Analysis of the truck transportation of eucalyptus logging residues to Portuguese power plants

Abstract

ABSTRACTTransportation of logging residues (LR) from eucalyptus plantations to regional bioenergy plants may incur high unit costs that restrict their removal from the forest, aggravating fire risk. This paper compares the cost of truck transportation of eucalyptus LR in Portugal, for alternative operational plans, aiming to improve biomass supply efficiency and to promote cost reduction. The following factors were analyzed: (1) the relation between truck configuration, biomass physical characteristics and payload, and (2) the relation between the transportation cost of a unit of mass and of a unit of heat and the biomass moisture content (MC). Direct transport of LR before comminution, with a 70 m3 semi-trailer, achieves 65% of the maximum payload, for the mean MC of 42%, and the cost represents46% of the payload value. Direct transport of shredded biomass with a 77 m3 semi-trailer achieves 76% of the maximum payload (mean MC of 43%) and the cost represents a fraction up to 62% of the payload value. Using a 90 m3 semi-trailer the payload increases to 80% of the maximum and the transportation cost decreases to less than 42% of the biomass value. For small scale logging operations a two echelon supply system promotes efficiency, allowing centralized shredding after additional natural drying that improves the quality of fuel, and involves a transportation cost of 10€ Mg−1 (MC of 43%) for a total distance of 33 km.