WOOD RESEARCH Volume 61, Number 2, 2016
Cosmin Spirchez, Aurel Lunguleasa, and Tatiana Griu (Dobrev)

Testing model for assessment of lignocellulose-based pellets

This paper aims to find a simple testing and assessment model applicable to lignocellulose-based pellets, for the purpose of making the appropriate selection from the market. It is analysed the main tests of pellets, as density, caloric value and shear strength, for three different types of pellets bought from the competitive market. Afterwards is detailed the method of operation for the shear strength due to its not so frequent use. Finally, based on the tested values and limits required by the existing standards, it is determined a simple method for assessing for pellets, pointing out the closeness of each tested value to the standard limits.

WOOD RESEARCH Volume 62, Number 3, 2017
Jarno Föhr, Tapio Ranta, Jemina Suikki, and Hanne Soininen

Manufacturing of torrefied pellets without a binder from different raw wood materials in the pilot plant

This paper concentrated on the production of torrefied without an additional binder from different raw wood materials. The torrefaction and pelletizing was carried out at the Torrec Ltd. pilot plant located in Eastern Finland and its effective capacity was 2,200 tonnes per year. Six different woodchips lots were tested in the pilot runs. The test was to identify whether the pelletizing process requires an additional sealant as a binder. The pelletizing process only exploited condensation water that came about from the torrefaction process. The temperature control range and the holding time were varied, regarding the driving parameters. Finally, quality factors were analysed from torrefied pellets and its raw wood materials after each pilot run. The maximum temperature of the reactor, 260°C, was perhaps too low to manufacture pellets of high energy content. Based on the study, the pelletizing process will not require an additional binder in the future.

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.