How to Calculate Final Pressure in a CO2-Saturated Sealed Vessel?

[nbcromp1]

I have a sealed vessel, it is 200 ml, it contains 25 ml of water which is then saturated with CO2 (bubbled through at 0.3 l/min unitil pH drops, ~ 1 h) at rt. The vessel is then heated to 130 °C. I wish to calculate the final pressure of the system.

Thus far I have calculated the volume of CO2 in the water using NIST solubility values.
I believe the total pressure of the system to be P= PsatW + Po + Pn + Pco2.
The saturation pressure of water is calculated using the Antonine equation
Then the partial pressures of oxygen, nitrogen and CO2 are calculated using the ideal gas eq.

However, I am not sure whether I can apply the ideal gas equation to the dissolved CO2.
Additionally I am not including Henry's Law to account for air dissolved in water as I am assuming the solution is saturated(or near enough) with CO2.

Is there another way of doing this? Does anyone know how to account for the dissolved CO2?

Thanks in advance

 

[Chestermiller]

The water has been saturated with CO2 in water initially at room temperature, and you know the partial pressure of the CO2 in equilibrium with the water at 25 C? Then you heat it up to 130 C in a 200 ml container with air and CO2 initially in the head space?

 

[nbcromp1]

Thanks for your enquiry,

I have a literature based value of what the partial pressure of the CO2 in equilibrium with water will be at 25C. Your second statement is also correct. I essentially want to ensure I am not going to break the 4 bar pressure limit on the vessel. I believe the CO2 should have an almost negligible effect, however I need to write a risk assessment.

 

[Chestermiller]

Thanks for your enquiry,

I have a literature based value of what the partial pressure of the CO2 in equilibrium with water will be at 25C. Your second statement is also correct. I essentially want to ensure I am not going to break the 4 bar pressure limit on the vessel. I believe the CO2 should have an almost negligible effect, however I need to write a risk assessment.

To be conservative, assume all the CO2 comes out of solution at 130 C. What is the vapor pressure of water at 130 C?

 

[nbcromp1]

Ok so I think what I have initially done is right then, calculated the vapour pressure of water using the Antonine to be 2.687 bar at 130 °C, then added the pressure of the total number of moles of gas, not accounting for final liquid volume and dissolution of gas in water. This should provide a safe estimate.