Narrow cut – two product separation

narrowcutfrac

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.