TY - JOUR
T1 - Demethanation Trend of Hydrochar Induced by Organic Solvent Washing and Its Influence on Hydrochar Activation
AU - Zhu, Xiangdong
AU - Liu, Yuchen
AU - Qian, Feng
AU - Lei, Zhongfang
AU - Zhang, Zhenya
AU - Zhang, Shicheng
AU - Chen, Jianmin
AU - Ren, Zhiyong
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/9/19
Y1 - 2017/9/19
N2 - Hydrochar derived from hydrothermal carbonization (HTC) has been recognized as a promising carbonaceous material for environmental remediation. Organic solvents are widely used to extract bio-oil from hydrochar after HTC, but the effects of solvent extraction on hydrochar characteristics have not been investigated. This study comprehensively analyzed the effects of different washing times and solvent types on the hydrochar properties. The results indicate that the mass loss of hydrochar by tetrahydrofuran washing occurred mainly in the first 90 min, and the loss ratios of elements followed a descending order of H > C > O, resulting in a decrease in the H/C atomic ratio and an increase in the O/C atomic ratio. The use of various solvents for washing brought about hydrochar loss ratios in a descending order of petroleum ether < dichloromethane < acetone < tetrahydrofuran. The results from the Van Krevelen diagram and Fourier transform infrared, 13C nuclear magnetic resonance, and X-ray photoelectron spectroscopies further confirmed that demethanation controlled this washing process. Most importantly, the surface area of hydrochar increased after bio-oil removal via washing, which promoted the surface area development for hydrochar-derived magnetic carbon composites, but to some extent decreased the microporosity. Additionally, hydrochar washing by organic solvent has important implications for the global carbon cycle and its remediation application.
AB - Hydrochar derived from hydrothermal carbonization (HTC) has been recognized as a promising carbonaceous material for environmental remediation. Organic solvents are widely used to extract bio-oil from hydrochar after HTC, but the effects of solvent extraction on hydrochar characteristics have not been investigated. This study comprehensively analyzed the effects of different washing times and solvent types on the hydrochar properties. The results indicate that the mass loss of hydrochar by tetrahydrofuran washing occurred mainly in the first 90 min, and the loss ratios of elements followed a descending order of H > C > O, resulting in a decrease in the H/C atomic ratio and an increase in the O/C atomic ratio. The use of various solvents for washing brought about hydrochar loss ratios in a descending order of petroleum ether < dichloromethane < acetone < tetrahydrofuran. The results from the Van Krevelen diagram and Fourier transform infrared, 13C nuclear magnetic resonance, and X-ray photoelectron spectroscopies further confirmed that demethanation controlled this washing process. Most importantly, the surface area of hydrochar increased after bio-oil removal via washing, which promoted the surface area development for hydrochar-derived magnetic carbon composites, but to some extent decreased the microporosity. Additionally, hydrochar washing by organic solvent has important implications for the global carbon cycle and its remediation application.
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U2 - 10.1021/acs.est.6b06594
DO - 10.1021/acs.est.6b06594
M3 - Article
C2 - 28823154
AN - SCOPUS:85029688261
SN - 0013-936X
VL - 51
SP - 10756
EP - 10764
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 18
ER -