Capture of CO(2) from flue gas via multiwalled carbon nanotubes

Abstract

Carbon nanotubes (CNTs) were modified by 3-aminopropyl-triethoxysilane (APTS) solution and were tested for its CO(2) adsorption potential at multiple temperatures (20-100 degrees C). The physicochemical properties of CNTs were changed after the modification, which makes CNTs adsorb more CO(2) gases. The adsorption capacities Of CO(2) via CNTs and CNTs(APTS) decreased with temperature indicating the exothermic nature of adsorption process and increased with water content in air at 0-7%. The mechanism of CO(2) adsorption on CNTs and CNTs(APTS) appears mainly attributable to physical force regardless of temperature change, which makes regeneration of spent CNTs at a relatively low temperature become feasible. The CNTs(APTS) have good adsorption performance Of CO(2) at 20 degrees C as compared to many types of modified carbon or silica adsorbents documented in the literature. This suggests that the CNTs(APTS) are promising low-temperature adsorbents for CO(2) capture from flue gas. (C) 2009 Elsevier B.V. All rights reserved.