thermodynamic excess functions for liquid mixtures. AIChE J. 1968, 14, 135−144. (21) Abrams, D. S.; Prausnitz, J. M. Statistical thermodynamics of liquid mixtures: A new expression for the excess Gibbs energy of partly or completely miscible systems. AIChE J. 1975, 21, 116−128. (22) BIPM IEC; IFCC I; IUPAC I. Evaluation of measurement dataguide for the expression of uncertainty in measurement. JCGM 100:2008. Citado en las, 2008: 167. (23) Cheng, N. Solvents Handbook, 3rd ed.; Chemical Industry Press: Beijing, 2002. (24) Yang, C.; Qian, Y.; Zhang, L.; Feng, J. Z. Solvent extraction process development and on-site trial-plant for phenol removal from industrial coal-gasification wastewater. Chem. Eng. J. 2006, 117, 179− 185. (25) Marciniak, A.; Krolikowski, M. Ternary liquid-liquid equilibria of bis(trifluoromethylsulfonyl)-amide based ionic liquids + methanol + heptane. Fluid Phase Equilib. 2012, 318, 56−60. (26) Wang, Z.; Wang, H.; Liu, D.; Chen, Y. Experimental study on removal of phenols from coal chemical wastewater. Chem. Eng. (China) 2016, 44, 7−11. (27) Sheng, C.; Gui, C.; Guang, G. Application of complexing centrifugal extraction in the treatment of high concentrated phenolic wastewater. Coal Chem. Ind. (in Chinese) 2009, 1, 42−44. (28) Magnussen, T.; Rasmussen, P.; Fredenslund, A. UNIFAC parameter table for prediction of liquid-liquid equilibriums. Ind. Eng. Chem. Process Des. Dev. 1981, 20, 331−339.

Yun Chen: 0000-0001-5784-2602 Author Contributions †

S.Z. and M.L.: equal contribution.

Funding

Financial support from the Fundamental Research Funds for the Central Universities, SCUT (2014ZZ0057) and SCUT (2015ZM046), the Project of the Science & Technology New Star of Pearl River in Guangzhou (2011J2200056), the Guangdong Science Foundation (2014A030310260), and National Science Foundation of China (20906028) is gratefully acknowledged. Notes

The authors declare no competing financial interest.

■

REFERENCES

(1) Ji, Q.; Tabassum, S.; Hena, S.; Silva, C. G.; Yu, G.; Zhang, Z. A review on the coal gasification wastewater treatment technologies: past, present and future outlook. J. Cleaner Prod. 2016, 126, 38−55. (2) Villegas, L. G. C.; Mashhadi, N.; Chen, M.; Mukherjee, D.; Taylor, K. E.; Biswas, N. A Short Review of Techniques for Phenol Removal from Wastewater. Curr. Pollution Rep. 2016, 2, 157−167. (3) Cypres, R.; Furfari, S.; Ghodsi, M. Hydropyrolysis-Third way for coal conversion. Erdol Kohle Erdgas Petrochemie 1983, 36, 471−477. (4) Zhou, J.; Duan, W.; Xu, J.; Yang, Y. Experimental and Simulation Study on the Extraction of p-Cresol Using Centrifugal Extractors. Chin. J. Chem. Eng. 2007, 15, 209−214. (5) Surkatti, R.; El-Naas, M. H. Biological treatment of wastewater contaminated with p-cresol using Pseudomonas putida immobilized in polyvinyl alcohol (PVA) gel. J. Water Process Eng. 2014, 1, 84−90. (6) del Olmo, M.; Díez, C.; Molina, A.; de Orbe, I.; Vílchez, J. L. Resolution of phenol, o-cresol,m-cresol and p-cresol mixtures by excitation fluorescence using partial leastsquares (PLS) multivariate calibration. Anal. Chim. Acta 1996, 335, 23−33. (7) Basheer, F.; Farooqi, I. H. Biodegradation of p-cresol by aerobic granules in sequencing batch reactor. J. Environ. Sci. 2012, 24, 2012− 2018. (8) Sanders, J. M.; Bucher, J. R.; Peckham, J. C.; Kissling, G. E.; Hejtmancik, M. R.; Chhabra, R. S. Carcinogenesis studies of cresols in rats and mice. Toxicology 2009, 257, 33−39. (9) Chen, Y.; Wang, H.; Lv, R.; Li, L. Liquid-liquid equilibria for methyl isobutyl ketone+cresols+water at 333.15K, 343.15K and 353.15K: Experimental results and data correlation. Fluid Phase Equilib. 2016, 427, 291−296. (10) Li, Z.; Wu, M.; Jiao, Z. Extraction of phenol from wastewater by N -octanoylpyrrolidine. J. Hazard. Mater. 2004, 114, 111−114. (11) Yang, C.; Yang, S.; Qian, Y. Simulation and Operation Cost Estimate for Phenol Extraction and Solvent Recovery Process of CoalGasification Wastewater. Ind. Eng. Chem. Res. 2013, 52, 12108−12115. (12) Lv, R.; Wang, Z.; Li, L.; Chen, Y. Liquid−liquid equilibria in the ternary systems water+cresols+methyl butyl ketone at 298.2 and 313.2K: Experimental data and correlation. Fluid Phase Equilib. 2015, 404, 89−95. (13) Telkikar, V. S.; Ramanarao, M. V.; Husain, A. Solubility & Equilibrium Data of ortho & para Cresols with Water in Methyl sobutyl Ketone, n-Butyl Acetate & Isoamyl Acetate at 30°C. Indian J. Technol. 1965, 3, 175−178. (14) Luo, L.; Liu, D.; Li, L.; Chen, Y. Measurements and thermodynamic modeling of liquid-liquid equilibria in ternary system 2-methoxy-2-methylpropane + p-cresol + water under atmospheric pressure. Chin. J. Chem. Eng. 2016, 24, 360−364. (15) Luo, L.; Li, L.; Liu, D.; Chen, Y. Ternary Liquid−Liquid Equilibria for the System 2-Methoxy-2-methylpropane + m-Cresol + Water at 298.15 and 313.15 K: Experimental Data and Correlation. J. Solution Chem. 2015, 44, 2393−2404. (16) Luo, L.; Liu, D.; Li, L.; Chen, Y. Experimental determination and correlation of liquid-liquid equilibria for the ternary system 2H

DOI: 10.1021/acs.jced.6b00825 J. Chem. Eng. Data XXXX, XXX, XXX−XXX