Numerical analysis of the characteristic times controlling supercritical antisolvent micronization

作者：Marra Francesco; De Marco Iolanda; Reverchon Ernesto^*

来源：Chemical Engineering Science, 2012, 71: 39-45.

DOI：10.1016/j.ces.2011.12.019

• Jet break-up time
• Dynamic surface tension vanishing time
• Cross-over time
• Mathematical modeling
• Supercritical antisolvent precipitation
• Supercritical carbon dioxide

In this work jet break-up time and of dynamic surface tension vanishing are considered as mechanisms in competition during supercritical antisolvent precipitation and a mathematical model, based on these two characteristic phenomena, is presented. %26lt;br%26gt;Jet break-up time has been evaluated solving continuity and conservation of momentum equations; on the other hand, dynamic surface tension vanishing time has been evaluated according to the time-evolution model proposed by Cahn and Hilliard. Phase equilibria have also been taken into account, considering the Peng and Robinson equation of state and the related mixing rules. %26lt;br%26gt;Calculations have been applied to yttrium acetate (YAc) as model solute, dimethylsulphoxide (DMSO) as liquid solvent and carbon dioxide (CO2) as antisolvent. %26lt;br%26gt;The cross-over times, between jet break-up dominated and dynamic surface tension vanishing dominated regions, have been calculated at different pressures for pure DMSO and at different YAc concentrations in the liquid solution; a good agreement with previous experimental results has been obtained. The numerical results also correctly describe the influence of solute concentration on the pressure at which cross-over between the two regions is obtained. %26lt;br%26gt;The characteristic times for acetone (AC) have also been evaluated, to perform a comparison with DMSO; in this case, cross-over has been observed in proximity of the mixture critical point pressure of the binary system.

• 出版日期2012-3-26