Narrow cut fractionation

 

Details of three narrow cut fractionation APC training sessions follow:

1. Distillation column configurations (100 minutes):

• Refresher of distillation theory.
• Key control handles: cut and fractionation.
• Heat balance and mass balance control configurations.
• Operational problems: purity inference, instabilities, constraints.
• Simple tray temperature inference.
• Pressure control configuration.
• APC requirements.

2. Distillation inference methodology (100 minutes):

• Empirical inference methods.
• The Petrocontrol GDS first principles model.
  • Prediction of distillation product purities.
  • RVP considerations.
• Flooding detection methods.
• Handling steady state inference models with dynamic inputs.
• The role of on-stream analyzers.

3. Distillation column APC (90 minutes):

• The classic dynamic interaction problem.
• Dynamic decouplers.
• Constraints and APC structure: CV’s, DV’s and MV’s for different column configuration.
• Pressure minimization considerations.
• Combining several columns in one MVPC controller.