Sorption properties of torrefied wood and charcoal

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • University of Helsinki
  • University of Jyväskylä


Pre-treating biomass by torrefaction is assumed to improve the material's storage properties because of reducing hydrophilicity. In order to assess the effect of sorption on storage properties, the adsorption of water vapour and capillary absorption of liquid water in torrefied and charred spruce and birch were studied. In addition, the chemical changes were evaluated through Fourier Transform Infrared (FT-IR) spectroscopy. Adsorption decreased notably as severity of treatment increased, as was expected due to degradation of the wood constituents, namely hemicelluloses and amorphous cellulose. Capillary absorption increased with increasing severity in spruce samples while birch showed less change, but the maximum volume for absorption increased with both species. FT-IR results showed an increase in aromatic structures that have a role in forming crystalline structures, possibly leading to increased porosity. Torrefied and charred material should not be stored outside, as liquid water absorbs readily into the material, turning it into a suitable substrate for fungi.


Original languageEnglish
Pages (from-to)170-178
Number of pages9
JournalWood Material Science and Engineering
Issue number3
Publication statusPublished - 2014
MoE publication typeA1 Journal article-refereed

    Research areas

  • Torrefaction, Wood, Charcoal, Sorption, Moisture

ID: 7048919