Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum ...Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost(TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68% and 25.40% saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second,temperature control tray locations are obtained according to the sensitivity criterion and singular value decomposition(SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Finally, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor controllability despite of a little bit of economy.展开更多
The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313....The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa.The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities.The average absolute deviations(AAD)of the correlation for binary and ternary systems are 2.48%and 1.77%,respectively.展开更多
A new dynamic ebulliometer is used to determine vapor-liquid equilibrium(VLE) data experimentally. In the equipment,both phases are recirculated. Its operation is a consequence of the Cotrell pump effect produced when...A new dynamic ebulliometer is used to determine vapor-liquid equilibrium(VLE) data experimentally. In the equipment,both phases are recirculated. Its operation is a consequence of the Cotrell pump effect produced when the mixture is heated in a double-walled inverted vessel. The reliability of the apparatus is tested with the mixtures studied previously by various authors. VLE data for the binary systems of methyl acetate + methanol and the methyl acetate + ethanol at 0.5 MPa are determined. The experimental data are confirmed with the point-to-point test of van Ness,applying the Fortran program of Frendslund et al. In addition,the experimental results are com-pared with the UNIFAC(including different versions) and ASOG prediction models.展开更多
Reactive distillation and dividing wall column distillation are two kinds of effective separation technologies,and their integrated configuration,reactive dividing wall column(RDWC),presents attractive advantages.In t...Reactive distillation and dividing wall column distillation are two kinds of effective separation technologies,and their integrated configuration,reactive dividing wall column(RDWC),presents attractive advantages.In this study,the rigorous simulation of RDWC for methyl acetate hydrolysis is performed,and sensitivity analysis is conducted to obtain the minimum reboiler duty.Then a comparison is made between the conventional process and RDWC process,and it shows that 20.1% energy savings can be achieved by RDWC process.In addition,the dynamic characteristic of RDWC is studied and an effective control strategy is proposed.The simple PI control scheme with three temperature loops can obtain reasonable control performance and maintain products at desired purities.It is proved that this RDWC process is an energy efficiency alternative with good controllability.展开更多
文摘Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost(TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68% and 25.40% saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second,temperature control tray locations are obtained according to the sensitivity criterion and singular value decomposition(SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Finally, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor controllability despite of a little bit of economy.
基金Supported by China Petrochemical Corporation(X505012)
文摘The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa.The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities.The average absolute deviations(AAD)of the correlation for binary and ternary systems are 2.48%and 1.77%,respectively.
文摘A new dynamic ebulliometer is used to determine vapor-liquid equilibrium(VLE) data experimentally. In the equipment,both phases are recirculated. Its operation is a consequence of the Cotrell pump effect produced when the mixture is heated in a double-walled inverted vessel. The reliability of the apparatus is tested with the mixtures studied previously by various authors. VLE data for the binary systems of methyl acetate + methanol and the methyl acetate + ethanol at 0.5 MPa are determined. The experimental data are confirmed with the point-to-point test of van Ness,applying the Fortran program of Frendslund et al. In addition,the experimental results are com-pared with the UNIFAC(including different versions) and ASOG prediction models.
基金Supported by the National Natural Science Foundation of China(No.21276279No.21476261)+1 种基金the Fundamental Research Funds for the Central Universities(No.14CX05030ANo.15CX06042A)
文摘Reactive distillation and dividing wall column distillation are two kinds of effective separation technologies,and their integrated configuration,reactive dividing wall column(RDWC),presents attractive advantages.In this study,the rigorous simulation of RDWC for methyl acetate hydrolysis is performed,and sensitivity analysis is conducted to obtain the minimum reboiler duty.Then a comparison is made between the conventional process and RDWC process,and it shows that 20.1% energy savings can be achieved by RDWC process.In addition,the dynamic characteristic of RDWC is studied and an effective control strategy is proposed.The simple PI control scheme with three temperature loops can obtain reasonable control performance and maintain products at desired purities.It is proved that this RDWC process is an energy efficiency alternative with good controllability.
