Abstract
This paper presents a thermodynamically consistent model for the phase equilibrium of water/caprolactam/nylon-6 mixtures, based on the POLYNRTL (polymer nonrandom two-liquid) activity-coefficient model. Our model predicts phase equilibrium for any binary or ternary mixture containing water, ε-caprolactam, and nylon-6 at industrially relevant temperatures and pressures with an average error of 1%. This paper also demonstrates its application to simulate a melt train and a bubble-gas kettle train for industrial production of nylon-6. Prior literature makes simplifying assumptions about liquid-phase (molten polymer) activities of water and ε-caprolactam; these assumptions are shown to be unrealistic.
Original language | English |
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Pages (from-to) | 3900-3913 |
Number of pages | 14 |
Journal | Industrial and Engineering Chemistry Research |
Volume | 42 |
Issue number | 17 |
DOIs | |
State | Published - Aug 20 2003 |