TY - JOUR
T1 - Introduction of cross-linking agents to enhance the performance and chemical stability of polyethyleneimine-impregnated CO2 adsorbents
T2 - Effect of different alkyl chain lengths
AU - Jeon, Sunbin
AU - Min, Jinseo
AU - Kim, Sung Hyun
AU - Lee, Ki Bong
N1 - Funding Information:
This work was supported by the KIST Institutional Program (Project No. 2E30250-20-042) and ?Energy Technology Development Business? of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean government Ministry of Trade, Industry & Energy (No. 20182020201260).
Funding Information:
This work was supported by the KIST Institutional Program (Project No. 2E30250-20-042 ) and “Energy Technology Development Business” of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean government Ministry of Trade, Industry & Energy (No. 20182020201260 ).
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/10/15
Y1 - 2020/10/15
N2 - Polyethyleneimine (PEI)-functionalized silica-based CO2 adsorbents are well known to irreversibly form urea during the regeneration process at high temperatures and under CO2-rich atmospheric conditions. The formation of urea is a critical drawback that substantially reduces the cyclic performance of PEI-functionalized adsorbents. In this study, epoxy cross-linkers were introduced to PEI to suppress the formation of urea. Pristine PEI and epoxy cross-linked PEI were impregnated into mesostructured cellular foam silica using a dry impregnation method. In particular, epoxy cross-linkers with different alkyl chain lengths were used, and the effect of the alkyl chain length of the cross-linkers on the chemical stability and CO2 adsorption performance of adsorbents was scrutinized. The suppression of urea formation improved as the alkyl chain length of the cross-linkers increased. The adsorbent functionalized with epoxy cross-linked PEI exhibited an approximately three times higher working capacity (0.71 mmol g−1) than the adsorbent functionalized with pristine PEI (0.23 mmol g−1) after 40 rapid cycles comprising adsorption at 100 °C with 15% CO2 balanced by N2 for 10 min and regeneration at 130 °C with 100% CO2 for 5 min. It is believed that the alkyl chain of the cross-linkers acted as a spacer that could hinder the urea formation, enhancing the chemical stability and CO2 adsorption performance of PEI-functionalized adsorbents.
AB - Polyethyleneimine (PEI)-functionalized silica-based CO2 adsorbents are well known to irreversibly form urea during the regeneration process at high temperatures and under CO2-rich atmospheric conditions. The formation of urea is a critical drawback that substantially reduces the cyclic performance of PEI-functionalized adsorbents. In this study, epoxy cross-linkers were introduced to PEI to suppress the formation of urea. Pristine PEI and epoxy cross-linked PEI were impregnated into mesostructured cellular foam silica using a dry impregnation method. In particular, epoxy cross-linkers with different alkyl chain lengths were used, and the effect of the alkyl chain length of the cross-linkers on the chemical stability and CO2 adsorption performance of adsorbents was scrutinized. The suppression of urea formation improved as the alkyl chain length of the cross-linkers increased. The adsorbent functionalized with epoxy cross-linked PEI exhibited an approximately three times higher working capacity (0.71 mmol g−1) than the adsorbent functionalized with pristine PEI (0.23 mmol g−1) after 40 rapid cycles comprising adsorption at 100 °C with 15% CO2 balanced by N2 for 10 min and regeneration at 130 °C with 100% CO2 for 5 min. It is believed that the alkyl chain of the cross-linkers acted as a spacer that could hinder the urea formation, enhancing the chemical stability and CO2 adsorption performance of PEI-functionalized adsorbents.
KW - Alkyl chain length
KW - CO capture
KW - Chemical stability
KW - Cross-linked PEI
UR - http://www.scopus.com/inward/record.url?scp=85085647891&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85085647891&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2020.125531
DO - 10.1016/j.cej.2020.125531
M3 - Article
AN - SCOPUS:85085647891
VL - 398
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
M1 - 125531
ER -