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Simulation And Experiment For Separation Of Acetonitrile-water Azeotropic Mixture

Posted on:2009-01-23Degree:MasterType:Thesis
Country:ChinaCandidate:T J HeFull Text:PDF
GTID:2121360272486422Subject:Pharmaceutical Engineering
Abstract/Summary:PDF Full Text Request
Acetonitrile is widely used in the pharmaceutical industry because of its excellent solubility of the inorganic and organic compounds,and it's necessary to recovery acetonitrile from waste water.For the separation of the homogeneous azeotropic mixture acetonitrile/water,the common distillation couldn't work any more.This paper discussed the technology of separation of acetonitrile-water azeotropic mixture by special distillation.The extractive distillation and pressure-swing-distillation for the separation of the homogeneous azeotropic mixture acetonitrile/water were simulated with chemical process simulation software Aspen Plus 2004.In the extractive distillation steady process,ethylene glycol was selected as the entrainer,WILSON model was used to calculate the activity coefficients of the liquid phase,ideal gas equation of state was used to predict the fugacity coefficients of the gas phase,the operation parameters were optimized,and the concentration of acetonitrile in the product approaches 99.9 wt%.For the pressure-swing-distillation steady process,the research focused on the confirmation of the feed location and temperature,including the raw material feed and the recycle feed from the atmospheric pressure column to the low-pressure column,the operation parameters for both columns were optimized,and the acetonitrile concentration of the product is 99.9 wt%.The batch distillation experiments of the pressure-swing-distillation and that with salt were carried out for the separation of the homogeneous azeotropic mixture acetonitrile/water.And the experiment results was in accordance with the simulation, when the concentration of NaI in the recycle feed reached 0.2 g/ml in the pressure- swing-distillation with salt,the shift in the azeotropic concentration becomes lager and reaches 7.71 wt%,the total energy consumption decreases to 44.95%,and the through- out for the same device increases 70.26%.The simulation and experimental results suggest that,there are several shortcuts in the separation of azeotropic mixtures acetonitrile/water with pressure-swing- distillation, such as huge recycle amount between columns,small throughout and high energy consumption.However, pressure-swing-distillation with salt could deal with these problems effectively,and its energy consumption is in the same level with the extractive distillation, so it could be used in the reconstruction of manufacture device or the design process.
Keywords/Search Tags:Pressure-swing-distillation with salt, Acetonitrile, Water, Azeotrope, Simulation
PDF Full Text Request
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