TY - JOUR
T1 - A strategy for the enhancement of trapping efficiency of gaseous benzene on activated carbon (AC) through modification of their surface functionalities
AU - Kim, Won Ki
AU - Younis, Sherif A.
AU - Kim, Ki Hyun
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/2/1
Y1 - 2021/2/1
N2 - Facile modification is a common, but effective, option to improve the uptake removal capacity of of activated carbon (AC) against diverse target volatile organic compounds (VOCs; e.g., benzene) in gaseous streams. To help design the routes for such modification, this research built strategies to generate three types of modified ACs by incorporating amine/sulfur/amino-silane groups under solvothermal or microwave (MW) thermal conditions. The adsorption performance has been tested using a total of six types of AC sorbents (three modified + three pristine forms) for the capture of 1 Pa benzene (1 atm and 298 K). The obtained results are evaluated in relation to their textural properties and surface functionalities. Accordingly, the enhancement of AC surface basicity (e.g., point of zero charge (PZC) = 10.25), attained via the silylation process, is accompanied by the reduced adsorption of benzene (a weak base). In contrast, ACs amended with amine/sulfur (electron-donating) groups using the MW technique are found to acquire high surface acidity (PZC of 5.99–6.05) to exhibit significantly improved benzene capturing capability (relative to all others). Their uplifted performance is demonstrated in terms of key performance metrics such as breakthrough volume (BTV10%: 163 → 443 L g−1), adsorption capacity (Q10%: 4.82 → 13.6 mg g−1), and partition coefficient (PC10%: 0.516 → 1.67 mol kg−1 Pa−1). Based on the kinetic analysis, the overall adsorption process is found to be governed by pore diffusion as the main rate-determining step, along with surface interaction mechanisms. The results of this research clearly support the critical role of surface chemistry of AC adsorbents and their textural properties in upgrading air/gas purification systems.
AB - Facile modification is a common, but effective, option to improve the uptake removal capacity of of activated carbon (AC) against diverse target volatile organic compounds (VOCs; e.g., benzene) in gaseous streams. To help design the routes for such modification, this research built strategies to generate three types of modified ACs by incorporating amine/sulfur/amino-silane groups under solvothermal or microwave (MW) thermal conditions. The adsorption performance has been tested using a total of six types of AC sorbents (three modified + three pristine forms) for the capture of 1 Pa benzene (1 atm and 298 K). The obtained results are evaluated in relation to their textural properties and surface functionalities. Accordingly, the enhancement of AC surface basicity (e.g., point of zero charge (PZC) = 10.25), attained via the silylation process, is accompanied by the reduced adsorption of benzene (a weak base). In contrast, ACs amended with amine/sulfur (electron-donating) groups using the MW technique are found to acquire high surface acidity (PZC of 5.99–6.05) to exhibit significantly improved benzene capturing capability (relative to all others). Their uplifted performance is demonstrated in terms of key performance metrics such as breakthrough volume (BTV10%: 163 → 443 L g−1), adsorption capacity (Q10%: 4.82 → 13.6 mg g−1), and partition coefficient (PC10%: 0.516 → 1.67 mol kg−1 Pa−1). Based on the kinetic analysis, the overall adsorption process is found to be governed by pore diffusion as the main rate-determining step, along with surface interaction mechanisms. The results of this research clearly support the critical role of surface chemistry of AC adsorbents and their textural properties in upgrading air/gas purification systems.
KW - Benzene vapor adsorption
KW - Breakthrough analysis
KW - Commercial activated carbon
KW - Kinetic modeling
KW - Surface modification strategies
UR - http://www.scopus.com/inward/record.url?scp=85097786100&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2020.116239
DO - 10.1016/j.envpol.2020.116239
M3 - Article
AN - SCOPUS:85097786100
VL - 270
JO - Environmental Pollution
JF - Environmental Pollution
SN - 0269-7491
M1 - 116239
ER -