Water vapour sorption properties of thermally modified and pressurised hot-water-extracted wood powder

Holzforschung ◽  
2019 ◽  
Vol 73 (12) ◽  
pp. 1059-1068 ◽  
Author(s):  
Kristiina Lillqvist ◽  
Susanna Källbom ◽  
Michael Altgen ◽  
Tiina Belt ◽  
Lauri Rautkari
Keyword(s):  
Water Vapour ◽  
Thermal Modification ◽  
Hot Water ◽  
Water Extraction ◽  
Hydroxyl Group ◽  
Wood Powder ◽  
Sorption Behaviour ◽  
Hot Water Extraction ◽  
Water Vapour Sorption ◽  
Vapour Sorption

Abstract The objective of the study was to investigate the water vapour sorption behaviour of thermally modified (TM) wood powder, e.g. ground wood prepared from waste streams of TM solid wood, and wood powder that was extracted in pressurised hot water. Solid spruce wood was TM in steam conditions (210°C for 3 h), milled and hot-water-extracted (HWE) at elevated pressure (140°C for 1 h). The results evidence that the hot-water extraction reduced the water sorption and the accessible hydroxyl group concentration by the removal of amorphous carbohydrates. In contrast, the enhanced cross-linking of the cell wall matrix and the annealing of amorphous matrix polymers during thermal modification reduced the sorption behaviour of wood additionally, without further reducing the hydroxyl accessibility. These additional effects of thermal modification were at least partially cancelled by hot-water extraction. The results bring novel insights into the mechanisms that reduce the water vapour sorption of wood by compositional and structural changes induced by heating.

The water vapour sorption behaviour of acetylated birch wood: how acetylation affects the sorption isotherm and accessible hydroxyl content

2013 ◽  
Vol 49 (5) ◽  
pp. 2362-2371 ◽  
Author(s):  
Carmen-Mihaela Popescu ◽  
Callum A. S. Hill ◽  
Simon Curling ◽  
Graham Ormondroyd ◽  
Yanjun Xie
Keyword(s):  
Water Vapour ◽  
Sorption Isotherm ◽  
Birch Wood ◽  
Hydroxyl Content ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption

Analysis of the water vapour sorption behaviour of Sitka spruce [Picea sitchensis (Bongard) Carr.] based on the parallel exponential kinetics model

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Callum A.S. Hill ◽  
Andrew Norton ◽  
Gary Newman
Keyword(s):  
Water Vapour ◽  
Sitka Spruce ◽  
Sorption Kinetics ◽  
Picea Sitchensis ◽  
Sorption Kinetic ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Different Temperatures

Abstract The water vapour sorption behaviour of Sitka spruce was analysed based on the parallel exponential kinetics (PEK) model. The PEK model deconvolutes the sorption kinetics curve into two exponential kinetics processes (fast and slow) which have characteristic times and moisture contents associated with them. The sorption kinetics was examined at different temperatures enabling the determination of activation energies for the sorption kinetic processes throughout the hygroscopic range (from 5% to 95% relative humidities). The physical interpretation of the PEK model is also discussed.

Investigating water vapour sorption kinetics of aluminium MOFs by powder X-ray diffraction

CrystEngComm ◽  
2019 ◽  
Vol 21 (15) ◽  
pp. 2551-2558 ◽  
Author(s):  
Dominik Fröhlich ◽  
Philipp Hügenell ◽  
Helge Reinsch
Keyword(s):  
Water Vapour ◽  
Water Sorption ◽  
Sorption Kinetics ◽  
X Ray Diffraction ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
X Ray ◽  
Vapour Sorption ◽  
Kinetics Of

The water sorption behaviour of aluminium MOF CAU-10 and CAU-15-Cit was followed by in situ powder X-ray diffraction.

Thermodynamic analysis of water vapour sorption behaviour of juvenile and mature wood of Abies alba Mill.

2015 ◽  
Vol 50 (22) ◽  
pp. 7282-7292 ◽  
Author(s):  
Cristina Simón ◽  
Luis García Esteban ◽  
Paloma de Palacios ◽  
Francisco García Fernández ◽  
Raquel Martín-Sampedro ◽  
...  
Keyword(s):  
Water Vapour ◽  
Thermodynamic Analysis ◽  
Abies Alba ◽  
Mature Wood ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption

Water vapour sorption behaviour of thermally modified wood

2013 ◽  
Vol 4 (3) ◽  
pp. 191-196 ◽  
Author(s):  
C A S Hill ◽  
J Ramsay ◽  
K Laine ◽  
L Rautkari ◽  
M Hughes
Keyword(s):  
Water Vapour ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Thermally Modified Wood ◽  
Modified Wood

The dynamic water vapour sorption behaviour of natural fibres and kinetic analysis using the parallel exponential kinetics model

2010 ◽  
Vol 46 (2) ◽  
pp. 479-489 ◽  
Author(s):  
Yanjun Xie ◽  
Callum A. S. Hill ◽  
Zaihan Jalaludin ◽  
Simon F. Curling ◽  
Rajesh D. Anandjiwala ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Water Vapour ◽  
Natural Fibres ◽  
Kinetics Model ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption

Water vapour sorption of wood modified by acetylation and formalisation – analysed by a sorption kinetics model and thermodynamic considerations

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 203-213 ◽  
Author(s):  
Sarah Himmel ◽  
Carsten Mai
Keyword(s):  
Cell Wall ◽  
Water Vapour ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Constant Factor ◽  
Sorption Data ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Surface Work

Abstract The water vapour sorption data of untreated (Wuntr), acetylated (Wac) and formaldehyde-treated (WFA) Scots pine (Pinus sylvestris L.) sapwood were analysed in terms of their sorption kinetics and were transformed into excess surface work (ESW) isotherms. The sorption kinetics were studied by fitting the non-linear parallel exponential kinetics (PEK) model to the experimental data in which the sorption kinetics curve is composed of two processes (fast and slow components). Wac and WFA showed evident differences in their sorption kinetics and their thermodynamic sorption behaviour. In contrast to acetylation, formalisation influenced both the extent of the slow sorption process and the shape of its pseudoisotherm. For Wuntr and Wac, it appears that some water associated with the slow process is adsorbed at sites for fast sorption newly generated upon swelling (previously postulated as extra water) and subsequently desorbed by the fast process. For WFA, the formation of extra water hardly occurs. ESW was reduced through acetylation with a constant factor over the whole hydroscopic range, whereas the ESW of WFA was reduced only after reaching the monolayer capacity compared to its control. The sorption behaviour of Wac was solely determined by cell wall bulking, whereas that of WFA was governed by the increased matrix stiffness due to cross-linking of the cell wall polymers.

Water vapour sorption behaviour of original and defatted wheat gluten

1996 ◽  
Vol 31 (6) ◽  
pp. 519-526 ◽  
Author(s):  
Gerard I.W. De Jong ◽  
Cornelius Van den Berg ◽  
Anita J. Kokelaar
Keyword(s):  
Water Vapour ◽  
Wheat Gluten ◽  
Sorption Behaviour ◽  
Water Vapour Sorption ◽  
Vapour Sorption
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