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What are essential parameters of a multi-pressure distillation system?

Q: I would like to be advised about the best technical points of a multi-pressure distillation system using vacuum in an ethanol production plant.

I currently work as an ethanol production supervisor for a plant with a production capacity of 100,000 l/d.

The distillation section using multi-pressure distillation columns has six main columns including mash column, hydro selection column, rectification column, alcohol column (fusel oil), methanol column (product) and heads concentration column. It also has a degasifying column and a sludge column for separating the CO₂ and sludge from the mash transferred from the fermentation section. The distillation section strips off the ethanol from 9% fermented mash (sugarcane molasses is used as feed stock) and increases the concentration of ethanol up to 96%.

Please advise me about some essential parameters that are important to be monitored daily, weekly or monthly to get the best condition in a multi-pressure distillation system.

Also, can you suggest technical information of distillation required for a supervisor to help me increase my knowledge of distillation such as information about trays, reflux ratio, problems, troubleshooting, columns adjustments, etc.?

A:

I suggest you get copies of Henry Z. Kister’s three books published by McGraw-Hill. They are “Distillation Operation,” (1990); “Distillation Design,” (1992); and “Distillation Troubleshooting,” (2006).

I am sure that if you spend time with these books you will find the answer to a lot of your questions.  Kister also has a course that covers the topics of your questions.

Additionally, Fractionation Research, Inc. (FRI) has a film (DVD or VHS) on trays know as Film A, which you can purchase that will answer some of your questions and show you video clips of trays in operation in its 4-foot-diameter test units.  Film A costs $400 for non-FRI members. This film is used by FRI’s members and universities as a training film about trays in distillation operation.

Additionally, you can get a 20-second look each at trays, packings and a liquid distributor in action on FRI’s Web site, www.fri.org.

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