孔结构和表面化学性质对活性炭吸附性能的影响

Effect of pore structure and surface chemical properties on adsorption properties of activated carbons

测定了室温下3种活性炭(GAC-C、GAC-P和GAC-T)对CO2、CH4和N2的吸附性能,并对颗粒活性炭孔结构和表面化学性质进行了表征,探讨了孔结构和表面化学性质对活性炭吸附性能的影响。结果表明:由于吸附机理、孔结构、表面含氧官能团和分子极性的差异,CO2、CH4和N2在活性炭上的饱和吸附量和吸附常数的关系为CO2>CH4>N2;CH4和N2的饱和吸附量主要受活性炭微孔孔容的影响,N2和CO2饱和吸附量的差异分别是由0.572～2.0 nm的微孔和0.4～6 nm的孔引起的;CH4吸附常数主要受较大中孔和大孔影响,N2吸附常数与微孔密切相关,大孔对CO2的吸附常数影响最大。

Adsorption isotherms of CO2,CH4 and N2 on three granular activated carbons（GAC-C,GAC-P and GAC-T） were determined at room temperature.Pore structure and surface chemical properties of granular activated carbons were characterized,and the effect of them on adsorption properties was investigated.The results showed that the relationships of gases adsorption capacity and uptake coefficient on granular activated carbons were CO2〉CH4〉N2,because of the differences of adsorption mechanism,pore structure,surface functional groups and molecular polarity.The adsorption capacities of CH4 and N2 were mainly controlled by micropore volume of activated carbon,and the differences of N2 and CO2 adsorption capacity were affected by micropores from 0.572 to 2.0 nm and pores from 0.4 to 6.0 nm,respectively.And uptake coefficient of CH4,was more relational with mesopore and macropore,while uptake coefficients of N2 and CO2 were mainly controlled by micropore and macropore,respectively.