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Enhancement of Carbon Dioxide Capture by Amine‐Functionalized Multi‐Walled Carbon Nanotube
Author(s) -
Khalili Soodabeh,
Ghoreyshi Ali Asghar,
Jahanshahi Mohsen,
Pirzadeh Kasra
Publication year - 2013
Publication title -
clean – soil, air, water
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 66
eISSN - 1863-0669
pISSN - 1863-0650
DOI - 10.1002/clen.201200339
Subject(s) - physisorption , adsorption , carbon nanotube , freundlich equation , sorption , chemisorption , amine gas treating , langmuir , chemical engineering , materials science , langmuir adsorption model , chemistry , organic chemistry , nanotechnology , engineering
Abstract In this study, crude multi‐walled carbon nanotubes (MWCNT) was functionalized by a two‐step process; first using strong mixed acids (H 2 SO 4 /HNO 3 ) and then treatment with 1,3‐phenylenediamine (mPDA). The equilibrium adsorption of CO 2 on pristine MWCNT and amine functionalized MWCNT (MWCNT‐NH 2 ) were investigated. Experiments were preformed via application of volumetric method in a dual sorption vessel at temperature range of 298–318 K and pressures up to 40 bars. The results obtained indicated that the equilibrium uptake of CO 2 increased after functionalizing of MWCNT. The increase in CO 2 capture by MWCNT‐NH 2 was attributed to the existence of great affinity between CO 2 molecules and amine sites on this adsorbent at low pressures. The experimental data were analyzed by means of Freundlich and Langmuir adsorption isotherm models. The data obtained revealed a fast kinetics for the adsorption of CO 2 in which most of adsorption occurred at initial period of adsorption experiments. This renders MWCNT as a suitable adsorbent for practical applications. Values of isosteric heat of adsorption were evaluated based on Clausius–Clapeyron equation. The results demonstrated that both chemisorption and physisorption played important role in CO 2 adsorption on MWCNT‐NH 2 , whereas the physisorption process was dominant for CO 2 adsorption on MWCNT.