Fuel quality changes in full tree logging residue during storage in roadside slash piles in Northwestern Ontario

The procurement of logging residue for energy production can be uneconomical due to high moisture content and low gross calorific value. High moisture content in biomass lowers the energy density and transportation becomes less efficient. Logging residue, from full tree logging operations stored in roadside beehive and windrow piles, were examined to determine the effect of storage method and duration on fuel quality in northwestern Ontario, Canada. The fuel attributes assessed were moisture content, gross calorific value and ash content. Windrows displayed lower moisture content than beehives. Softwoods generally displayed lower moisture content and higher gross calorific values than hardwoods. Smaller diameter stems displayed higher gross calorific value and ash content than larger diameter stems. The moisture content (green basis) reduced from a green state to 15.1% after two years of storage in roadside slash piles, whereas gross calorific value and ash content did not change significantly with storage time. The gross calorific values ranged from 19.5 to 23.1 MJ kg−1 and the ash content ranged from 0.4% to 8.4% for all species, components and storage years. The study demonstrates that the storage regime plays a significant role on the fuel quality of logging residue. Proper storage and drying techniques improve the fuel quality and net energy yield from logging residue biomass, thereby leading to an overall cost reduction of the biomass feedstock.

► Feasibility of using full tree logging residues for bioenergy investigated.
► Effect of storage duration, pile type, species and diameter effect on fuel quality.
► Fuel qualities measured were gross calorific value, ash and moisture content.
► Moisture reduced during storage, no effect on gross calorific value or ash content.
► Field storage for certain period can improve energy yield and transportation cost.