TY - JOUR
T1 - Rice husk waste-derived super-biochar with the max surface area and Philic-CO2 textural structure
T2 - Boosting effect and mechanism of post-desilication
AU - Sun, Jingxiang
AU - Yan, Wen
AU - Liu, Xiaosheng
AU - Hu, Tao
AU - Xiong, Ya
AU - Tian, Shuanghong
AU - Feng, Jinxi
AU - Huang, Zhen
AU - Zhao, Zengli
PY - 2024/6/15
Y1 - 2024/6/15
N2 - A super-carbon material as adsorbents of CO2 were prepared with rice husk waste by a new two-step process, pyrolysis-activation and HF post-desilication process. This paper was focused on investigating the boosting effect and mechanism of post-desilication. It was found that the function of the post-desilication was considerably different from that of the reported pre-desilication. It could not only effectively remove Si element from rice husk biochar (RHC) but also significantly improve its performance, producing a super-biocarbon with a well-developed pore structure, rich C-F groups, and a 4230-m2 g−1 surface area, which is the max surface area of known biocarbon. It could adsorb 341.5 mg g−1 CO2, a max CO2 adsorption capacity of reported biocarbon, and its CO2/N2 and CO2/H2O adsorption selectivity index reached as high as 22.2 and 2.1, respectively. The large surface area was mainly originated from the expansion effect of SiF4 gas from the post-desilication, generating numerous ultra-microspores, while these C-F groups were generated by the co-reactions of the post-desilication. The ultra-high adsorption capacity was mainly from the fill-adsorption driven by the size effect of these ultra-micropores and the strong CO2-affinity of C-F groups, and the adsorption selectivity was confirmed to depend on water-resistant and CO2-philic characteristics of its C-F groups by theoretical calculations and experimental observations. These findings presented not only an advanced CO2-capture material but also a facile way to tailor textural structure of other biochars. © 2024 Elsevier B.V.
AB - A super-carbon material as adsorbents of CO2 were prepared with rice husk waste by a new two-step process, pyrolysis-activation and HF post-desilication process. This paper was focused on investigating the boosting effect and mechanism of post-desilication. It was found that the function of the post-desilication was considerably different from that of the reported pre-desilication. It could not only effectively remove Si element from rice husk biochar (RHC) but also significantly improve its performance, producing a super-biocarbon with a well-developed pore structure, rich C-F groups, and a 4230-m2 g−1 surface area, which is the max surface area of known biocarbon. It could adsorb 341.5 mg g−1 CO2, a max CO2 adsorption capacity of reported biocarbon, and its CO2/N2 and CO2/H2O adsorption selectivity index reached as high as 22.2 and 2.1, respectively. The large surface area was mainly originated from the expansion effect of SiF4 gas from the post-desilication, generating numerous ultra-microspores, while these C-F groups were generated by the co-reactions of the post-desilication. The ultra-high adsorption capacity was mainly from the fill-adsorption driven by the size effect of these ultra-micropores and the strong CO2-affinity of C-F groups, and the adsorption selectivity was confirmed to depend on water-resistant and CO2-philic characteristics of its C-F groups by theoretical calculations and experimental observations. These findings presented not only an advanced CO2-capture material but also a facile way to tailor textural structure of other biochars. © 2024 Elsevier B.V.
KW - Adsorption
KW - Biochar
KW - CO2
KW - Post-desilication
KW - Rice husk
KW - Supercarbon
UR - http://www.scopus.com/inward/record.url?scp=85191990164&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85191990164&origin=recordpage
U2 - 10.1016/j.cej.2024.151583
DO - 10.1016/j.cej.2024.151583
M3 - RGC 21 - Publication in refereed journal
SN - 1385-8947
VL - 490
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 151583
ER -