Solubilities of Sodium 1- and 2-Naphthalenesulfonate in Aqueous


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Solubilities of Sodium 1- and 2-Naphthalenesulfonate in Aqueous Sodium Hydroxide Solutions and Its Application for Optimizing the Production of 2-Naphthol Rui-Xiong Zhao, Kang-Kang Pei, Guoliang Zhang, qing xia, and Fengbao Zhang Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.7b02516 • Publication Date (Web): 18 Aug 2017 Downloaded from http://pubs.acs.org on August 22, 2017

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Solubilities of Sodium 1- and 2-Naphthalenesulfonate in Aqueous Sodium Hydroxide Solutions and Its Application for Optimizing the Production of 2-Naphthol Rui-Xiong Zhao, Kang-Kang Pei, Guo-Liang Zhang, Qing Xia*, Feng-Bao Zhang* School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, PR China. ABSTRACT: The solubilities of sodium 1- and 2-naphthalenesulfonate (1- and 2-SNS) in aqueous sodium hydroxide solutions were measured over the temperature range from 276 to 337 K at atmospheric pressure by a dynamic method. The experimental results showed that the solubilities of 1- and 2-SNS both increased with temperature and decreased with concentrations of aqueous sodium hydroxide solutions. The experimental data were correlated with the new electrolyte nonrandom two-liquid (E-NRTL) model. The calculated results showed good agreement with the experimental data. A new strategy, based on the solubility difference between 1- and 2-SNS in aqueous sodium hydroxide solutions was carried out in laboratory scale. This new strategy, in which the current process of blowing naphthalene was replaced by removing the by-product according to the solubility difference, overcame the drawbacks of blowing naphthalene and made a good separation effect. The best separation effect was attained when the concentration of aqueous sodium hydroxide solution was 0.07 and the operating temperature was 298.15 K. The purities of obtained 1- and 2-SNS were 0.8369 and 0.9854 in this operating condition,

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respectively. The new strategy had potential in the industrial application for optimizing the production of 2-naphthol. 1. INTRODUCTION

2-naphthol (MF C10H8O, CAS No. 135-19-3) is a critical material of fine chemicals in the production of organic dyes and dyeing intermediates,1-3 which is widely used in the synthesis of medicine, perfume, catalyst, rubber chemicals, et al.4-8 Its down-stream products also have extensive market foreground which are applied to the synthesis of photosensitive materials like 1-hydroxy-2-naphthoic acid and liquid crystals.9 China and India have become the main producers now. The sulfonation-alkali fusion process,10 as the most mature synthesis technology,11,12 is used in current production of 2-naphthol. The main processes are illustrated in Figure 1,13 which consists of sulfonation, hydrolyzation, neutralization, alkali fusion and acidification procedures.14 Firstly, naphthalene is sulfonated by excess amount of concentrated sulfuric acid at about 438.15 K. Then, sodium sulfite is introduced

to

the

residue

of

sulfonation

reaction

to

obtain

sodium

2-naphthalenesulfonate (2-SNS). Next, solid 2-SNS, which is separated after crystallization and filtration, is used to obtain sodium 2-naphthol by alkali fusion at around 598.15 K. Finally, 2-naphthol is obtained from mother liquor of alkali fusion reaction by attenuation, acidification, washing, desiccation and distillation.15,16

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Figure 1. The synthetic route of 2-naphthol. There are two main products in the sulfonation of naphthalene, the target product 2-naphthalenesulfonic acid (2-NSA) (about 0.85 mole fraction) and by-product 1-naphthalenesulfonic acid (1-NSA) (about 0.15 mole fraction).17 In the current industrial process, byproduct 1-NSA is removed by hydrolysis into naphthalene and sulfuric acid at 413.15-418.15 K.18 Naphthalene is blown out by pressurized steam and reused in sulfonation reaction.19 Extra concentrated sulfuric acid is consumed by repeated sulfonation and hydrolysis. Meanwhile, large amount of steam is consumed, and the working environment becomes worse because of blowing naphthalene.20 Therefore, further improvement in the process is needed. As we all know, there are many differences in properties between position isomers such as boiling point, solubility, toxicity et al. We hope to remove the by-product by solubility difference of position isomer. However, it is hard to separate 1-NSA and 2-NSA (1- and 2-NSA) in the sulfonation mixture. For this reason, we focus on separation them after neutralization reaction, that is, separation 1-SNS and 2-SNS. The feasibility of the new strategy depends on the solubility difference of 1- and 2-SNS in aqueous sodium hydroxide solutions. However, no relative solubility data can be found in popular reference books and databases. In this work, the solubilities of 1- and 2-SNS in aqueous sodium hydroxide solutions have been measured by a dynamic method over the temperature range from 276 to 337 K and concentrations of aqueous sodium hydroxide solutions range from 0.00 to 0.09 (solute-free mass fraction of sodium hydroxide) at atmospheric pressure.

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The experimental data were correlated with the new electrolyte nonrandom two-liquid (E-NRTL) model which could provide reliable results for mixed solvent electrolyte systems.21 According to the determined solubility data, a new method for optimizing the production of 2-naphthol is proposed and discussed. 2. EXPERIMENTAL SECTION 2.1. Materials Preparation. The information of the materials used in the experiment is listed in Table 1. The purchased 1- and 2-SNS were recrystallized three times from deionised water and then dried in a vacuum oven to constant weight at 333.15 K before measurement. High Performance Liquid Chromatography (HPLC, Hitachi L-7100, Japan) has been used to test the purity of 1-and 2-SNS, the results are presented in Figure S1 and Figure S2 (Supporting Information). Table 1. Provenance and Mass Fraction Purity of the Materials Used in This Study. Mass fraction Materials

sources purity

1-SNS

0.99

TCI(Shanghai)Development Co.,Ltd.Shanghai,China

2-SNS

0.99

Adamas-beta Chemical Reagents Co.Shanghai,China. GuangFu Technoligy Development Co. Ltd.Tianjin,

sodium hydroxide

0.98 China.

deionized water

Nankai Chemical Reagents Co.Tianjin,China.

2.2. Apparatus and Procedure of Solubility Measurement. The solubility was measured by the dynamic method, combined with the laser monitoring observation 4 ACS Paragon Plus Environment

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technique to observe the dissolving processes and determine the temperature of solid-liquid equilibrium (SLE). A cold-water condenser tube was connected with the glass vessel to cool the evaporation of the solvent. The apparatus and procedure of the solubility experiments were described in detail previously.22,23 Prepared solvent and solute were weighed using an electronic analytical balance (Gibertini, Crystal 200, Italy, accuracy of ± 0.0001g) and transferred into a jacketed glass vessel. The mixtures were stirred continuously with a magnetic stir bar and heated slowly at a rate less than 0.2 K·h−1. The temperature of the solution, which was controlled by a refrigerated/heating circulator (Julabo FP45-HE, Germany, temperature stability ±0.01 K), was measured by a platinum resistance thermometer (PT-100, calibrated with an accuracy of 0.01 K). The temperature of the SLE was recorded when the last crystal disappeared, meanwhile, the intensity of the laser beam reached a maximum value and kept steady.

3. RESULTS AND DISCUSSION 3.1. Solubility Data and Correlation. 3.1.1. Solubility Data. The molality solubility data of 1- and 2-SNS in aqueous sodium hydroxide solutions are presented in Tables S1 and S2 (Supporting Information), where T exp is the measured absolute temperature, m1 and m2 are molality solubilities of 1- and 2-SNS in aqueous sodium hydroxide solutions, respectively, and w30 is the solute-free mass fraction of sodium hydroxide in the solvent. 3.1.2. Solubility Equations Description. Solubility product is used to describe the SLE, and it is shown as follows: 5 ACS Paragon Plus Environment

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K s = a+v + a−v − = (γ + x+ ) v + (γ − x− ) v −

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(1)

where v , a , γ , x denote the electrolyte stoichiometric number, activity, activity coefficient, and the molarity of the ions, respectively. The subscripts (+) and (-) indicate cation and anion, respectively. K s is the solubility product constant, which can be calculated by the Van’t Hoff equation as follows: ln K s = A +

B T

(2)

where T is the absolute temperature in Kelvin; A and B , which are given in Table S3, are constants obtained by regressing solubility data. 3.1.3. The E-NRTL Thermodynamic Model Description. The E-NRTL model, which is suitable for electrolyte systems, is used for calculation of the activity coefficients in this work.24 The activity coefficients of naphthalene sulfonate are denoted as unsymmetric activity coefficients because of their strong polarity. The E-NRTL thermodynamic model for this work is defined as follows24: ln γ i* = ln γ i* PHD + ln γ i*lc

(3)

ln γ i*lc = ln γ ilc − ln γ ilc ,∞

(4)

where i = c,a , c and a refer to the cation and anion, respectively. The superscript

∗ denotes the unsymmetric reference. ln γ i* PHD is the Long-Range Interaction Contribution of electrolyte system represented by the Pitzer-Debye-Hückel (PDH) equation. ln γ i*lc is the Short-Range Interaction Contribution, which is between molecular and ionic species, and described by the NRTL equation. The activity coefficients of cation and anion are normalized to the unsymmetric activity coefficients by the formula (4). The detailed expressions of ln γ i* PDH , ln γ ilc

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are given by the paper of Chen et al.25 The expression of ln γ ilc ,∞ in the naphthalene sulfonate + NaOH + water systems is described as:

ln γ ilc ,∞ = zi ( Gimτ im + τ mi )

(5)

Gim = f (Gnj ),τ im = g (τ nj ),τ mi = h(τ nj )

(6)

Gnj = exp ( −ατ nj ) ( n ≠ j )

(7)

where zi , α represent the charge number of cation and anion, nonrandomness factor parameter which is fixed as the constant 0.2, respectively. G and τ are the E-NRTL model parameters which are expressed as the function of temperature. Gim ,

τ im , τ mi are used when solutes are described by ions, Gnj and τ nj are used when solutes are described by molecules. The relationships between Gim and Gnj , τ mi and τ nj , τ im and τ nj are described in detail elsewhere.24 Subscript i , m refer to the ions and solvent, respectively. Both n and j denote the components in the mixture, which are sodium naphthalene sulfonate, sodium hydroxide and water in present work. The format of τ nj is written as follows:

τ nj = anj + bnj / T ( n ≠ j )

(8)

where anj and bnj given in Table S4 are constants which represent the temperature dependence of τ nj . 3.1.4. Correlation of Experimental Data. The Nelder-Mead Simplex Method26 combined with Matlab (Mathwork, MA) are used to determine the E-NRTL model parameters. The optimization process was aimed at minimizing the following objective function.

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2 N  σ = ∑ (T exp − T ) / ( N − 1)   i =1 

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0.5

(9)

where the σ given in Table S5 denotes the RMSD (root-mean-square deviations) between T exp and T . N represents the count of experimental points. The root-mean-square deviations range from 0.03 to 0.45 K. It can be proved that the calculated solubility data show good agreement with the experimental data. Figures 2 and 3 show the plots of m1 and m2 versus temperature at 0.00 ≤ w30 ≤ 0.03 and 0.04 ≤ w30 ≤ 0.09, respectively.

Figure 2. Equilibrium solubility m1 (m2 ) of 1-SNS (2-SNS) in aqueous sodium hydroxide solutions (0.00 ≤ w30 ≤ 0.03) at different temperatures. Mass fractions of sodium hydroxide on the solute-free basis are as follows: (■,□) w30 =0.00; (●,○)

w30 =0.01; (▲,△) w30 =0.02; (▼, ▽ ) w30 =0.03; solid symbols (■●▲▼) express molality solubility of 1-SNS; hollow symbols (□○△▽) express molality solubility of 8 ACS Paragon Plus Environment

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2-SNS; (—) express the calculated results of the E-NRTL model.

Figure 3. Equilibrium solubility m1 (m2 ) of 1-SNS (2-SNS) in aqueous sodium hydroxide solutions (0.04 ≤ w30 ≤ 0.09) at different temperatures. Mass fractions of sodium hydroxide on the solute-free basis are as follows: (◆,◇) w30 =0.04; (★,☆)

w30 =0.05; (◀,◁) w30 =0.07; (▶,▷) w30 =0.09; solid symbols (◆,★,◀,▶) express molality solubility of 1-SNS; hollow symbols (◇,☆,◁,▷) express molality solubility of 2-SNS; (—) express the calculated results of the E-NRTL model.

3.2. Discussion of Solubility Data. It can be seen from Figures 2 and 3 that the solubilities of 1- and 2-SNS both increase with temperature and decrease with the concentration of aqueous sodium hydroxide solutions. The maximal and the minimum solubilities are obtained in pure water and w30 =0.09 aqueous sodium hydroxide solution. Therefore, 1- and 2-SNS can be nearly precipitated by adjusting w30 > 0.09 . 9 ACS Paragon Plus Environment

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The solubility difference of 1- and 2-SNS in the same concentration of aqueous sodium hydroxide solutions is also shown in Figures 2 and 3. The solubility difference ( m1 / m2 ) increases with temperature and the concentration of aqueous sodium hydroxide solution. At room temperature, the solubility of 1-SNS is more than ten times larger than that of 2-SNS when w30 > 0.04 . For this reason, it is feasible to use the solubility difference to separate 1- and 2-SNS.

3.3. Application of the Solubility Difference. 3.3.1. Improvement in the 2-Naphthol Process. The above determined solubility data are used to design a new strategy which is shown in Figure 4. Hydrolysis of 1-NSA is omitted. 1- and 2-NSA which are produced in sulfonation reaction are neutralized by sodium sulfite to form the mixture of 1-SNS and 2-SNS. The mole ratio of 2-SNS and 1-SNS should be 85:15 according to the industrial practice. Next, according to the solubility of 2-SNS in water, water is added to make 2-SNS saturated solution at a certain temperature

T set . The solution is cooled to room temperature with continuous stirring after a certain amount of sodium hydroxide is added. The suitable concentration of aqueous sodium hydroxide solution and temperature T set will be determined in section 3.3.2. After cooling to room temperature and filtrating, the cake 1 (mainly 2-SNS) is sent to the alkali fusion step, and the filtrate 1, which contains 1-SNS, sodium hydroxide and water, is concentrated in the evaporation-crystallization step to w30 > 0.09 . Then cooling to room temperature and separating the mixture, cake 2 and filtrate 2 are obtained. It is designed to obtain 2-SNS in cake 1 as much as possible, and obtain 1-SNS in cake 2 as much as possible. The separated 1-SNS can be sold as by-product

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because of its extensive application.27,28 And the filtrate 2 (almost sodium hydroxide and water) can be reused in the separation of 1- and 2-SNS, as shown in Figure 4.

Figure 4. The flow sheet of new strategy. 3.3.2. Determination of the Operating Conditions of the New Strategy. It is crucial to determine the suitable concentration of aqueous sodium hydroxide solution and the operating temperature T set in the first separation. Both purity of 1-SNS in cake 2 and purity of 2-SNS in cake 1 are dependent on the first separation. As the solubility of 1-SNS is more than ten times larger than that of 2-SNS when w30 > 0.04 at room temperature, the concentration range of the aqueous sodium

hydroxide solution w30 =0.05 to w30 =0.09 and the operating temperature range 298.15 K to 333.15 K are considered. According to the determined solubility data, we calculate the purity of 1- SNS in cake 2 and 2-SNS in cake 1 when the concentration of aqueous sodium hydroxide solution is w30 =0.05, w30 =0.07 and w30 =0.09, respectively. All the calculations obey the hypothesis that the solubilities of 1- and 2-SNS are independent, and no 1-SNS or 2-SNS stays in filtrate 2. It is assumed that

S1− SNS and S 2− SNS express mole of 1-SNS and 2-SNS in cake 1, l1− SNS and l2− SNS express

mole

of

1-SNS

and

2-SNS

in

cake

2.

Therefore,

(S 2-SNS + l2-SNS ) / (S1− SNS + l1− SNS ) = 85 : 15 , and the calculated purity of 1-SNS in cake 2 cal η1cal − SNS and purity of 2-SNS in cake 1 η 2 − SNS are defined as :

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η1cal − SNS =

l1− SNS l1− SNS + l2 − SNS

η 2cal− SNS =

S2 − SNS S2 − SNS + S1− SNS

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(10)

(11)

The calculation results are showed in Figure 5.

Figure 5. The calculated purity of 1-SNS in cake 2 η1cal − SNS and 2-SNS in cake 1

η 2cal− SNS vs operating temperature T set when the concentration of aqueous sodium hydroxide solution is w30 =0.05, w30 =0.07 and w30 =0.09, respectively. (■,□) w30 =0.05; (●,○) w30 =0.07; (▲,△) w30 =0.09; solid symbols (■●▲) express the purity

of 2-SNS in cake 1; hollow symbols (□○△) express the purity of 1-SNS in cake 2. It can be seen from Figure 5, when w30 =0.05, the nearly pure 2-SNS can be 0 obtained in cake 1, but η1cal − SNS is very low. When w3 =0.07, nearly pure 2-SNS can

still be obtained in cake 1 at low temperature, at the same time, η1cal − SNS can be kept to a moderate level. So, the most suitable concentration of aqueous sodium hydroxide 12 ACS Paragon Plus Environment

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solution is considered to be w30 =0.07. But it is just the results of calculation. Actually, when both 1- and 2-SNS are dissolving together in aqueous sodium hydroxide solutions, the solubilities of 1- and 2-SNS are interactional. To verify the calculation results, the process described in section 3.3.1 is carried out in laboratory scale under w30 =0.07. The actual purity of 1-SNS in cake 2 and purity of 2-SNS in cake 1 are

analyzed by HPLC combined with external standard method. The experimental purity of 1- and 2-SNS ( η exp ) and the yield of 1- and 2-SNS under w30 =0.07 at different operating temperatures are described in Figure 6 and Figure 7, respectively.

Figure 6. The comparison between calculated purity η cal and experimental purity

η exp of 1- and 2-SNS separated by aqueous sodium hydroxide solution of w30 =0.07 at predetermined operating temperature: (■,□) the purity of 1-SNS; (●,○) the purity of 2-SNS. solid symbols (■,●) express calculated purity of 1- and 2-SNS; hollow symbols (□,○) express experimental purity of 1- and 2-SNS; T set denotes the 13 ACS Paragon Plus Environment

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operating temperature at which 2-SNS is saturated in water. In Figure 6, the experimental purities are more or less lower than calculated purities, which is due to the hypothesis that the solubilities of 1-SNS and 2-SNS do set not affect each other. The η1cal first, then maintains the same − SNS increases with T

level with T set . But the experimental results show that η1−expSNS increases with T set first, then decreases with T set in the high temperature range, which is different from

η1−calSNS . In the high temperature range, when T set increases, the mass of water reduces. Both l1− SNS and l2 − SNS decrease even though the solubilities of 1- and 2-SNS at this time increase, and the decreasing degree of l1− SNS is supposed to be the same as l2 − SNS . According to the equation (11), η1−calSNS remains stable with T set . In fact, the solubilities of 1- and 2-SNS are interactional when both 1- and 2-SNS are in aqueous sodium hydroxide solutions. And there are a lot of 2-SNS in aqueous sodium hydroxide solutions. The large amount of 2-SNS changes the solubility difference of 1- and 2-SNS at this time, which increases the solubility of 2-SNS and decreases the solubility of 1-SNS in some ways. So the decreasing degree of l2 − SNS is far less than exp that of l1− SNS , which is the reason why η1−SNS decreases with T set .

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Figure 7. Plots of yield of 1- and 2-SNS versus the different operating temperature separated by w30 =0.07 aqueous sodium hydroxide solution: ▲ the yield of 1-SNS; △ the yield of 2-SNS; T set denotes the operating temperature at which 2-SNS is saturated in water. It can be seen in Figure 7, the yield of 2-SNS almost maintains the same level with T set , but the yield of 1-SNS decreases with T set , especially at high temperature. The mass of water, which is used to make 2-SNS saturated, reduces with T set . Then more and more 1-SNS remained in the cake 1. Therefore, the yield of 1-SNS in cake 2 decreases with T set obviously. Meanwhile, purity of 2-SNS in cake 1 decreases as shown in figure 6. As for the 2-SNS, the amount of 2-SNS is much more than 1-SNS in the cake 1, so the yield of 2-SNS does not change a lot though more 1-SNS remains in the cake 1 as the temperature increases. When the range of T set is from 295.15 K 15 ACS Paragon Plus Environment

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to 308.15 K, both yield of 1- and 2-SNS are more than 95%. Making a comprehensive consideration about the purity and the yield, the most suitable operating condition is set as: w30 =0.07, T set =298.15 K. The purities of obtained 1- and 2-SNS are 0.8369 and 0.9854 under this operating condition.

4. CONCLUSIONS Using a laser monitoring observation technique, the solubilities of 1- and 2-SNS in aqueous sodium hydroxide solutions have been investigated in a temperature range from 276 to 337 K. Both of them increase with temperature and decrease with concentrations of aqueous sodium hydroxide solutions. The experimental data were correlated with the new electrolyte nonrandom two-liquid (E-NRTL) model. The results calculated by the model show good agreement with the experimental data. A new strategy, based on the solubility difference between 1- and 2-SNS in aqueous sodium hydroxide solutions for optimizing the production of 2-naphthol, is carried out in laboratory scale. The best separation effect is attained when the concentration of aqueous sodium hydroxide solution is 0.07 and the operating temperature is 298.15 K. The purities of 1- and 2-SNS are 0.8369 and 0.9854 in this operating condition, respectively. The 1-SNS can be sold as by-product because of its extensive applications after purification. The new strategy has potential in the industrial application of 2-naphthol production. But further pilot scale experiments need to be carried out before this new strategy is used in industrial production.

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Supporting Information Tables of the experimental solubilities of Sodium 1-and 2-Naphthalenesulfonate at

T exp and solute-free mass fraction of sodium hydroxide in binary sodium hydroxide + water solvent mixtures; the parameters of K s ; E-NRTL model parameters and root-mean-square

deviations

σ

of

1-SNS−NaOH−H2O

system

and

2-SNS−NaOH−H2O system; The Results of HPLC Analysis, TGA, and X-Ray Diffraction about 1- and 2-SNS.

AUTHOR INFORMATION Corresponding Author Qing XIA Professor School of chemical engineering and technology Tianjin University Tianjin, 300072, P. R. of China Telephone number: 86-22-27408778 E-mail address: [email protected] ORCID: 0000 0003 0941 8852 Fengbao ZHANG Professor School of chemical engineering and technology Tianjin University Tianjin, 300072, P. R. China Telephone number: 86-22-27408778 E-mail address: [email protected]

Notes The authors declare no competing financial interest.

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REFERENCES (1) Aiken, S.; Gabbutt, C. D.; Gillie, L. J.; Heywood, J. D.; Jacquemin, D.; Rice, C. R.; Heron, B. M. The Remarkable Hyperchromicity of Ketohydrazone Dyes and Pigment Lakes Derived from 4-Morpholino-2-naphthol. Eur. J. Org. Chem. 2013, 36, 8097-8107. (2) Satam, M. A.; Raut, R. K.; Sekar, N. Fluorescent azo disperse dyes from 3(1,3-benzothiazol-2-yl) naphthalen-2-ol and comparison with 2-naphthol analogs.

Dyes Pigment. 2013, 96, 92-103. (3) Wang, H. Recent advances in asymmetric oxidative coupling of 2-naphthol and its derivatives. Chirality. 2010, 22, 827-37. (4) Raynaud-Lacroze, P. O.; Tavare, N. S. Separation of 2-naphthol: hydrotropy and precipitation. Ind. Eng. Chem. Res. 1993, 32, 685-691. (5) Roman, G.; Nastasa, V.; Bostanaru, A. C.; Mares, M. Antibacterial activity of Mannich bases derived from 2-naphthols, aromatic aldehydes and secondary aliphatic amines. Bioorg. Med. Chem. Lett. 2016, 26, 2498-502. (6) Moosavi-Zare, A. R.; Zolfigol, M. A.; Zarei, M.; Zare, A.; Khakyzadeh, V. Application of silica-bonded imidazolium-sulfonic acid chloride (SBISAC) as a heterogeneous nanocatalyst for the domino condensation of arylaldehydes with 2-naphthol and dimedone. J. Mol. Liq. 2015, 211, 373-380. (7) Li, T. S.; Zhang, Z. H.; Yang, F.; Duan, H. Y.; Li, B. Z.; Tewari, B. B. A facile procedure for the oxidative coupling of 2-naphthol and 2-naphthalenethiol in solid

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state. Chin. Chem. Lett. 1998, 9, 603-604. (8) Wang, K. L.; Hu, Y. N.; Li, Z.; Wu, M.; Liu, Z. H.; Su, B.; Yu, A.; Liu, Y.; Wang, Q. M. A Simple and Efficient Oxidative Coupling of Aromatic Nuclei Mediated by Manganese Dioxide. Synthesis. 2010, 7, 1083-1090. (9) Kusumoto, T.; Saito, Y.; Takehara, S. Manufacture of 2-naphthol derivative used as synthetic intermediate for liquid crystals, involves reacting brominating agent with tetrahydro naphthalenone and reducing resulting 1-bromo-2-naphthol derivative. JP. patent 2,004,091,361, 2004. (10) Kenyon, R. L.; Boehmer, N. Phenol by sulfonation. Ind. Eng. Chem. 1950, 42, 1446-1455. (11) Kirk, R. E.; Othmer, D. F.; Kroschwitz, J. I. Kirk-Othmer encyclopedia of

chemical technology; Wiley: New York, 1998. (12) Mares, J. R. Production of cresols and higher phenols by fusion. U.S. Patent 2,139,372, 1938. (13) Sumikin; Kako; KK. Preparation of beta-naphthol for dyes, fungicides, anti mould agents, antiseptics etc. - comprises sulphonation of naphthalene, neutralisation, sepn and crystallisation steps. JP. Patent 5,339,184, 1993. (14) May, C. E. Beta Naphthol. J. Am. Chem. Soc. 1922, 44, 650-651. (15) Sumikin; Kako; KK. Improvement in naphtholate (s) prodn. - by sulphonation and subsequent alkali fusion of naphthalene, neutralising while controlling water content. JP. Patent 4,134,040, 1992. (16) Sumikin; Kako; KK. Purification of naphthol by distillation - by sulphonation of

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naphthalene, alkali fusion, distillation to remove boiling matter residue, for use in dyes, pigments, medicines, etc. JP. Patent 4,145,037, 1992. (17) Ansink, H. R; Zelvelder, E.; Cerfontain, H. Sulfonation of a series of naphthalenes containing two different oxy substituents. Recl. Trav. Chim. Pays-Bas-J.

Roy. Neth. Chem. Soc. 1993, 112, 216-225. (18) Feng, H.; Luo, G. L. Tower type negative pressure continuous inert gas extracting naphthalene blowing involves taking sulfonating reaction mixture in hydrolyzing reaction kettle, and entering into first-stage blowing naphthalene tower. CN. Patent 104,628,608, 2015. (19) Bildstein, S.; Heck, J.; Schmid, D.; Schmiedel, K. Naphthalene sulphonation mixt. purificn. by hydrolysis of alpha-acid - by circulating through trickling column in countercurrent to steam. EP. Patent 500,660, 1991. (20) Chen, J.; Pan, B.C.; Xiong, Y. Method of treating naphthalene-blowing effluence and recovering resource in 2-naphthol producing process. CN. Patent 1,384,069,2002. (21) Song, Y.; Chen, C. C. Symmetric Electrolyte Nonrandom Two-Liquid Activity Coefficient Model. Ind. Eng. Chem. Res. 2009, 48, 7788-7797. (22) Xia, Q.; Zhang, F. B.; Zhang, G. L.; Ma, J. C.; Zhao, L. Solubilities of sebacic acid in binary water plus ethanol solvent mixtures. J. Chem. Eng. Data. 2008, 53, 838-840. (23) Liu, T.; Zou, W.; Zhao, W.; Zhang, F. B.; Zhang, G. L.; Xia, Q. Measurement and correlation for the solubilities of dimethyl succinylsuccinate in (methanol plus water) and (methanol plus dimethyl succinate) binary solvent mixtures. Fluid Phase Equilib.

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2014, 374, 102-107. (24)Tech, A., Aspen Physical Property System 11.1. Aspen Technology, Inc.,

Cambridge, MA, USA 2001. (25) Chen C. C.; Britt H. I.; Boston J. F. Local composition model for excess Gibbs energy of electrolyte systems. Part I: Single solvent, single completely dissociated electrolyte systems. AICHE J. 1982, 28, 588-596. (26) Nelder, J. A.; Mead, R. A. simplex method for function minimization. Comput.

J.1965, 7, 308-313. (27) Cai, X.; Tan, S.; Yu, A.; Zhang, J.; Liu, J.; Mai, W.; Jiang, Z. Sodium 1-Naphthalenesulfonate-Functionalized Reduces Graphene Oxide Stabilizes Silver Nanoparticles with Lower Cytotoxicity and Long-Term Antibacterial Activity.

Chem.-Asian J. 2012, 7, 1664-1670. (28) Considine, T.; Patel, H, A.; Singh, H. Influence of binding of sodium dodecyl sulfate, all-trans-retinol, palmitate, and 8-anilino-1-naphthalenesulfonate on the heat-induced unfolding and aggregation of β-lactoglobulin B. J. Agric. Food Chem.

2005, 53, 3197-3205.

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Table of Contents Graphic

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Figure 1. The synthetic route of 2-naphthol. 177x32mm (300 x 300 DPI)

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Figure 2. Equilibrium solubility of 1-SNS (2-SNS) in aqueous sodium hydroxide solutions (0.00 ≤ ≤ 0.03) at different temperatures.Mass fractions of sodium hydroxide on the solute-free basis are as follows: (■,□) =0.00; (●,○) =0.01; (▲,△) =0.02; (▼,▽) =0.03; solid symbols (■●▲▼) express molality solubilities of 1-SNS; hollow symbols (□○△▽) express molality solubilities of 2-SNS; (—) express the calculated results of the E-NRTL model. 152x107mm (300 x 300 DPI)

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Figure 3. Equilibrium solubility of 1-SNS (2-SNS) in aqueous sodium hydroxide solutions (0.04 ≤ ≤ 0.09) at different temperatures. Mass fractions of sodium hydroxide on the solute-free basis are as follows: (◆,◇ ) =0.04; (★,☆) =0.05; (◀,◁) =0.07; (▶,▷) =0.09; solid symbols (◆,★,◀,▶) express molality solubilities of 1-SNS; hollow symbols (◇,☆,◁,▷) express molality solubilities of 2-SNS; (—) express the calculated results of the E-NRTL model. 152x107mm (300 x 300 DPI)

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Figure 4. The flowsheet of the new strategy. 177x44mm (300 x 300 DPI)

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Figure 5. The calculated purity of 1-SNS in cake 2 and 2-SNS in cake 1 vs operating temperature when the concentration of aqueous sodium hydroxide solution is =0.05, =0.07 and =0.09, respectively. (■,□) =0.05; (●,○) =0.07; (▲,△) =0.09; solid symbols (■●▲) express the purity of 2-SNS in cake 1; hollow symbols (□○△) express the purity of 1-SNS in cake 2. 152x107mm (300 x 300 DPI)

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Figure 6. The comparison between calculated purity and experimental purity of 1- and 2-SNS separated by aqueous sodium hydroxide solution of =0.07 at predetermined operating temperature: (■,□) the purity of 1-SNS; (●,○) the purity of 2-SNS. solid symbols (■,●) express calculated purity of 1- and 2-SNS; hollow symbols (□,○) express experimental purity of 1- and 2-SNS; denotes the operating temperature at which 2SNS is saturated in water. 152x107mm (300 x 300 DPI)

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Figure 7. Plots of yield of 1- and 2-SNS versus the different operating temperature separated by =0.07 aqueous sodium hydroxide solution: ▲ the yield of 1-SNS; △ the yield of 2-SNS; denotes the operating temperature at which 2-SNS is saturated in water. 152x107mm (300 x 300 DPI)

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TOC 82x41mm (300 x 300 DPI)

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