Oxygen Absorption into Stirred Emulsions of n-Alkanes. (25th July 2012)

• Record Type: Journal Article
• Authors: Ngo, Thanh Hai; Schumpe, Adrian
• Other Names: Teixeira Jose Academic Editor.
• Is Part Of: International journal of chemical engineering. Volume 2012(2012)
• Publication Date: 2012-07-25
• Subjects: Chemical engineering -- Periodicals; Chemical engineering; Electronic journals; Periodicals; 660
• DOI: 10.1155/2012/265603
• Languages: English
• ISSNs: 1687-806X

Abstract

Abstract : Absorption of pure oxygen into aqueous emulsions of n-heptane, n-dodecane, and n-hexadecane, respectively, has been studied at 0 to 100% oil volume fraction in a stirred tank at the stirring speed of 1000 min −1 . The volumetric mass transfer coefficient, k L a, was evaluated from the pressure decrease under isochoric and isothermal (298.2 K) conditions. The O/W emulsions of both n-dodecane and n-hexadecane show a k L a maximum at 1-2% oil fraction as reported in several previous studies. Much stronger effects never reported before were observed at high oil fractions. Particularly, all n-heptane emulsions showed higher mass-transfer coefficients than both of the pure phases. The increase is by upto a factor of 38 as compared to pure water at 50% n-heptane. The effect is tentatively interpreted by oil spreading on the bubble surface enabled by a high spreading coefficient. In W/O emulsions of n-heptane and n-dodecane k L a increases with the dispersed water volume fraction; the reason for this surprising trend is not clear.