Abstract:

The technology of separating light hydrocarbon from oil field to produce solvent oil by dividing wall distillation is studied. The separation process is modeled by Aspen process simulation software, and the separation effect and influencing factors are studied. The effects of theoretical tray number, liquid phase partition ratio, gas phase partition ratio and other parameters on the separation effect of light hydrocarbons and the distribution of sulfide in solvent oil products are investigated. The results show that under the conditions of 95 trays, overhead pressure of 88 kPa, reflux ratio of 4.0, liquid phase partition ratio of 0.5 and gas phase partition ratio of 1.05, 6^# solvent oil and 120^# solvent oil products meeting the quality requirements could be obtained. The sulfide in 6^# solvent oil is mainly C₆ thioether and thiophene, the sulfide in 120^# solvent oil is mainly C₇～C₉ complex thiophene, and at the bottom of the dividing tower is above C₁₀ sulfide. Using the separation technology of dividing wall column to produce solvent oil products, the investment cost of the unit is about 35 million yuan, and the annual sales of light hydrocarbons is increased by 49.65 million yuan.

Key words: dividing wall column, oil field light hydrocarbon separation, number of trays, liquid phase partition ratio, gas phase partition ratio, 6# solvent oil, 120# solvent oil, organic sulfur distribution

摘要：

研究了采用分壁精馏技术对油田轻烃进行分离生产溶剂油的工艺。利用Aspen流程模拟软件对分离过程进行了建模，研究分离效果及影响因素。考察了理论塔板数、液相分配比、气相分配比等参数对轻烃分离效果及溶剂油产品中硫化物分布的影响规律。结果表明：在95层塔板、塔顶压力88 kPa、回流比4.0、液相分配比0.5、气相分配比1.05的条件下，可以获得满足质量指标要求的6号溶剂油(宽馏程)和120号溶剂油产品。6号溶剂油中硫化物以C₆硫醚、噻吩为主，120号溶剂油中硫化物以C₇～C₉复杂噻吩为主，分壁塔底为C₁₀以上硫化物。采用分壁塔分离技术生产溶剂油产品，装置投资费用约3 500万元，轻烃年销售额增加4 965万元。

关键词: 分壁精馏塔, 油田轻烃分离, 塔板数, 液相分配比, 气相分配比, 6号溶剂油, 120号溶剂油, 有机硫分布