Abstract In this study, subcritical water extraction (SCWE) was used for dynamic extraction of crude oil of Nannochloropsis salina. The effect of three parameters including water temperature, flow rate and sample loading on the extraction efficiency was investigated and the whole process was simulated by using a two-phase mathematical model. Water temperature, flow rate and sample loading were varied from 150 to 200 °C, from 1 to 4 mL/min and from 1 to 4 g, respectively. The best operating conditions were selected to be 175 °C, 4 mL/min and 1 g and at those conditions, the fatty acids profile was compared with the Folch method. Because of the nature of the biomass and small particle sizes of the cells, a mathematical model based on the shrinking core model (SCM) was developed to evaluate the behavior of the extraction process. Kinetic parameters of the model incl. external film mass transfer coefficient (kf), solute-solvent binary diffusion coefficient (D12), axial dispersion coefficient (Dax) and effective diffusivity (De) in solid particle were determined. The later one was selected as the tuning parameter of the model and the others were attained from available correlations. The model predictions were in good agreement with experimental data.

中文翻译：

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亚临界水提取盐生藻油的收缩核心模型

摘要 本研究采用亚临界水萃取(SCWE)技术对盐生小球藻原油进行动态萃取。考察了水温、流速和上样量三个参数对萃取效率的影响，并利用两相数学模型模拟了整个过程。水温、流速和上样量分别从 150 到 200 °C、1 到 4 mL/min 和 1 到 4 g。最佳操作条件选择为 175 °C、4 mL/min 和 1 g，在这些条件下，将脂肪酸谱与 Folch 方法进行比较。由于生物量的性质和细胞的小粒径，开发了基于收缩核心模型 (SCM) 的数学模型来评估提取过程的行为。模型的动力学参数包括 测定了外膜传质系数（kf）、溶质-溶剂二元扩散系数（D12）、轴向分散系数（Dax）和固体颗粒中的有效扩散系数（De）。后一个被选为模型的调整参数，其他的则从可用的相关性中获得。模型预测与实验数据吻合良好。