微乳液增溶吸收甲苯传质机理及影响因素

Mass transfer and influence factors for solubilization absorption of toluene with microemulsion

利用甲苯可以和非离子表面活性剂Tween-20以及助表面活性剂形成微乳液,从而增大甲苯表观溶解度,吸收净化含甲苯有机废气。研究了吸收过程传质机理及Tween-20液相浓度、液相转速、助表面活性剂和温度对吸收的影响。结果表明:液相传质系数kL=3.242×10-6m/s,气相传质系数kG=8.136×10-7mol/(m2.s),吸收为液膜控制过程;吸收速率和吸收物质的量随着Tween-20浓度的增大而升高,尤其当浓度高于临界胶束浓度时,吸收速率及吸收物质的量增加更显著;添加助表面活性剂和降低温度更有利于微乳液增溶吸收甲苯有机废气。

Nonionics Tween-20 and cosurfactant were used to absorb toluene from volatile organic compounds containing gas stream by formation of microemulsion. The solubility of toluene can be enhanced by the microemulsion. Mass transfer and influence factors such as Tween-20 concentration,rotational speed of liquid phase,cosurfactant,and temperature on absorption were investigated. The results indicate that the mass transfer coefficient of liquid phase kL is 3.242×10-6 m/s,the mass transfer coefficient of gas phase kG is 8.136×10-7 mol/（m2·s）,and the vast majority of resistance exists in liquid film. With increasing the concentration of Tween-20,the absorption rate and absorption capability of toluene are enlarged accordingly,especially when the concentration of surfactants is higher than critical micelle concentration. Tween-20 solution has a significant effect on the kinetics at low temperature and by adding cosurfactants.