A refined equation for predicting the solubility of vegetable oils in high-pressure CO₂

详细信息	查看全文 | 推荐本文 |

• 作者：Jos&eacute ; M. del Valle^a ; ^{delvalle@ing.puc.cl} ; Juan C. de la Fuente^b ; Edgar Uquiche^c
• 关键词：Modeling ; Solubility ; Supercritical CO2 ; Triglycerides ; Vegetable oils
• 刊名：The Journal of Supercritical Fluids
• 出版年：2012
• 期刊代码：60_08968446
• 类别：ce
• 出版时间：July, 2012
• 卷：67
• 期：Complete
• 页码：60-70
• 文件大小：488 K

摘要

The solubility of vegetable oils in high-pressure CO₂ can be best modeled as a direct function of solvent density (蟻) and absolute temperature (T) having as model parameters an association number, k (number of solvent molecules forming a complex with a single solute molecule), and the total heat requirement for synthesizing the complex, 螖H (sum of heats of solution in CO₂ and vaporization of the solute). A General Model was developed in this work that considered the solubility of the vegetable oil in CO₂ under a reference condition (8.07 g kg^鈭? oil/CO₂ at 40 掳C and 30 MPa), a density-correction depending on k, and an absolute-temperature-correction depending on 螖H, and best-fit values were estimated using 235 data points from fifteen studies in literature involving eleven different vegetable substrates. The model was validated with many additional data points from seventeen additional vegetable substrates from twenty-one extra studies. The General Model is capable of predicting the solubility of vegetable oils in high-pressure CO₂ to within 卤40%of the experimental values. It is valid from 7.7 MPa at 20 掳C to 21 MPa at 68 鈮?#xA0;T 鈮?#xA0;100 掳C in the low-pressure range, and from 80 MPa at 20 鈮?#xA0;T 鈮?#xA0;94 掳C to 77.5 MPa at 100 掳C in the high-pressure range. The model can be used only for triacylglycerols of fatty acids containing mostly 18 carbon atoms, including triolein. Statistical analysis suggested that k depends on 蟻 and that 螖H depends on T.