In hot water extraction (HWE) wood is treated in high-temperature water (above 100 °C) that is kept in liquid phase with elevated pressure. Previous studies on HWE-treatment have focused on wood powders, particles or chips and its potential as a pretreatment method for lignocellulosic materials prior to pulping and for extracting wood components for the conversion into value added products (Ragauskas et al. 2006; Amidon and Liu, 2007). HWE may potentially be applied to larger wood products (e.g. sawn timber) as well, which can then be utilized as modified wood. However, previous studies have demonstrated that the wood chip size affects the extraction rate of hemicelluloses significantly (Krogell et al. (2013) and Li et al. (2013)). Our research investigates how this phenomenon applies to larger samples of solid wood. Therefore, Scots pine sapwood samples of different sizes were hot water extracted at different temperature-time environments and the changes in chemical composition of the solid residue and the process water were analyzed.
Keywords: hot water extraction (HWE), wood samples, chemical composition
Authors
Suvi Kyyrö
Aalto University, Department of Bioproducts and Biosystems
Michael Altgen
Lauri Rautkari
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