Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1223-1229.doi: 10.3866/PKU.WHXB201202234

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Adsorption of Low Concentration CO2 by Modified Carbon Nanotubes under Ambient Temperature

YE Qing1, ZHANG Yu1, LI Ming2, SHI Yao1   

  1. 1. Institute of Industrial Ecology and Environment, Department of Chemical and Biological Engineering, Faculty of Engineering, Zhejiang University, Hangzhou 310028, P. R. China;
    2. Zhejiang Shuren University, Hangzhou 310015, P. R. China
  • Received:2011-10-18 Revised:2012-01-18 Published:2012-04-26
  • Contact: SHI Yao
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20976159).

Abstract: Solid amine adsorbents for low concentration CO2 removal were developed using carbon nanotubes (CNTs) impregnated with tetraethylenepentamine (TEPA) and triethylenetetramine (TETA). The adsorbents were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FITR), N2 adsorption/desorption, elemental analysis and thermogravimetric analysis (TGA). After impregnation, the shapes, fundamental channels and pore structures of the adsorbents were unchanged. However, the surface area and pore volume decreased. The adsorption behavior toward low concentration CO2 was investigated in a fixed-bed column. The results indicated that the adsorption capacity was enhanced substantially by modification. The CO2 adsorption capacity of CNTs-TEPA was higher than that of CNTs-TETA with the same amount of amine loading. The adsorption capacity increased steadily from 126.7 to 139.3 mg·g-1 for CNTs-TEPA and from 101.2 to 110.4 mg·g-1 for CNTs-TETA as the temperature increased from 20 to 30 ℃. The adsorption capacity of the raw CNTs experienced a modest increase, but began to decrease gradually with further temperature increases. Suyadal and Yasyerli deactivation models were applied to investigate the experimental breakthrough curves of raw and modified CNTs. It was concluded that the Yasyerli deactivation model is more appropriate to analyze the breakthrough curves of CO2 adsorption on solid amine adsorbents.

Key words: Carbon nanotube, CO2 adsorption, Triethylenetetramine, Tetraethylenepentamine, Deactivation model