Aspen Plus: Distillation Modeling

Course Id:  EAP250   |   Duration:  2.00 day(s)   |   CEUs Awarded:  1.4   |   Level:  Intermediate

Course Objective

Take a deep dive into distillation modeling. Learn how to handle complex distillation such as azeotropic, 3-phase, and reactive distillation, how to set up pumparounds, side draws, multiple condensers and how to optimize the feed location and number of stages. Learn how to perform Sizing/Rating of trayed and packed towers. Troubleshoot convergence issues.

Course Overview

This course will help you prepare for the certification exam and the exam fee is waived with this course

  • Learn how to synthesize the best separation sequences that achieve desired separation tasks
  • Learn how to simulate complex features in distillation processes, including azeotropic, three-phase, and reactive distillation as well as columns with features such as pumparounds, side draws, multiple condensers, etc. using Aspen Plus
  • Learn to troubleshoot distillation column models, enhance convergence, and evaluate model quality


  • Gain the skills and knowledge to model complex distillation processes
  • Reduce process design time by using advanced features of RadFrac
  • Determine separation schemes using conceptual design tools
  • Perform Tray Sizing/Rating and Packed Sizing/Rating calculations
  • Apply Aspen Rate-Based Distillation to accurately model column with real trays and packing
  • Use column analysis tools to optimize the feed location and number of stages and improve energy utilization
  • Improve distillation model stability and accuracy


Engineers familiar with Aspen Plus with some experience simulating distillation processes who wish to improve their ability to simulate more difficult distillation processes.


  • Discussion about the general approach and the key elements for successful simulations
  • Instructor-guided demonstrations of features
  • Detailed course notes
  • Hands-on workshops that apply learned concepts, including experience troubleshooting distillation models
  • Extra application-based workshops


Must have attended the EAP101 Aspen Plus: Process Modeling training course or have previous experience in using Aspen Plus.

Subsequent Courses

EAP201 Physical Properties for Process Engineers
EAP2411 Improved Process Operability and Control Through Aspen Plus Dynamic Models

Class Schedule

Class Agenda

EAP250: Aspen Plus: Distillation Modeling

Introduction to Distillation Synthesis and Conceptual Design

  • Review and explain the Conceptual Design tools
  • Discuss how to use Ternary Maps to analyze distillation sequences
  • Workshop: Design a separation sequence using the Ternary Maps 
Conceptual Design Block
  • Identify and explain the Aspen Plus conceptual distillation design block, CONSEP
  • Workshop: Ester separation from ether and alcohol
Distillation Using RadFrac
  • Preview available multistage separation models in Aspen Plus
  • Review the RadFrac model for single columns and functionality regarding Rating and Design
  • Workshop: HCL column setup 
  • Review and explain the different types of efficiencies available in RadFrac 
Sizing and Rating of Trays and Packing
  • Review and explain Column Analysis for Sizing (Design) and Rating of trays and packing
  • Workshop: Perform tray rating on an HCl column
NQ Curves
  • Review how the NQ Curve feature can be used to optimize the feed stage location and the total number of stages of a distillation column
  • Workshop: Use NQ Curves to optimize the feed stage location and number of stages for a hydrocarbon fractionation unit
Reporting Features
  • Review and explain the following reporting features of the RadFrac block: Heat Curves, Pseudo Streams
Complex Configurations
  • Learn how to model: zero flow in bottoms or distillate streams, pumparounds and bypasses, thermosiphon reboilers, and divided wall columns
  • Workshop: C2 splitter with side heater
Reactive Distillation
  • Review and explain how to model a reactive distillation column in Aspen Plus
  • Workshop: Specify a reactive distillation case 
Three Phase Distillation
  • Review and explain how to model a distillation column where two liquid phases may be present on some or all stages
  • Workshop: Model a methylchloroacetate column
Three Phase Distillation (Free and Dirty Water)
  • Review and explain how to model a column that has two liquid phases, when one of the liquid phase is assumed to be pure water or mostly water
  • Demonstrate how to model a quench tower that uses the free-water option
Rate-Based Distillation
  • Review differences between equilibrium and rate-based distillation models
  • Recognize the capabilities of Aspen Plus Rate-Based Distillation
  • Workshop: Model a methanol-water distillation column using rate-based techniques
RadFrac Convergence and Troubleshooting
  • Review the convergence algorithms used by RadFrac 
  • Explain the recommendations for selecting an appropriate convergence algorithm
  • Review and explain common convergence problems
  • Analyze how to troubleshoot and converge difficult columns
  • Workshop: Apply troubleshooting techniques to converge a series of RadFrac models 

Aspen Technology, Inc. awards Continuing Education Units (CEUs) for training classes conducted by our organization. One CEU is granted for every 10 hours of class participation.