Abstract:

To address the issue of high steam consumption in the propane removal tower of the three tower gas fractionation process in refineries, it is proposed to use a high and low pressure dual tower propane removal process instead of the single tower propane removal process in the original process. The process was simulated under steady?state conditions using Unisim Design process simulation software. The steam load of the high?pressure depropanizer and the hot water load of the deethanizer were analyzed, and the main operating parameters were optimized. The results showed that under the operating conditions of n(top C₃ production)/n(total feed C₃)=0.6, top pressure of 1.81 MPa, feed tray position of the 10th plate, and feed positions of the 114th and 126th plates at the top of the propane removal tower and low?pressure propane removal tower respectively, using the high and low?pressure double tower propane removal process can save 56.12% of steam load compared to the original process, save 49.83% of hot water load in the ethane removal tower compared to before optimization, reduce total energy consumption by 235.4 kW, and save about 339.71 yuan in thermal utility costs per hour.

Key words: Gas fractionation, Separation of high and low pressure twin towers, Energy conservation and consumption reduction, Optimize the design, Process simulation

摘要：

针对炼厂气体三塔分馏工艺中脱丙烷塔蒸汽消耗量较大的问题，提出使用高低压双塔脱丙烷工艺代替原流程中的单塔脱丙烷工艺。利用Unisim Design流程模拟软件对该工艺进行稳态模拟，分析了高压脱丙烷塔的蒸汽热负荷变化与脱乙烷塔的热水热负荷变化，并优化了主要操作参数。结果表明，在高压脱丙烷塔的n(塔顶C₃采出量)/n(进料C₃总量)=0.6、塔顶压力为1.81 MPa、进料位置为第10块塔板，且脱乙烷塔塔底与低压脱丙烷塔塔顶进入丙烯精馏塔的进料位置分别为第114、126块塔板的操作条件下，与原流程相比，使用高低压双塔脱丙烷工艺可以节约56.12%的蒸汽热负荷，脱乙烷塔比优化前节约了49.83%的热水热负荷，总耗能减少了235.4 kW，每小时可节省热公用工程费用约339.71元。

关键词: 气体分馏, 高低压双塔分离, 节能降耗, 优化设计, 流程模拟