The Study On Optimization Of Air Separation Process

As a major energy and chemical industry country,the demand for a wide range of air separation products and air separation plants is increasing in all walks of life.Liquid oxygen as an important product of air separation,to explore the impact of different processes is of great significance.In this paper,the process of air separation is studied by the method of internal expansion and expansion of air into upper tower,and to obtain the influence factors of liquid oxygen production through the research and analysis of the process.And compared to argon distillation and without argon distillation,determining the argon tower to impact to oxygen production on the air separation process,resulting in differences of liquid oxygen production about different processes.The process is modeled by Aspen Plus V8.4,according to the production process data of air separation process flow,Adopting corrected the physical properties of RKS-BM,which can be used for effectively calculating distillation process.Through the simulation of Aspen Plus,determine the key influencing factors about the production of air separation process,such as the reflux ratio of the lower tower,the amount of liquid nitrogen withdrawn,the oxygen content in the bottom of the column,the amount of corrupt liquid nitrogen withdrawn in the upper tower,the amount of argon distillate withdrawn and recovery position,etc.,and through debugging and analysis of these factors,obtain the best value of the process.The volume flow rate of air feed was 77600 Nm3/h,the oxygen production is 15500 Nm3/h,in the process with argon production,the vapor oxygen production is 15140 Nm3/h,the liquid oxygen production is 360 Nm3/h,the purity is 99.6%,the extraction rate is about 95%;the liquid argon production is 460 Nm3/ h,The purity of the liquid argon is more than 99.99%;the nitrogen production is 30700 Nm3/h,and the purity is more than 99.99%.In the process without argon production,the oxygen production was 15400 Nm3/h,the vapor oxygen production was 14570 Nm3/h,the liquid oxygen production was 830 Nm3/h,the purity is 99.6%,the extraction rate is about 94%;nitrogen production is 30700 Nm3/h,purity is more than 99.99%.The simulation of the two processes shows that when the expansion air volume accounts for 14% of the processing air volume in air separation system,the production of liquid oxygen without argon tower is much higher than that of with argon tower,the relative increase of liquid oxygen production is about 130%,the economic benefits of liquid oxygen production increased significantly.However,the oxygen extraction without argon system is lower than that of the argon system,indicating that the production of oxygen to a certain extent consumption.Through exploring the VB and Aspen Plus automation interface,realizing VB to read and write the internal data of Aspen Plus,user can easily achieve optimal operation of oxygen production by adjusting the variables of the air separation process in a VB interface,reducing the user operation.