The introduction of advanced biofuels – A consequential assessment of environmental and climate aspects in the context of European legislation

Abstract

In face of observed and predicted adverse effects of a changing climate, measures are currently implemented aiming at reducing (anthropogenic) greenhouse gas (GHG) emissions. To this end, legislation was implemented worldwide targeting a reduction in the use of fossil-derived energy in the transportation and energy sectors. Within the EU, the Renewable Energy Directive (RED) was implemented in 2008 to facilitate the introduction of alternative fuels. Supported by the directive, biofuels mainly made from food and feed crops, so called first generation (1G) biofuels, entered the market. The RED II, enacted in 2018, capped the contribution of 1G biofuels to the overall European renewable energy targets. Instead, the RED II promotes the introduction of biofuels made from agricultural residues and wastes, so called advanced or second generation (2G) biofuels. Novel biorefinery concepts producing such fuels bear the potential to yield numerous other products aside from fuels. Thereby, these concepts could present an integral part of a non-fossil-based economy. Their introduction and the cessation of existing 1G biofuel production eventually triggers changes in other markets to which products of these concepts are provided. The thesis provides a deeper understanding of such changes in GHG emissions arising from the introduction of novel biorefinery concepts and the implications of methodological choices made to evaluate these changes. The evaluation shows that the introduction of 2G concepts can lead to a reduction of GHG emissions. Aside from the displacement of fossil fuels, the provision of other products plays an important role due to potentially occurring substitution effects. The inclusion of these substitution effects show that their magnitude can exceed potential emission reduction occurring within the production chain and due to the use of the fuel. The results shows a high variability of potential changes in GHG emissions depending on where feedstock is sourced and to which markets products are provided and that temporal aspects of GHG emissions should be taken into account. The displacement of existing 1G biofuel provision by 2G concepts can potentially result in a net increase in emissions under certain circumstances. Such effects could occur if co-products currently provided by 1G concepts are no longer provided and need to be supplied by other means that potentially entail high GHG emissions. The results show that the GHG emission evaluation methodology provided by the RED II is incapable of reflecting occurring changes in emissions arising from changes within the biofuel sector. It is concluded that the focus of present legislation, i.e. the RED II, targeting single sectors only might hinder an effective reduction in GHG emissions due to the risk of burden shifting. Furthermore, the RED II’s strong focus on concepts providing energy and fuels might impede the introduction of integrated biorefineries yielding multiple other products than fuel and energy carriers. It is therefore recommended to extend present legislation in order to facilitate a more effective reduction in GHG emissions and to avoid burden shifting.