Measurement and Modeling for Isobaric Vapor–Liquid Equilibrium of

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Measurement and Modeling for Isobaric Vapor−Liquid Equilibrium of Binary 1,3,5-Trichlorobenzene + 3,5-Dichloroaniline and 3‑Chloroaniline + 3,5-Dichloroaniline Systems Shuo Han,† Gan-Bing Yao,† Yun-Hao Zhong,‡ Cun-Bin Du,† Long Meng,† and Hong-Kun Zhao*,† †

College of Chemistry & Chemical Engineering, Yang Zhou University, Yang Zhou, Jiangsu 225002, People’s Republic of China Overseas Education College, Nanjing Tech University, Nanjing, Jiangsu 225002, People’s Republic of China

‡

S Supporting Information *

ABSTRACT: The isobaric vapor−liquid equilibrium data for binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) were measured experimentally under pressures of 20.00, 60.00 and 101.20 kPa using an inclined ebulliometer. Thermodynamic consistency of the vapor−liquid equilibrium data was tested by means of the Herington semiempirical method, and the isobaric vapor−liquid equilibrium data were correlated with three activity coefficient models, which were Wilson, NRTL and UNIQUAC. The energy interaction parameters were acquired by a nonlinear leastsquares regression method for the three thermodynamic models. Results indicate that all the three activity coefficient models can describe the measured isobaric vapor−liquid data acceptably. The isobaric vapor−liquid equilibrium data determined in the present work are important in the design and operation for purification of 3,5-dichloroaniline by distillation.

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Herington Test (Area Test) method and (3) fit the isobaric vapor−liquid equilibrium data by Wilson, NRTL and UNIQUAC models.

INTRODUCTION 3,5-Dichloroaniline (CAS: 626-43-7) is a specific chlorinated aniline derivative. It is an important substance for production of agricultural fungicides, herbicides, insecticides and plant growth adjusting agents. Furthermore, in medicine industry, it is also applied to synthesis of quinoline derivatives.1,2 In recent years, some new applications have been found for 3,5-dichloroaniline. It is of importance to study 3,5-dichloroaniline for improvement of ring phthalimide agricultural fungicide.3−10 Many methods have been put forward to produce 3,5dichloroaniline. The earliest way reported in the literature was the reduction of 3,5-dichlorobenzene,11 which is still an important method in producing 3,5-dichloroaniline at present. However, some reactants and byproducts, e.g., 1,3,5-trichlorobenzene and 3-chloroaniline, exist in the aim product during the preparation process. The crude 3,5-dichloroaniline should be purified from its mixture before use. Distillation is an effective operation process to purify the crude mixtures, and the saturated vapor pressure data and vapor−liquid equilibrium for the system of 3,5-dichloroaniline + 1,3,5-trichlorobenzene + 3-chloroaniline must be known in advance. To the best of the authors’ present knowledge, the saturated vapor pressure data of pure 3,5dichloroaniline were determined by Li and co-workers.12 However, the vapor−liquid equilibrium data of the 3,5dichloroaniline with 1,3,5-trichlorobenzene and 3-chloroaniline, which are essential for the design of a suitable distillation tower, have not been reported so far. To enrich the detailed fundamental data of distillation for engineering fields, the object of the present paper is to (1) determine the isobaric vapor−liquid equilibrium data for binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5dichloroaniline (2) under 20.00, 60.00 and 101.20 kPa by using an inclined ebulliometer, (2) check thermodynamic consistency of the vapor−liquid equilibrium data by the © 2015 American Chemical Society

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EXPERIMENTAL SECTION Materials. 3,5-Dichloroaniline was provided by Jiangsu Kuai Da chemical Co., LTD, China, and had a purity of 0.978 with mass fraction. It was further refined by mean of recrystallization in (methanol + water) mixture with the volume ratio of 1:1. The final purity of 3,5-dichloroaniline used in experiment was confirmed by gas chromatography equipped with a flame ionization detector (Agilent 7890A Infinity GC, Agilent Technologies), the mass fraction of which was 0.9972. 1,3,5Trichlorobenzene and 3-chloroaniline were provided from Shanghai Ziyi Reagent Factory, which had a purity of 0.9964 and 0.9989 in mass fraction, respectively. No further purification was made for the two substances. More details about the 3,5dichloroaniline, 1,3,5-trichlorobenzene and 3-chloroaniline are summarized and presented in Table 1S of the Supporting Information. Apparatus and Procedure. The apparatus employed to measure the vapor−liquid equilibrium data was described elsewhere.13,14 The apparatus consisted of an inclined ebulliometer, a set of digital vacuum pressure controller with high accuracy and a vacuum pump (U4.20 model, Becker, Germany). The pressure was adjusted by a needle valve and recorded by means of a pressure sensor (type: RL-P-Y). The precision of the pressure controller was about 0.02 kPa for the range from 0 to 200 kPa. A Hewlett-Packard quartz thermometer (model Received: Revised: Accepted: Published: 3706

January 4, 2015 March 19, 2015 March 27, 2015 April 6, 2015 DOI: 10.1021/acs.iecr.5b00031 Ind. Eng. Chem. Res. 2015, 54, 3706−3710

Article

Industrial & Engineering Chemistry Research

Figure 1. Isobaric vapor−liquid equilibrium data for the 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) binary system. (a) 20.00 kPa; (b) 60.00 kPa; (c) 101.20 kPa; (■, ●) experimental data in this work; dotted line represents correlated data with Wilson model; dashed line represents correlated data with NRTL model; solid line represents correlated data with UNIQUAC model.

ρ = (τ 2 − B)/A

2810A) with a 2850A sensing probe was employed to measure the boiling point temperature, which was calibrated with a standard platinum resistance thermometer (model 8163-B) beforehand. The total uncertainty in the boiling point measurement was evaluated to be no more than 0.02 K, which was within the limits of investigated temperature. The good performance of the equipment was confirmed in the previous experiment. In this study, about 75 g of sample (1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) or 3-chloroaniline (1) + 3,5dichloroaniline (2) with different ratios) was put into the inclined ebulliometer. The pressure was maintained to a desired value by the vacuum pump. The vapor phase and the liquid phase were continuously circulating to ensure sufficient contact of the phases. The vapor phase was condensed in the condenser. When the constant temperature was kept at least 35 min, the equilibrium was assumed to be achieved. In order to confirm the equilibrium condition, the condensate and the liquid phase were examined with an interval of 15 min until the two phase composition did not vary. When equilibrium was reached, the equilibrium temperature was recorded. The samples of the equilibrium vapor phase and liquid phase were taken out simultaneously and then were analyzed by GC. Density Measurement. The density of 3,5-dichloroaniline and 1,3,5-trichlorobenzene in liquid state are not found in the previous publications. They were measured by a digital densimeter (Anton Paar, model DMA 45) at 360.15 K in the present work. The temperature was measured by a glass thermometer with a precision of ±0.02 K, and controlled by a constant temperature water bath. The density of the sample in the vibrating U-tube can be calculated according to the oscillation period, τ, by using eq 1

(1)

where A and B represent equipment constants, which are calibrated in advance with the reference densities of pure water and dry air at 360.15 K. The uncertainty of the calculated density was estimated to be ±1 kg·m−3. Analysis. The contents of the equilibrium vapor phase and liquid phase were analyzed by gas chromatography (GC, Model 7890A, Agilent Technologies), which was equipped with a flame ionization detector (FID). The type of capillary column used in the experiment was DB-1701 (30m × 0.32 mm × 0.25 μm). The carrier gas was high purity of nitrogen, the speed of which was 10 mL·min−1. The temperature of the injection chamber was maintained at 573 K. At first the detector temperature was set to 410 K, and then it raised to 510 K with a heating rate of 10 K· min−1. The three compounds can be separated well under such conditions. The GC analysis was calibrated with a series of standard solutions prepared by an electronic balance (precision: ± 0.0001 g). The injected sample volume of each phase taken for analysis was 0.2 μL. The absolute error was no greater than 0.001 in mole fraction. The analysis was carried out three times for each sample, and the average value of the three measurements was considered as the final value.

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RESULTS AND DISCUSSION Densities. The measured densities of 3,5-dichloroaniline and 1,3,5-trichlorobenzene were 1580.8 and 1220.4 kg·m−3 at 360.15 K, which are shown in Table 1S of the Supporting Information. The density value of 3-chloroaniline was 1215.9 kg·m−3 at 293.15 K, which showed good agreement with the literature value (1216.1 kg·m−3). 3707

DOI: 10.1021/acs.iecr.5b00031 Ind. Eng. Chem. Res. 2015, 54, 3706−3710

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Industrial & Engineering Chemistry Research

Figure 2. Isobaric vapor−liquid equilibrium data for the 3-chloroaniline (1) + 3,5-dichloroaniline (2) binary system. (a) 20.00 kPa; (b) 60.00 kPa; (c) 101.20 kPa; (■, ●) experimental data in this work; dotted line represents correlated data with Wilson model; dashed line represents correlated data with NRTL model; solid line represents correlated data with UNIQUAC model.

Vapor−Liquid Equilibrium Data. The measured isobaric vapor−liquid equilibrium data for the binary 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5dichloroaniline (2) systems at 20.00, 60.00 and 101.20 kPa are reported in Tables 2S and 3S of the Supporting Information. Furthermore, the plots of T−x−y and y−x at the three pressures are plotted in Figures 1 and 2. It can be seen from these figures that the two binary systems are not azeotropic. Thermodynamic Consistency Test. Some experimental errors could be introduced from deviation of the activity coefficients derived from the Gibbs−Duhem equation.15 To confirm the reliability of the data for isobaric vapor−liquid equilibrium, the thermodynamic consistency of the experimental data for the binary systems under three pressures was checked by the Herington semiempirical method.16,17 According to the test of the Herington area, if the (D − J) value is less than 10, the vapor−liquid equilibrium data are regarded as to be thermodynamically consistent. D and J can be expressed by eqs 2 and 3, respectively.

minimum boiling points of the studied binary systems, respectively. The activity coefficient, γi, can be evaluated according to the experimental vapor−liquid equilibrium data. The calculated values of (D − J) for the two binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3chloroaniline (1) + 3,5-dichloroaniline (2) under 20.00, 60.00 and 101.20 kPa are presented in Table 4S of the Supporting Information, which illustrates that the isobaric vapor−liquid equilibrium data measured in the present work can meet the criteria and are confirmed to be thermodynamically consistent. Data Correlations. When a vapor−liquid system reaches equilibrium, the chemical potential or fugacity of each component are equal in two phases. The thermodynamic relationships for the vapor−liquid phase equilibrium can be expressed as18 S ⎫ ⎧ L ⎪ Vi (p − p ) ⎪ i ⎬ yi φi V p = xiγipiS φiSexp⎨ ⎪ ⎪ RT ⎩ ⎭

where T is equilibrium temperature under pressure p, ViL represents the molar volume of constituent i, φiV and φiS represent the fugacity coefficients of constituent i in the vapor phase and in the pure state, γi represent the activity coefficient of constituent i, pSi represents the saturated vapor pressure of pure constituent, yi and xi represent the content of component i in molar fraction in the vapor phase and liquid phase, respectively, and R is the universal gas constant. As the experimental pressure studied in the present work is low, the exponential term in eq 4 is 1. The vapor phase can be regarded as ideal gas; as a result, the values of φVi and φSi are also equal to 1. Equation 5 can be deduced from eq 4, which is usually used to calculate the activity coefficients for equilibrium liquid phase and vapor phase.

x =1

D = 100 ×

∫x =1 0 ln(γ1/γ2)dx1 1

x1= 1

∫x = 0 |ln(γ1/γ2)|dx1 1

J = 150 ×

Tmax − Tmin Tmin

(4)

(2)

(3)

where ∫ xx11==01|ln(γ1/γ2)|dx1 is total area of ln(γ1/γ2) − x1 above the x-axis and below the x-axis, and ∫ x1x1==01ln(γ1/γ2)dx1, the difference between the area of ln(γ1/γ2) − x1 above the x-axis and below the x-axis. Tmax and Tmin stand for the maximum and 3708

DOI: 10.1021/acs.iecr.5b00031 Ind. Eng. Chem. Res. 2015, 54, 3706−3710

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Industrial & Engineering Chemistry Research γi =

pyi piS xi

no more than 0.11 K and 0.0013 for the Wilson equation, 0.14 K and 0.0016 for the NRTL equation and 0.33 K and 0.0045 for the UNIQUAC equation. Therefore, the three models, Wilson model, NRTL model and UNIQUAC model, can satisfactorily describe the vapor−liquid equilibrium behavior of the binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) at the different pressures. In general, the Wilson model gives the best correlated results for the two binary systems. To illustrate the effect of pressure on the isolation of 3,5dichloroaniline via distillation, the relative volatilities (αi) of the two binary system at different pressures were evaluated by means of the equation expressed as follows x 2iy1i αi = x1iy2i (9)

(5)

The isobaric vapor−liquid equilibrium data determined in the present work at three different pressures (20.00, 60.00 and 101.20 kPa) were correlated by three activity coefficient models, Wilson, NRTL and UNIQUAC, respectively (for details, see the Three Activity Coefficient Models of the Supporting Information). The two parameters’ values of UNIQUAC model for 3,5dichloroaniline, 1,3,5-trichlorobenzene and 3-chloroaniline are listed in Table 5S of the Supporting Information. Based on the vapor−liquid equilibrium data, the values of interaction parameters Λji in the Wilson equation, Δgij in the NRTL equation and uji − uii in the UNIQUAC equation were obtained by a method of nonlinear least-squares regression. The objective function (OF) is expressed as 2 ⎡⎛ ⎛ Δp ⎞2 ⎤ ΔTi ⎞ ⎢ ⎟ + ⎜⎜ i ⎟⎟ ⎥ OF = ∑ ⎜⎜ ⎢⎝ σT , i ⎟⎠ ⎝ σp , i ⎠ ⎥⎦ k=1 ⎣

where i refers to the equilibrium temperature. The evaluated relative volatilities are presented in Tables 2S and 3S of the Supporting Information. It shows that the relative volatilities increase with decreasing in pressure for 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) system; however, for the system of 3-chloroaniline (1) + 3,5-dichloroaniline (2), the effect of pressure on the relative volatility was not obvious. Furthermore, to understand the nonideality of the binary systems studied, the excess Gibbs free energies GE were evaluated from the following equation:

N

(6)

Where N stands for the number of experimental point. T is the boiling point temperature. σT,i and σp,i are estimated standard deviations in measured temperature and pressure for the ith experiment, respectively. For all calculations with the original data presented in this work, they were assigned values σT,i = 0.01 K and σp,i = 0.0005pexpt,i for all observations as a priori estimated from the properties of the experimental setup. The Antoine constants for 3,5-dichloroaniline, 1,3,5-trichlorobenzene and 3-chloroaniline are collected and shown in Table 6S of the Supporting Information. The regressed binary interaction parameters for the Wilson, NRTL and UNIQUAC models are presented in Table 7S of the Supporting Information. The root-mean-squared deviations (σT and σy1) between the evaluated and experimental values are defined as

GE(J·mol−1) = RT (x1ln γ1 + x 2 ln γ2)

(10)

where γi represents the activity coefficient, which can be evaluated from the corresponding activity coefficient model. In Figures 3 and 4, the variation of GE with the composition of 1,3,5-

N

σT =

∑i = 1 (Tical − Tiexp)2 N

(7)

N

σy1 =

∑i = 1 (y1cal − y1exp )2 i i N

(8)

The calculated root-mean-squared deviations are also given in Table 7S of the Supporting Information. The calculated temperature and vapor mole fraction by using the Wilson, NRTL and UNIQUAC models are presented in Tables 2S and 3S of the Supporting Information, and plotted in Figures 1 and 2. Furthermore, the absolute deviation of the vapor fraction (Δy) and equilibrium temperature (ΔT) between the experimental and calculated data of the vapor composition and the temperature for the systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) are also listed in Tables 2S and 3S of the Supporting Information, respectively. The results show that the calculated data have a good agreement with the experimental ones. For the 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) system, the average absolute deviations (AD) of the boiling point and the vapor mole fraction fitted by activity coefficient models are no more than 0.60 K and 0.0055 for the Wilson equation, 0.42 K and 0.0055 for the NRTL equation and 0.57 K and 0.0078 for the UNIQUAC equation. For the system of 3-chloroaniline (1) + 3,5-dichloroaniline (2), the average absolute deviations (AD) are

Figure 3. Calculated excess energy from Wilson equation against liquid molar composition for the binary system of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2): ---, 20.00 kPa; -·-, 60.00 kPa; , 101.20 kPa.

trichlorobenzene and 3-chloroaniline is plotted. Figures 3 and 4 illustrate that positive deviations behavior from the Raoult’s law is observed for the binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) at the different pressures over the whole composition range.

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CONCLUSIONS The isobaric vapor−liquid equilibrium data for the binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) were determined at 20.00, 60.00 and 101.20 kPa, respectively. The two binary systems exhibited no azeotropic behavior. The 3709

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(4) Gu, X.; Li, D.; Zhang, Q. H.; Jiang, J. L.; Liu, X. Q. Synthesis of 3,5Dichloroaniline by Catalytic Hydrogenation-Catalytic Hydrogenation of Pentachloronitrobenzene. Agrochemicals 2010, 49, 723 (China). (5) Jersak, U. D. C. D.; Scheuermann, H. D. C. D. Verfahren Zur Herstellung Von 3,5-Dihalogenanilinen. DE Patent 2,720,316, November 16, 1978. (6) Li, X. N.; Lu, C. S. Method for Synthesizing Halogen Aromatic Amines by High-Selectivity Liquid Phase Hydrogenation under the Condition of no Solvent. CN Patent 101,811,973, August, 25, 2010. (7) Qiu, Z. G. Method for Preparing Halogenated Nitrobenzene Selective Hydrogenation High-Activity Nano-Ruthenium Catalyst. CN Patent 101,569,859, November 4, 2009. (8) Li, J. X. 3,5-Dichloroaniline Preparing Process. CN Patent 1,690,040, November 2, 2005. (9) Smith, J. O.; Petruska, M. A.; Longlet, J. J. Process for the Preparation of Substituted Halogenated Aniline. WO Patent 2,004,054,961, July 1, 2004. (10) Wang, S.; Gu, X. Three Steps of para-Chloronitrobenzene Synthesis Method of 3,5-Dichloroaniline Process Optimization and Research. Guangxi J. Light Ind. 2008, 24, 17 (China). (11) Valentovic, M. A.; Rogers, B. A.; Meadows, M. K.; Conner, J. T.; Williams, E.; Hong, S. K.; Rankin, G. O. Characterization of Methemoglobin Formation Induced by 3,5-Dichloroaniline, 4-Amino2,6-dichlorophenol and 3,5-Dichlorophenylhydroxylamine. Toxicology 1997, 118, 23. (12) Li, Y. X.; Zhao, H. K.; Mao, M. L.; Yang, Z. P. Measurement and Correlation of the Vapor Pressure of 3,5-Dichloroaniline. J. Chem. Eng. Data 2013, 58, 1629. (13) Yao, G. B.; Yang, Z. P.; Zhang, B.; Xu, H.; Zhao, H. K. Vapor Pressure and Isobaric Vapor−Liquid Equilibrium for Dichloronitrobenzene Isomers. Fluid Phase Equilib. 2014, 367, 103. (14) Dong, H.; Wu, C.; Yang, X. F.; Qiu, H. Y. Measurement and Correlation of Saturated Vapor Pressure of 2,4,6,8,10-Pentamethylcyclopentasiloxane by means of an Inclined Ebulliometer. Thermochim. Acta 2009, 483, 66. (15) Jackson, P. L.; Wilsak, R. A. Thermodynamic Consistency Tests Based on the Gibbs-Duhem Equation Applied to Isothermal, Binary Vapor-Liquid Equilibrium Data: Data Evaluation and Model Testing. Fluid Phase Equilib. 1995, 103, 155. (16) Herington, E. F. G. Test of Experimental Isobaric Vapor-Liquid Equilibrium Data. J. Inst. Petrol. 1951, 37, 457. (17) Chen, S. H.; Bao, Z. B.; Lü, Z. Z.; Yang, Y. W.; Xu, W. G.; Chen, Z. M.; Ren, Q. L.; Su, B. G.; Xing, H. B. Vapor−Liquid Equilibrium for the 1,1,1-Trifluorotrichloroethane + Sulfuryl Chloride System at 101.3 kPa. J. Chem. Eng. Data 2014, 59, 16. (18) Ness, H. V.; Smith, J.; Abbott, M. Introduction to Chemical Engineering Thermodynamics, 6th ed.; McGraw-Hill: New York, 2001.

Figure 4. Calculated excess energy from Wilson equation against liquid molar composition for the binary system of 3-chloroaniline (1) + 3,5dichloroaniline (2): ---, 20.00 kPa; -·-, 60.00 kPa; , 101.20 kPa.

thermodynamic consistency of the experimental data was checked by using the Herington semiempirical method, and all the vapor−liquid equilibrium data were confirmed to be thermodynamically consistent. The isobaric vapor−liquid equilibrium data were correlated by three thermodynamic models, which corresponded to Wilson, NRTL and UNIQUAC. The average absolute deviations (AD) of the boiling point and the vapor mole fraction calculated by three thermodynamic models are all least than 0.60 K and 0.0079 for the two systems. The calculated results using the three models agree well with experimental values for the binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) at three different pressures.

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ASSOCIATED CONTENT

S Supporting Information *

Equations of Three Activity Coefficient Models listing equations of the three activity coefficient models, Wilson, NRTL and UNIQUAC, tables showing provenance and purity of the materials, experimental vapor−liquid equilibrium data, thermodynamics consistency test for two systems, values of r and q, the Antoine constants of the three compounds used in the present work, and correlation interaction parameters. This material is available free of charge via the Internet at http://pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Author

*H.-K. Zhao. E-mail: [email protected]. Tel.: + 86 514 87975568. Fax: + 86 514 87975244. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We thank the National Natural Science Foundation of China for their support (Project number: 21406192). Furthermore, the Yangzhou City Science and Technology Bureau, China (Project numbers 2012038-3 and YZ2011139) are also appreciated.

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REFERENCES

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DOI: 10.1021/acs.iecr.5b00031 Ind. Eng. Chem. Res. 2015, 54, 3706−3710