利用液化天然气冷能空分新流程及模拟分析

提出了利用液化天然气（LNG）冷能空分新流程,产品是用于满足电厂富氧燃烧的气态富氧空气。空气视为N2（79.1 mol%）和O2（20.9 mol%）二元混合气体,采用Aspen Plus软件进行了流程模拟,物性方法选择Peng-Robinson方程。模拟结果表明,生产95.08 mol%富氧空气的能耗是0.667 kW.h/（kg.O2）,液化天然气（LNG）的消耗量是87.64 mol/（kg.O2）。与文献[7]生产多种液态产品模拟结果比较,单位氧气的能耗大致相等,LNG消耗减少约50%,精馏塔冷凝蒸发器两侧的传热温差从1.2 K增大到2.8 K,可大大减小换热器的面积。

A Novel Process for Air Separation by Utilization of Liquefied Natural Gas Cold Energy and Performance Analysis by Numerical Simulation

A novel process for air separation by utilization of liquefied natural gas cold energy was proposed based on the existing studies,in which the product is oxygen-enriched air for oxy-combustion in power plant.The process simulation was carried out by Aspen Plus software with the simulated air（N2,79,1 mol%,O2,20.9 mol%） and Peng-Robinson equation was chosen for property method.The results show that energy consumption is 0.667 kW·h/（kg·O2）and the LNG consumption is 87.64 mol/（kg·O2）for production of air with 95.08 mol% oxygen.A comparison with reference[7]was also carried out,the results indicate that as for producing per kg oxygen,energy consumption for both process are equal and LNG amount could reduce roughly 50%.The heat transfer temperature difference in condenser in cryogenic distillation column increased from 1.2 K to 2.8 K,which could lead to a greatly reduction in heat exchanger areas.