|
| Effects of physical aging on the physicochemical properties and thermal stability of different straw biochars |
| Received:June 18, 2025 |
| View Full Text View/Add Comment Download reader |
| KeyWord:aging;biochar;physicochemical properties;structural characteristics;thermal stability;recalcitrance index |
| Author Name | Affiliation | E-mail | | FAN Runchuan | College of Water Sciences, Beijing Normal University, Beijing 100875, China | | | HAO Caiwei | Xizang Datang Zala Hydropower Development Co., Ltd., Changdu 854000, China | | | LI Wenbo | Xizang Datang Zala Hydropower Development Co., Ltd., Changdu 854000, China | | | ZHU Ying | Advanced Materials Institute, Qilu University of Technology(Shandong Academy of Sciences), Jinan 250000, China | | | ZHENG Lei | College of Water Sciences, Beijing Normal University, Beijing 100875, China | | | CHENG Hongguang | College of Water Sciences, Beijing Normal University, Beijing 100875, China | | | YANG Kai | College of Water Sciences, Beijing Normal University, Beijing 100875, China | yangk@bnu.edu.cn |
|
| Hits: 63 |
| Download times: 0 |
| Abstract: |
| To investigate the effect of physical aging on the physicochemical properties and thermal stability of straw biochars, two artificial accelerated aging methods, including wet-dry cycling and freeze-thaw cycling, were applied to wheat straw biochar(WBC300, WBC400, WBC500)and maize straw biochar(MBC300, MBC400, MBC500)produced under different pyrolysis temperatures(300, 400 ℃, and 500 ℃). The physicochemical properties and thermal decomposition characteristics of fresh and aged biochars were compared, and the recalcitrance index(R50)was used to assess their carbon sequestration potential. The results showed that under the same pyrolysis temperature, WBC exhibited higher aromaticity, while MBC demonstrated greater stability due to its higher ash content. Increasing pyrolysis temperature enhanced both the aromaticity and R50 of biochar via promoting the carbonization reactions. Wet-dry and freeze-thaw cycling reduced the pH while increasing the hydrophilicity and polarity of biochar via inducing oxidation on its surface. Both aging treatments increased the mesopore quantity in WBC500 and MBC500, thus increasing their specific surface areas. The periodic evaporation of wet-dry cycling had a more pronounced effect on the modification of pore structure, which is particularly evident in MBC500. Both aging treatments obviously increased the thermal stability of WBC500 but reduced that of MBC300 and MBC400, which is mainly attributed to the differences in feedstock composition and oxidation degree. The two aging treatments significantly increased the R50 of WBC samples produced under different pyrolysis temperatures by 2.18%-5.80%, while only wet-dry cycling significantly increased the R50 of MBC500 by 2.31%. This study demonstrates that aged high-temperature straw biochars possess superior pore structure and carbon sequestration potential, which is significantly influenced by feedstock characteristics. |
|
|
|
