Changes of major chemical components in larch wood through combined treatment of drying and heat treatment using superheated steam
- 162 Downloads
The effects of the combined treatment of drying and heat treatment using superheated steam (SHS) were studied relative to the changes of the major chemical components in larch wood. The green lumber was dried and heat-treated in SHS conditions of 250 °C and 0.5 MPa for 18 h, and the relative percentage contents of sugars, lignin, and extractives were investigated and compared with the relative percentage contents in the lumber heat-treated in hot air conditions of 250 °C and atmospheric pressure for 18 h. After both heat treatment methods, the relative percentage contents of xylan, mannan, galactan, and arabinan were greatly decreased, whereas that of the Klason lignin was increased, additionally that of glucan and extractives remained almost unchanged. Lignin may bind with furan compounds decomposed from hemicellulose following heat treatment, thus contributing to the increase in the apparent relative percentage contents of the Klason lignin. In addition, the condensate collected in the condenser after combined drying and heat treatment using SHS was investigated qualitatively and quantitatively by high-performance liquid chromatography (HPLC). A large amount of furfural and acetic acid decomposed from hemicellulose was detected and some sugar components composed of cellulose and hemicellulose were detected in the liquid condensate.
KeywordsCombined treatment Superheated steam Wood component Wood drying Wood heat treatment
This work was financially supported by the Forest Science and Technology Projects (S121315L010100) provided by Korea Forest Service and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planning (NRF-2015R1D1A1A01060308).
- 1.Militz H (2002) Heat treatment technologies in Europe: scientific background and technological state of art. In: Proceedings of conference on enhancing the durability of lumber and engineered wood products. Forest Products Society, Kissimmee, Orlando, Madison, USAGoogle Scholar
- 7.Yang Y, Zhan TY, Lu JX, Jiang JH (2015) Influence of thermo-vacuum treatment on colors and chemical compositions of alder birch wood. BioResources 10(4):7936–7945Google Scholar
- 8.Wang Z, Yang X, Sun B, Chai Y, Liu J, Cao J (2016) Effect of vacuum heat treatment on the chemical composition of larch wood. BioResources 11(3):5743–5750Google Scholar
- 11.Esteves BM, Pereira HM (2009) Wood modification by heat treatment: a review. BioResources 4(1):370–404Google Scholar
- 14.Kim OS, Lee DH, Chun WP (2008) Eco-friendly drying technology using superheated steam. Korean Chem Eng Res 46(2):258–273Google Scholar
- 16.Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D (2006) Determination of sugars, byproducts, and degradation products in liquid fraction process samples. National Renewable Energy Laboratory, Golden, pp 3–9Google Scholar
- 21.Weiland JJ, Guyonnet R (2003) Study of chemical modifications and fungi degradation of thermally modified wood using DRIFT spectroscopy. Holz Roh Werkst 61(3):216–220Google Scholar