微量醇及电解质强化气液传质的研究

在气升式内环流反应器中考察了微量醇类物质(乙醇、叔丁醇、季戊四醇)及电解质(CaCl2)对氧的液相体积传质系数和气含率的影响。结果表明，向空气-水体系中添加微量醇类物质可以明显改善气液传质性能，同时醇类物质强化气-液传质存在一极限浓度，超过此浓度后，氧的液相体积传质系数略有降低；当表观气速增加时，去离子水体系和含醇体系的气含率都增加，但醇体系的气含率明显高于去离子水体系。此外，添加电解质CaCl2也会使氧的液相体积传质系数有所提高，并从离子强度的角度对其抑制气泡聚并的机理进行了分析。

Intensification of Gas-Liquid Mass Transfer by the Addition of Alcohols or Electrolyte

A study focusing on the liquid-side volumetric mass transfer coefficient and gas holdups in aqueous solutions of alcohols (ethanol,tertiary butanol,pentaerythritol) or electrolyte (CaCl_2) was carried out in an internal airlift loop reactor.The experimental results showed that the oxygen transfer coefficient increased significantly as the addition of alcohols into the water due to the change of gas-liquid interfacial status.However,the liquid-side volumetric mass transfer coeffi- cient of oxygen decreased slightly beyond a limiting concentration.Gas holdups in the water and aqueous solutions of alcohols both increased significantly with the increase of gas superficial veloci- ty,but the latter was higher at the same gas superficial velocity.It was found that the liquid-side volumetric mass transfer coefficient of oxygen increased with the addition of minute quantities of electrolyte into water,which was discussed based on ionic strength.