Glycerol-water boiling point diagram 1

[perapera]

Hello,
Does anyone have boiling point diagram for binary system glycerol-water (under vacuum). I only found this in Ullmann's encyclopedia but its not very useful...

 

[Matt17]

If you're looking for liquid-vapour equilibrium data, try this:

Table 13-1, Perry's Chemical Engineers' Handbook, 7th Edition.

PS: reference pressure is 101.3 kPa, it could be not usefull for your purposes.

Regards,

Matt17
Process Engineer

 

[perapera]

There is no data for this binary system in Perry's Handbook.

 

[unclesyd]

ere are two links to some information on Glycerol/Water mixtures.

http://www.dow.com/webapps/lit/litorder.asp?filepath=glycerine/pdfs/noreg/115-00677.pdf&pdf=true

http://www.google.com/url?sa=t&source=web&cd=32&ved=0CBgQFjABOB4&url=http://

http://www.aciscience.org/docs/Phys...htC6BA&usg=AFQjCNFgIHc6wBaJ7KaD4nBEHZAXeclP0Q

 

[perapera]

There are some data on that links ,vapor pressure, viscosity etc... but no liquid-vapor equilibrium diagram.

 

[maddocks]

Throw it into a process simulator and see if you can reconcile the results against the small amount of data you have?

 

[unclesyd]

Check my references and checked with the library where I worked and there is no diagram per se.

I would call Dow and see if one exists or do they jut calculate each point.

Another possibility is to get your lab to run a set of boiling points for you. If I recall correctly the boiling point cure is two parallel lines with the most of the pressure coming from the water at lower temperatures/

 

[sshep]

Hey perapera,

That diagram you gave looks like exactly what you want if the pressures are in the right range. I think it is possible that you are confused in how to read it. I attached an example- hopefully I got this right.

Find your initial (liquid) composition on the x-axis. Run vertically to the liquid line at your pressure and read the temperature off the y-axis. This is the bubble point temperature, which we commonly call the boiling point of the mixture. The composition of the first vapor generated is found by reading the x-axis value for the corresponding vapor line at the same temperature. This first vapor is essentually pure water for a starting mixture of more than 20% water.

The same approach (but going to the vapor line) can give you the dew point, and composition of the first liquid formed. In between (the 2-phase region) you can get the vapor and liquid composition at any temperature. The starting composition does not affect the phase compositions, but does determine how much of each phase is present- you can use the inverse lever rule to calculate graphically.

Your curves look pretty ideal so depending on how much accuracy is needed, you can probably do the flash calculations (bubble-T, dew-T, or general flash) using the pure component boiling points, and Raoults law. It is worth a quick try to compare against the diagram.

best wishes,
sshep

 

[perapera]

I know how to read it but i need more accurate diagram.
How to simulate this in Aspen plus? I`m trying FLASH2, V-DRUM1, NRTL base method. Any suggestions how to set up the simulator?

 

[sshep]

Use uUNIFAC opset, then go to menu: tools/analysis/property/binary and generate a TXY diagram for any pressure you need.

 

[sshep]

This is an ethylene glycol-water screenshot.

 

[perapera]

OK i managed to plot glycerol-water. Thanks!!

 

[Matt17]

Hi perapera,

what edition of Perry's Handbook do you have?

Note that I quoted the 7th (last binary data, page 13-14, 13-15), the Table 13.1 in the 8th has been reduced.

Regards,

Matt17
Process Engineer