Selective solubilization of 1,3-propanediol using a water-supercritical CO sub(2) microemulsion with Ls-45 as surfactant

• Published in: RSC advances 2013-04, Vol.3 (20), p.7585-7590
• Main Authors: Yu, Wen, Zhou, Dan, Yin, Jian-zhong, Gao, Jin-ji
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Broths; Carbon dioxide; Dilution; Ethyl alcohol; Fermentation; Microemulsions; Solubilization
• ISSN: 2046-2069
• DOI: 10.1039/c3ra23429k

In order to purify the fermentation broth efficiently, this paper focuses on solubilizing polyalcohols from their dilute aqueous solution using a supercritical CO sub(2) microemulsion (W-C microemulsion). The phase behavior of four systems was studied, including Ls-45/CO sub(2), Ls-45/CO sub(2)/H sub(2)O, Ls-45/CO sub(2)/1,3-propanediol (1,3-PDO), and Ls-45/CO sub(2)/H sub(2)O/1,3-PDO , with 1,3-PDO dilute aqueous solution used to simulate the real fermentation broth, supercritical CO sub(2) (scCO sub(2)) as the continuous phase, and the non-fluorous and non-silicon non-ionic Ls-45 as surfactant. The effects of Ls-45 concentration and 1,3-PDO concentration on the selective solubilization of 1,3-PDO in the Ls-45/CO sub(2)/1,3-PDO/H sub(2)O quaternary system are discussed at temperatures of 29.5-49.9 degree C and at pressures of 7.22-19.27 MPa. The results show that a thermodynamically stable microemulsion can be formed by controlling the operating pressure and temperature and can selectively solubilize 1,3-PDO from its dilute aqueous solution. Both the Ls-45 concentration and 1,3-PDO concentration in the system have great influence on the selectivity of solubilzing 1,3-PDO from dilute aqueous solution. Moreover, it is found that the addition of ethanol (EtOH) can significantly decrease the operating pressure of forming the W-C microemulsion system. This result is useful for further research on the selective extraction of polyalcohols in biotechnology and helpful for industrialization.