改性活性炭对低浓度二氧化硫吸附动力学模型研究  

Study on adsorption kinetics model of modified activated carbon on SO_(2) with low-concentration

作　　者：王志强 张俊杰 刘相成 金梧凤[1] WANG Zhiqiang;ZHANG Junjie;LIU Xiangcheng;JIN Wufeng(Tianjin Key Laboratory of Refrigeration Technology,School of Mechanical Engineering&Tianjin Commercial University,Tianjin 300134,China)

机构地区：[1]天津市制冷技术重点实验室,天津商业大学机械工程学院,天津300134

出　　处：《无机盐工业》2022年第9期69-76,共8页Inorganic Chemicals Industry

基　　金：天津市教委科研计划重点项目(No.2017ZD16)。

摘　　要：碱改性活性炭是一种广泛应用于半导体工业和数据中心净化室内吸附二氧化硫的高效材料,但是鲜有针对符合真实建筑环境的低浓度二氧化硫吸附实验及动力学模型进行研究。首先研究了氧化铜-氢氧化钾改性活性炭(CuO-KOH@AC)、氢氧化钾改性活性炭(KOH@AC)、氢氧化镁改性活性炭[Mg(OH)_(2)@AC]等3种碱改性活性炭在温度为25℃、相对湿度(RH)为50%、二氧化硫质量浓度为2612 mg/L条件下对二氧化硫的吸附性能,结果显示碱改性活性炭对二氧化硫的吸附能力受碱负荷量的影响更多。然后测定了CuO-KOH@AC在二氧化硫质量浓度为522~13400 mg/L的吸附等温曲线实验值,验证了Langmuir模型、Freundlich模型、Dubin-Radushkevich(D-R)模型的有效性,其中Freundlich模型在低二氧化硫浓度条件(二氧化硫质量浓度为522 mg/L,误差为-12.18%)下拟合效果最好。CuO-KOH@AC在二氧化硫质量浓度为2612 mg/L、不同RH(1%、50%、75%)条件下的吸附实验表明,RH增加能够促进二氧化硫在吸附剂表面的吸附。傅里叶变换红外光谱对CuO-KOH@AC吸附二氧化硫后的分析表明,吸附剂表面的吸附物种为—SO_(3)(或SO_(4)^(2-))和—SO_(2)。X射线光电子能谱对CuO-KOH@AC吸附二氧化硫后的分析结果显示,吸附剂表面S^(6+)形态占80%~90%,其比例随着RH的增加而增加。CuO-KOH@AC最终以SO_(4)^(2-)形式吸附气态二氧化硫,吸附过程以化学吸附为主。Alkali-modified activated carbon is used as an efficient adsorption material for the purification of SO_(2)in the clean room of semiconductor industries and data centre.However,there are few lowconcentration SO_(2)adsorption experiments and model studies that conform to the real building environment.The adsorption performance of three alkalimodified activated carbons,namely copper oxidepotassium hydroxide modified activated carbon,potassium hydroxide modified activated carbon and magnesium hydroxide modified activated carbon,at a temperature of 25℃,a relative humidity(RH)of 50%and SO_(2)mass concentration of 2612 mg/L was firstly investigated.The results showed that the adsorption capacity of the alkalimodified activated carbon samples to SO_(2)was more affected by the alkali load.The experimental values of the adsorption isotherm curves of activated carbon loaded with potassium hydroxidecopper oxide were then measured at SO_(2)mass concentrations ranging from 522 to 13400 mg/L.The validity of the Langmuir model,Freundlich model and DubinRadushkevich(D-R)model was verified,with the Freundlich model fitting best at low concentrations(SO_(2)mass concentration of522 mg/L,error-12.18%).The experiments on alkalimodified activated carbon at a sulphur dioxide mass concentration of2612 mg/L and different RH(1%,50%and 75%)showed that increased RH promoted the adsorption of sulphur dioxide on the samples surface.Analysis of the modified activated carbon by fourier transform infrared spectroscopy showed that the absorbents on the surface of the samples were—SO_(3)(or SO_(4)^(2-))and—SO_(2).X-ray photoelectron spectroscopy showed that the S^(6+)form was accounted for 80%to 90%and the proportion was increased with the increase of RH.The alkalimodified activated carbon eventually adsorbed gaseous SO_(2)in the form of SO_(4)^(2-)and the adsorption process was dominated by chemical adsorption.

关 键 词：碱改性活性炭 二氧化硫吸收 吸附模型 低浓度二氧化硫 

分 类 号：O647.33[理学—物理化学]