imatasb
Chemical
- Jul 17, 2003
- 32
Hello,
As a waste stream from a process we have a strea that contains:
water, 8500 kg/h
ammonia 1.5 kg/h
NaCl 420 kg/h
CaCl2 1041 kg/h
the idea is to try to decrease the amount of ammonia. The first flash is from 1.7 bara to 1.4 (118 to 110.5 C)bara and the second one to atmospheric pressure (to 101.7 C).
To calculate the Ki I have assumed (based on the conditions) that the vapour mixture,the vapour behaves as an ideal and the Poynting factor is negligible.
So the equation becomes
Ki=Pvap * Activity Coeff for Liquid / Total Pressure
Based on some experimental data and I have calculted a activity factor around 0.22 for ammonia and 1 for water. I have some more data for the effect of NaCl and the concentrations we have the influence is very small but I haven't got any data on CaCl2.
My flash calculations show an ammonia content in the vapour stream of the flash with a lower value than we have, so I guess that the CaCl2 must have a higher impact,also higher concetration than NaCl.
Any ideas on this?
SOmeone has mentioned to me OLI systems, it is possible with this software to get the partial pressures of solutions that contain salts? Looking at the web it seems as it can run as a plugin to HYSYS.
Anyone has got experience with it.
I was reading a little bit about solvation theory which seems to work ok, but I haven't been able to find any solvation number for the system.
I appreciate your comments.
Inigo
As a waste stream from a process we have a strea that contains:
water, 8500 kg/h
ammonia 1.5 kg/h
NaCl 420 kg/h
CaCl2 1041 kg/h
the idea is to try to decrease the amount of ammonia. The first flash is from 1.7 bara to 1.4 (118 to 110.5 C)bara and the second one to atmospheric pressure (to 101.7 C).
To calculate the Ki I have assumed (based on the conditions) that the vapour mixture,the vapour behaves as an ideal and the Poynting factor is negligible.
So the equation becomes
Ki=Pvap * Activity Coeff for Liquid / Total Pressure
Based on some experimental data and I have calculted a activity factor around 0.22 for ammonia and 1 for water. I have some more data for the effect of NaCl and the concentrations we have the influence is very small but I haven't got any data on CaCl2.
My flash calculations show an ammonia content in the vapour stream of the flash with a lower value than we have, so I guess that the CaCl2 must have a higher impact,also higher concetration than NaCl.
Any ideas on this?
SOmeone has mentioned to me OLI systems, it is possible with this software to get the partial pressures of solutions that contain salts? Looking at the web it seems as it can run as a plugin to HYSYS.
Anyone has got experience with it.
I was reading a little bit about solvation theory which seems to work ok, but I haven't been able to find any solvation number for the system.
I appreciate your comments.
Inigo
