液化天然气分离的多效蒸馏工艺

Multi-effect distillation process for separation of LNG

采用化工过程模拟软件Aspen Plus计算模型,模拟研究了液化天然气分离得iC4,nC4和C5+的过程,比较了现有常规蒸馏工艺和采用双效蒸馏以及热集成新工艺的能耗情况。结果表明,在相同的处理量和塔板数下,双效蒸馏和热集成新工艺的能耗都比常规蒸馏工艺有大幅度降低,而尤以热集成的节能效果最好。双效蒸馏工艺比常规蒸馏方案节能31.9%,热集成工艺节能达35.8%左右。对于此分离过程,采用双效蒸馏以及热集成新工艺都有应用前景,值得进一步推广应用。

The separation process of liquefied natural gas to obtain iC4, nC4 and C5^＋ was simulated with commercial software Aspen Plus, and the existing conventional distillation process was compared with new double-effect distillation arrangement and heat-integrated arrangement. The simulated resuhs show that at the same flow-rate and with the same numbers of total tower plates, the two modified processes consume much less energy than the existing conventional series, of which the heat-integrated one has the best energy-saving effect. The double-effect distillation arrangement can save energy by 31.9%, and the heat-integrated process can reach 35.8% compared with the conventional arrangement. Both of the new separation processes are prosperous and worth of propagation in industrial application.