WOOD RESEARCH Volume 61, Number 2, 2016
Oliver-Villanueva José-Vicente, García-Andújar Enrique, and Gascón-Garrido Patricia

Analysis of durability and dimensional stability of hydrothermal carbonized wooden pellets

Hydrothermal carbonization (HTC) is a chemical pretreatment of wood waste for convert it in biochar by the application of high temperatures and pressures in a reaction time that do not exceed 10 hours. One of the main applications of the HTC biochar is as pellets. In this research durability against fungal decay and dimensional stability associated with relative humidity changes of HTC pellets were analyzed and evaluated. A comparison of these properties between HTC pellets and wooden EN+ pellets has been carried out. HTC pellets are significantly more durable against fungal attack, more dimensionally stable against relative humidity changes and denser than wood pellets, which confers better properties for logistics processes like storage and transport.

WOOD RESEARCH Volume 62, Number 6, 2017
Christian Brischke, Antje Gellerich, HOLGER MILITZ, and Michael Starck

Performance of coated and uncoated horizontal lap-joint members during 20 years of outdoor exposure

Horizontal lap-joint trials were set up using eleven different wood species representing a wide range of natural durability. Coated and uncoated lap-joint specimens as well as non-jointed reference specimens were exposed for up to 20 years and evaluated with respect to decay, formation of cracks and performance of the coating. The tropical wood species Tatajuba, Cedrorana, and Dark Red Meranti performed still very well and also some Europe-grown softwoods with coloured heardwood were still in good shape. The lap-joint set up turned out to be a method that can be used also for determining the durability and performance of untreated naturally durable wood, but suffered from several drawbacks such as time-consuming and costly specimen preparation, difficult to detect onset of decay, and generally long exposure times needed for a reliable durability assessment. Cracks were often the starting point for internal decay, but did not exclusively occur in the lap area.

WOOD RESEARCH Volume 62, Number 5, 2017
Osman Emre Özkan, Ali Temiz, and Hasan Vurdu

Effects of heat treatment on Turkish fir wood properties

In this study, Turkish fir wood (Abies nordmanniana subsp. bornmulleriana) was subjected to two heat treatment process with varying temperatures (150, 180 and 200°C) and durations (2, 4 and 6 h). Some properties of the heat treated Turkish fir wood; mass change, water absorption, volumetric swelling, bending strength, modulus of elasticity (MOE), compression strength parallel to grain, color change and surface roughness have been tested and evaluated by statistical analysis. Consequently, volumetric swelling and water absorption values of the heat treated wood samples reducing. Bending strength, modulus of elasticity and compression strength parallel to grain values were decreased by heat treatment at high temperatures. Additionally, color change and surface roughness values of heat treated wood decreased with weathering compared to those of control samples.

WOOD RESEARCH Volume 64, Number 2, 2019
Seung-Won Oh, In Yang, Dae Hak Park, Soo Min Lee, and Byoung Jun Ahn

Lignin and sugars contents of Liriodendron tulipifera L. sawdust immersed in acidic/alkaline solutions and the fuel characteristics of wood pellets fabricated with the sawdust

This study was conducted to determine the lignin and sugars contents of yellow poplar (YP) sawdust immersed in tap water (TW), sulfuric acid (AC) and sodium hydroxide (AK) solutions. Klason lignin content of TW- and AC-immersed YP sawdust was higher than that of AK-immersed YP sawdust. Glucose showed the highest content among sugars extracted from YP sawdust. Durability of non-immersed YP pellets was the highest, followed by TW-, AC- and AK-immersed YP pellets. YP pellets became more durable by increasing the Klason lignin and xylose contents as well as decreasing the glucose content. Through microscopic observations and quantitative analysis of lignin distribution, lignin content on the surface of non-immersed YP pellets was higher than that of TW-, AC- and AK-immersed YP pellets. In conclusion, there are significant correlations between lignin or sugars contents of YP sawdust and fuel characteristics of wood pellets fabricated with the YP sawdust.