The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecula...The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecular simulation presents great potential in research on the properties of fluids.Therefore,in this work,Gibbs ensemble Monte Carlo was applied to successfully predict the vapour-liquid phase equilibrium data of binary and ternary systems containing benzene,thiophene and N,Ndimethylformamide(DMF) at P=101.3 kPa.The explicit hydrogen version of the transferable potentials for phase equilibria potential model was chosen for benzene and thiophene,whereas the OPLS potential model was selected for DMF.The predicted phase diagrams were compared with experimental data and the UNIQUAC thermodynamic model.A good agreement was obtained,which corroborated the validity of the potential models.In addition,the extraction mechanism was explored by radial distribution function(RDF) of the liquid-phase structure.The RDFs showed that thiophene and benzene shared a similar liquidphase structure because of the intermolecular interaction.The distinct difference between the RDFs of DMF/benzene and those of DMF/thiophene is that the oxygen atom of DMF is more associated with hydrogen atoms of thiophene than that of benzene,which may be responsible for the extraction effect of DMF.展开更多
Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a mo...Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained.展开更多
A suitable mixing rule is important for vapor liquid equilibrium(VLE)investigations for mixed refrigerants.In this work,a new excess free energy mixing rule(MRv)was proposed at zero pressure based on the linear relati...A suitable mixing rule is important for vapor liquid equilibrium(VLE)investigations for mixed refrigerants.In this work,a new excess free energy mixing rule(MRv)was proposed at zero pressure based on the linear relationship between dimensionless parameter 1/(u-1)and a.MRv mixing rule was explicit adopted variable liquid molar volume.The applicable temperature range of MRv could be extended by means of an empirical method to estimate the liquid molar volume for components at high temperatures.Three mixing rules modified Huron-Vidal mixing rule(MHV1),Wong-Sandler mixing rule(WS),and MRv at two reference pressures were used to compare the VLE data in the calculation of 37 mixed refrigerants.Results demonstrated that MRv had a relatively similar accuracy to MHV1 and WS for component and pressure calculation.Moreover,the average excess Gibbs free energy using the MRv mixing rule for the 37 selected mixed refrigerants(0.0013)was much lower than those using the MHV1(0.0078)and WS(0.0809)mixing rules,which was very valuable for the design and optimization of thermodynamic systems using mixed refrigerants.展开更多
用改进的Rose平衡釜测定恒压下(99.9 k Pa)甲缩醛-甲醇二元系的汽液平衡数据。用Herrington检验法对实测数据进行了热力学一致性检验。对Wilson和NRTL活度系数模型进行了关联,回归得到模型参数与温度之间的关系。与实验数据相比较,用Wil...用改进的Rose平衡釜测定恒压下(99.9 k Pa)甲缩醛-甲醇二元系的汽液平衡数据。用Herrington检验法对实测数据进行了热力学一致性检验。对Wilson和NRTL活度系数模型进行了关联,回归得到模型参数与温度之间的关系。与实验数据相比较,用Wilson模型预测的汽相组成其相对平均偏差为7.99%,温度平均偏差为0.12 K;NRTL模型的偏差分别为7.66%和0.22 K。结果表明用两种模型参数预测二元系的泡点与实验值能很好地吻合。展开更多
The extraction of aromatics with N-formylmorpholine (NFM) has been widely used in petrochemical and coal tar industries.However, the vapor-liquid equilibrium (VLE) data of N-formylmorpholine-aromatics systems are very...The extraction of aromatics with N-formylmorpholine (NFM) has been widely used in petrochemical and coal tar industries.However, the vapor-liquid equilibrium (VLE) data of N-formylmorpholine-aromatics systems are very limited, and no isobaric VLE data can be found in literature.The VLE data of benzene-NFM system were determined by using an improved VLE equipment EC-2.The experimental VLE data were correlated with the thermodynamic models NRTL and UNIQUAC, and the corresponding binary interaction parameters for these two models were obtained.The results showed that the VLE data agreed well with the two models, and passed the thermodynamic consistency test of Herington.By comparison with these models from literature, it is found that these two models are more suitable for VLE prediction for NFM systems above 80℃.The VLE data and model parameters obtained are essential for the engineering design of N-formylmorpholine-aromatics distillation processes.展开更多
文摘The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecular simulation presents great potential in research on the properties of fluids.Therefore,in this work,Gibbs ensemble Monte Carlo was applied to successfully predict the vapour-liquid phase equilibrium data of binary and ternary systems containing benzene,thiophene and N,Ndimethylformamide(DMF) at P=101.3 kPa.The explicit hydrogen version of the transferable potentials for phase equilibria potential model was chosen for benzene and thiophene,whereas the OPLS potential model was selected for DMF.The predicted phase diagrams were compared with experimental data and the UNIQUAC thermodynamic model.A good agreement was obtained,which corroborated the validity of the potential models.In addition,the extraction mechanism was explored by radial distribution function(RDF) of the liquid-phase structure.The RDFs showed that thiophene and benzene shared a similar liquidphase structure because of the intermolecular interaction.The distinct difference between the RDFs of DMF/benzene and those of DMF/thiophene is that the oxygen atom of DMF is more associated with hydrogen atoms of thiophene than that of benzene,which may be responsible for the extraction effect of DMF.
基金supported by State Key Laboratory of Chemical Engineering Foundation
文摘Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained.
基金supported by the Nation Natural Science Foundation of China(Grant No.52076185)the Natural Science Foundation of Zhejiang Province(No.LZ19E060001)。
文摘A suitable mixing rule is important for vapor liquid equilibrium(VLE)investigations for mixed refrigerants.In this work,a new excess free energy mixing rule(MRv)was proposed at zero pressure based on the linear relationship between dimensionless parameter 1/(u-1)and a.MRv mixing rule was explicit adopted variable liquid molar volume.The applicable temperature range of MRv could be extended by means of an empirical method to estimate the liquid molar volume for components at high temperatures.Three mixing rules modified Huron-Vidal mixing rule(MHV1),Wong-Sandler mixing rule(WS),and MRv at two reference pressures were used to compare the VLE data in the calculation of 37 mixed refrigerants.Results demonstrated that MRv had a relatively similar accuracy to MHV1 and WS for component and pressure calculation.Moreover,the average excess Gibbs free energy using the MRv mixing rule for the 37 selected mixed refrigerants(0.0013)was much lower than those using the MHV1(0.0078)and WS(0.0809)mixing rules,which was very valuable for the design and optimization of thermodynamic systems using mixed refrigerants.
文摘用改进的Rose平衡釜测定恒压下(99.9 k Pa)甲缩醛-甲醇二元系的汽液平衡数据。用Herrington检验法对实测数据进行了热力学一致性检验。对Wilson和NRTL活度系数模型进行了关联,回归得到模型参数与温度之间的关系。与实验数据相比较,用Wilson模型预测的汽相组成其相对平均偏差为7.99%,温度平均偏差为0.12 K;NRTL模型的偏差分别为7.66%和0.22 K。结果表明用两种模型参数预测二元系的泡点与实验值能很好地吻合。
文摘The extraction of aromatics with N-formylmorpholine (NFM) has been widely used in petrochemical and coal tar industries.However, the vapor-liquid equilibrium (VLE) data of N-formylmorpholine-aromatics systems are very limited, and no isobaric VLE data can be found in literature.The VLE data of benzene-NFM system were determined by using an improved VLE equipment EC-2.The experimental VLE data were correlated with the thermodynamic models NRTL and UNIQUAC, and the corresponding binary interaction parameters for these two models were obtained.The results showed that the VLE data agreed well with the two models, and passed the thermodynamic consistency test of Herington.By comparison with these models from literature, it is found that these two models are more suitable for VLE prediction for NFM systems above 80℃.The VLE data and model parameters obtained are essential for the engineering design of N-formylmorpholine-aromatics distillation processes.
