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Numerical analysis of temperature profiles during thermal modification of wood: chemical reactions and experimental verification

  • Miroslav Trcala and Petr Čermák EMAIL logo
Published/Copyright: August 22, 2014
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Abstract

Numerical analysis of temperature profiles during thermal modification of wood was carried out. The numerical solution – based on finite element analysis, FEA – of the 3D problem of transient nonlinear heat transfer model is presented for wood as a typical anisotropic material. The numerical model was enhanced for describing chemical reactions of cellulose, hemicelluloses and lignin (pyrolysis model), which takes into account the exothermic reactions as an internal source of heat energy. Experimental as well as theoretical process schedules were applied and the influence of sample dimensions (sample geometry) and wood species was studied. The influence of wood species was negligible on heating time to reach the highest temperature, i.e., the temperature differences were about 2°C during the drying phase. A expected, the sample size played an important role in the heating duration and in terms of the exothermic reactions of wood. The experimental and numerical data are generally in good agreement. The numerical error increased in the range of higher temperatures. The results can be improved by consideration of wood species (mass of wood compounds) and boundary conditions in the pyrolysis model, thus, better insight into details of thermal modification of wood could be reached.


Corresponding author: Petr Čermák, Faculty of Forestry and Wood Technology, Department of Wood Science, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic, Phone: +420 545 134 550, e-mail:

Acknowledgments

This work was supported by OP Education for Competitiveness (European Social Fund and the state budget of the Czech Republic) CZ.1.07/2.3.00/30.0017 Postdocs in Biological Sciences at MENDELU; CZ.1.07/2.3.00/30.0031 Postdocs in Technical and Economical Sciences at MENDELU and project “The Establishment of an International Research Team for the Development of New Wood-based Materials” reg. no. CZ.1.07/2.3.00/20.0269.

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Received: 2014-4-13
Accepted: 2014-7-23
Published Online: 2014-8-22
Published in Print: 2015-4-1

©2015 by De Gruyter

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