Adsorption of CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; on Polyethyleneimine 10k—&amp;lt;i&amp;gt;Mesoporous silica&amp;lt;/i&amp;gt; Sorbent: XPS and TGA Studies

M M Khader,Sardar Ali,M J Al-Marri,E P Giannelis,G Qi

doi:10.4236/ajac.2015.64026

Adsorption of CO&lt;sub&gt;2&lt;/sub&gt; on Polyethyleneimine 10k—&lt;i&gt;Mesoporous silica&lt;/i&gt; Sorbent: XPS and TGA Studies

M M Khader, Sardar Ali + Show 3 more

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https://doi.org/10.4236/ajac.2015.64026

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Abstract

A CO2 solid sorbent based on polyethyleneimine 10k (PEI-10k) impregnated into mesoporous silica (MPS) foam was synthesized and utilized to capture CO2 at temperatures ranged from 65°C to 95°C. The calculated nitrogen and carbon contents in the bulk of the PEI-10k/MPS sorbent were similar to the XPS results measured on the surface of the foam, suggesting that the PEI was homo-geneously distributed throughout the MPS support. After CO2 adsorptionthe N 1s peak was broadened and could be resolved into two components: a high binding energy component (~401 eV) and a lower binding energy one (396 eV), respectively. The former nitrogen states are consistent with a protonated amine, presumably, due to carbamate formation. The lower binding energy component (~396 eV) could possibly be due to strongly chemisorbed CO2. The maximum sorption capacity was about 4 mmole CO2/g sorbent at 85°C and 1 bar. This capacity was doubled by raising the CO2 pressure to 24.95 bars. The adsorption results can be described by a Langmuir adsorption isotherm.

Highlights

Carbon dioxide is one of the major greenhouse gases (GHGs)
polyethyleneimine 10k (PEI-10k) was chosen for immobilization on the mesoporous silica (MPS) support because of its high thermal stability at the desired temperatures for CO2 capturing (70 ̊C to 90 ̊C)
The morphology of the support before and after amine impregnation was investigated by nano scanning electron microscope (NSEM)

Summary

Introduction

Carbon dioxide is one of the major greenhouse gases (GHGs). Starting early in 19th century, extensive anthropogenic CO2 emissions due to fossil fuel utilization have led to carbon dioxide accumulation in the atmosphere.How to cite this paper: Khader, M.M., Al-Marri, M.J., Ali, S., Qi, G. and Giannelis, E.P. (2015) Adsorption of CO2 on Polyethyleneimine 10k—Mesoporous silica Sorbent: XPS and TGA Studies. According to the Intergovernmental Panel on Climate Change (IPCC) the increase in greenhouse gases has triggered serious climate changes demonstrated more obviously as an increase in earth temperature In this context, the development of highly efficient CO2 sorbents for trapping large amounts of CO2 from concentrated sources such as natural gas processing and power plants emission emerges as a pressing issue. Amine functionalized solid sorbents are appealing [8]-[18] because the high capture capacity of the amine molecules is retained [15] [16] Various other adsorbents such as zeolites [19] [20], activated carbons [21]-[24], activated aluminas [25]-[27], and membranes [28] have been investigated. Since these sorbents absorb moisture and other gases, their CO2 separation selectivity is low, resulting in large separation systems with high operational cost in practical applications

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