Research And Analysis Of Air Separation Process

Depending on the simulation software HYSYS as the calculating tool as well as the knowledge of principles of chemical engineering and thermodynamics, two air separation units (ASU) in our company have been modeled. Through the research on the key factors related to running capabilities of the equipment, the relationship between these factors has been analyzed. The influences of species distribution caused by the changing of those key factors and the leakage problems of equipments have been discussed too.To sum up, several basic problems on the air separation unit have been discussed in the paper: first,the correlations of oxygen output and oxygen purity, average nitrogen purity, and air input are analyzed. Second, through simulation the problem of sensitivity about the oxygen purity and average nitrogen purity to the oxygen output and oxygen recovery ratio is presented. Then, the influence caused by the input and overheating state of expanding air into the upper column is discussed. The effect of oxygen recovery ratio and oxygen purity is quantified and the max oxygen recovery ratio is determined. The distribution of argon component in the main column system and the influence of the distribution caused by oxygen and nitrogen output and purity have been also discussed. Finally,the leakage problem on the equipment of KDONAr-7300/1500/120 has been analyzed with the help of software HYSYS.Conclusions are as follows: The trend of the change of the oxygen output which is same as that of average nitrogen purity is opposite to that of oxygen purity. Compared with the average nitrogen purity and oxygen purity, the change of the former has more sensitive influence on the oxygen output and the nominal oxygen recover ratio. With the decrease of overheating state of expanding air into the upper column, the volume fraction of oxygen component in the oxygen production decreases, but the volume fraction of nitrogen component in nitrogen production increases. Meanwhile the output of the liquid oxygen increases as well as the oxygen recover ratio. When the input of expanding air into the upper column changed, relative properties changed correspondingly. The maximum oxygen recovery ratio is determined through the restriction of relative conditions. Argon component has less effect on the distillation state of the lower column than the upper one. When the output of the oxygen increases or its purity decreases, the argon-rich region shifts downward and vise versa. Through the analysis on the leakage problem of...