Small-scale wood pellet producers often use a trial-and-error approach for determining adequate blending of available wood processing residues and pelletizing parameters. Developing general guidelines for optimizing wood pellet quality and meeting market standards would facilitate their market entry and profitability. Four types of hardwood residues, including green wood chips, dry shavings, and solid and engineered wood sawdust, were investigated to determine the optimum blends of feedstocks and pelletizing conditions to produce pellets with low friction force, high density and high mechanical strength. The feedstock properties reported in this study included particle size distribution, wood moisture content, bulk density, ash content, calorific values, hemicelluloses, lignin, cellulose, extractives, ash major and minor elements, and carbon, nitrogen, and sulfur. All residues tested could potentially be used for wood pellet production. However, high concentrations of metals, such as aluminum, could restrict their use for accessing markets for high-quality pellets. Feedstock moisture content and composition (controlled by the proportions of the various residue sources within blends) were the most important parameters that determined pellet quality, with pelletizing process parameters having less overall influence. Residue blends with a moisture content of 9%-13.5% (dry basis), composed of 25%-50% of sawdust generated by sawing of wood pieces and a portion of green chips generated by trimming of green wood, when combined with a compressive force of 2000 N or more during pelletizing, provided optimum results in terms of minimizing friction and increasing pellet density and mechanical strength. Developing formal relationships between the type of process that generates residues, the properties of residues hence generated, and the quality of wood pellets can contribute to optimize pellet production methods. deliver 120 exajoules (EJ) (50% of the world's energy needs) for heat, 15% EJ for transport, and 18 EJ (7%) for electricity [2,3].In temperate and boreal countries, forest biomass, in the form of wood chips and wood pellets, is used for power and/or heat production, with boilers of various capacities ranging from small community heating systems up to large power plants. Relative to wood chips, pellets have a higher energy density per unit of mass and volume, are easier to store and handle in large volumes, and show less heterogeneity in physical and chemical properties [4,5]. Whereas wood chips are often preferred for small-scale facilities for which feedstock can be sourced over short distances, wood pellets can be used in larger-scale installations and/or for transport and trade over long distances (e.g., transatlantic and transpacific trade) [6].In the province of Quebec (Canada), the primary and secondary wood processing sectors generate large amounts of wood residues annually. In 2013, the hardwood flooring industry generated about 400 × 10 3 metric tons of wood residues including sawdust, wood chips, and wood...
