乙烯装置丙烯精馏塔优化设计

Optimization design of propylene rectifying column in ethylene plant

针对近年来大型乙烯装置中的丙烯精馏塔操作不稳定、能耗大的问题,利用PRO/Ⅱ软件模拟分析该塔流程,总结出随着装置规模大型化该塔采用多溢流塔板形式,计算中应考虑塔板形式对板效率取值的影响。当进料组成与设计工况不符或装置负荷增大时导致产品不达标的情况,可增设进料口在非设计工况下不同位置进料以满足分离的要求,并且塔顶冷凝器和塔底再沸器需要考虑充分的设计余量。并创造性提出了,在传统工艺流程基础上在塔顶冷凝器后增设排放冷凝器进一步回收丙烯的节能优化方案,为实际生产提供建议性指导。

According to high energy consumption and instable operation problems of propylene rectifying column in large-scale ethylene plants, the propylene rectifying column system was simulated with PRO/Ⅱ software. The conclusion is that the influence of the tray type on the tray efficiency should be considered in calculation, and it is better to use multi-overflow tray type for large-scale ethylene plant. If the propylene product is substandard in the inconsistent feed composition case or the increased duty case, the added feed nozzles are prefered to switch the diftierent feed location for different case. Enough design margin should be considered for the top condenser and the bottom reboiler. The energy saving optimization scheme that adding a new vent condenser after the top condenser to recover more propylene product is creatively put forward, which provides the constructive guidance for the actual production.