Article Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Solid−Liquid Phase Equilibria of the Ternary System (2Naphthaldehyde + 4‑Methylphthalic Anhydride + Ethyl Acetate) at (288.15, 298.15, and 308.15) K Xiaoqiang Gao,† Fang Zhang,‡ Yi Yu,† Yonghui Dou,† Li Xu,*,† and Guoji Liu*,† †
School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, Henan 450001, People’s Republic of China School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450001, People’s Republic of China
‡
ABSTRACT: The solubility of 2-naphthaldehyde (2-NA) and 4-methylphthalic anhydride (4-MA) in ethyl acetate at temperatures from 283.15 to 313.15 K and solid−liquid equilibrium of ternary (2-NA + 4-MA + ethyl acetate) system at temperatures of (288.15, 298.15, and 308.15) K were measured under pressure of 101.3 kPa. Three isothermal phase diagrams were plotted according to the ternary solubility data. For the ternary system, two pure 2-NA and 4-MA solids were formed at each temperature and determined by the wet residue method of Schreinemaker. The crystalline region of 2-NA decreases with the increase in temperature, and 4-MA is just the opposite. The crystallization region of 2-NA was found to be smaller than that of 4-MA. The solubility data of the system were correlated and calculated by NRTL and Wilson models. The results show that the NRTL model agrees well with the experimental data compared with the Wilson model. Furthermore, the densities of equilibrium solutions were determined at the corresponding temperatures.
1. INTRODUCTION 2-Naphthaldehyde (2-NA) is an important intermediate for organic synthesis. It is widely employed in the field of plant regulators, antitumor drugs, inhibitors of Mycobacterium tuberculosis protein tyrosine phosphatase PtpA, and fluorogenic indicators for human aldehyde dehydrogenases and oxidases.1−4 In the present industrial manufacture, 2-NA is mainly produced via 2-naphthonitrile reacting with ether, hydrogen chloride, and stannous chloride.5 However, the chlorinecontaining wastewater produced in this process is harmful to the environment and costs a large amount of treatment fee. Zhang et al.6 studied the vapor−solid catalytic oxidation of 2methylnaphtalene to deal with this problem. The reaction system utilizes 2-methylnaphtalene as the feed material, V2O5− K2SO4−TiO2 as the catalyst, and air as the oxidant. The selectivity and yield of 2-NA are about 45 and 23%, respectively.7 The main products of this reaction system are 2-NA, phthalic anhydride (PA), and 4-MA. All of them are useful and valuable chemicals. It is hard to acquire high-purity 2-NA from the mixtures by distillation because the compounds’ boiling points are approximate to each other. It is available to separate the desired product from mixtures by solution crystallization, and the solubility of compounds is indispensable to design the crystallization process. The solubility data of 2-methylnaphtalene, 2-NA, and PA in some pure organic solvents has been investigated in the literature.8−10 On the basis of the acquired solubility data, Yu et al.11 studied the solid−liquid phase equilibrium of 2-NA + PA + 1,4-dioxane ternary system. However, there still exist some ternary systems, which need to be studied for separating 2-NA from the © XXXX American Chemical Society
mixtures. The ternary 2-NA + 4-MA + ethyl acetate system is one of them and has not been reported in the previous literature. The present work mainly investigates the solid− liquid phase equilibrium of 2-NA + 4-MA + ethyl acetate ternary system using Schreinemaker’s wet residue method,12,13 builds the phase diagram at (288.15, 298.15, and 308.15) K, and correlates the solubility data with Wilson model and NRTL model.14,15 In addition, the densities of equilibrium solutions for the ternary systems were measured at different temperatures.
2. EXPERIMENTAL SECTION Materials. 2-NA and 4-MA (0.98 in mass fraction, both) were purchased from Aladdin Chemical Reagent and TCI Chemical Reagent, respectively. The raw materials were purified by recrystallization three times in acetone. The final purity of 2-NA and 4-MA used for solubility determination was 0.998 and 0.996 in mass fraction, which was determined by a high-performance liquid chromatography (HPLC). The solvent ethyl acetate with an analytical grade was provided by Sinopharm Chemical Reagent Co. Ltd., with a mass fraction purity of 0.995, and used without further purification. The detailed information on these materials is presented in Table 1. Melting Properties Measurements. Although the melting temperature Tm of 4-MA was given in the publications,16−18 Received: March 2, 2018 Accepted: May 31, 2018
A
DOI: 10.1021/acs.jced.8b00170 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
Table 1. Source and Properties of Materials Used in This Work chemicals
CAS number
MW/g·mol−1
mass fraction
purification method
2-NAa 4-MAd ethyl acetate
66-99-9 19438-61-0 141-78-6
172.18 162.14 88.11
≥0.998 ≥0.996 ≥0.995
recrystallization recrystallization none
benzoic acid toluene
65-85-0 108-88-3
122.12 92.14
≥0.996 ≥0.995
none none
source
Tm/K
ΔfusH/J·mol−1
Aladdin Chemical Reagent Co. Ltd. TCI Chemical Reagent Co. Ltd. Sinopharm Chemical Reagent Co. Ltd. Aladdin Chemical Reagent Co. Ltd. Sinopharm Chemical Reagent Co. Ltd.
333.27b 361.30
15664.85b 18840.67
analysis method HPLCc HPLCc GCe HPLCc GCe
2-NA, 2-naphthaldehyde. bTaken from ref 9; standard uncertainties u are u(Tm) = 1 K, u(ΔfusH) = 500 J·mol−1, and u(p) = 500 Pa under 101.3 kPa. High-performance liquid chromatography. d4-MA, 4-methylphthalic anhydride. eGas chromatography.
a c
the melting enthalpy ΔfusH has not been reported in the present literature. In this work, the melting enthalpy ΔfusH of 4MA was measured by a differential scanning calorimetry instrument (SDT Q600, TA Instruments, USA) under a nitrogen atmosphere. The temperature and heat flow scales of the DSC instrument were calibrated at 5 K·min−1 by using purity zinc (mass fraction: 0.99999; Tfus = 692.68 K, ΔfusH = 108.70 J·g−1). About 5 mg of 4-MA was put into an aluminum pan; then, the sample was heated from 293.15 to 523.15 K at a rate of 5 K·min−1. Apparatus and Procedure. The experimental facilities and procedures used in this study were described in our previous work.9,11 Here we give a brief overview. The ternary phase equilibrium data were determined by a method of isothermal saturation,19,20 and the composition of equilibrium solid was confirmed through Schreinemaker’s wet residue method.12,13 For the binary systems of 2-NA + ethyl acetate and 4-MA + ethyl acetate, excess pure 2-NA or 4-MA was added into a double-jacketed glass vessel with a certain volume of ethyl acetate. For the ternary system of 2-NA + 4-MA + ethyl acetate, a known mass of 2-NA and 4-MA was added to that vessel containing ethyl acetate. The mixture was stirred by magnetic stirring for at least 18 h and settled for 8 h to make sure that the system has reached equilibrium. The temperature of the system was controlled by an isothermal water bath circulator (Blon DCW 4600, Shanghai). The actual temperature of the solution was monitored by a precision thermometer (uncertainty: ±0.01 K) inserted into the vessel. After the system reached equilibrium, 1 mL of the saturated liquid was withdrawn with a 3 mL preheated plastic syringe. The sample and the wet solid phase adhering some saturated liquid were transferred to a 25 mL volumetric flask, diluted to the mark, and analyzed quantitatively. This procedure was repeated by varying the mass of 2-NA and 4-MA to obtain different compositions of the equilibrium liquid phases and solids. The density of the equilibrium liquid phase was determined by the pycnometry method. The equilibrium liquid mass was acquired by weighing the pycnometer before and after filled with the equilibrium liquid. The density was determined by the mass of the equilibrium liquid and the volume of the pycnometer. To verify the reliability of the experimental method, the solubility of benzoic acid in toluene was measured with this apparatus. The experimental values were compared with the literature data.21,22 The corresponding results are listed in Table 2 and shown graphically in Figure 1. The relative average deviation between the experimental value and literature data is
