Dynamic simulation and nonlinear control of a rigorous batch reactive distillation.

Area of Science:

• Chemical Engineering
• Process Control
• Reaction Engineering

Background:

• Batch distillation columns with chemical reactions are crucial for producing esters like butyl acetate.
• Optimizing purity and conversion in reactive distillation requires advanced modeling and control strategies.

Purpose of the Study:

• To develop and evaluate a control scheme for a high-purity batch distillation column with an esterification reaction.
• To achieve high product purity and near-complete reactant conversion through an effective distillate strategy and advanced control.

Main Methods:

• Formulation of a detailed process model including variable holdup, UNIQUAC thermodynamics, tray hydraulics, and pseudohomogeneous reaction kinetics.
• Development of an iterative approach for vapor flow computation under rigorous energy balance.
• Implementation of a distillate policy for sequential removal of water and enrichment of butyl acetate.
• Design and comparison of two forms of nonlinear generic model controllers (GMC) for top product purity control.

Main Results:

• The proposed iterative method ensures fast convergence for vapor flow calculations.
• The distillate policy effectively separates water and concentrates butyl acetate, achieving high conversion.
• The generic model control strategy successfully maintains high product purity at the top of the column.
• Closed-loop simulations demonstrate the effectiveness of the combined control and distillate strategy.

Conclusions:

• The integrated approach of a specific distillate policy and generic model control is highly effective for reactive batch distillation.
• This strategy leads to both high-purity butyl acetate production and near-complete conversion of reactants.
• The developed model and control system offer a robust solution for optimizing esterification processes in batch distillation columns.