Long-term sustainability assessment of fossil-free fuel production concepts

The number of possible combinations of feedstock, feedstock pre-treatment, and downstream processes for large-scale production of different types of biofuel is substantial. Different productionroutes will obviously perform very differently with respect to profitability and carbon footprint. Furthermore, large-scale production of biofuels requires substantial strategic investment decisions, requiring a prospective assessment approach. Evaluation of future biorefinery concepts using today’s conditions can be heavily misleading, and it is therefore essential that possible future conditions and related uncertainties are taken into account. This work explores methodological choices and assumptions of Techno-Economic Assessment (TEA) and Life Cycle Assessment (LCA) methods and tools used in four research groups in Sweden for assessing the long-term economic and carbon footprint performance of large future biorefinery concepts.The report presents an in-depth analysis of the methods and tools used in the participating groups, and clearly establishes the need for increased collaboration and data exchange between biorefinery process developers, value chain modellers, TEA and LCA practitioners and large-scale energy and material system modellers. The work presented constitutes a significant step in this direction by clearly establishing the potential strength of prospective TEA and LCA in combination with scenarios describing possible future developments of the background energy system in which future biofuel production systems will operate. The report presents new results for one of the bio-methane production routes investigated in the “METDRIV - Methane as vehicle fuel – a well-to-wheel analysis” study conducted by B\uf6rjesson et al (2016) with respect to energy, greenhouse gas emissions (GHG) and cost performance. The input data used in the original METDRIV study were based on average prices/costs and GHG emission factors valid at the time of the study. In this work, new input data is adopted that reflects possible energy market development pathways generated by the ENPAC energy market scenario tool developed at Chalmers. For the selected production route, the results show that assumptions for costs and greenhouse gas emission factors related to increased use of biomass are of utmost significance, and that there is a clear need for further work in this area.Finally, the report discusses some of the major challenges that remain to be addressed when developing scenarios for the “background” energy system to be used in prospective assessment studies of future biorefinery concepts:Handling the possible consequences of future limited biomass availability on biomass feedstock prices and emission factors.Handling future development of the electric power grid, as well as other large-scale grid energy systems (e.g. district heating) in a carbon-constrained worldIntegration issues: large-scale biorefinery concepts are likely to be co-located at existing industrial sites, which will also evolve in reaction to policy instruments, thereby affecting opportunities for integration of material and energy flows

Large-scale deployment of grass in crop rotations as a multifunctional climate mitigation strategy

The agriculture sector can contribute to climate change mitigation by reducing its own greenhouse gas (GHG) emissions, sequestering carbon in vegetation and soils, and providing biomass to substitute for fossil fuels and other GHG-intensive products. The sector also needs to address water, soil, and biodiversity impacts caused by historic and current practices. Emerging EU policies create incentives for cultivation of perennial plants that provide biomass along with environmental benefits. One such option, common in northern Europe, is to include grass in rotations with annual crops to provide biomass while remediating soil organic carbon (SOC) losses and other environmental impacts. Here, we apply a spatially explicit model on >81,000 sub-watersheds in EU27 + UK (Europe) to explore the effects of widespread deployment of such systems. Based on current accumulated SOC losses in individual sub-watersheds, the model identifies and quantifies suitable areas for increased grass cultivation and corresponding biomass- and protein supply, SOC sequestration, and reductions in nitrogen emissions to water as well as wind and water erosion. The model also provides information about possible flood mitigation. The results indicate a substantial climate mitigation potential, with combined annual GHG savings from soil-carbon sequestration and displacement of natural gas with biogas from grass-based biorefineries, equivalent to 13%–48% of current GHG emissions from agriculture in Europe. The environmental co-benefits are also notable, in some cases exceeding the estimated mitigation needs. Yield increases for annual crops in modified rotations mitigate the displacement effect of increasing grass cultivation. If the grass is used as feedstock in lieu of annual crops, the displacement effect can\ua0even be negative, that is, a reduced need for annual crop production elsewhere. Incentivizing widespread deployment will require supportive policy measures as well as new uses of grass biomass, for example, as feedstock for green biorefineries producing protein concentrate, biofuels, and other bio-based products

The prospects for willow plantations for wastewater treatment in Sweden

The concept of willow vegetation filters for the treatment of nutrient-rich wastewater has the potential to address two of our most serious environmental problems today -water pollution and climate change- in a cost-efficient way. Despite several benefits, including high treatment efficiency, increased biomass yields, improved energy and resource efficiency, and cost savings, willow vegetation filters have so far only been implemented to a limited degree in Sweden. This is due to various kinds of barriers, which may be the result of current institutional, structural and technical/geographical conditions. This paper discusses the prospects of a more widespread utilisation of willow plantations for wastewater treatment in Sweden, including existing incentives and barriers, based on current knowledge and experience. \ua9 2005 Elsevier Ltd. All rights reserved

Cadmium accumulation and Salix-based phytoextraction on arable land in Sweden

Cadmium accumulation in arable soils causes concern due to possible direct environmental effects and health risks associated with exposure of humans to cadmium through agricultural products. This paper discusses the problem of cadmium accumulation in Swedish arable land, and evaluates Salix (Salix vinimalis) cultivation as a tool for addressing the problem. It is found that Salix cultivation offers an effective option for addressing the cadmium accumulation, especially when the topsoil has high cadmium content due to anthropogenic inflows, and the subsoil naturally contains little cadmium. The estimated practical potential for Salix-based cadmium management (ca. 490 000 ha) is very large compared to the present Salix plantation area in Sweden (ca. 15 000 ha). However, the estimates of the net economic value of cadmium removal from arable land indicate that the economics of Salix production will not improve dramatically due to an induced cadmium removal. Salix-based cadmium management will therefore most likely take place in counties where Salix cultivation can be expected to expand as a response to an unfilled biomass demand in the energy sector. \ua9 2003 Elsevier B.V. All rights reserved