Troubleshooting Distillation Controls

Topic Process Operations

CPD Hours 11.5*

Price IChemE Member £1140 + VAT / Non-member £1425 + VAT


Live online course – from 25 April, 16:00–21:00 BST.

Join recognised expert Henry Kister online to learn how to get the best performance from a distillation column control system. 

Through Henry's extensive experience, you will learn how to troubleshoot a distillation control system and identify causes of poor performance, evaluate existing column control performance, avoid common causes of instability, and develop improvements to your column control system. Henry will use case studies throughout to illustrate the principles and highlight control systems that did not work. 

Teaching will be delivered via three live sessions (approximately five hours in length each).

An e-certificate will be issued at the end of the course to confirm attendance and CPD hours logged. Please note that you must attend all modules to receive the certificate.

Learning outcomes

By the end of this course you will understand how to:

  • troubleshoot a distillation control system and identify causes of poor performance
  • evaluate existing column control performance and develop new designs
  • avoid common causes of instability, off-spec products, excessive energy consumption, hammering, fouling, and other operating issues resulting from deficiencies in the control system
  • incorporate lessons from past experience for developing or improving a column control system.

Who will benefit

  • Engineers and operation personnel responsible for operating, troubleshooting, designing and revamping distillation columns in the chemical, petrochemical and oil refining industries
  • Process control engineers engaged in control system optimisation and improvements
  • Managers and supervisors endeavouring to get the best performance from an existing or new distillation unit 

Course outline

Module 1 – Distillation control overall schemes troubleshooting

  • Assembling control loops into an overall scheme: what works, what causes instability, and what impairs efficiency
  • The three most common causes of control assembly failure: no material balance control, fighting between temperature controllers, and level control on a small stream
  • What may happen in the absence of adequate material balance control?
  • The three most common column control schemes: pros and cons
  • Is it better to connect the column temperature (or composition) control to the boilup or to the reflux?
  • Is there a control scheme that can handle ambient disturbances better?
  • What can go wrong with controlling a liquid level on a small stream?
  • What makes violation of this principle the No. 1 control problem in refineries (and in many chemical plants)?
  • Is your fractionator immune?

Module 1 – Troublesome temperature controls and sidedraw controls

  • How does subcooling affect internal reflux flow rate and its control?
  • Is internal reflux control useful?
  • Why distillation control schemes often break down in the presence of a side draw and what can be done to make them work
  • Can internal reflux control help?
  • Temperature control: is it better to have the control thermocouple in the liquid or in the vapour?
  • Best temperature control tray location: is there a reliable method that can find?
  • Using simulations to search and find
  • Application to several case studies: what does this method reveal about the tower in each case, and how it can guide the solutions
  • What is the effect of non-key components?
  • Issues with enhanced distillation column controls: azeotropic distillation and extractive distillation, and what has achieved success in controlling them
  • Analyser controls: is it the panacea for composition control?
  • What has been the experience with an analyser control cascading onto a temperature control?

Module 2 – Pressure and condenser process controls troubleshooting

  • What makes good pressure control so critical?
  • A vapour top product: how pockets in vapour lines destabilise pressure controls
  • Flooded condenser pressure controls for total condensers: how can the piping connections to the reflux drum make or break the control stability?
  • Why can flooded condenser pressure controls break down in the presence of non-condensables, undersized equalizing lines, slots in the dip pipe entering the reflux drum, and what can help avoid these issues?
  • Does inert padding help, and at what cost?
  • Understanding hot vapour bypasses: why some work while others don’t
  • Hot vapour bypass good and bad practices
  • Flooded reflux drums: pros and cons
  • Manipulating the coolant rate: when can it be troublesome?
  • How manipulating the cooling water flow can accelerate fouling and corrosion
  • Liquid product with a small vapour vent stream: why controlling the cooling water may sometimes be unavoidable, and what can be done to overcome shortcomings
  • Interference between vacuum and coolant controls

Module 2 – Reboiler process controls troubleshooting

  • Reboilers heated by condensing steam or vapour: a control valve is in the steam inlet line versus valve in the condensate outlet line
  • Is the dynamic response with the steam inlet valve always better?
  • Reboiler seal loss with the condensate outlet valve and how it is avoided
  • When does the condensate outlet valve scheme have a major energy-efficiency advantage?
  • Fouling, corrosion, and thermal stresses: which of the schemes can handle each of these issues better?
  • Steam trap unreliability issues with the steam inlet valve scheme: how to overcome
  • Startup and low rate operation with the steam inlet valve scheme: reboiler “stall”, instability, and how to prevent
  • Hammering: how a scheme incompatible with your condensate system can lead to instability and hammering
  • Equalising lines to the condensate pot: checking out for poor configurations that can induce instability, hammering
  • Tube leaks: which scheme is better suited to handle a potential tube leak in different circumstances?
  • Reboilers heated by sensible heat: why are the controls of these far less troublesome, and a brief discussion of their few issues
  • Case studies: control systems that did not work

Module 3 – Extra discussion session

This session provides an opportunity to briefly discuss plant issues with the instructor and with other participants. Participants who wish to take this opportunity are encouraged to prepare presentation materials in a simplified form that everyone in the audience can easily follow.

Avoid elaborate P&I’s and detailed drawings, but have detailed information available of the configuration of lines connecting to drums and seal pots (enter from the top or bottom, via slotted pipes or bare nozzles, into the vapor or liquid space, etc).

Participants who wish to discuss plant issues need to inform IChemE ahead of the course so they can be allocated discussion time in this session. This information should be accompanied with a problem statement and sketch to be forwarded to the instructor so he can review ahead of the session.

Please note

The following topics are outside the scope of this course and will not be covered:

  • advanced controls of distillation columns
  • constraints controls
  • batch distillation controls
  • reactive distillation controls
  • controls of dividing wall columns
  • setting tuning constants
  • control valve selection
  • actuators
  • control hardware. 

Previous delegates said

"It is easy to see why Henry is the industry expert. Super enthusiastic and kept me engaged throughout the course...I learnt so much in such a short space of time. Not a minute was wasted."
B Robinson, Syngenta, UK

"Mr Kister is not only a great expert in the topic, but also a fantastic lecturer. He delivered the course very well, in a dense but understandable manner. Thank you!"
A Volford, Pannonia Bio Zrt, Hungary

"Great case study examples / stories that really helped with the understanding and context of the theory, and were very engaging."
B-A Ward, Essar Oil, UK

"Henry is an excellent presenter and obviously knows his stuff. The fact he can draw from a wealth of experience in the field adds a lot of credibility."
M Walters, Johnson Matthey, UK

"The best thing about the course was the breadth and depth of knowledge of the presenter and the fact it had multi-industry based examples...Henry Kister is an inspiring and engaging presenter."
G Tayor, Chivas Brothers, UK


Module 1

Tuesday 25 April 2023, 16:00–21:00 GMT.

Module 2

Wednesday 26 April 2023, 16:00–21:00 GMT.

Module 3

Thursday 27 April 2023, 16:00–21:00 GMT.

The session times are approximate – the session may last longer depending on Q&A. There will be a break of approximately 40 minutes during this time.

Not available then? Register your interest in future dates. 


  • IChemE Member: £1140 + VAT
  • Non-member: £1425 + VAT


Discounts are available to companies booking more than one place:

  • 2 places–10% discount
  • 3 places–15% discount
  • 4 or more places–20% discount.

Bookings must be made at the same time to receive the discount.


Modules will be delivered via Microsoft Teams. If you don't already have this installed, you can join as a guest in order to access the training. We'll share information about how to do this after you've registered.

Train your team

This course can be delivered to corporate teams, either on-site or online. Content can be tailored to your specific requirements, and this could be a cost-effective option if you have several people requiring the training. To find out more and request a quotation, visit our in-company training page.

* CPD hours should be used as an approximate guide and will vary depending on the preferred approach of the delegate and to what extent additional learning is completed.

Contact Phone +44 (0)1788 534496

Contact Email

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Associated course

Practical Distillation Technology

Explore distillation technology with 'tower doctor' Henry Kister, with a focus on the problems that can occur and how to solve them.

Henry Kister, FIChemE


Henry Kister, FIChemE


Henry, 'the tower doctor', is a recognised specialist with a vast background in all phases of distillation, including operation, troubleshooting, controls, design, start-up, and research.

At Fluor he designs, revamps and advises on distillation processes, equipment and controls for the chemical, petrochemical and oil industries. He is also extensively involved in field consulting, start-up and troubleshooting assignments and in developing Fluor’s in-house distillation technology.

He is the author of three textbooks - Distillation Operation and Distillation Design (McGraw-Hill Inc., 1990 and 1992) and Distillation Troubleshooting (Wiley Interscience 2006) - the Distillation Equipment chapter in Perry's Handbook (2008, 2018), over 120 technical articles, and has presented IChemE's Practical Distillation Technology course over 500 times.

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