Comparison of Drying Rates of Ground Western Red Cedar with Hemlock, Birch, Aspen, and Spruce/Pine/Douglas Fir

Abstract

HighlightsWRC and SPF generate the largest fraction of small particles (<0.5 mm) during grinding.WRC is slightly low in total sugars, high in lignin content (should make durable pellets), and high in extractives.Aspen followed by WRC has the highest drying rate and the shortest drying time amongst all samples.Smoke point is similar for all wood species and is ~180°C.Abstract.Western red cedar () and yellow cedar () are among the most valuable tree species in British Columbia. These species make up about 20% of the coastal timber volumes and mostly are used as lumber for construction applications where resistance against decay is important. The use of red cedar for pellet production has been uncertain because it appears cedar has a tendency to cause fires in rotary drum dryers when compared to other wood species like pine and Douglas Fir. The scientific reasons for the reported fire incident are not known. The goal of the current study is to investigate the drying rates and the range of combustion temperature for western red cedar and five other wood species that either are used or have potential to be used for palletization purposes in British Columbia. Red cedar and Spruce/Pine/Fir (SPF) generate the largest fraction of small particles (<0.5 mm) during grinding. Almost 93% of cedar particles are less than 1 mm. Cedar has a high carbon content and low oxygen content that causes cedar has higher calorific value than other species. During a drying process, aspen following by cedar has the highest drying rate and the shortest drying time amongst all samples. The smoke point is similar for all wood species and is ~180°C. So, in the case of high temperature drying (beyond the smoke point) of mixed feedstocks with similar size, red cedar dries faster and starts smoking at dryer output. Keywords: Chemical composition, Drying rate, Physical characterization, Smoke point, Western red cedar.