Antero Laitinen

OLDSHUE-RUSHTON COLUMN IN SUPERCRITICAL FLUID EXTRACTION

The performance of a mechanically agitated Oldshue–Rushton column using carbon dioxide solvent at 10 MPa and 313 K to extract ethanol from aqueous feed was investigated. The overall mass-transfer coefficient K od a, the height equivalent to a theoretical stage (HETS), dispersed phase holdup, as well as the column capacity data were measured as a function of solvent-to-feed ratio and rotor speed. The values of overall mass transfer coefficient K od a generally ranged from 0.009 to 0.012 s−1, and the values of the HETS ranged from 0.44 to 0.74 m. The total throughput of the Oldshue–Rushton column without agitation was approximately 68 m3·h−1·m−2, whereas at 300 rpm the total throughput was approximately 48 m3·h−1·m−2.

Physical solvent extraction of levulinic acid from dilute aqueous solution with 2-methyltetrahydrofuran

ABSTRACT The results of the present investigation reveal that 2-methyltetrahydrofuran is a potential solvent for the extraction of levulinic acid from dilute aqueous solution. This conclusion is based on the relatively high values of distribution coefficient Kd (1.3-1.6) measured for the system of levulinic acid – water – 2-methyltetrahydrofuran at temperatures 298.2 K, 313.2 K, and 328.2 K, as well as encouraging performance of the continuous counter current Kühni column. The results give reason to believe, that 2-methyltetrahydrofuran can be considered for the extraction of other low molecular weight acids, such as formic or lactic acid, as well.