轻油部分循环对丙丁烷收率的影响及其应用

Improving the Recovery of Propane and Butane by Partially Refluxing natural Gasoline

油田轻烃回收装置随着原料气气质、气量的变化，丙丁烷的收率普遍偏低。提高丙丁烷的收率成了许多浅冷装置急待解决的问题。轻油部分循环法是方法之一，该方法从脱丁烷塔塔底引一股稳定轻油循环至蒸发器前的管线中，从而对汽液平衡施加影响。本文考虑温度、压力和组成对烃类混合物相平衡的影响，选用ＳＲＫ真实气体状态方程研究轻油循环掺合比与丙丁烷收率的关系。经计算表明，在温度、压力一定时，只要有轻油循环，丙丁烷的收率就要提高，且随着掺合比的增加而增加，但增幅不尽相同。适宜的掺合比应根据经济分析的结果来确定。在油田气轻烃回收浅冷分离工艺的技术改造中运用轻油部分循环法可有效地提高丙丁烷的收率。

In natural gas liquids (NGL) plants, the recovery of propane and butane usually declines with the variation in composition and flow rate of the raw gas. The method of partially refluxing natural gasoline, which uses a pipe to connect the evaporator with the exit at the bottom of the debutanizer in order to let a part of steady gasoline return to the evaporator, is one of the ways to improve the recovery. Taking into consideration of influences of composition, temperature and pressure on phase equilibrium of hydrocarbon mixtures, the SRK real gas state equation is used to study the relationship between sophistication ratio and recovery of propane and butane. The result shows that under steady temperature and pressure conditions, improved recovery can be obtained with gasoline cycling and with the increase in sophistication ratio. The most appropriate sophistication ratio can be determined through economic analysis. 