Structural characteristics integrated computer-aided molecular design

Article Cite This: Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

pubs.acs.org/IECR

Structural Characteristic Integrated Computer-Aided Molecular Design for Phenols Removal Considering Synergistic Effect Chao Guo, Yinshuang Zhang, Yu Qian, and Siyu Yang* School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China

Downloaded via KAOHSIUNG MEDICAL UNIV on August 12, 2018 at 10:09:21 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

S Supporting Information *

ABSTRACT: Zero liquid discharge (ZLD) of coal chemical wastewater is a significant strategy for sustainable management of water resources. Efficient removal of phenols has high significance for the realization of ZLD. In this study, a method of structural characteristics integrated computer-aided molecular design (CAMD) is used for phenols removal considering synergistic effect. Solvent mixture for synergistic extraction of phenols by using methyl propyl ketone (MPK) in combination with n-pentanol is proposed with the volume ration of MPK to n-pentanol 8:2. Using solvent mixture (80% MPK, 20% n-pentanol), the phenols removal efficiencies are observably better than that using methyl isobutyl ketone (MIBK) or diisopropyl ether (DIPE). The total phenols concentration of coal gasification wastewater can be removed from 6273 mg/L to less than 300 mg/L after two-stage extraction. In addition, solvent mixture (MPK, n-pentanol) can also achieve the total phenols target if the volume fraction of n-pentanol was no more than 70%, the wide range volume fraction of which has potential application in industry.

1. INTRODUCTION The shortage of water resources has become the bottleneck of sustainable development in the coal chemical industry. Zero liquid discharge (ZLD) is mandatory to preserve both local water resources and ecosystems.1 The realization of ZLD of coal chemical wastewater is a significant strategy for sustainable management of water resources. A variety of wastewater treatment processes have been developed, but none of them have yet achieved ZLD in practice. In order to ensure reusable water quality from ZLD, new water treatment indexes for each unit have been proposed.2 According to the index system, it is very important to control the content of total phenols to less than 300 mg/L by phenols removal. However, the existing industrial applications show that total phenols concentration exceeds this target, with about 500−700 mg/L.3 The efficient removal of phenols has high significance for the realization of ZLD. Solvent selection is the key step for phenol removal. The solvents methyl isobutyl ketone (MIBK) and diisopropyl ether (DIPE) have been used in plants. The industrial practice showed that the total phenols concentration of wastewater is still high after extraction by DIPE. The extraction efficiency of monohydric phenols, catechol, and resorcinol by using MIBK is observably higher than that of DIPE. However, the solvent’s efficiency for hydroquinone is still low.4 This is the reason the total phenols concentration cannot achieve the target value. In recent years, extraction efficiencies of phenols with some new solvents have been measured, such as methyl isopropyl ketone (MIPK),5 methyl n-butyl ketone (MBK),6 3-heptanone,7 mesityl oxide,8 and so forth, and these solvents are © XXXX American Chemical Society

considered high quality solvents. However, the extraction efficiency of these solvents is still low. Solvent mixtures in which two solvents have a synergistic effect would perform with higher efficiency than single solvent, and are considered an efficient way to improve efficiency.9,10 Many efforts have been made to select better solvent mixtures for extracting phenols. Liao et al.11 proposed a new solvent mixture with molar fraction of 95% toluene and 5% MIBK for extracting phenols. However, this solvent mixture was likely to perform less efficiently due to the unequal proportions. Cui et al.3 analyzed the proportion of this solvent mixture, and found that the optimum volume fraction of this solvent mixture was taken as 95% MIBK and 5% toluene. However, enhancement of the extraction efficiency was not obvious. The distribution coefficient of hydroquinone is about 18.5.12 It is imperative to select the appropriate solvent mixture systems. Computer-aided molecular design (CAMD) is broadly considered a systematic and effective method for selection of solvents.13−15 Throughout the years, various CAMD approaches have been developed, applied, and extended to solving a wide range of chemical product design problems. Among them, one often used method is called “generate-andsearch”.16 However, it cannot distinguish the differences of extraction efficiency among the isomers due to limitations of the UNIFAC model.17 The carbon number is a function of the Received: Revised: Accepted: Published: A

March 1, 2018 May 3, 2018 July 26, 2018 July 26, 2018 DOI: 10.1021/acs.iecr.8b00925 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article

Industrial & Engineering Chemistry Research

where wo and ww are mass fraction of hydroquinone in organic phase and aqueous phase, respectively. DA, DB, and Dmix are the distribution coefficients of hydroquinone using solvent A, B, and their mixture, respectively. xA is volume fraction of solvent A in their mixture. All the concentration values of phenols are measured in duplicate with the uncertainty within 5%. 2.3. Structural Characteristic Integrated CAMD. The method of structural characteristic integrated CAMD for solvent selection was established in our recent work,19 and the framework of the new method is described as Figure 1. The method consists of four steps:

number of possible isomers. It can be noted that when the carbon number is 20, there are more than 0.3 million possible saturated carbon chain isomers, and more than 4 million unsaturated carbon chain isomers.18 Structural characteristics of molecules included the influences of carbon number, carbon chain isomerism, and carbon chain unsaturation degree on the extraction efficiency of solvents. Appropriately using the characteristics can identify the differences of isomers’ extraction efficiency. Therefore, the new method of structural characteristic integrated computer-aided molecular design (CAMD) has been proposed to solve this problem.19 The new method can design the more excellent solvent due to consideration of the thermodynamic model as well as the regularity of structural characteristics. In this paper, the method of structural characteristic integrated CAMD is used to select the suitable single solvents, and then, synergistic effects are used to improve extraction efficiency of main solvents. This paper is organized as follows: in the next section, the method of structural characteristic integrated CAMD in selection of solvents is described briefly. Then, the synergistic effects between main solvent and its additive are analyzed. After that, solvent mixtures are designed, and the efficiencies of selected solvent mixture are verified by using coal gasification wastewater.

2. MATERIALS AND METHODS 2.1. Reagents. The solvents used in the experiments are purchased from Aladdin reagent company (Shanghai, China) (99% purity). Hydroquinone is purchased from Aladdin reagent company (Shanghai, China) (99.5% purity). All reagents are used without further purification. Deionized and distilled water is used in extraction experiments. 2.2. Extraction Experiments. Hydroquinone has two phenolic hydroxyls in para position with higher intermolecular hydrogen bonding. This leads to a lower distribution coefficient than catechol and resorcinol in extraction. For simplicity, hydroquinone is selected as the representatively difficult extraction phenols. According to the content of dihydric phenols in coal gasification wastewater, the concentration of hydroquinone in simulation wastewater is about 2000 mg/L. The experimental data are measured with a 100 mL glass equilibrium cell. The mixture of the solvent mixtures and simulation wastewater is fed into the glass cell with volume ratio 1:4, and is vigorously agitated with a magnetic stirrer for at least 1 h, and then left to stand for at least 2 h to ensure phase equilibrium. The mass fraction of hydroquinone in aqueous phase and organic phase are measured. The analysis method for concentration of hydroquinone is made by using a gas chromatograph (GC7890A, Agilent Technologies), and the details of method are described in our previous work.20 Experimental distribution coefficient (D) of hydroquinone is calculated by eq 1. The obtained synergism of solvent mixture can be expressed in terms of a synergistic coefficient (R), which is defined as eq 2. R determines whether a solvent mixture system yields a synergistic extraction effect; R > 1 indicates synergistic extraction, whereas R < 1 implies antagonistic extraction, and R = 1 denotes no synergistic effect. D=

wo ww

(1)

R=

Dmix DA xA + DB(1 − xA )

(2)

Figure 1. Proposed method of structural characteristic integrated CAMD in selection of solvents.

Step 1 is to define the main solvents functional groups. Step 2 is to analyze the influences of the structural characteristics on the extraction efficiency. Considering the limitation of UNIFAC model, UV spectrophotometry (U3010, Hitachi, ±0.0001 precision) is employed to determine the extraction efficiency of carbon chain isomers. In Step 3, if the target properties of the preferred molecular structure meet the requirements, then go to next step. If not, go back to Step 2 and select the other molecular structures until the properties are satisfied. If target properties can be found in the DECHEMA, the values from the databank are regarded as the ultimate results. If not, the values are calculated from property prediction models.16,21,22 In Step 4, the selected solvents’ distribution coefficient and solvent loss are calculated, and are ranked in order of decreasing distribution coefficient. UNIFAC group contribution method is usually used for distribution coefficient prediction,23−27 and is described in Supporting Information (eqs S1-S6). In this paper, group parameters consisting of volume parameters, surface area parameters, and interaction parameters are obtained from the liquid−liquid equilibria (LLE) table.28 These parameters are listed as Table S1 and S2 (Supporting Information). Compared with the previous generate-and-search method, the proposed method considers the difference of extraction efficiency among the carbon chain isomers. Therefore, it can select the more efficient solvents. B

DOI: 10.1021/acs.iecr.8b00925 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article


previous work.19 It is found that a carbon chain with CC bond has better extraction efficiency than one with a C−C bond. The influences of carbon number and carbon chain isomerism on extraction efficiency are expressed as follows. 3.2.1. Carbon Number. The influence of carbon number on extraction efficiency is investigated on the recovery of hydroquinone with the solvents whose molecular structures are CH3O-R, HO-R, CH3COO-R, and CH3O-R and are listed in Table S3 (Supporting Information). The influences of carbon number on distribution coefficient and solubility are shown in Figure 3. It can be seen that as the carbon number

3. RESULTS AND DISCUSSION 3.1. Synergistic Effects between Main Solvent and Its Additive. In solvent mixtures, main solvents play a decisive role. Therefore, the functional groups of main solvents are determined first. According to new water treatment index system for ZLD, the content of ammonia nitrogen in recycled water should be less than 5 mg/L,2 and it is very difficult to reach this index for treatment of ammonia nitrogen.29,30 Therefore, this paper excludes nitrogen-containing solvents due to the increase in the content of nitrogen. Solvents of aldehydes are excluded due to the stronger chemical activity of formyl group. According to the previous analysis,19 main solvents with functional groups of hydroxyl, carbonyl, ester, or ether are selected. After the main functional groups have been determined, its corresponding additive will be added to improve the separation ability of the main solvent. These functional groups that can form hydrogen bonds have a synergistic effect, which would perform at higher efficiency. The hydroxyl group is a hydrogen bond acceptor as well as a hydrogen bond donor. The carbonyl, ester, or ether group is a hydrogen bond acceptor. Therefore, it is conceivable that a hydrogen bond is formed between functional groups of hydroxyl and (carbonyl, ester, or ether). Therefore, synergistic effects functional groups including (hydroxyl, carbonyl), (hydroxyl, ester), and (hydroxyl, ether) are selected. To verify our analyses, extraction experiments have been built to measure the experimental distribution coefficient of the hydroquinone using single solvents and their solvent mixtures. MIBK, isopentanol, n-butyl acetate, and DIPE are the representative ketones, alcohols, esters, and ethers, respectively. Therefore, six solvent mixtures (MIBK, isopentanol), (nbutyl acetate, isopentanol), (DIPE, isopentanol), (n-butyl acetate, MIBK), (DIPE, MIBK), and (DIPE, n-butyl acetate) are employed to analyze synergistic effects among these functional groups using synergistic coefficient. The experimental results of six solvent mixtures are shown in Figure 2.

Figure 3. Influence of carbon number on distribution coefficient (D) and solubility (S).

increases, the distribution coefficient and solubility decrease. This confirms that the solvent with low carbon number can achieve a higher distribution coefficient. 3.2.2. Carbon Chain Isomerism. Four pairs of single solvents (n-pentanol, isopentanol), (MBK, MIBK), (n-propyl acetate, isopropyl acetate), and (methyl n-pentyl ether, methyl tert-pentyl ether) are selected to study the extraction efficiencies of the carbon chain isomers. These solvents’ structures are listed in Table S4 (Supporting Information). In terms of the structure, it is obvious that branch chain molecular structure has more “−CH3” than straight chain molecules. As shown in Figure 4, the solvent with the straight chain structure is better than that of the branched chain structure. The steric hindrance reduces the hydrogen bond and intermolecular forces between the solvent and hydroquinone. This causes a decrease in extraction efficiency. In selection of solvents,

Figure 2. Synergistic effects of six solvent mixtures.

According to the synergistic coefficient (R), it can be seen that isopentanol has a synergistic effect with MIBK, n-butyl acetate, or DIPE. However, there are no synergistic effects among MIBK, n-butyl acetate, and DIPE. These results are consistent with our analyses above. 3.2. Structural Characteristics. The influences of structural characteristics of ketones, alcohols, or esters on the extraction efficiency of single solvents are analyzed in our

Figure 4. Influence of carbon chain isomerism on extraction efficiency. C


Article

Industrial & Engineering Chemistry Research Table 1. Properties of Selected Solvents azeotropic point no.

structure

Tbp/K

Ta/K

proportion/%

ρ/(g/cm3)

S/%

Dcal

1 2 3 4 5 6 7 8 9 10

CH3COCHC(CH3)2 CH3CO(CH2)2CH3 CH3CO(CH2)3CH3 CH3COCH2CH(CH3)2 OH(CH2)4CH3 CH3COO(CH2)2CH3 CH3COO(CH2)3CH3 CH3O(CH2)3CH3 CH3O(CH2)4CH3 (CH3)2CHOCH(CH3)2

402.95 374.35 400.15 387.85 410.85 374.75 399.65 343.31 372 341.45

364.85 356.95 363.15 361.05 368.25 355.95 364.15 337.45 356.55 335.35

70.1 80.4 68.6 75.7 45.6 83.8 71.3 94.2 83.1 95.4

0.854 0.803 0.811 0.796 0.810 0.888 0.883 0.741 0.758 0.718

2.8 4.3 1.6 1.7 2.2 2.1 0.64 0.89 0.47 0.87

20.8 18.5 12.5 12.3 7.8 7.3 4.6 2.3 1.0 1.0

preference is given to those straight-chain molecule among carbon chain isomers. 3.3. Selection of Solvent Mixtures. In order to select efficient solvent mixtures, main solvent and its additive should be the best single solvent. The proposed method of structural characteristic integrated generate-and-search approach is applied to select main solvent and its additive. According to the analyses in section 3.2, it is suggested that solvents with low carbon number, straight chain structure, or carbon chain with CC bond are selected. In the case of the phenols extraction process, the solvents’ boiling points should be between 333.15 and 413.15 K. According to industrial experience, density (ρ) is better lower than 0.9 g/cm3 for the easy separation of solvent and raffinate phase. Solubility should be less than 5%. Moreover, main solvent and its additive should be mutually soluble. In addition to the properties above, other properties, such as toxicity, chemical stability, and thermal stability, should be considered if considering industrialization. By using the proposed method of structural characteristic integrated CAMD, the selection results are obtained and listed in order of decreasing distribution coefficient as shown in Table 1. It should be note that solvent 1, 3, 8, and 9 are bought only at very expensive prices. From this perspective, they are excluded as potential solvents. According to the order of distribution coefficient, solvent 2 (MPK), solvent 5 (npentanol), solvent 6 (n-propyl acetate), and solvent 10 (DIPE) are selected as the appropriate ketones, alcohols, esters, and ethers, respectively. Experimental results and mechanism analyses in section 3.1 show that alcohols are the additives for ketones, esters, or ethers. According to results of structural characteristics integrated CAMD, n-pentanol is selected as the additive for MPK, n-propyl acetate, and DIPE. The synergistic extraction efficiencies of the three solvent mixtures of (MPK, n-pentanol), (n-propyl acetate, n-pentanol), and (DIPE, n-pentanol) are investigated on extraction of hydroquinone by using extraction experiments. The experimental results are shown in Figure 5 with different volume fraction of n-pentanol in the solvent mixtures. It can be seen that all solvent mixtures perform better than their corresponding single solvents. In addition, the distribution coefficient of solvent mixture (MPK, n-pentanol) is better than others. The solvent mixture (n-propyl acetate, n-pentanol) is better than the mixture (DIPE, n-pentanol) except at 10% volume fraction of n-pentanol. DIPE and n-pentanol show remarkable synergistic effect in that composition. The maximum distribution coefficient of the solvent mixture (DIPE, n-

Figure 5. Comparison of extraction efficiencies of three solvent mixtures.

pentanol) is still less than 20, and this solvent mixture is excluded in the following analysis. However, this solvent mixture can be used for improvement of those processes with DIPE as solvent. Solvent mixture (MPK, n-pentanol) has higher extraction efficiency. Finally, the optimum composition of solvent mixture (MPK, n-pentanol) is the volume ration of MPK to n-pentanol 8:2. The distribution coefficients of hydroquinone were measured using solvent mixture (80% MPK, 20% n-pentanol) under atmospheric pressure at 298.15 K, and are listed in Table S5 (Supporting Information), and are compared with those of solvents reported in the available literature such as methyl isobutyl ketone,4 methyl butyl ketone,6 and methyl isopropyl ketone5 at 298.15 K. Some of the distribution coefficient data are obtained directly from the literature, and others are calculated based on the binary interaction parameters from the literature.20 The distribution coefficients with different solvents versus mass fraction of hydroquinone in organic phase are presented in Figure 6. The distribution coefficients of hydroquinone slightly decrease with the increase of mass fraction of hydroquinone in the organic phase. It has been found that a solvent mixture with volume ration of MPK to npentanol of 8:2 has a higher distribution coefficient than other solvents. 3.4. Comparison of Efficiencies by Using Coal Gasification Wastewater. Coal gasification wastewater samples are taken from the Datang coal-to-SNG project in Inner Mongolia in China. The analytical results show that total phenols concentration is about 6273 mg/L, in which volatile D


Article


Compared with single solvents, the volume ratio of main solvent and its additive will change a bit after running for a long period in industrial application. Therefore, extraction efficiencies of solvent mixture (MPK, n-pentanol) in other compositions are investigated. As shown in Figure 8, it is

Figure 6. Comparison of distribution coefficient of proposed solvent mixture with solvents reported in available literature.

phenols, nonvolatile phenols, and hydroquinone are 3751, 2522, and 1362 mg/L, respectively. The three-stage extraction experiment is carried out to compare the extraction efficiencies of selected solvent mixture with two common solvents MIBK and DIPE. The extraction experimental parameters are temperature T = 298.15 K, pH = 7, and solvent/water ratio (volume) = 1:5.5, respectively. The concentrations of volatile phenols, nonvolatile phenols, and total phenols of the raffinate are determined. The analytical methods are the same as our previous work.31 The water quality of wastewater after three-stage extraction is shown in Figure 7. It is obvious that, by using solvent

Figure 8. Analysis of extraction efficiencies of solvent mixture at different volume fractions of n-pentanol.

clearly seen that the total phenols concentration can also reach the targets after two-stage extraction if volume fraction of npentanol was no more than 70%. Therefore, the novel solvent mixture not only can easily reach the target of phenols, but also has relatively wide range of proportion in application, which performs a potential application in industries.

4. CONCLUSIONS In this paper, the method of structural characteristic integrated CAMD is used to select efficient solvents for treatment of high phenols wastewater. The influence of structural characteristics on extraction efficiency of solvents has been analyzed. The results show that the solvent structure with low carbon number and straight chain is the preferred candidate, and these solvents perform with high extraction efficiencies. Synergistic effects among functional groups of hydroxyl, carbonyl, ester, and ether are investigated and analyzed. The hydroxyl group has a synergistic effect with carbonyl, ester, or ether groups. By using the method, MPK, n-pentanol, n-propyl acetate, and DIPE are selected as the appropriate ketones, alcohols, esters, and ethers, respectively. The distribution coefficient of solvent mixture (MPK, n-pentanol) is better than others. Compared with the solvents reported in the literature, the solvent mixture (80% MPK, 20% n-pentanol) has higher distribution coefficient. Finally, the extraction efficiencies of solvent mixture (80% MPK, 20% n-pentanol) with two common solvents MIBK and DIPE are compared by three-stage extraction. Using the solvent mixture (80% MPK, 20% n-pentanol), the removal efficiencies of phenols are observably better than that using MIBK or DIPE. The total phenols concentration of wastewater can be reduced to 187 mg/L after two-stage extraction. In addition, (MPK, n-pentanol) can achieve the total phenols target value if volume fraction of n-pentanol was no higher than 70%.

Figure 7. Phenols concentration of wastewater after three-stage extraction.

mixture (80% MPK, 20% n-pentanol), the extraction efficiencies on nonvolatile phenols and total phenols are observably better than that using MIBK or DIPE. The total phenols concentration can be reduced from 6273 mg/L to 187 mg/L after two-stage extraction with solvent mixture. After three-stage extraction, the total phenols concentration can also be reduced to less than 300 mg/L by using MIBK. However, industrial application shows that the actual extraction measurement stage is lower than design calculation theoretical stage after industrial amplification, and it is approximately 2. Therefore, MIBK cannot achieve the phenols target in industrial practice. Therefore, the solvent mixture can make contribution to achieve the ZLD as well as sustainable development of coal chemical industry. E


Article


■

(12) Yang, S.; Ma, D. H.; Cui, P. Z. Liquid-liquid equilibrium data and correlation for the quaternary systems water + polyphenol (hydroquinone, catechol, and resorcinol) + methyl isobutyl ketone + methylbenzene. J. Chem. Eng. Data 2018, 63, 63−68. (13) Mai, N. L.; Koo, Y. M. Computer-aided design of ionic liquids for high cellulose dissolution. ACS Sustainable Chem. Eng. 2016, 4, 541−547. (14) Paduszyński, K.; Królikowski, M.; Zawadzki, M.; Orzeł, P. Computer-aided molecular design of new task-specific ionic liquids for extractive desulfurization of gasoline. ACS Sustainable Chem. Eng. 2017, 5, 9032−9042. (15) Doshi, R.; Mukherjee, R.; Diwekar, U. M. Application of adsorbate-solid solution theory to design novel adsorbents for arsenic removal using CAMD. ACS Sustainable Chem. Eng. 2018, 6, 2603− 2611. (16) Ng, L. Y.; Chong, F. K.; Chemmangattuvalappil, N. G. Challenges and opportunities in computer-aided molecular design. Comput. Chem. Eng. 2015, 81, 115−129. (17) Gmehling, J.; Schedemann, A. Selection of solvents or solvent mixtures for liquid-liquid extraction using predictive thermodynamic models or access to the Dortmund Data Bank. Ind. Eng. Chem. Res. 2014, 53, 17794−17805. (18) Gani, R.; Constantinou, L. Molecular structure based estimation of properties for process design. Fluid Phase Equilib. 1996, 116, 75−86. (19) Guo, C.; Tan, Y. T.; Yang, S. Y.; Qian, Y. Development of phenols recovery process with novel solvent methyl propyl ketone for extracting dihydric phenols from coal gasification wastewater. J. Clean. Prod. 2018, 198, 1632−1640. (20) Guo, C.; Tan, Y. T.; Qian, Y.; Yang, S. Y. Liquid-liquid equilibria for ternary (methyl propyl ketone+ hydroquinone or resorcinol+ water) systems at 298.15, 318.15, and 333.15 K. J. Chem. Eng. Data 2018, 63, 1994−2001. (21) Scilipoti, J.; Cismondi, M.; Brignole, E. A. Prediction of physical properties for molecular design of solvents. Fluid Phase Equilib. 2014, 362, 74−80. (22) Cismondi, M.; Mollerup, J. Development and application of a three-parameter RK-PR equation of state. Fluid Phase Equilib. 2005, 232, 74−89. (23) Zhou, T.; Zhou, Y. G.; Sundmacher, K. A hybrid stochasticdeterministic optimization approach for integrated solvent and process design. Chem. Eng. Sci. 2017, 159, 207−216. (24) Cheng, H. C.; Wang, F. S. Computer-aided biocompatible solvent design for an integrated extractive fermentation-separation process. Chem. Eng. J. 2010, 162, 809−820. (25) Gebreslassie, B. H.; Diwekar, U. M. Homogenous multi-agent optimization for process systems engineering problems with a case study of computer aided molecular design. Chem. Eng. Sci. 2017, 159, 194−206. (26) Jonuzaj, S.; Adjiman, C. S. Designing optimal mixtures using generalized disjunctive programming: Hull relaxations. Chem. Eng. Sci. 2017, 159, 106−130. (27) Marcoulaki, E. C.; Kokossis, A. C. On the development of novel chemicals using a systematic optimization approach. Part II. Solvent design. Chem. Eng. Sci. 2000, 55, 2547−2561. (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. (29) Zhao, Q.; Han, H. J.; Xu, C. Y.; Zhuang, H. F.; Fang, F.; Zhang, L. H. Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater. Bioresour. Technol. 2013, 142, 179−185. (30) Ma, W. W.; Han, Y. X.; Ma, W. C.; Han, H. J.; Zhu, H.; Xu, C. Y.; Li, K.; Wang, D. X. Enhanced nitrogen removal from coal gasification wastewater by simultaneous nitrification and denitrification (SND) in an oxygen-limited aeration sequencing batch biofilm reactor. Bioresour. Technol. 2017, 244, 84−91. (31) Yang, C. F.; Qian, Y.; Zhang, L. J.; Feng, J. Z. Solvent extraction process development and on-site trial-plant for phenol removal from

ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.iecr.8b00925. Equations of UNIFAC model’s combinatorial and residual parts, group volume parameters, surface area parameters and UNIFAC group interaction parameter, molecular structures with different carbon number, structures of carbon chain isomers, and experimental distribution coefficients of hydroquinone (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Phone: +86-20-87112056, +86-18588887467. ORCID

Siyu Yang: 0000-0002-4871-7460 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS We would like to express our appreciation to the China NSF key project (No. 21736004) and National Key Research and Development Program of China (No. 2016YFB0600501) for their great funding and support of this study.

■

REFERENCES

(1) Tong, T. Z.; Elimelech, M. The global rise of zero liquid discharge for wastewater management: Drivers, technologies, and future directions. Environ. Sci. Technol. 2016, 50, 6846−6855. (2) Cui, P. Z.; Qian, Y.; Yang, S. Y. New water treatment index system toward zero liquid discharge for sustainable coal chemical processes. ACS Sustainable Chem. Eng. 2018, 6, 1370−1378. (3) Cui, P. Z.; Chen, B. K.; Yang, S. Y.; Qian, Y. Optimal design of an efficient polyphenols extraction process for high concentrated phenols wastewater. J. Clean. Prod. 2017, 165, 1395−1406. (4) Yang, C. F.; Jiang, Y. B.; Zhang, L. J.; Qian, Y. Liquid-liquid equilibria for the ternary system methyl isobutyl ketone + water + hydroquinone. J. Chem. Eng. Data 2006, 51, 2107−2109. (5) Chen, Y.; Lv, R.; Wang, H. M.; Liao, M. C.; Li, L. B. Ternary liquid-liquid equilibria for methyl isopropyl ketone + (resorcinol or hydroquinone) + water systems at different temperatures. Fluid Phase Equilib. 2016, 429, 93−97. (6) Chen, Y.; Wang, Z.; Li, L. B. Liquid-liquid equilibria for ternary systems: methyl butyl ketone + phenol + water and methyl butyl ketone + hydroquinone + water at 298.15 and 323.15 K. J. Chem. Eng. Data 2014, 59, 2750−2755. (7) Xu, G. J.; Yang, D. L.; Ning, P. G.; Wang, Q. J.; Gong, F. C.; Cao, H. B. Measurements and correlation of liquid-liquid equilibrium data for the ternary (3-heptanone + phenol + water) system. J. Chem. Thermodyn. 2017, 106, 295−302. (8) Liu, D.; Li, L. B.; Lv, R.; Chen, Y. Liquid-liquid equilibria for the ternary system mesityl oxide + phenol + water at 298.15, 313.15, and 323.15 K. J. Chem. Eng. Data 2016, 61, 2493−2498. (9) Sun, X. Q.; Waters, K. E. Synergistic effect between bifunctional ionic liquids and a molecular extractant for lanthanide separation. ACS Sustainable Chem. Eng. 2014, 2, 2758−2764. (10) Zhao, Z. Y.; Sun, X. Q.; Dong, Y. M.; Wang, Y. L. Synergistic effect of acid-base coupling bifunctional ionic liquids in impregnated resin for rare earth adsorption. ACS Sustainable Chem. Eng. 2016, 4, 616−624. (11) Liao, M. S.; Zhao, Y. H.; Ning, P. G.; Cao, H. B.; Wen, H.; Zhang, Y. Optimal design of solvent blend and its application in coking wastewater treatment process. Ind. Eng. Chem. Res. 2014, 53, 15071−15079. F


Article

Industrial & Engineering Chemistry Research industrial coal-gasification wastewater. Chem. Eng. J. 2006, 117, 179− 185.

G


Structural characteristics integrated computer-aided molecular design

Recommend Documents