Field-drying logging residues for use as an industrial fuel

Abstract

Faced with rising energy costs, forest industries have been seeking ways to better utilize wood residues for fueling plant operations. A major problem with this fuel is its high moisture content when produced from green trees, which seriously reduces the heat of combustion. In light of this a study was conducted to determine the moisture content, drying rates, and fuel value of logging residues produced in three of Virginia's physiographic zones. Samples were taken from the residues at intervals over a two year period to monitor moisture and fuel value changes under a variety of environmental conditions. It was concluded that these residues (tree tops, branches, and cull trees) had become dry enough for fuel use after as little as one or two months of field-drying in a suitable location. In other situations, drying rates were too slow to consider the method a viable alternative. The main factors affecting the field drying process were found to be size of the residue, geographic location, and season.