燃煤烟气在13X分子筛上的吸附行为与热力学分析

采用静态容积法测定SO2,NO,CO2,N2和O2在13X分子筛上的吸附等温线,通过Langmuir,Sips和Toth等温方程进行拟合。研究结果表明:Sips具有较好的拟合效果。在烟气温度为75℃下,SO2,NO,CO2,N2和O2的饱和吸附量分别为:65,49,869,154和105μmol/g。由等量吸附热的计算表明:吸附热均随吸附量的升高而增大,SO2,NO,CO2,N2和O2的最大吸附热分别为:-9.35,-12.93,-31.96,-29.38和-25.09 kJ/mol。运用负载比关联模型预测5种气体的竞争吸附行为发现:多组分竞争吸附导致SO2,NO和CO2吸附量降为单组分气体吸附量的一半。在常压吸附真空解吸下可实现SO2,NO和CO2富集的体积分数为8.3%,2.9%和51.0%。

Equilibrium isotherms and thermodynamics for flue gases on 13X zeolite

Adsorption equilibriums for SO2,NO,CO2,N2 and O2 on 13X zeolite were obtained at different temperatures by a volumetric apparatus.Langmuir,Sips and Toth equations were used to correlate the experimental data.The results show that Sips equation has good simulation accuracy.According to Sips equation,the saturated adsorption amount for SO2,NO,CO2,N2 and O2 is 65,49,869,154,and 105 μmol/g,respectively.Isosteric heat of adsorption was calculated by Clausis-Clapeyron equation: it all increases with the increase of adsorption coverage,and the maximum heat for SO2,NO,CO2,N2 and O2 is -9.35,-12.93,-31.96,-29.38 and -25.09 kJ/mol,respectively.Laden ratio correlation model was used to predict the competitive adsorption of flue gas,and the adsorption amount of SO2,NO and CO2 in flue gas all reduces half.The concentration of SO2,NO and CO2 increases to 8.3%,2.9% and 51.0%,respectively if vacuum swing adsorption is used for regeneration.