1 reply to this topic

[sharonlae]

Hi, 

 

I am posting this to all industrial experts out there who might like to give me some guidance on designing a distillation column to separate propylene glycol from water and PGME. I would like to know if such a process is common in the industry and what are the operating conditions of such columns, i.e. vacuum/atmospheric etc. 

I would also like to know the material of construction of such columns if possible and if PG and PGME are corrosive at high temperatures. 

 

Currently, I'm simulating my column at a pressure of 2bar to prevent the high cost of vacuum operation but I would like to know if PG would degrade substantially/produce acids that might corrode the material within the column at such high column temperatures.  

 

I am unable to find such information on textbooks and most literature and would like to reach out for help from the actual industry.

 

Thank you.

[saeed.s]

Hi sharonlae

 

propylene glycol process is similar to ethylen glycol process. to do this, first remove water in 2 or 3 columns in positive pressure  ( you can use pinch technology to decrease steam consumption - steam from top of first column use to heat up second column re boiler) then

Purify MPG in negative pressure to decrease temp in bottom of column .

 

1-  what are the operating conditions of such columns, i.e. vacuum/atmospheric etc. : columns pressure start at positive to negative.

 

2-  PG and PGME are corrosive at high temperatures. = NO

 

3-I'm simulating my column at a pressure of 2 bar to prevent the high cost of vacuum operation but I would like to know if PG would degrade substantially/produce acids = will be polymerized to heavy molecules ( TEG &....)

 

4-material of construction : Usually SS 304 Because MPG is an additive in food industry , if you want to sell it to food factory, your product should pass standards.