Exploratory Study Of Removing Toluene By Activated Carbon In Rotating Packed Bed

With the development of our economy, the emission of industry organic waste gases haveincreased year after year which is seriously harmful to our environment and health. Given this,the government has to pursue efforts to control VOCs and the novel VOCs treatments havebeen the research focus. The purification methods of toluene gases are reviewed, and theadsorption technique of our country lags behind abroad, new materials research andtechnology have been limitation. Although the traditional adsorption equipment are widelyused in industry, less contact area between gas and adsorbent，large occupation area of theequipment are exist. Rotating packed bed （RPB） is a kind of radial flow adsorption bed whosepacking way is circular can fill the gaps of traditional. In this paper, the exploratory study ofadsorption in a rotating packed bed have been done.Firstly，RPB was stood to simulate a radial flow adsorption bed，and the effects ofbreakthrough curve by the initial concentration of the gas，gas velocity and bed thickness wereinvestigated. Concluded that the best operating parameters in experiments: H=25mm,u=0.2m/s, C₀=811-1392ppm. Yoon-Nelson model, monolayer adsorption model and D-Rmodel were used to fit the experimental data. The results showed that, when C₀=811ppm,u=0.2m/s, H=25mm，an excellent agreement was observed between data obtained fromYoon-Nelson model and experimental results, R²=0.976. The fitting degree of Langmuir andD-R were0.979,0.984, respectively.Next, a primary study of removing toluene by activated carbon in rotating packed bed hasbeen done. The effects of breakthrough curve by the motor speed，initial concentration of the gas and gas velocity were investigated. Meanwhile， Yoon-Nelson model， monolayeradsorption model and D-R model were used to fit the experimental data. And mainlyinvestigated the influence of different high gravity factors on adsorption rate and diffusioncoefficient. The results indicated that the best operating parameters in experiments: the motorspeed is200rpm, C₀=1370-1830ppm, u=0.1m/s.The high gravity factor is good for adsorption rate and diffusion coefficient to a certaindegree. When the motor speed is400rpm, the adsorption effect in a rotating packed bed isnearly equal to a radial flow adsorption bed. With the increasing of the motor speed, theadsorption rate and diffusion coefficient are both increase first and then decrease. When themotor speed is200rpm, the max adsorption rate is68.4min^-1, the max diffusion coefficient is1.787×10⁷cm²/s.