Post-combustion CO2 Capture Using Polyethylenimine Impregnated Mesoporous Cellular Foams

• Author / Creator

  Liu, Zhengyi

• Abstract
  In this work, mesoporous cellular foams (MCFs) were synthesized and impregnated with different weight percentage of polyethylenimine (PEI) using wet impregnation method. The synthesized adsorbents were characterized using nitrogen adsorption/desorption, SEM, TEM, and FTIR analysis. The CO2 adsorption capacity of PEI-impregnated MCFs was measured using thermogravimetric analyzer (TGA). The effects of PEI loadings, adsorption temperatures, and CO2 partial pressures on CO2 adsorption performance using PEI-impregnated MCFs were explored. 70 wt % PEI loading was found to be the optimum for the highest CO2 adsorption capacity of about 5 mmol/g in 95% CO2/5% N2 gas mixture and 4 mmol/g in 10% CO2/90% N2 gas mixture, at 75 °C. The effect of moisture on the CO2 adsorption performance in simulated flue gases was studied. It was found the CO2 adsorption performance of PEI-impregnated MCFs can be improved with the presence of moisture, especially at low adsorption temperatures. The adsorbent with optimum PEI loading was then tested for multi-cycle stability and adsorption/desorption kinetics in both humid and dry conditions. Good stability of the adsorbent in multi-cycle tests was found as no significant change in CO2 adsorption capacity was observed. Various equilibrium adsorption isotherms, such as Langmuir and Freundlich adsorption isotherms, were applied to describe the CO2 adsorption behavior. Different kinetic models were developed to study the CO2 adsorption kinetics of this type of adsorbents. John-Mehl-Avrami (JMA) model was found to be well fitted with the experimental data, indicating another possible way to describe the kinetics of CO2 adsorption process under isothermal conditions. The heat of adsorption of CO2 adsorption process using PEI-impregnated MCFs was also calculated.

• Subjects / Keywords

  • Mesoporous cellular foams
  • Post-combustion CO2 capture

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3NV99K04

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.