Liquid-phase mass-transfer coefficients of Mellapak structured packings under desorption of oxygen from primary alcohols

• Published in: Chemical engineering research & design 2017-11, Vol.127, p.1-9
• Main Authors: Rejl, F.J., Haidl, J., Valenz, L., Marchi, A., Moucha, T., Petříček, R., Brunazzi, E.
• Format: Article
• Language: English
• Subjects: Absorption; Alcohol; Alcohols; Columns (structural); Desorption; Distillation; Ethanol; Flow velocity; Fluid dynamics; Liquid flow; Mass transfer; Mass-transfer coefficient; Methanol; Oxygen; Structured packing; Volumetric analysis
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2017.09.002

•Liquid-side mass-transfer coefficient for organic systems on structured packings.•Common correlation for alcohols, water and several sizes of packing.•Dependence on the flow rate found similar for organic and aqueous systems.•Indirect dependence of kL on the square root of the surface tension. Volumetric mass-transfer coefficient in the liquid phase, kLa, for Mellapak 250.Y, 350.Y and 500.Y structured packings has been measured by standard method of desorption of oxygen into nitrogen from pure methanol, ethanol and n-propanol in the column of i.d. of 150mm. Although utilization of organic solvents for absorption experiments provides valuable behavior interlink between properties of aqueous absorption systems and ordinary (organic) systems under distillation conditions, studies of such kind are not published in the open literature. The behavior of the kLa data on alcohol systems do not differ significantly from that found for aqueous system, the kLa values rise with the liquid load powered to ∼0.5–0.78. For one solvent the kLa are almost identical for all three packings under the same liquid load. According to the expectations the kLa values under the same superficial liquid flow rate are highest for the solvent with the lowest viscosity and the highest diffusivity of oxygen, methanol, and decrease in the order ethanol, n-propanol and water. The kL data for all three packings, alcohols and also for water has been successfully correlated by dimensionless correlation Sh=0.207∙Re0.798Fr−0.563We0.511Sc0.528 with mean relative deviation of 12%.