301 research outputs found
Attractive Systems for Bioenergy Feedstock Production in Sustainably Managed Landscapes– Contributions to the Call
Task 43 launched an initiative to identify attractive examples of landscape management and design for bioenergy and the bioeconomy. The aim of this initiative to catalogue and highlight world-wide examples of biomass production systems, throughout all stages of production, that can contribute positively to biodiversity and the generation of other ecosystem services. Information about biomass production systems and their impacts, as well as information about governance and policy initiatives that encourage adoptions of solutions leading to positive outcomes are welcomed. The goal of this initiative is to compile innovative examples as a means of showcasing how the production of biomass for bioenergy can generate positive impacts in agriculture and forestry landscapes. These examples are also meant to serve as sources of inspiration that other biomass producers can use to enhance the sustainability of their own activities.All contributions that are within scope and meet the set quality requirement are included in this Report. Selected contributions will be invited to submit a manuscript for a Special Collection in the peer review journal WIREs Energy and Environment, published by Wiley
Geospatial supply-demand modeling of lignocellulosic biomass for electricity and biofuels in the European Union
Bioenergy can contribute to achieving European Union (EU) climate targets while mitigating impacts from current agricultural land use. A GIS-based modeling framework (1000 m resolution) is employed to match biomass supply (forest and agricultural residues, complemented by lignocellulosic energy crops where needed) with biomass demand for either electricity or bio-oil production on sites currently used for coal power in the EU-28, Norway, and Switzerland. The framework matches supply and demand based on minimizing the field-to-gate costs and is used to provide geographically explicit information on (i) plant-gate supply cost; (ii) CO2 savings; and (iii) potential mitigation opportunities for soil erosion, flooding, and eutrophication resulting from the introduction of energy crops on cropland. Converting all suitable coal power plants to biomass and assuming that biomass is sourced within a transport distance of 300 km, would produce an estimated 150 TW h biomass-derived electricity, using 1365 PJ biomass, including biomass from energy crops grown on 6 Mha. Using all existing coal power sites for bio-oil production in 100-MW pyrolysis units could produce 820 PJ of bio-oil, using 1260 PJ biomass, including biomass from energy crops grown on 1.8 Mha. Using biomass to generate electricity would correspond to an emissions reduction of 135 MtCO2, while using biomass to produce bio-oil to substitute for crude oil would correspond to a reduction of 59 MtCO2. In addition, energy crops can have a positive effect on soil organic carbon in most of the analyzed countries. The mitigation opportunities investigated range from marginal to high depending on location
Towards multifunctional landscapes coupling low carbon feed and bioenergy production with restorative agriculture: Economic deployment potential of grass-based biorefineries
Grass-based biomass from grasslands can be used as feedstock in green biorefineries (GBs) that produce a range of biobased products. In addition, adjustments made as part of crop rotation to increase areas under temporary grasslands can yield benefits such as carbon sequestration, increased soil productivity, reduced eutrophication and reduced need for pesticides. In this paper, a flexible modeling framework is developed to analyze the deployment options for GBs that use grass–clover to produce protein feed and feedstock for bioenergy. The focus is placed on optimal deployment, considering system configuration and operation, as well as land use changes designed to increase grass–clover cultivation on cropland. A case study involving 17 counties in Sweden showed that the deployment of GB systems could support biomethane and protein feed production corresponding to 5–60 and 13–154%, respectively, of biomethane and soybean feed imports to Sweden in 2020
Are biofuel mandates cost-effective? - An analysis of transport fuels and biomass usage to achieve emissions targets in the European energy system
Abatement options for the hard-to-electrify parts of the transport sector are needed to achieve ambitious emissions targets. Biofuels based on biomass, electrofuels based on renewable hydrogen and a carbon source, as well as fossil fuels compensated by carbon dioxide removal (CDR) are the main options. Currently, biofuels are the only renewable fuels available at scale and are stimulated by blending mandates. Here, we estimate the system cost of enforcing such mandates in addition to an overall emissions cap for all energy sectors. We model overnight scenarios for 2040 and 2060 with the sector-coupled European energy system model PyPSA-Eur-Sec, with a high temporal resolution. The following cost drivers are identified: (i) high biomass costs due to scarcity, (ii) opportunity costs for competing usages of biomass for industry heat and combined heat and power (CHP) with carbon capture, and (iii) lower scalability and generally higher cost for biofuels compared to electrofuels and fossil fuels combined with CDR. With a -80% emissions reduction target in 2040, variable renewables, partial electrification of heat, industry and transport, and biomass use for CHP and industrial heat are important for achieving the target at minimal cost, while an abatement of remaining liquid fossil fuel use increases system cost. In this case, a 50% biofuel mandate increases total energy system costs by 123–191 billion €, corresponding to 35%–62% of the liquid fuel cost without a mandate. With a negative -105% emissions target in 2060, fuel abatement options are necessary, and electrofuels or the use of CDR to offset fossil fuel emissions are both more competitive than biofuels. In this case, a 50% biofuel mandate increases total costs by 21–33 billion €, or 11%–15% of the liquid fuel cost without a mandate. Biomass is preferred in CHP and industry heat, combined with carbon capture to serve negative emissions or electrofuel production, thereby utilising biogenic carbon several times. Sensitivity analyses reveal significant uncertainties but consistently support that higher biofuel mandates lead to higher costs
Co-recycling of natural and synthetic carbon materials for a sustainable circular economy
Circular economy approaches are commonly depicted by two cycles, where the biological cycle is associated with regeneration in the biosphere and the technical cycle with reuse, refurbishment, and recycling to maintain value and maximize material recovery. This work, instead, presents an alternative vision to the management of carbonbased materials that integrates the two cycles and enables the phasing-out of fossil carbon from the material system. The aim is to investigate the benefits and global potential of a co-recycling system, as an alternative to conventional recycling systems that separate biomass-based materials (e.g., wood, paper) from fossil-based materials (e.g., plastics). Thermochemical recycling technologies enable the conversion of carbon-based waste materials into high-quality synthetic products, promoting circularity and avoiding carbon losses such as carbon emissions and waste accumulation in landfills and nature. Here, the construction and analysis of co-recycling scenarios show how the deployment of thermochemical recycling technologies can decouple the material system from fossil resource extraction. Furthermore, energy use is reduced if pyrolysis and/or gasification are included in the portfolio of recycling technologies. In a decarbonized energy system, deployment of co-recycling can lead to near-zero carbon emissions, while in more carbon-intensive energy systems the choice of thermochemical recycling route is key to limiting carbon emissions
Asymmetries of cattle and crop productivity and e ciency during Brazil\u27s agricultural expansion from 1975 to 2006
Brazil has global importance for food production and conservation of natural resources. The country has plans to increase yields and commitments to decrease deforestation that require higher productivity. Plans and policies for the growth of Brazilian agriculture, however, have been made without an integrated analysis of the harvest and not supported by a universal metric regarding its e ciency. Applying methods to model ows of energy and matter along food supply chains for agricultural production from 1975 to 2006, we found that crop and cattle harvests and their productivity have increased during the last four decades in consolidated and deforestation frontier regions. Yet in 2006, crop protein production was 20 times larger than cattle protein, using an area 2.6 times smaller than pastures. Crop protein productivity was 0.25 ton.ha–1 with emissions of 2 ton GHG per ton of protein, while cattle productivity was 0.01 ton. ha–1 with emissions of 283 ton GHG per ton of protein. From 1975 to 2006, the portion of crop protein and energy going to feed increased while the portion going to direct human consumption decreased. Our ndings suggest that more e cient food systems would be achieved by a combination of intensi cation of cattle systems, optimization of feed-meat systems and an increase in the share of the consumption of crops as a source of protein. We suggest an initial road map to the expansion of the cultivated area and intensi cation of agriculture for zero deforestation, e cient and sustainable land use and food systems where cattle pasture intensi cation is a transition that will last until the expansion of crops replace all pasture present on suitable arable land. During this transition, pasture area will decrease until it is lim- ited only to marginal non-arable lands. Such change could be achieved by a robust strategy that combines penalties and incentives and prevents the risks of a rebound e ect for the intensi cation of agriculture
Water impacts of U.S. biofuels: Insights from an assessment combining economic and biophysical models
Biofuels policies induce land use changes (LUC), including cropland expansion and crop switching, and this in turn alters water and soil management practices. Policies differ in the extent and type of land use changes they induce and therefore in their impact on water resources. We quantify and compare the spatially varying water impacts of biofuel crops stemming from LUC induced by two different biofuels policies by coupling a biophysical model with an economic model to simulate the economically viable mix of crops, land uses, and crop management choices under alternative policy scenarios. We assess the outputs of an economic model with a high-resolution crop-water model for major agricultural crops and potential cellulosic feedstocks in the US to analyze the impacts of three alternative policy scenarios on water balances: a counterfactual ‘no-biofuels policy’ (BAU) scenario, a volumetric mandate (Mandate) scenario, and a clean fuel-intensity standard (CFS) scenario incentivizing fuels based on their carbon intensities. While both biofuel policies incentivize more biofuels than in the counterfactual, they differ in the mix of corn ethanol and advanced biofuels from miscanthus and switchgrass (more corn ethanol in Mandate and more cellulosic biofuels in CFS). The two policies differ in their impact on irrigated acreage, irrigation demand, groundwater use and runoff. Net irrigation requirements increase 0.7% in Mandate and decrease 3.8% in CFS, but in both scenarios increases are concentrated in regions of Kansas and Nebraska that rely upon the Ogallala aquifer for irrigation water. Our study illustrates the importance of accounting for the overall LUC and shifts in agricultural production and management practices in response to policies when assessing the water impacts of biofuels
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
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