Modeling CO2 adsorption on amine-functionalized mesoporous silica: 1. A semi-empirical equilibrium model

Research output: Contribution to journalArticle


Research units

  • University of Ottawa


An equilibrium model capable of describing CO2 adsorption isotherms on amine-grafted mesoporous silica using a semi-empirical method was developed. The proposed model is based on the assumption that adsorption of CO2 occurs via two independent mechanisms: (i) chemical adsorption on the amine-functional groups, and (ii) physisorption on the surface of the adsorbent. The CO2 adsorption isotherms on triamine-grafted pore-expanded MCM-41 silica were measured at different temperatures and used to develop the proposed model. The equilibrium modelwascapable of describingCO2 adsorption over a wide range of pressure, from 0.001 to 20 bar. Furthermore, when applied in a temperature-dependent form, it fitted experimental data at different temperatures between 25 and 55 °C. The adequacy of the model was reflected by the low values of the normalized standard deviations (2 isotherms of a triamine-grafted mesoporous silica with lower amine content and five varieties of monoamine-grafted SBA-15, as well as experimental data for H2S adsorption at 25, 35 and 50 °C. Moreover, the heat of CO2 and H2S adsorption calculated using the temperature-dependent parameters of the proposed model was in excellent agreement with experimental data.


Original languageEnglish
Pages (from-to)173-181
Number of pages9
JournalChemical Engineering Journal
Issue number1-2
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

    Research areas

  • Adsorption isotherm, Aminosilane grafting, CO adsorption, Heat of adsorption, MCM-41

ID: 4457180