聚酰亚胺膜回收不凝气中CO_2模拟研究

Simulant Research of the Polyimide Membrane Separation on the CO_2 of Low Temperature Fractionating Noncondensable Gas Based on PRO Ⅱ Platform Software

采用PROⅡ工艺软件对胜利油田EOR驱低温液化站塔顶不凝气进行了膜法分离效果研究。以应用较为广泛的聚酰亚胺膜为研究对象,建立分离规模为1 000 m^3/d的单级膜计算模型进行仿真计算,以压缩机二级压缩压力、进膜气体温度、膜面积、渗透侧排气压力(增压或抽真空)为工艺变量,计算不同参数对渗透侧和高压侧产品的影响规律。使不凝气中的烃类和CO_2得到回收利用。研究发现达到最优效果的边界条件是二级压缩压力为1. 6 MPa,气体温度为40℃,渗透侧出气压力为0. 2 MPa,在此条件下,膜面积最少,CO_2收率和浓度、烃类收率、浓度和热值等参数均达到最优值。

In this paper, PRO Ⅱ process software is used to study the membrane separation effect of the low temperature liquid station overhead noncondesnsable gas at Shengli oilfield. Taking the polyimide membrane which is widely used as the object, a single-stage membrane calculation model with a separation scale of 1 000 m^3 / d was established for simulation and calculation. The effects of secondary compression pressure, inlet gas temperature, membrane area, and osmotic exhaust pressure(supercharge or vacuum) on the osmotic side and high-pressure side products are calculated to recover the hydrocarbon and CO2 in noncondensable gas. The results show that the optimal process parameters are achieved at the secondary compression pressure of 1.6 MPa, the inlet gas temperature of 40 ℃, and the osmotic exhaust pressure of 0.2 MPa. The comprehensive performance is good under this condition, and the membrane material is the least used. The CO2 concentration, CO2 yield, hydrocarbon concentration, hydrocarbon yield and hydrocarbon calorific value are all optimal.