The Effects of Local Biomass Availability and Possibilities for Truck and Train Transportation on the Greenhouse Gas Emissions of a Small-Diameter Energy Wood Supply Chain

Abstract

The work presents a method of assessing the greenhouse gas (GHG) emissions of forest-based biomass supply chains on a site-specific level. The method includes biomass availability and transportation network assessments based on geographical information system data, and GHG emission assessment based on life-cycle assessment methods. The GHG assessment takes into account distances traveled on the various types of road by trucks. Two case studies are presented, with 720 TJ year−1 of small-diameter energy wood chips delivered to two locations in Finland: Mikkeli and Rovaniemi. In the case studies, possibilities for train transportation from distant supply areas were included. Regarding railway transportation, it was assumed that the end-points have direct railway connections. The case study results show that if direct truck transportation around the plants were supplemented with one trainload per week (230 TJ year−1) from suitably located railway loading points, GHG emission savings of 8 % could be achieved in both cases. The most GHG-efficient supply chains around the railway loading points were found to be based on transportation of loose trees to the loading spots. Because of better biomass availability and better roads, the emissions of the least GHG-emitting supply chain were 9 % lower in Mikkeli’s case than for Rovaniemi. The results indicate that site-specific biomass availability and transportation possibilities should be taken into account in assessment of the GHG emissions of a particular biomass supply chain. Also, if suitable conditions exist, railway transportation offers potential for reduced supply-chain GHG emissions.