Solubility of Water IN CO2 medium?

[ksj_david]

Now there is alot of studies done in solubility of CO2 gas IN water, however I'm trying to get water solubility in CO2 environment, condition(155C, 600psi)

 

so i get a sealed chamber, which is connected to a camera then get a drop of water in the tip which is focused by a camera.

 

 

water drop seems fine when chamber is under 600 psi with no temperature, but then water simply dissappear when it is heating up to 155C.

 

I don't quiet understand why water drop is gone so quickly (~5 second) because it is under some pressure. Im not convinced its evaporation....

 

anyone can explain the phenomena? or any suggestion to conserve my water drop so i can monitor its volume (PVT)

[insane_alien]

well, the CO2 is pretty close to being a supercritical fluid at that point. what you're looking at here is not likely solvency but miscibility.

 

edit: hang on, if you wanted to look at the solubility of water in CO2 wouldn't you want to look at the liquid phase of CO2?

 

and a droplet of water would evapourate quire quickly at that temperature provided the humidity of the CO2 gas was low.

Edited February 11, 2010 by insane_alien

[ksj_david]

thanks alot. I appreciate it.

 

It turns out that I wanted to find out the solubility of CO2 in water. So, ideally I want my droplet of water increase in volume due to dissolved CO2 ( which is absorbed by my little droplet)

 

my droplet is fine during 600psi with NO TEMPERATURE, but if i increase temperature in slightest bit, it would simply evaporate. the phase diagram of water tells me that my droplet should remain liquid, not vapor (room temperature up to 155).

 

Now I need some kind of suggestion to prevent evaporation and keep my droplet (eg. freezing my droplet, increasing the initial volume of my droplet....)

[insane_alien]

what do you mean by 'no temperature' this is a nonsensical phrase as everthing has temperature(well, except perhaps a vacuum).

 

so, do you know what the relative humidity in the CO2 is? if it is 0% then the droplet WILL evapourate quickly at a raised temperature. in the phase diagram, you seem to be confusing system pressure and partial pressure of water vapour in the system.

 

if you want to prevent the droplet from evapourating then you need a partial pressure of water of about 6 bar in the system to get the droplet to remain there.

[ksj_david]

by no temperature, i meant no heating sry.

 

anywayz i think my CO2 humidity is zero.. i'll try to increase it.

 

thanks for the BIG BIG help!