Vapor-Liquid Equilibrium of Ammonia-Water System

Vapor-Liquid Equilibrium of Polluting Materials in Seawater (part 1)

Abstract

It is very important to investigate the behavior of volatile polluting materials in an MSF desalination plant when the product water from seawater is used. In this work, the vapor-liquid equilibria of ammonia-water system were measured at some pH values, salinities and pressures by using Othmer type of equilibrium distillation apparatus.
The variation of pH in these experimental parameters had the largest influence upon the vaporliquid equilibrium ratio (K=y/x) of this system. Ammonia was considerably concentrated into vapor phase at pH 8 and above, but it was hardly concentrated below pH 6. The K-values of ammonia-water system incresed as the system pressures were higher. On the other hand, the Kvalues decreased as the salinities of aqueous solutions increased.
The tendency obtained by simple batch distillation of ammonia-water system agreed well with the tendency in case of equilibria of the same system.