Drying Mechanism of Unutilized Cedar Logs as a Source of Heating Fuel

Abstract

-In Japan, small, forested areas are often destroyed because neglect due to a slump in wood prices and a shortage of labor. Promotion of forest maintenance along with the use of unused woody biomass is desired. In this study, the drying mechanism of Cedar (Cryptomeria japonica) logs destined to be used as heating was examined. The experimental results show that cedar samples reached the fiber saturation point after 4-5 months of drying on site. The water in the wood moved to the cut ends and evaporated because of the high pressure differences on the surfaces of the cut ends. The water content in the center of the logs was higher than that at the cut ends because closed pits in the vessel structures prevented the passage of water.

Water Flow Evaluation in Eucalyptus and Corymbia Short Logs

“…Zanuncio et al (2015), found a moisture content greater than 30% in Eucalyptus and Corymbia logs after 90 days of drying. The water evaporated depends on factors such as anatomy, density, and piece dimensions (Rezende et al, 2010;Monteiro et al, 2017;Hoang et al, 2015), as well as environmental factors such as temperature, relative humidity and wind speed (Rémond et al, 2013). Few studies have assessed water flow, above and below the fiber saturation point, or the behavior of the drying curve in Round wood.…”

Drying Methods of Unutilized Cedar Logs for Use as a Source of Heating Fuel

“…According to the results of previous drying experiments, heating and wind are important factors for cedar drying [4]. Short (0.5-m) logs dried more rapidly than long (4-m) logs, and cedar log samples (0.5-m logs) reached the fiber saturation point (FSP) after 4-5 months of drying on the study site, which had good ventilation and plenty of sunlight [4].…”

“…Because drying is essential to prepare the biomass fuel, conserving energy during drying can significantly decrease the overall operating costs [3]. Therefore, in terms of energy savings, a natural drying process, sun drying, is better than forced-drying methods for energy production in rural areas.According to the results of previous drying experiments, heating and wind are important factors for cedar drying [4]. Short (0.5-m) logs dried more rapidly than long (4-m) logs, and cedar log samples (0.5-m logs) reached the fiber saturation point (FSP) after 4-5 months of drying on the study site, which had good ventilation and plenty of sunlight [4].…”

“…Short (0.5-m) logs dried more rapidly than long (4-m) logs, and cedar log samples (0.5-m logs) reached the fiber saturation point (FSP) after 4-5 months of drying on the study site, which had good ventilation and plenty of sunlight [4]. When the cedar logs dried, the water in the wood moved to the Manuscript…”

“…In the cedar logs, most of the water was contained in the outer parts of the log, although water remained in the center of the logs because closed pits in the vessel structures prevented the passage of water [5].…”