Co-reporter:Jun Li, Yinmei Ye, Lifang Chen, and Zhiwen Qi
Journal of Chemical & Engineering Data February 9, 2012 Volume 57(Issue 2) pp:
Publication Date(Web):December 29, 2011
DOI:10.1021/je201197m
The solubilities of CO2 in solvent poly(ethylene glycols) (PEGs) with molecular weights of 150, 200, 300, and 400 were measured over the range of pressure from (100 to 1200) kPa and temperature from (303.15 to 333.15) K. Henry's constant was obtained by linear fitting of the experimental data, and thermodynamic properties of solutions were calculated from the correlation of Henry's constant. It indicates that the solubility of CO2 increases with increasing molecular weights of PEGs. Henry's constant based on mole fraction and the molality of CO2 in PEG400 vary from (4.78 to 7.09) MPa and (1.56 to 2.48) MPa·kg·mol–1 from (303.15 to 333.15) K, respectively.
Co-reporter:Zhen Song, Teng Zhou, Zhiwen Qi, and Kai Sundmacher
ACS Sustainable Chemistry & Engineering April 3, 2017 Volume 5(Issue 4) pp:3382-3382
Publication Date(Web):February 17, 2017
DOI:10.1021/acssuschemeng.7b00024
For the selection of industrially suitable ionic liquids (ILs) as extraction solvents, a systematic method combining phase equilibrium calculation, physical property prediction, and process simulation is presented. The conductor-like screening model for real solvents is used to predict the liquid–liquid equilibria of the systems composed of the target mixture to be separated and different ILs at the specific global composition of interest, thereby prescreening ILs with higher mass-based distribution coefficient and selectivity as well as lower solvent loss. Group contribution methods are then employed to estimate the key physical properties of the prescreened ILs and further suggest candidates meeting certain physical property constraints. Afterward, the performance of the top IL candidates in a continuous process is analyzed by Aspen Plus to identify finally process-based optimal solvents. The proposed method is illustrated with an extractive desulfurization case study and two most promising ILs for this process are consequently determined.Keywords: Extractive desulfurization; Ionic liquids screening; Liquid−liquid equilibrium; Physical property; Process simulation;
Co-reporter:Daili Peng, Jianan Zhang, Hongye Cheng, Lifang Chen, Zhiwen Qi
Chemical Engineering Science 2017 Volume 159(Volume 159) pp:
Publication Date(Web):23 February 2017
DOI:10.1016/j.ces.2016.05.027
•A computer-aided ionic liquid design methodology (CAILD) is developed.•Extended GC-COSMO is established to estimate σ-profile and cavity volume of an ionic liquid.•Contribution parameters of 61 cation groups are regressed and validated.•The CAILD methodology is tested by examples of extraction and absorption.For design of ionic liquid (IL) solvents for a specific separation process, a computer-aided ionic liquid design (CAILD) method based on multi-scale simulations is presented. A new group contribution based approach GC-COSMO for ILs is established for estimating the σ-profiles and cavity volumes of cations, where ILs are structured by three parts, i.e., one anion, one cation skeleton, and substituents on cation skeleton. Prediction models, including the COSMO-SAC model for thermodynamic properties and semi-empirical models for physical properties, are integrated into a computational IL design framework. A mixed-integer nonlinear programming (MINLP) problem is then formulated to optimize the separation performance combing the constraints of structural feasibility and physical properties. The optimal IL solvents are identified using a deterministic optimization method with branch and bound algorithm. The CAILD method is successfully tested for two typical separation examples, i.e. extraction of benzene from cyclohexane and post-combustion CO2 capture.Download high-res image (254KB)Download full-size image
Co-reporter:Lei Qin, Jianan Zhang, Hongye Cheng, Lifang Chen, Zhiwen Qi, and Weikang Yuan
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 2) pp:583
Publication Date(Web):November 22, 2015
DOI:10.1021/acssuschemeng.5b01330
Deodorizer distillate as a byproduct of vegetable oil refining is an important source of natural vitamin E. Simple and green extraction can be employed to recover vitamin E from deodorizer distillate, and its performance strongly relies on the solvent used in the process. In order to screen an imidazolium-based ionic liquid (IL) as entrainer, a methodology integrating theoretical and experimental evaluations was applied. ILs composed of 47 types of anions were first investigated by COSMO-RS to figure out the most promising one, and the effect of the alkyl chain on the imidazolium ring was addressed by experiments. The IL [C6MIm]Ac was finally determined as the most promising solvent with the selectivity of 108.23 and the partition coefficient of 8.182 for α-tocopherol. The liquid–liquid equilibrium data and the extraction result for corn oil deodorizer distillate indicate its superior performance for the extraction process dealing with a low concentration of vitamin E.Keywords: Deodorizer distillate; Extraction; Hydrogen bond; Interaction forces; Ionic liquid; Solvent selection; Vitamin E;
Co-reporter:Zhen Song, Qian Zeng, Jinwei Zhang, Hongye Cheng, Lifang Chen, Zhiwen Qi
Journal of Molecular Liquids 2016 Volume 224(Part A) pp:544-550
Publication Date(Web):December 2016
DOI:10.1016/j.molliq.2016.10.026
•Solubilities of 220 ILs in 7 model fuel hydrocarbons were predicted by COSMO-RS.•Molecular interactions between IL and hydrocarbon in IL-in-hydrocarbon systems were analyzed.•Effect of IL and hydrocarbon character on IL-in-hydrocarbon solubility was well understood by the molecular interactions.•Solubilities of 5 representative ILs in hydrocarbons were experimentally determined to validate the COSMO-RS predictions.When applying ionic liquids (ILs) in extractive and oxidative desulfurization of fuel oils, the potential solubility of IL in fuel phase is an important concern whereas research particularly on this issue is still scarce. In this work, COSMO-RS was first employed to predict the solubilities of 220 imidazolium-based ILs (11 cations and 20 anions) in 7 model fuel hydrocarbons (namely, n-hexane, n-heptane, n-octane, i-octane, cyclohexane, benzene and toluene), which cover different characters of ILs and hydrocarbons. To understand the effect of IL and hydrocarbon on the IL-in-hydrocarbon solubility, different types of molecular interactions between IL and hydrocarbon were further analyzed from COSMO-RS point of view. Finally, the solubilities of 5 representative ILs in the studied hydrocarbons were experimentally determined by nitrogen analyzer, demonstrating the good qualitative and acceptable quantitative ability of COSMO-RS for predicting IL-in-hydrocarbon solubilities.
Co-reporter:Shaohua Zheng, Hongye Cheng, Lifang Chen, Zhiwen Qi
The Journal of Chemical Thermodynamics 2016 Volume 93() pp:127-131
Publication Date(Web):February 2016
DOI:10.1016/j.jct.2015.10.003
•Lactate esters were studied as solvent to remove butanol from aqueous media.•(Liquid + liquid) equilibrium data were measured at T = 298.15 K and 1 atm.•Selectivity and 1-butanol partition coefficient were calculated.•COSMO-based study of separation efficiency on solvent structure was conducted.As bio-based solvents, lactate esters can be used as extractant for removing 1-butanol from the aqueous fermentation broths. In order to evaluate the separation efficiency of butyl lactate and 2-ethylhexyl lactate for the extraction of 1-butanol from its mixture with water, the (liquid + liquid) equilibrium for the ternary systems {water (1) + 1-butanol (2) + lactate ester (3)} were measured at T = 298.15 K. The 1-butanol partition coefficient varied in the range of 4.46 to 10.29, and the solvent selectivity within 32.12 to 108.18. For the separation of low-concentration butanol from fermentation broths, butyl lactate exhibits higher partition coefficient and lower selectivity than 2-ethylhexyl lactate. The NRTL model was employed to correlate the experimental data, and the COSMO-RS theory was utilized to predict the (liquid + liquid) equilibria and to analyze the influence of lactate esters on extraction efficiency.
Co-reporter:Zhen Song, Jingjing Zhang, Qian Zeng, Hongye Cheng, Lifang Chen, Zhiwen Qi
Fluid Phase Equilibria 2016 425() pp: 244-251
Publication Date(Web):15 October 2016
DOI:10.1016/j.fluid.2016.06.016
Co-reporter:Jun Li, Chenjia You, Zhaoxian Lyu, Chi Zhang, Lifang Chen, Zhiwen Qi
Separation and Purification Technology 2015 Volume 149() pp:9-15
Publication Date(Web):27 July 2015
DOI:10.1016/j.seppur.2015.05.012
•Dehydration of bio-ethanol with gasoline additive MTBE as entrainer is proposed.•The product of mixture of ethanol and MTBE can be mixed directly with gasoline.•Residue curve maps are applied for process conceptual design.•The dehydration process can significantly reduce the energy consumption.To reduce the heavy energy consumption of the conventional dehydration process of bioethanol production from biomass fermentation broth, this work aims to develop a fuel-based ethanol dehydration process directly extracted by gasoline additive. Methyl tert-butyl ether (MTBE) is screened and validated as an available entrainer of heteroazeotropic distillation from gasoline additives by analyzing and determining residue curve maps on the basis of simulation and experimental method. Two fuel-based ethanol separation processes with MTBE as entrainer, i.e. direct-cycle scheme and three-column scheme, are proposed and optimized by using ASPEN PLUS. It indicates that the proposed dehydration process with MTBE as entrainer can significantly reduce the energy and entrainer consumption, and the product can be directly used in gas pool. The techno-economic evaluation indicates MTBE scheme with 8000 ton/year ethanol production presents lower capital and utility costs than isooctane scheme.
Co-reporter:Chenjia You;Chi Zhang;Lifang Chen
Applied Organometallic Chemistry 2015 Volume 29( Issue 10) pp:653-660
Publication Date(Web):
DOI:10.1002/aoc.3342
Highly dispersed palladium nanoclusters incorporated on amino-functionalized silica sphere surfaces (Pd/SiO2-NH2) were fabricated by a simple one-pot synthesis utilizing 3-(2-aminoethylamino)propyltrimethoxysilane (AAPTS) as coordinating agent. Uniform palladium nanoclusters with an average size of 1.1 nm can be obtained during the co-condensation of tetraethyl orthosilicate and AAPTS owing to the strong interaction between palladium species and amino groups in AAPTS. The palladium particle size can be controlled by addition of AAPTS and plays a significant role in the catalytic performance. The Pd/SiO2-NH2 catalyst exhibits high catalytic activity for succinic acid hydrogenation with 100% conversion and 94% selectivity towards γ-butyrolactone using 1,4-dioxane as solvent at 240°C and 60 bar for 4 h. Moreover, the Pd/SiO2-NH2 catalyst is robust and readily reusable without loss of its catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Wenrong Cao, Lifang Chen, Zhiwen Qi
Journal of Molecular Catalysis A: Chemical 2015 401() pp: 81-89
Publication Date(Web):
DOI:10.1016/j.molcata.2015.02.023
Co-reporter:Wenrong Cao;Lifang Chen
Catalysis Letters 2014 Volume 144( Issue 4) pp:598-606
Publication Date(Web):2014 April
DOI:10.1007/s10562-013-1183-3
Highly dispersed silver sulfate nanoparticles deposited on ZnO nanoflakes (ASZ) were successfully prepared by a simple solvothermal method with different silver contents. The prepared 3ASZ composite shows improved photocatalytic activity for rhodamine B degradation under UV–vis light irradiation compared with pure ZnO, Ag2SO4, and commercial TiO2 (P25). The remarkable photocatalytic activity for ASZ composite maybe due to the synergistic effects between photo-reduced Ag and SO42− on the surface of ZnO nanoflakes, which promote efficient separation of electron–hole pairs.
Co-reporter:Jun Li, Lifang Chen, Yinmei Ye, and Zhiwen Qi
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 6) pp:1781-1787
Publication Date(Web):April 18, 2014
DOI:10.1021/je400947t
Mixed solvents of monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), and N-methyldiethanolamine (MDEA) with poly(ethylene glycol) 200 (PEG200) as cosolvent were analyzed by thermal gravimetric analysis to select an available CO2 absorber. MEA-PEG200 has the lowest onset temperature (the temperature at which the weight loss begins) of 363 K and thus is not appropriate for CO2 capture at high temperature. The viscosities of the mixtures decrease as temperature increases, and are mainly decided by the viscosity of PEG200 at a high temperature. The solubility of CO2 in mixed solvents of alkanolamine (DGA, DEA, and MDEA) and PEG200 was measured over the range of pressure from (10 to 1600) kPa and temperature from (313.15 to 393.15) K in intervals of 40 K. DEA and DGA solutions show relatively high CO2 capacity at 313.15 K owing to a chemical reaction with CO2, while MDEA solution presents the property of physical absorber. When temperature further increases to 393 K, the capacity decreases significantly. The solubility was correlated by Jou and Mather’s model.
Co-reporter:Cuihua Wang, Lifang Chen and Zhiwen Qi
Catalysis Science & Technology 2013 vol. 3(Issue 4) pp:1123-1128
Publication Date(Web):29 Jan 2013
DOI:10.1039/C2CY20692G
Highly-dispersed gold nanoparticles embedded in amorphous silica (Au/M-SiO2) were prepared by a facile one-pot process utilizing thioether functional groups to anchor AuCl4−. A surprisingly high TOF up to 21097 h−1 was obtained over the 0.2% Au/M-SiO2 catalyst, and the 1.5% Au/M-SiO2 catalyst exhibited a high catalytic activity of 22.7% for cyclohexane conversion and 80.6% selectivity to cyclohexanol and cyclohexanone under dipolar non hydrogen bond donor (HBD) acetone solvent at 423 K and 1.5 MPa O2 for 3 h.
Co-reporter:Teng Zhou, Long Chen, Yinmei Ye, Lifang Chen, Zhiwen Qi, Hannsjörg Freund, and Kai Sundmacher
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 17) pp:6256-6264
Publication Date(Web):April 16, 2012
DOI:10.1021/ie202719z
To properly screen and use ionic liquids (ILs) as environmental-friendly solvents in chemical reactors and separation processes, the knowledge of their solubilities with water is essential. In the present work, mutual solubilities of 1500 ILs (50 cations, 30 anions) with water at 298.15 K were predicted by using the conductor-like screening model for real solvents (COSMO-RS) as a thermodynamic model. On the basis of the COSMO-RS calculations, the influence of the types of anion and cation, side chain modifications and substituent groups on the mutual solubility with water was extensively analyzed. The data obtained can be used for the prescreening of ILs as solvent candidates. Moreover, to understand the intrinsic solubility behavior in detail, different types of molecular interactions between ILs and water in solution were compared on the basis of the determination of multiple water–IL interaction energies from COSMO-RS computation. The results confirm that hydrogen bonding interactions between anions and water molecules have the dominant influence on the solubility. Finally, for the purpose of fast solubility estimation and solvent selection, COSMO-RS derived molecular descriptors which indicate the strength of anionic HB acceptors were calculated for typical anions and anion families.
Co-reporter:Teng Zhou, Ziyun Wang, Yinmei Ye, Lifang Chen, Jing Xu, and Zhiwen Qi
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 15) pp:5559-5564
Publication Date(Web):March 27, 2012
DOI:10.1021/ie202728j
Separation of benzene and cyclohexane is one of the most important and difficult processes in the petrochemical industry, especially for low benzene concentration. In this work, three ionic liquids (ILs), [Bmim][BF4], [Bpy][BF4], and [Bmim][SCN], were investigated as the solvent in the extraction of benzene from cyclohexane. The corresponding ternary liquid–liquid equilibria (LLE) were experimentally determined at T = 298.15 K and atmospheric pressure. The LLE data were correlated with the nonrandom two-liquid model, and the parameters were fitted. The separation capabilities of the ILs were evaluated in terms of the benzene distribution coefficient and solvent selectivity. The effect of the IL structure on the separation was explained based on a well-founded physical model, COSMO-RS. Finally, the extraction processes were defined, and the operation parameters were analyzed. It shows that the ILs studied are suitable solvents for the extractive separation of benzene and cyclohexane, and their separation efficiency can be generally ranked as [Bmim][BF4] > [Bpy][BF4] > [Bmim][SCN]. The extraction process for a feed with 15 mol % benzene was optimized. High product purity (cyclohexane 0.997) and high recovery efficiency (cyclohexane 96.9% and benzene 98.1%) can be reached.
Co-reporter:Jun Li, Chenjia You, Lifang Chen, Yinmei Ye, Zhiwen Qi, and Kai Sundmacher
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 37) pp:12081-12088
Publication Date(Web):August 28, 2012
DOI:10.1021/ie301164v
To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution.
Co-reporter:Gai Miao;Lifang Chen
European Journal of Inorganic Chemistry 2012 Volume 2012( Issue 35) pp:5864-5871
Publication Date(Web):
DOI:10.1002/ejic.201200833
Abstract
Morphology and crystalline-phase control of titanium dioxide is a crucial issue in the study of photocatalytic activity. Here, we present a facile synthetic path combing the sol–gel method with solvothermal treatment to form hybrid mesoporous and microporous TiO2. The TiO2 precursor was obtained by the sol–gel method, and this was self-assembled into mesopores and micropores by NH4F corrosiveness on the surface of TiO2 under hydrothermal conditions. Powder X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), X-ray photoelectron spectroscopy (XPS), N2 adsorption measurements, transmission electron microscopy (TEM) and Raman spectroscopy were used to characterise the titania powders. The results reveal that NH4F not only improved the formation of the crystallised anatase phase but also served as a corrosive agent modified on the surface of TiO2 precursors. Defective voids among these nanoparticles formed micropores by hydrothermal reaction of NH4F and TiO2 over a long time. When the NH4F concentration was 1.0 mol L−1, micropores became dominant,and few mesopores were obtained, and this results in a smaller average pore size. Thus, mesoporous and microporous structures were formed. Furthermore, these crystallised mesoporous and microporous anatase titania nanoparticles with uniform structure and high surface area have a higher photocatalytic activity for azo dye degradation under near UV irradiation.
Co-reporter:Teng Zhou, Ziyun Wang, Lifang Chen, Yinmei Ye, Zhiwen Qi, Hannsjörg Freund, Kai Sundmacher
The Journal of Chemical Thermodynamics 2012 Volume 48() pp:145-149
Publication Date(Web):May 2012
DOI:10.1016/j.jct.2011.12.006
In the catalytic hydrogenation of benzene to cyclohexane, the separation of unreacted benzene from the product stream is inevitable and essential for an economically viable process. In order to evaluate the separation efficiency of ionic liquids (ILs) as a solvent in this extraction processes, the ternary (liquid + liquid) equilibrium of 1-alkyl-3-methylimidazolium hexafluorophosphate, [Cnmim][PF6] (n = 4, 5, 6), with benzene and cyclohexane was studied at T = 298.15 K and atmospheric pressure. The reliability of the experimentally determined tie-line data was confirmed by applying the Othmer–Tobias equation. The solute distribution coefficient and solvent selectivity for the systems studied were calculated and compared with literature data for other ILs and sulfolane. It turns out that the benzene distribution coefficient increases and solvent selectivity decreases as the length of the cation alkyl chain grows, and the ionic liquids [Cnmim][PF6] proved to be promising solvents for benzene–cyclohexane extractive separation. Finally, an NRTL model was applied to correlate and fit the experimental LLE data for the ternary systems studied.Highlights► Measured ternary LLE for {cyclohexane (1) + benzene (2) + [Cnmim][PF6] (3)}. ► Well correlated the LLE data with the NRTL model. ► Determined the benzene distribution coefficient and solvent selectivity. ► Very promising for the extraction of benzene from cyclohexane. ► Very helpful for overcoming drawbacks of the conventional separation process.
Co-reporter:Long Chen, Teng Zhou, Lifang Chen, Yinmei Ye, Zhiwen Qi, Hannsjörg Freund and Kai Sundmacher
Chemical Communications 2011 vol. 47(Issue 33) pp:9354-9356
Publication Date(Web):18 Jul 2011
DOI:10.1039/C1CC12989A
Ionic liquid (IL) 1-octyl-3-methylimidazolium chloride was found to effectively intensify cyclohexanol oxidation and resulted in 100% conversion of cyclohexanol with 100% selectivity to cyclohexanone using hydrogen peroxide as an oxidant and WO3 as a catalyst. The effect of the IL as a solvent is discussed with the support of COSMO-RS theory.
Co-reporter:Liwei Tong, Lifang Chen, Yinmei Ye, Zhiwen Qi
Chinese Journal of Chemical Engineering (March 2015) Volume 23(Issue 3) pp:520-527
Publication Date(Web):1 March 2015
DOI:10.1016/j.cjche.2014.03.004
Isooctane is a promising gasoline additive that could be produced by dimerization of isobutene (IB) with subsequent hydrogenation. In this work, the dimerization of IB has been carried out in a batch reactor over a temperature range of 338–383 K in the presence of laboratory prepared Ni/Al2O3 as a catalyst and n-pentane as solvent. The influence of various parameters such as temperature, catalyst loading and initial concentration of IB was examined. A Langmuir–Hinshelwood kinetic model of IB dimerization was established and the parameters were estimated on the basis of the measured data. The feasibility of oligomerization of IB based on the reactive distillation was simulated in ASPEN PLUS using the kinetics developed. The simulation results showed that the catalyst of Ni/Al2O3 had higher selectivity to diisobutene (DIB) and slightly lower conversion of IB than ion exchange resin in the absence of polar substances.A kinetic model of IB dimerization with Ni/Al2O3 as the catalyst was developed in this work. The kinetics was applied to simulate the process of IB dimerization in RD. Simulation results show that the concentration of DIB in the reactive zone is maintained at a relatively low level, which suppresses the formation of TIB and higher oligomers. High purity of DIB (> 0.86) can be acquired as the bottom product. Meanwhile, the conversion of IB is 98.84% and the selectivity to DIB is 84.91% which is higher than ion exchange resin as a catalyst in the same condition.Download full-size image
Co-reporter:Xueqing Kang, Hongye Cheng, Liwei Tong, Lifang Chen, Zhiwen Qi
Chinese Journal of Chemical Engineering (December 2016) Volume 24(Issue 12) pp:1742-1749
Publication Date(Web):1 December 2016
DOI:10.1016/j.cjche.2016.05.025
A bifurcation analysis approach is developed based on the process simulator gPROMS platform, which can automatically trace a solution path, detect and pass the bifurcation points and check the stability of solutions. The arc-length continuation algorithm is incorporated as a process entity in gPROMS to overcome the limit of turning points and get multiple solutions with respect to a user-defined parameter. The bifurcation points are detected through a bifurcation test function τ which is written in C ++ routine as a foreign object connected with gPROMS through Foreign Process Interface. The stability analysis is realized by evaluating eigenvalues of the Jacobian matrix of each steady state solution. Two reference cases of an adiabatic CSTR and a homogenous azeotropic distillation from literature are studied, which successfully validate the reliability of the proposed approach. Besides the multiple steady states and Hopf bifurcation points, a more complex homoclinic bifurcation behavior is found for the distillation case compared to literature.Fig. 1 Development of bifurcation algorithms based on gPROMS and the calculated bifurcation diagramsA bifurcation analysis method was developed based on gPROMS platform. The pseudo arc-length continuation algorithm and bifurcation test functions were incorporated in gPROMS for tracing solution paths, locating the bifurcation points and checking the stability of solutions. The method was verified successfully by two classic examples of a CSTR and an azeotropic distillation. Besides the multiple steady states and Hopf bifurcation points which were in agreement with literature, a more complex homoclinic bifurcation phenomenon was found for the distillation process.Download high-res image (278KB)Download full-size image
Co-reporter:Zhaoxian Lyu, Teng Zhou, Lifang Chen, Yinmei Ye, Kai Sundmacher, Zhiwen Qi
Chemical Engineering Science (3 July 2014) Volume 113() pp:45-53
Publication Date(Web):3 July 2014
DOI:10.1016/j.ces.2014.04.011
•[C4mim][AlCl4] is selected as proper solvent to separate benzene and cyclohexane.•COSMO-RS is applied to screen solvent from combinations of 12 cations and 22 anions.•Interaction between ionic liquids and benzene is investigated by DFT calculation.•Continuous extraction processes are simulated using [C4mim][AlCl4] and sulfolane as solvent.In order to screen ionic liquids (IL) as suitable solvents for the separation of benzene and cyclohexane, the extraction efficiency of ILs (12 cations and 22 anions) was estimated based on COSMO-RS predictions of infinite dilution activity coefficients of benzene and cyclohexane in different ILs..[C4mim][AlCl4] was found to be the most promising solvent. To provide deep insight on how the IL structure influences the extraction efficiency, molecular interactions between IL ions and benzene were determined from DFT calculations. Moreover, liquid–liquid equilibrium data of the ternary system benzene–cyclohexane—[C4mim][AlCl4] were experimentally determined and used to fit parameters of the NRTL activity coefficient model. Based on the NRTL model the continuous extraction process was simulated and compared with a reference process using sulfolane as solvent. For the extraction process using [C4mim][AlCl4], high cyclohexane product purity (99.65 wt%) and high benzene recovery efficiency (98.03%) can be reached with at much lower energy consumption and higher product yield compared to conventional extraction solvents. In conclusion, the ionic liquid [C4mim][AlCl4] is a promising solvent for the extractive separation of benzene and cyclohexane.
Co-reporter:Jianan Zhang, Daili Peng, Zhen Song, Teng Zhou, Hongye Cheng, Lifang Chen, Zhiwen Qi
Chemical Engineering Science (27 April 2017) Volume 162() pp:355-363
Publication Date(Web):27 April 2017
DOI:10.1016/j.ces.2016.12.022
•COSMO-GC-IL method is proposed to predict σ-profiles and cavity volumes of ionic liquids.•Isomers of ionic liquids are completely distinguishable.•COSMO descriptors are established and two parameters are utilized for modification.•The method is validated by activity coefficients and LLE compositions.When applying COSMO-based models in Computer-Aided Ionic Liquid Design (CAILD), the generation of surface charge density profiles (σ-profiles) and cavity volumes (VCOSMO) of ILs is particularly important but too computationally expensive with quantum chemical calculations. In this work, a modified group contribution methodology, the COSMO-GC-IL method, is proposed for quick prediction of IL σ-profiles and VCOSMO based on σ-profiles of IL groups in their reference states (COSMO descriptors), together with two modification parameters (stretch and translation parameters). The influence of molecular environment on target groups can be well described and IL isomers are thereby distinguishable. To verify the method, σ-profiles and VCOSMO generated from the present method and from the DMol3 database are employed to calculate activity coefficients of 28,644 binary systems and 3410 liquid-liquid equilibria of ternary mixtures. Their close results in most cases demonstrate the reliability of the COSMO-GC-IL method.
Co-reporter:Jianan Zhang, Lei Qin, Daili Peng, Teng Zhou, Hongye Cheng, Lifang Chen, Zhiwen Qi
Chemical Engineering Science (27 April 2017) Volume 162() pp:364-374
Publication Date(Web):27 April 2017
DOI:10.1016/j.ces.2016.12.023
•A computer-aided ionic liquid design (CAILD) strategy is developed.•A mixed simulated annealing-genetic algorithm is presented to solve the MINLP problem.•The CAILD strategy is tested by two examples of extraction process.A computer-aided ionic liquid design (CAILD) framework is presented to identify optimal structures of ionic liquids (ILs) for specific separation processes. The design task is formulated as an optimization problem with the objective of maximizing the IL separation performance. In order to result in ILs with high practical application potential, constraints on their physicochemical properties are considered in CAILD. IL candidates are represented by rooted trees, which facilitate the prediction of their σ-profiles and cavity volumes from the COSMO-GC-IL method proposed in the first part of this work. A mixed simulated annealing-genetic algorithm (MSAGA) algorithm is developed and used for solving the optimization-based CAILD problem. The proposed CAILD framework is tested to design ILs for two extraction processes, i.e., separation of benzene-cyclohexane and heptane-thiophene. The result demonstrates that MSAGA can reliably and efficiently solve the problem and the finally identified ILs show improved separation performance than literature-reported ones.
Co-reporter:Liwei Tong, Lifang Chen, Yinmei Ye, Zhiwen Qi
Chemical Engineering Science (17 March 2014) Volume 106() pp:190-197
Publication Date(Web):17 March 2014
DOI:10.1016/j.ces.2013.11.036
•Concept of reactive distillation directly intensified by an auxiliary reaction is presented.•RCMs is developed to analyze the intensification mechanism with two reactions and multiple components.•The methyl acetate hydrolysis intensified by methanol dehydration is studied as example.•A novel process of MeOAc hydrolysis is designed with 100% conversion of MeOAc.•No additional H2O is needed in feed while high purity DME and HAc are products.A reactive distillation (RD) process directly intensified by an auxiliary reaction is presented. The methyl acetate (MeOAc) hydrolysis intensified by methanol (MeOH) dehydration is studied as an example where the latter serves as the auxiliary reaction. A residue curve maps (RCMs) is developed to analyze the mechanism of intensification for the case with two reactions and multiple components. The analysis of thermodynamics and RCMs reveals that the reaction of MeOH dehydration is the controlling step which limits the conversion of MeOAc. Based on the chemical equilibrium and kinetically controlled design, a novel process is developed to hydrolyze MeOAc and MeOH in the process of polyvinyl alcohol. Compared to traditional processes, no additional water is required to feed into the RD column and the process is significantly simplified. With equal mole of MeOAc and MeOH as feed and a set of pre-reactor, closely 100% conversion of MeOAc and MeOH can be achieved and high purity dimethyl ether and acetic acid are the products in the RD column.
Co-reporter:Zhaoxian Lyu, Teng Zhou, Lifang Chen, Yinmei Ye, Kai Sundmacher, Zhiwen Qi
Chemical Engineering Science (1 August 2014) Volume 115() pp:186-194
Publication Date(Web):1 August 2014
DOI:10.1016/j.ces.2014.05.032
•[C4mim][AlCl4] is selected as proper solvent to separate benzene and cyclohexane.•COSMO-RS is applied to screen solvent from combinations of 12 cations and 22 anions.•Interaction between ionic liquids and benzene is investigated by DFT calculation.•Continuous extraction processes are simulated using [C4mim][AlCl4] and sulfolane as solvent.In order to screen ionic liquids (IL) as suitable solvents for the separation of benzene and cyclohexane, the extraction efficiency of ILs (12 cations and 22 anions) was estimated based on COSMO-RS predictions of infinite dilution activity coefficients of benzene and cyclohexane in different ILs..[C4mim][AlCl4] was found to be the most promising solvent. To provide deep insight on how the IL structure influences the extraction efficiency, molecular interactions between IL ions and benzene were determined from DFT calculations. Moreover, liquid–liquid equilibrium data of the ternary system benzene–cyclohexane—[C4mim][AlCl4] were experimentally determined and used to fit parameters of the NRTL activity coefficient model. Based on the NRTL model the continuous extraction process was simulated and compared with a reference process using sulfolane as solvent. For the extraction process using [C4mim][AlCl4], high cyclohexane product purity (99.65 wt%) and high benzene recovery efficiency (98.03%) can be reached with at much lower energy consumption and higher product yield compared to conventional extraction solvents. In conclusion, the ionic liquid [C4mim][AlCl4] is a promising solvent for the extractive separation of benzene and cyclohexane.
Co-reporter:Long Chen, Teng Zhou, Lifang Chen, Yinmei Ye, Zhiwen Qi, Hannsjörg Freund and Kai Sundmacher
Chemical Communications 2011 - vol. 47(Issue 33) pp:NaN9356-9356
Publication Date(Web):2011/07/18
DOI:10.1039/C1CC12989A
Ionic liquid (IL) 1-octyl-3-methylimidazolium chloride was found to effectively intensify cyclohexanol oxidation and resulted in 100% conversion of cyclohexanol with 100% selectivity to cyclohexanone using hydrogen peroxide as an oxidant and WO3 as a catalyst. The effect of the IL as a solvent is discussed with the support of COSMO-RS theory.
Co-reporter:Cuihua Wang, Lifang Chen and Zhiwen Qi
Catalysis Science & Technology (2011-Present) 2013 - vol. 3(Issue 4) pp:NaN1128-1128
Publication Date(Web):2013/01/29
DOI:10.1039/C2CY20692G
Highly-dispersed gold nanoparticles embedded in amorphous silica (Au/M-SiO2) were prepared by a facile one-pot process utilizing thioether functional groups to anchor AuCl4−. A surprisingly high TOF up to 21097 h−1 was obtained over the 0.2% Au/M-SiO2 catalyst, and the 1.5% Au/M-SiO2 catalyst exhibited a high catalytic activity of 22.7% for cyclohexane conversion and 80.6% selectivity to cyclohexanol and cyclohexanone under dipolar non hydrogen bond donor (HBD) acetone solvent at 423 K and 1.5 MPa O2 for 3 h.
![Methane,bis[(trifluoromethyl)sulfonyl]-](http://img.cochemist.com/ccimg/500/428-76-2.png)
![Methane,bis[(trifluoromethyl)sulfonyl]-](http://img.cochemist.com/ccimg/500/428-76-2_b.png)
