摘要
在固定床吸附反应器内对一种商业活性炭进行了汞吸附实验,考察了入口汞浓度和吸附温度对活性炭吸附汞的影响。采用4个简化的吸附动力学模型,即内扩散模型、准一阶和准二阶动力学模型,耶洛维奇(Elovich)模型从动力学的角度探讨了入口汞浓度和吸附温度对汞吸附的影响机制。分析了汞吸附过程的机制和控制过程。结果表明:入口汞浓度的增加,或者吸附温度的降低,均有利于活性炭对汞的吸附,其主要原因是提高了颗粒内扩散速率、初始吸附速率以及准一级反应速率。汞吸附过程主要由化学吸附控制,主要分为表面吸附和内扩散吸附2个阶段,初始吸附阶段呈现较快吸附速率,该阶段和表面吸附有关;随着表面活性位被占据,颗粒内扩散起主要控制作用,吸附速率下降。
An experimental study on mercury adsorption of a commercial activated carbon was carried out in a ftxed-bed reactor. The effects of inlet mercury concentration and temperature on mercury adsorption efficiency were explored. Four simplified adsorption kinetic models, including intraparticle diffusion model, pseudo-first and pseudo-second order kinetic models, and Elovich model, were used to investigate the mechanism of mercury adsorption, adsorption rate, and the controlling process from the kinetic point of view. The results show that the increase of inlet mercury concentration or the decrease of temperature is beneficial to promoting the mercury adsorption capacity, due to the enhancement of intraparticle diffusion rate, initial adsorption rate, and pseudo-first order reaction rate. The mercury adsorption process is controlled dominantly by chemisorption, which comprises two steps： surface adsorption and intraparticle diffusion adsorption. The Hg~ adsorption rate is higher in the initial stage, which is determined by the surface adsorption. After that the adsorption rate drops continuously as the surface active sites are occupied and the intraparticle diffusion dominates the adsorption.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第29期10-17,2,共8页
Proceedings of the CSEE
基金
国家自然科学基金项目(51076030)
江苏省环保科研课题基金项目(201113)
江苏省产学研联合创新资金项目(BY2013073-10)
煤燃烧国家重点实验室开放基金项目(FSKLCC1002)~~
关键词
活性炭
汞吸附
动力学模型
控制过程
吸附机制
activated carbon
mercury adsorption
kineticmodel
control process
adsorption mechanism
