气体搅拌萃取过氧化氢实验研究

在内径为50 mm的筛板塔内,研究了空气-水-蒽醌工作液三相体系萃取过氧化氢过程.萃取温度为40℃,空气和分散相的表观流速分别为(1.31～3.22)×10-3m·s-1和(1.27～1.70)×10-3 m·s-1,分散相和连续相的表观流速之比为50:1.结果表明,在普通液-液萃取过氧化氢过程中引入气体作搅拌,可减小分散相的液滴直径,增大相际接触面积,明显提高萃取效率,降低萃余相中过氧化氢的含量.传质单元高度随气体表观流速的增加而降低,传质系数随气体表观流速的增加而增大.

Experimental Investigation of a Gas-Agitated Sieve Plate Column for Hydrogen Peroxide Extraction

The novel process of extracting hydrogen peroxide from anthraquinone working solution by deionized water in a sieve plate column with bottom gas injection was investigated. Oxidized anthraquinone working solution and deionized water were used as dispersed and continuous phases, respectively. And the air was used as stirred gas, which flows upward cocurrently with dispersed phase. The flow rate ratio of the dispersed and continuous phases was kept at 50:1. The results show that when the extraction process is with gas-agitaion, the concetration of hydrogen peroxide in raffinate phase is obviously lower than that of the conventional liquid- liquid extraction process and the height of transfer unit (HTU) is greatly reduced, which is only 1/2 of that of conventional liquid-liquid extraction column. The mass-transfer coefficient of the hydrogen peroxide from anthraquinone working solution to water in a gas-agitated sieve plate column is about 2 times higher than that of conventional liquid-liquid extraction. This may attribute to the improvements of dispersed phase droplets dispersion and surface renewal, which in turn enhances the mass transfer.