Exploring the environmentally best use of short-rotation Eucalyptus exported from Brazil to Norway for Energy using Life Cycle Assessment

Abstract

Biomass energy demand is increasing due to the potential of climate change mitigation in substitution of fossil fuels. There is a need investigate the environmental profile and compare different options for the biomass. All the way from growing, through upgrade, transport, and final energy conversion in a holistic manner. In this way, the deployment of innovative supply chain technologies can be guided, to maximize the effect and avoid problem- shifting.

An attributive and comparative life cycle assessment is used for evaluating the systems, while mass and energy balances were central in the model development. The ecoinvent 3.1 database was used as the main inventory. In addition to global warming potential, the impact categories of acidification, eutrophication and photochemical oxidant formation potentials investigated. The indicators used for calculations were CML-IA baseline 3.03 midpoint categories, for both energetic and mass- based functional units

Results were presented for four energy services that presented uses in form of heat, electricity as well as Fischer-Tropsch diesel production. The substitution of fossil fuels was looked at in detail. Results for impacts specific to storage of carbon and driving on biodiesel produced was included. The model included two energy carriers, pellets and torrefied pellets. Additional model options were explored in a sensitivity analysis.

A Combined heat and power plant with carbon capture and storage is advised for its negative emissions of greenhouse gases, and low impacts in other categories. However, the incurred energy penalty in addition to cost can prove to be barriers. Pellets had lowest global warming potential, while torrefied pellets had lower impacts in the other categories investigated. Future scenarios show the opportunities for substantial amounts of energy production without incurring high land use change impacts.