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Volatile matter characterization of birch biochar produced under pressurized conditions

Abstract

The volatile matter (VM) content and composition of birch biochars produced at 320 °C under elevated pressure (0.1–11 MPa) and constant pressure or constant volume reactor conditions were characterized by thermogravimetry/mass spectrometry (TG/MS) and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). Some of the thermal properties of the biochars and the composition of the VMs varied as a function of the maximal pressure applied during carbonization. The samples prepared at higher pressures released more volatiles up to 320 °C, while the maximal rate of thermal decomposition at around 440 °C showed decreasing tendency with the carbonization pressure. In terms of VM composition, the most apparent effect was the significant increase of the amounts of apoallobetulins from biochars prepared at elevated pressures, which were formed by dehydration, ring closure and rearrangement from the betulin content of birch. The change in the ratio of the evolved guaiacol and 4-methylguaiacol as well as that of syringol and 4-methylsyringol as a function of the maximal pressure of carbonization indicated a modification of the lignin decomposition mechanism. © The Author(s) 2024.
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Category

Academic article

Language

English

Author(s)

  • Bence Babinszki
  • István Sándor Czirok
  • Robert L. Johnson
  • Zoltán Sebestyén
  • Emma Jakab
  • Liang Wang
  • Scott Turn
  • Øyvind Skreiberg
  • Zsuzsanna Czégény

Affiliation

  • SINTEF Energy Research / Termisk energi
  • Eötvös Loránd University
  • Hungarian Academy of Sciences
  • University of Hawaii at Manoa

Year

2024

Published in

Journal of Thermal Analysis and Calorimetry

ISSN

1388-6150

Volume

149

Page(s)

10915 - 10926

View this publication at Norwegian Research Information Repository