The role of efficient forest biomass logistics on optimisation of environmental sustainability of bioenergy

Abstract

Forest biomass is a crucial element in the energy system in many parts of the world, especially in Finland, and it is expected to play a similar, if not a more important, role in the near future as countries aim to replace fossil fuel with renewable energy systems. Since biomass is widely distributed and readily available, it is recognised as a potential renewable local alternative to fossil fuel, especially coal. However, the logistics of biomass extraction are one of the bottlenecks that hinder it from being used as a carbonneutral source of energy. The majority of optimisations in the sustainability of bioenergy have primarily been derived from economic incentives, but little attention has been paid to optimising the environmental sustainability of bioenergy. Even if there are cases of the optimisation of environmental sustainability, this may not have been the primary objective but rather an auxiliary objective to cost optimisation.

The main objective of this dissertation was to investigate the improvement potential of environmental sustainability in terms of reducing the greenhouse gas emissions from the bioenergy supply chain. The main objective was realised in two themes: the improvement of life cycle assessment in the bioenergy sector and improvement by means of efficient logistics regarding resource utilisation.

One of the sub-objectives of this dissertation was to introduce dynamic simulation to life cycle assessment in order to assess the greenhouse gas emissions from forest biomass logistics and investigate the role of temporal aspects of the supply chain on greenhouse gas emissions. The second sub-objective of the dissertation was to investigate the biomass supply chain in order to identify the best possible feedstock and supply chain route in terms of environmental performance in the delivery of forest biomass to consumers of different sizes. In addition to the route, the effect of biomass densification and transportation to the final destination was also studied.

The study shows that the introduction of dynamic simulation or agent-based modelling to the life cycle assessment of a forest biomass supply chain integrates the temporal aspects of a supply chain and helps refine the outcomes of the life cycle assessment with respect to local conditions. In addition, the introduction of the temporal aspects of the supply chain were found to be crucial at the decision-making level, which was critical in reducing greenhouse gas emissions. On the other hand, the climate-friendly route of a biomass chain depends on the size of the delivery or the size of user demand. Thus, when conducting life cycle assessments in the future, it is recommended that local conditions are taken into consideration in order to achieve precise and representative results.