Aqua-ammonia vaporisation- Absorption refrigeration

[Nielse]

Perhaps a very basic question but can you tell me if when heating an aqua-ammonia (33%NH4)solution @400psi, the temperature of such would be held at the Vaporisation temperature of the ammonia, untill all the ammonia was vaporised.Then the temperature of the water could rise ????

 

[Latexman]

Will a mixture of 0+ to 33 % NH4OH, act like 100% NH3?

No!

Good luck,
Latexman

 

[Nielse]

Thank you for your reply,

What effect would the ammonia have on the temperature rise of the solution?. Would the solution temperature still rise to the vaporising temp of the water, but just slower?.

 

[Latexman]

The ammonia-water system has been used industrially for a very long time. My 5th Ed. of Perry's has an enthalpy vs. concentration graph. You can Google "ammonia-water system" and get over 500 hits. The first hit has something that may help you:

http://www.cheresources.com/questions/separation_technology-301.html

It's a T-x diagram with bubble points and dew points at 1 atm and 10 atm of pressure.

Good luck,
Latexman

 

[Latexman]

Notice in the 0 to 33% range, the liquid behaves more like water and the vapor behaves more like ammonia as it gets more concentrated, temperature-wise that is. Also, it looks like the NRTL correlation for activity coefficients does a good job of fitting the data if you are going to use software for your work.

Good luck,
Latexman