Gibbs ensemble Monte Carlo simulation using an optimized potential model: pure acetic acid and a mixture of it with ethylene

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• 作者：Minhua Zhang ; Lihang Chen ; Huaming Yang ; Xijiang Sha…
• 刊名：Journal of Molecular Modeling
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：22
• 期：7
• 全文大小：1,773 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Computer Applications in Chemistry
  Biomedicine
  Molecular Medicine
  Health Informatics and Administration
  Life Sciences
  Computer Application in Life Sciences
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：0948-5023
• 卷排序：22

文摘

Gibbs ensemble Monte Carlo simulation with configurational bias was employed to study the vapor–liquid equilibrium (VLE) for pure acetic acid and for a mixture of acetic acid and ethylene. An improved united-atom force field for acetic acid based on a Lennard-Jones functional form was proposed. The Lennard-Jones well depth and size parameters for the carboxyl oxygen and hydroxyl oxygen were determined by fitting the interaction energies of acetic acid dimers to the Lennard-Jones potential function. Four different acetic acid dimers and the proportions of them were considered when the force field was optimized. It was found that the new optimized force field provides a reasonable description of the vapor–liquid phase equilibrium for pure acetic acid and for the mixture of acetic acid and ethylene. Accurate values were obtained for the saturated liquid density of the pure compound (average deviation: 0.84 %) and for the critical points. The new optimized force field demonstrated greater accuracy and reliability in calculations of the solubility of the mixture of acetic acid and ethylene as compared with the results obtained with the original TraPPE-UA force field.KeywordsAcetic acidEthyleneGibbs ensembleVapor–liquid equilibriumMolecular simulationForce field