Forest residues are being considered as potential feedstock for a biomass-to-ethanol facility in Minnesota (USA), using residues from major wood-producing counties in Minnesota, Wisconsin, and Michigan. Results indicate that marginal residue costs delivered to a conversion facility would be $56-80/Mg for a small (95-189 MM liters) plant, and about $81/Mg for a larger (379 MM liters) plant. Output beyond these levels would involve substitution of lower-cost market pulpwood as the plant feedstock because of relatively high marginal residue costs. Sensitivity analysis indicates that either a 20-percent increase or decrease in the quantity of available residue would impact marginal cost estimates by no more than $15/Mg. |