A new methodology was proposed for predicting the multiphase behavior of a supercritical CO₂–heavy oil–water–solvent system during supercritical CO₂ extraction. The cubic-plus-association equation of state (CPA EoS) was used to model the hydrogen bond association between asphaltene and water and to develop a nine-step characterization method for asphaltene-containing oil. Results showed that the proposed method could represent phase behavior for three equilibrium phases: the vapor phase and high-density and low-density liquid phases. The absolute average relative deviation between the predicted and experimental phase boundary pressures was 3.6–11.8%, smaller than those (7.0–20.8%) calculated using Soave–Redlich–Kwong EoS with Huron–Vidal mixing rules. Moreover, case studies on appropriate extraction conditions showed that the extraction pressure increased with increasing molecular weight and critical pressure of each pseudocomponent. Increasing extraction pressure for H₂O-containing systems was beneficial for improving extraction efficiency.

提出了一种新的方法来预测超临界 CO ₂ -重油 - 水 - 溶剂系统在超临界 CO _{2期间的多相行为}萃取。立方加缔合状态方程 (CPA EoS) 用于模拟沥青质和水之间的氢键缔合，并开发了含沥青质油的九步表征方法。结果表明，所提出的方法可以表示三个平衡相的相行为：气相以及高密度和低密度液相。预测相边界压力和实验相边界压力之间的绝对平均相对偏差为 3.6-11.8%，小于使用 Soave-Redlich-Kwong EoS 和 Huron-Vidal 混合规则计算的偏差 (7.0-20.8%)。此外，对适当萃取条件的案例研究表明，萃取压力随着每种假组分的分子量和临界压力的增加而增加。增加 H 的萃取压力₂含 O 系统有利于提高提取效率。