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Distillation

Distillation by Frank Rukovena, Vice President - Marketing and Sales, Fractionation Research, Inc.

Frank Rukovena is Vice President - Marketing and Sales of Fractionation Research, Inc., Stillwater, Oklahoma. Previously, he spent more than 25 years with Norton Chemical Process Products (later Saint-Gobain Norpro), including more than 10 years as director of mass transfer technology and, before that, as director of engineering, development and manufacturing. He holds a number of patents in the field and has written extensively about mass transfer operations.

How do I calculate the void space in a column?
How do I calculate the void space in a column? Actually we are putting ½-inch balls in a 14-inch pipe. Height of packing will be 3 inches. Above the ½-inch balls we will put ¼-inch balls and the packing height will be the same (3 inches). How many balls can I put in the column?
Category: Distillation

How does a water draw off vessel work?
I need to design water draw off vessel. How does a water draw off vessel work?
Category: Distillation

Why would the distillation column stop working well?
We recently installed a liquid seal loot in the outlet take line off of one distillation column in order to increase the take-off rate. Initially, this worked and knocked hours off the distillation time. However, after about four runs its benefits disappeared. Do you know why?
Category: Distillation

Why don't ethanol producers use multiple effect distillation to remove ethanol from fermentation broth?
Why don't ethanol producers use multiple effect distillation to remove ethanol from fermentation broth? Energy costs in processing cellulosic beers (with ethanol concentrations around 3%) must surely be holding the industry back, and MED could help. I am expecting that it is a practical issue of heat exchanger fouling, but is there more to it than that?
Category: Distillation

How does filtered water differ from reverse osmosis water?
I work in a bio-ethanol production plant equipped with a multi-pressure distillation system.

In order to decrease the cost of water treatment, we are going to change the process water (which is mainly used in the fermentation section) from a good quality water (reverse osmosis) to the filtered water having the following data:

EC:2920 µs
TDA:1500 µs/cm
TURBIDITY:0.6
Cl₂:0.5 ppm

I would appreciate if you could advise me whether the aforementioned water is good for the distillation system and why?

What are disadvantages with the distillation equipment (e.g., heat exchangers) using this water?
Category: Distillation

Distillation: Could scale be the reason for an increase in steam consumption?
The steam consumption has increased in our distillation plant. Is it possible that the re-boilers have gotten scale? What are the possible causes of an increase in the steam consumption rate of a multi-pressure distillation plant producing ethanol?
Category: Distillation

Solving Problems with Vacuum Distillation Systems
In our vacuum distillation system, we are getting 0.4 Torr vacuum while in reactor we are getting 8 Torr. Our client requirement is 1 Torr. Do you think there is any problem from the vacuum system side?

System volume is 5,000 liters; air leakage is 1kg/hour; and carry over load of 1kg/hr (MW 137). Vacuum system of 570 ACFM (Mech booster backed by Dry Vacuum pump)supplied. We have 4-inch pipe line.
Category: Distillation

What are essential parameters of a multi-pressure distillation system?
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.?
Category: Distillation

The difference between cohobation and rectification columns
Is there any difference between a cohobation column and a rectification column -- or are they used as synonyms?
Category: Distillation

Does Double Weight Valve Tray Influence Column Scale-Up?
Distillation: What can the double weight valve tray do to the column scale-up effect?
Category: Distillation

Computing the diameter of a multicomponenant distillation column
To design a multicomponenant distillation/fractionation column, I have studied the McCabe-Thiele method concerning the number of theoretical trays and feed trays and have looked to the Fenske equation for information on total reflux. I am still, however, facing difficulty in computing the required diameter and spacing between plates and trays. How do today's column designers compute the diameter of a multicomponenant distillation column?
Category: Distillation

Vacuum column wetting rate
What is the wetting rate in a vacuum column and how is it related with the performance of the slop wax bed section of a vacuum column?
Category: Distillation

Checking columns internals
What are the most important things I should pay attention to while checking the columns internals such as tray, beam, supporting rings and so on in the pre-installing process?
Category: Distillation

Column riser area
I am working on a refinery project with a column internals vendor for designs and review of designs. While reviewing one of the columns (a Hydrocracker unit - fractionator), I observed that the total draw-off trays are designed with a riser cross sectional area of approximately 11.5%, which is far less than general practice of 15%. The other concern is draw-off nozzle sump dimensions. Vendors have followed licensor datasheets and provided sump width 3 times the draw nozzle diameter. However, general practice is 2 times the diameter. This resulted in a reduction of an area to locate the risers on the tray and a reduction in the number of risers and, hence, the riser area. May I request your opinion and recommendations?
Category: Distillation

Vapor outlet line nozzle location
I suspect that the bottom of LPG/NGL splitter column (designed to separate LPG and NGL) is flooded as the vapor boil-up entry point appears to be submerged in the bottom liquid. For vapor generation, a kettle type reboiler is used. I do not have design data and want to know where the nozzle should have been located. The only reference I found is Kern’s article in Hydrocarbon Processing (December 1968), which I also do not have.
Category: Distillation

Evaporator boilover
How does one set the constraints (startup or operation) to avoid excessive heat flux or pressure change that results in the bumping or boilover of an evaporator or batch stripper, especially at vacuum. What correlations for pressure change and or heat flux would be used to establish the prudent rate of change constraints?
Category: Distillation