Heavy oil or residual are often characterized as four pseudo-components according to the different solubility in organic solvents: saturates (S), aromatics (A), resins (R) and asphaltenes (As). Molecular dynamics simulations were performed to calculate the solubility parameters (δ) of SARA molecules and n-alkane (C3-C5) at various temperatures. As a result, it was found that the solubility parameters of the structures with fused aromatic and naphthenic rings are less affected by temperature compared to the homologs with long alkyl chains. And a reliable correlation between molecular structures, solubility parameters and their responses to temperature were determined and analyzed from the aspect of intermolecular interactions and molecular conformation. Then, regular solution theory was applied in binary system of SARA molecules and n-alkane to predict the solubility behavior of SARA molecules under the influence of solvent type and temperature. Hence the selectivity and solubility performance of SARA components in n-alkane deasphalting were described systematically by both experimental and theoretical approaches. The different solubility performances caused by temperatures are mainly due to the significant variation in solubility parameters of SARA molecules and n-alkane. The boundary values of Flory-Huggins parameters for solvent deasphalting (SDA) process were proposed by the combination of molecular simulation and experimental study. Furthermore, a simplified prediction model was established based on activity coefficient, and the overall absolute average deviations (AAD) of predicted EP_i for SARA were <2.7%, which can help to control and optimize the deasphalting process, as well as provide a better route for understanding the process.

根据在有机溶剂中溶解度的不同，重油或渣油通常被表征为四种假组分：饱和物 (S)、芳烃 (A)、树脂 (R) 和沥青质 (As)。进行分子动力学模拟以计算溶解度参数（δ) 在不同温度下的 SARA 分子和正烷烃 (C3-C5)。结果发现，与具有长烷基链的同系物相比，具有稠合芳环和环烷环的结构的溶解度参数受温度的影响较小。并从分子间相互作用和分子构象方面确定和分析了分子结构、溶解度参数及其对温度响应之​​间的可靠相关性。然后，将规则溶液理论应用于SARA分子和正构烷烃的二元体系中，预测了SARA分子在溶剂类型和温度影响下的溶解行为。因此，通过实验和理论方法系统地描述了 SARA 组分在正烷烃脱沥青中的选择性和溶解性能。温度引起的溶解度性能不同主要是由于SARA分子和正烷烃的溶解度参数存在显着差异。结合分子模拟和实验研究，提出了溶剂脱沥青(SDA)工艺的Flory-Huggins参数边界值。此外，建立了基于活动系数的简化预测模型，预测EP的总体绝对平均偏差（AAD）SARA的_i <2.7%，有助于控制和优化脱沥青过程，并为了解过程提供更好的途径。