Research On Process Selection Method Of Cryogenic Air Separation Unit

The air separation process determines the investment,energy consumption,operation safety,operation stability and operability of the Air Separation Unit(ASU)from the source.The optimization and selection of air separation process is a process to solve the concerns of all stakeholders related to ASU.This paper mainly studies the process selection method of cryogenic air separation unit.Firstly,ASPEN HYSYS software was used to systematically model and calculate the typical external compression process,internal compression process and liquid-air separation process involved in cryogenic air separation.The effects of key factors(such as extraction way of nitrogen products,liquid product ratio,pressure of oxygen products and argon system)on the recovery percentage and energy consumption etc.of the process were deeply studied and analyzed.Next,this essay classified and summarized each module from four common modules of cryogenic air separation process: air compression and pretreatment module,refrigeration module,heat exchange module and distillation module.By analyzing the key factors affecting the cyrogenic air separation process and summarizing the common characteristics of cryogenic air separation process,the characteristics and rules of the selection of cryogenic air separation process were obtained.Based on the above work,this thesis took the whole conventional cryogenic air separation process as the research project,broke the traditional classification method of cryogenic air separation process,and put forward the selection principles of cryogenic air separation process from the aspects of oxygen demand,nitrogen demand and argon demand.Finally,through the practical application cases of C company,the selection principles of the cryogenic air separation process were further explained and verified.