Abstract
The aim of the present study is to identify the preferred region of the thermodynamic surface for the separation of a mixture of ethyl esters of oleic and palmitic fatty acids within the framework of the authors' original method. This method is based on the concept of the dual nature of the mass transfer mechanism in supercritical fluid extraction processes for systems exhibiting type I and II phase behavior. Results are presented for the separation of a binary mixture of ethyl oleate and ethyl palmitate. The process was carried out in asymptotic proximity to the critical point of the CO2–ethyl oleate system. As a result, in one of the extract samples, an ethyl oleate concentration of 94 wt.% was achieved within a 20-minute process duration, starting from an initial content of 25.28 wt.% in the feed mixture. A comparison with the separation results obtained for the same mixture under asymptotic proximity to the critical point of the CO2–ethyl palmitate system revealed the superiority of the aforementioned conditions. The proposed separation method is not limited to the specific mixture discussed here and is proposed for the first time.