Mass-transfer characteristics in a rotating zigzag bed as a Higee device

摘要

A rotating zigzag bed, as a Higee device, has successfully achieved the industrialization of Higee in the commercial continuous distillation process. To increase applicability of rotating zigzag bed in the gas-liquid mass-transfer processes, the mass-transfer characteristics of the rotor of rotating zigzag bed were examined. The effective interfacial area (a(e)) and local liquid-side mass-transfer coefficient (k(L)) were measured using a chemical absorption of CO2 in NaOH solution. Based on two-film theory, the local gas-side mass-transfer coefficient (k(G)) was obtained from the overall volumetric gas-side mass-transfer coefficient (K(G)a(e)) which was measured using a stripping of ethanol from an ethanol-water mixture by air. The effects of rotational speed, liquid volumetric flow rate and gas volumetric flow rate on these mass-transfer parameters were investigated. Compared to the conventional rotating packed bed, the k(L) of the rotor of rotating zigzag bed was as about 2.5 times higher as that of conventional RPB rotor, and the a(e) and k(G) of the rotor of rotating zigzag bed matched with those of the rotor of conventional rotating packed bed. Therefore, rotating zigzag bed has good mass-transfer performance with a great potential for the industrial application. (C) 2017 Elsevier B.V. All rights reserved.