Pyrolysis of sucrose-derived hydrochar

Autor: Michael Tiemann, Elise Diestelhorst, Klaus Sattler, Jan Biedinger, Wiebke Hachmann, Bruno Hüsgen, Günter Reiss, Natalie Frese, Michael Westphal, Bennet Brockhagen, Christian Weinberger, Claudia Schmidt, Martin Wortmann, Waldemar Keil, Yanjing Zhao
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Popis: The electrochemical properties of carbonaceous materials produced by hydrothermal carbonization, referred to as hydrochar, can be substantially improved by post-carbonization via pyrolysis. Although these materials have been widely studied for a variety of applications, the mechanisms underlying the pyrolysis are yet poorly understood. This study provides a comprehensive temperature-resolved characterization of the chemical composition, morphology and crystallinity of sucrose-derived hydrochar during pyrolysis. Thermogravimetric analysis, differential scanning calorimetry, and elemental analysis have shown that the dry hydrochar loses about 41% of its dry mass due to the exothermic disintegration of oxygen-containing groups until the carbonization is completed at about 850 degrees C with a total carbon yield of 93%. The carbonization and aromatization of the initially furanic and keto-aliphatic structure were analyzed by 13C solid-state nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The transition from an amorphous to a nanocrystalline graphitic structure was analyzed using X-ray diffraction and Raman spectroscopy. The pore formation mechanism was examined by helium ion microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The results indicate the formation of oxygen-rich nanoclusters up to 700 degrees C, which decompose up to 750 degrees C leaving behind equally sized pores, resulting in a surface area of up to 480 m2/g.
Databáze: OpenAIRE
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