油水乳液体系水合分离塔的模拟计算

Simulation of hydrate separation tower for water-in-oil emulsion system

在水合物法辅助分离乙烯裂解气流程中,水合物分离塔是非常关键的单元操作设备。气体混合物在塔内的分离过程与气体吸收塔类似,但因涉及气-液-液-固4相,所以计算更加复杂。将速率法和平衡级法相结合,提出了油水微乳体系吸收-水合分离塔的模拟计算方法。模拟计算了一典型乙烯裂解气在水合分离塔内的分离状况。为了确定适宜的操作条件,分别考核计算了操作温度和气液比对分离效果及能量消耗的影响。所得结果对水合分离塔的设计、操作条件的确定以及乙烯裂解气分离流程的制定有很重要的意义。计算结果还表明,通过水合物技术在0℃左右可实现氢气、甲烷和C2以上组分的有效分离,因此可以节约大量制冷功耗。

The hydrate separation tower is the most important unit operation equipment in the process of separating pyrolysis gas with the aid of hydrate technique for recovering ethylene.The water-in-oil emulsion could enhance the hydrate formation rate and improve the flow behavior of hydrate slurry.In this work,the simulation algorithm of absorption-hydration separation tower for the water-in-oil emulsion system was developed,which was involved with the vapor-liquid-liquid-hydrate four phase equilibria.The operation conditions,separation efficiency and energy consumption of the hydrate separation tower were studied under the different gas-liquid ratio conditions by combining the equilibrium and non-equilibrium stage approach.The calculation results indicated that the lower gas-liquid ratio could improve the separation efficiency,but may bring about the high energy consumption.The results also showed that hydrogen and methane could be separated effectively from C2 plus-components at around 0℃ through hydrate technique.The calculation results are of significance for the design of hydrate separation equipment,the determination of operation conditions and the planning of separation process for the ethylene pyrolysis gas.