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Life cycle assessment of enzymatic poly(ethylene terephthalate) (PET) recycling highlights key challenges and opportunities for improving environmental impacts.

Limiting global warming to under 2°C would require stringent mitigation and likely additional carbon dioxide removals (CDR) to compensate for hard-to-avoid emissions. The relatively low cost and potential co-benefits of biochar as a soil amendment has gained attention in this context. We use a global multisector model to analyze biochar deployment in the context of energy system uses of biomass with CDR under different carbon price trajectories. We find that biochar can create an annual sink of up to 2.8 GtCO2, reducing global mean temperature increases by an additional 0.5-1.8% across scenarios by 2100 for a given carbon price path. In our scenarios, biochar’s deployment is dependent on potential crop yield gains and application rates, and the competition for resources with other CDR measures. We find that biochar can serve as a competitive CDR strategy, especially at lower carbon prices when bioenergy with carbon capture and storage is not economical.

This paper showcases the suitability of an environmentally extended input-output framework to provide macroeconomic analyses of an expanding bioeconomy to allow for adequate evaluation of its benefits and trade-offs. It also exemplifies the framework's applicability to provide early design stage evaluations of emerging technologies expected to contribute to a future bioeconomy. Here, it is used to compare the current United States (U.S.) bioeconomy to a hypothetical future containing additional cellulosic ethanol produced from two near-commercial pathways. We find that the substitution of gasoline with cellulosic ethanol is expected to yield socioeconomic net benefits, including job growth and value added, and a net reduction in global warming potential and nonrenewable energy use. The substitution fares comparable to or worse than that for other environmental impact categories including human toxicity and eutrophication potentials. We recommend that further technology advancement and commercialization efforts focus on reducing these unintended consequences through improved system design and innovation. The framework is seen as complementary to process-based technoeconomic and life cycle assessments as it utilizes related data to describe specific supply chains while providing analyses of individual products and portfolios thereof at an industrial scale and in the context of the U.S. economy.

Summary Esterases have emerged as important biocatalysts for enzyme-based polyester recycling of poly(ethylene terephthalate) (PET) to terephthalic acid (TPA) and ethylene glycol (EG). Here, we present process modeling, techno-economic, life-cycle, and socioeconomic impact analyses for an enzymatic PET depolymerization-based recycling process, which we compare with virgin TPA manufacturing. We predict that enzymatically recycled TPA (rTPA) can be cost-competitive and highlight key areas to achieve this. In addition to favorable long-term socioeconomic benefits, rTPA can reduce total supply chain energy use by 69%–83% and greenhouse gas emissions by 17%–43% per kg of TPA. An economy-wide assessment for the US estimates that the TPA recycling process can reduce environmental impacts by up to 95% while generating up to 45% more socioeconomic benefits, also relative to virgin TPA production. Sensitivity analyses highlight impactful research opportunities to pursue toward realizing biological PET recycling and upcycling.

Current biomass production and trade volumes for energy and new materials and bio-chemicals are only a small fraction to achieve the bioenergy levels suggested by many global energy and climate change mitigation scenarios for 2050. However, comprehensive sustainability of large scale biomass production and trading has yet to be secured, and governance of developing biomass markets is a critical issue. Fundamental choices need to be made on how to develop sustainable biomass supply chains and govern sustainable international biomass markets. The aim of this paper is to provide a vision of how widespread trade and deployment of biomass for energy purposes can be integrated with the wider (bio)economy. It provides an overview of past and current trade flows of the main bioenergy products, and discusses the most important drivers and barriers for bioenergy in general, and more specifically the further development of bioenergy trade over the coming years. It discusses the role of bioenergy as part of the bioeconomy and other potential roles; and how it can help to achieve the sustainable development goals. The paper concludes that it is critical to demonstrate innovative and integrated value chains for biofuels, bioproducts, and biopower that can respond with agility to market factors while providing economic, environmental, and societal benefits to international trade and market. Furthermore, flexible biogenic carbon supply nets based on broad feedstock portfolios and multiple energy and material utilization pathways will reduce risks for involved stakeholder and foster the market entry and uptake of various densified biogenic carbon carriers.

The global pellet market is growing but with different characteristics in different countries and regions. In this paper we trace developments between 2008 and 2016. For 2008, production was reported at 9.8 Tg, expanding globally to 14.3 Tg in 2010 and surpassing 26 Tg in 2015. Global hot spots are North America (production) and Europe (consumption). Sustainability certification was applied for about 9 Tg in 2016. Nevertheless, projections for future development are difficult as low pellet prices and uncertain sustainability obligations may hinder further expansion. In general, there is a strong dependency of the pellet market on the policy framework.

Farm operations in the USA and Europe have seen a radical change in the last decades: small sized farms are disappearing, and farm size and total livestock on larger farms are increasing. The resulting spatial density of animals causes several environmental impacts. Anaerobic digestion is one promising technical solution to alleviate most of these impacts while simultaneously providing a regional energy source. This analysis assesses the economic viability of using dairy-cow manure for either (i) the on-farm production and use of biogas to generate electricity and heat or (ii) the upgrading biogas to biomethane, a natural-gas substitute. A non-linear optimization model was developed to optimize plant capacity for anaerobic digestion and maximize the net present value for each option by farm size. In this study, we used Idaho‘s dairy farms as a case study. The analysis implies that at least 3000 cows per farm are required for an economically viable anaerobic-digestion plant operation. For farms with up to 3600 animals, the highest net present value was achieved for the on-farm use of biogas. Farms larger than that achieved their best economic results via the production of biomethane. In total about 45% of Idaho’s dairy manure could be utilized by economically feasible biogas and biomethane plants. A higher manure utilization rate could be achieved through joint, cooperative anaerobic digestion plants and manure transportation. The results can be transferred to other regions and countries, respectively, to reduce the negative impact of intensive livestock farming.

Isobutanol and aromatic-rich hydrocarbons (ARHC) are two biomass-derived high-octane blendstocks that could be blended with petroleum gasoline for use in optimized spark-ignition engines in light-duty vehicles, potentially increasing engine efficiency. To evaluate technology readiness, economic viability, and environmental impacts of these technologies, we use detailed techno-economic analysis (TEA) and life-cycle analysis (LCA). We assumed isobutanol is produced via biochemical conversion of an herbaceous feedstock blend while ARHC is produced via thermochemical conversion of a woody feedstock blend. The minimum estimated fuel selling price (MFSP) of isobutanol ranged from $5.57/gasoline gallon equivalent (GGE) ($0.045/MJ) based on today’s technology to $4.22/GGE ($0.034/MJ) with technology advancements. The MFSP of ARHC could decline from $5.20/GGE ($0.042/MJ) based on today’s technology to $4.20/GGE ($0.034/MJ) as technology improves. Both isobutanol and ARHC offer about 73% greenhouse gas (GHG) emissi...

Many factors may globally affect the trade pattern for industrial-grade wood pellets, with one such factor being the decision strategies by potential buyers and suppliers to optimize feedstock pric...

Twenty-four biomass-derived compounds and mixtures, identified based on their physical properties, which could be blended into fuels to improve spark ignition engine fuel economy, were assessed for their economic, technology readiness, and environmental viability. These bio-blendstocks were modeled to be produced biochemically, thermochemically, or through hybrid processes. To carry out the assessment, 17 metrics were developed for which each bio-blendstock was determined to be favorable, neutral, or unfavorable. Cellulosic ethanol was included as a reference case. Overall economic and, to some extent, environmental viability is driven by projected yields for each of these processes. The metrics used in this analysis methodology highlight the near-term potential to achieve these targeted yield estimates when considering data quality and current technical readiness for these conversion strategies. Key knowledge gaps included the degree of purity needed for use as a bio-blendstock. Less stringent purificati...

Expanding the domestic bioeconomy can help diversify the use of national resources and reduce emissions. Evaluating the sustainability of a growing bioeconomy, however, is inherently complex since it spans several sectors and supply chains. It requires a comprehensive, integrated analysis framework to assess the developments across the traditional sustainability dimensions. Further, the assessment of bioeconomy developments requires a robust baseline of historic data and trends. In this paper, we analyze the evolution of the biofuel portion of the US bioeconomy, focusing on two fuels that had an exponential growth in the last two decades: corn ethanol and soybean biodiesel. For this purpose, we created a novel time series of harmonized environmentally-extended input-output (EEIO) tables based on a publicly available model from the US Environmental Protection Agency and expanded its disaggregation to reflect the main supply chains of the biofuels sectors. The EEIO time series provides the historical evolution of these biofuels relative to the rest of the economy as well as on an energy-unit basis. We find that, except for energy use, the broader US economy declined in both resource intensity and most environmental impacts when normalized per one million dollars of gross domestic product. Deviating from this trend are freshwater ecotoxicity and human toxicity, mainly attributable to the expansion of commodity crops and the increase of domestic oil and gas extraction respectively. We also find that the biofuel industry's total socioeconomic, resource use and environmental impacts grew with their production increases over time. However, the industry's maturation and scale-up, combined with higher feedstock yields, contributed to a reduction of most impacts on an energy-unit basis over time.

Competitive international markets imply adjustments towards competitive spatial equilibrium in which excess from one market is transferred to another and prices are equilibrated except for remaining differences that can be assigned to transfer costs. The European market for wood pellets used in small-scale heating systems has been expanding significantly over the past decade. Small scale pellet heating is arguably a mature technology, but whether the market is mature is another question. In this paper we analyse recent data on trade flows and price developments between Italy, Austria, Germany and France to understand the developments of wood pellet market efficiency and to draw conclusions about market function. The objective of this study is to establish a framework to test the European residential wood pellet market for competitive spatial equilibrium using modern trade theory. We find mainly inefficiently integrated markets with remaining positive marginal profits and detectable arbitrageurs’ activity. Based on a thorough discussion of these findings and the underlying data we outline possible methodology advancements and list policy recommendations to secure access and affordability of this renewable heating commodity in the long run.

Decentralized biomass processing facilities, known as biomass depots, may be necessary to achieve feedstock cost, quantity, and quality required to grow the future U.S. bioeconomy. In this paper, we assess three distinct depot configurations for technical difference and economic performance. The depot designs were chosen to compare and contrast a suite of capabilities that a depot could perform ranging from conventional pelleting to sophisticated pretreatment technologies. Our economic analyses indicate that depot processing costs are likely to range from ∼US$30 to US$63 per dry metric tonne (Mg), depending upon the specific technology implemented and the energy consumption for processing equipment such as grinders and dryers. We conclude that the benefits of integrating depots into the overall biomass feedstock supply chain will outweigh depot processing costs and that incorporation of this technology should be aggressively pursued.

Pioneer cellulosic biorefineries across the United States rely on a conventional feedstock supply system based on one-year contracts with local growers, who harvest, locally store, and deliver feedstock in low-density format to the conversion facility. While the conventional system is designed for high biomass yield areas, pilot scale operations have experienced feedstock supply shortages and price volatilities due to reduced harvests and competition from other industries. Regional supply dependency and the inability to actively manage feedstock stability and quality, provide operational risks to the biorefinery, which translate into higher investment risk. The advanced feedstock supply system based on a network of depots can mitigate many of these risks and enable wider supply system benefits. This paper compares the two concepts from a system-level perspective beyond mere logistic costs. It shows that while processing operations at the depot increase feedstock supply costs initially, they enable wider system benefits including supply risk reduction (leading to lower interest rates on loans), industry scale-up, conversion yield improvements, and reduced handling equipment and storage costs at the biorefinery. When translating these benefits into cost reductions per liter of gasoline equivalent (LGE), we find that total cost reductions between –$0.46 to –$0.21 per LGE for biochemical and –$0.32 to –$0.12 per LGE for thermochemical conversion pathways are possible. Naturally, these system level benefits will differ between individual actors along the feedstock supply chain. Further research is required with respect to depot sizing, location, and ownership structures. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

The expected use of solid biomass for large-scale heat and power production across North–West Europe (NW EU) has led to discussions about its sustainability, especially due to the increasing import dependence of the sector. While individual Member States and companies have put forward sustainability criteria, it remains unclear how different requirements will influence the availability and cost of solid biomass and thus how specific regions will satisfy their demand in a competitive global market. We combined a geospatially explicit least-cost biomass supply model with a linear optimization solver to assess global solid biomass trade streams by 2020 with a particular focus on NW EU. We apply different demand and supply scenarios representing varying policy developments and sustainability requirements. We find that the projected EU solid biomass demand by 2020 can be met across all scenarios, almost exclusively via domestic biomass. The exploitation of domestic agricultural residue and energy crop potentials, however, will need to increase sharply. Given sustainability requirements for solid biomass as for liquid biofuels, extra-EU imports may reach 236 PJ by 2020, i.e., 400% of their 2010 levels. Intra-EU trade is expected to grow with stricter sustainability requirements up to 548 PJ, i.e., 280% of its 2010 levels by 2020. Increasing sustainability requirements can have different effects on trade portfolios across NW EU. Excluding pulpwood pellets may drive the supply costs of import dependent countries, foremost the Netherlands and the UK, whereas excluding additional forest biomass may entail higher costs for Germany and Denmark which rely on regional biomass. Excluding solid biomass fractions may create short-term price hikes. Our modeling results are strongly influenced by parameterization choices, foremost assumed EU biomass supply volumes and costs and assumed relations between criteria and supply. The model framework is suited for the inclusion of dynamic supply–demand interactions and other world regions.

An analysis by Sterman et al (2018 Environ. Res. Lett. 13 015007) suggests that use of wood for bioenergy production results in a worse climate outcome than from using coal. However, many of the assumptions on which their primary wood bioenergy scenario is based are not realistic and therefore are not informative. Assumptions of uncharacteristically long rotations for southern pine plantations, no utilization of wood for longer-duration products, and a single harvest over 100 years understate the carbon performance of current forest management practices. We provide references that support realistic modeling of forest carbon dynamics that are reflective of current practice and therefore more informative.

Past research on identifying potentially negative impacts of forest management activities has primarily focused on traditional forest operations. The increased use of forest biomass for energy in recent years, spurred predominantly by policy incentives for the reduction of fossil fuel use and greenhouse gas emissions, and by efforts from the forestry sector to diversify products and increase value from the forests, has again brought much attention to this issue. The implications of such practices continue to be controversially debated; predominantly the adverse impacts on soil productivity and biodiversity, and the climate change mitigation potential of forest bioenergy. Current decision making processes require comprehensive, differentiated assessments of the known and unknown factors and risk levels of potentially adverse environmental effects. This paper provides such an analysis and differentiates between the feedstock of harvesting residues, roundwood, and salvage wood. It concludes that the risks related to biomass for energy outtake are feedstock specific and vary in terms of scientific certainty. Short-term soil productivity risks are higher for residue removal. There is however little field evidence of negative long-term impacts of biomass removal on productivity in the scale predicted by modeling. Risks regarding an alteration of biodiversity are relatively equally distributed across the feedstocks. The risk of limited or absent short-term carbon benefits is highest for roundwood, but negligible for residues and salvage wood. Salvage operation impacts on soil productivity and biodiversity are a key knowledge gap. Future research should also focus on deriving regionally specific, quantitative thresholds for sustainable biomass removal.

The temporal imbalance between the release and sequestration of forest carbon has raised a fundamental concern about the climate mitigation potential of forest biomass for energy. The potential carbon debt caused by harvest and the resulting time spans needed to reach pre-harvest carbon levels (payback) or those of a reference case (parity) have become important parameters for climate and bioenergy policy developments. The present range of analyses however varies in assumptions, regional scopes, and conclusions. Comparing these modeling efforts, we reveal that they apply different principle modeling frameworks while results are largely affected by the same parameters. The size of the carbon debt is mostly determined by the type and amount of biomass harvested and whether land-use change emissions need to be accounted for. Payback times are mainly determined by plant growth rates, i.e. the for- est biome, tree species, site productivity and management. Parity times are primarily influenced by the choice and construction of the reference scenario and fossil carbon displacement effi- ciencies. Using small residual biomass (harvesting/processing), deadwood from highly insect- infected sites, or new plantations on highly productive or marginal land offers (almost) immediate net carbon benefits. Their eventual climate mitigation potential however is determined by the effectiveness of the fossil fuel displacement. We deem it therefore unsuitable to define politi- cal guidance by feedstock alone. Current global wood pellet production is predominantly resi- due based. Production increases based on low-grade stemwood are expected in regions with a downturn in the local wood product sector, highlighting the importance of accounting for regional forest carbon trends. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

The political will to reduce global GHG emissions has largely contributed to increased global biofuel production and trade. The expanding cultivation of energy crops may drive changes in the terrestrial ecosystems such as land cover and biodiversity loss. When biomass replaces fossil energy carriers, sustainability criteria are therefore crucial to avoid adverse impacts and ensure a net positive GHG balance. The European Union has set mandatory sustainability criteria for liquid biofuels in its Renewable Energy Directive (RED) 2009/28/EC to ensure net positive impacts of its biofuel policy. The adoption of sustainability criteria in other world regions and their extension to solid and gaseous biomass in the EU is ongoing. This paper examines the effect of the EU RED sustainability criteria on the availability of biomass resources at global and regional scale. It quantifies the relevance of sustainability criteria in biomass resource assessments taking into account the criteria’s spatial distribution. This assessment does not include agricultural and forestry residues and aquatic biomass. Previously unknown interrelations between sustainability criteria are examined and described for ten world regions. The analysis concludes that roughly 10% (98.5 EJ) of the total theoretical potential of 977.2 EJ occurs in areas free of sustainability concerns.

In an effort to reduce fossil fuel consumption, the use of woody biomass for heat and power generation is growing. Key destination markets will be countries within the European Union, particularly the United Kingdom, the Netherlands, Denmark and Belgium. While demand from Asia (particularly South Korea and Japan) will also increase, it will continue to play a secondary role. Across the EU, adoption of sustainability criteria for forest biomass based on the Renewable Energy Directive (RED) 2009/28/EC or similar criteria is likely. In the United Kingdom, the largest market for traded wood pellets, such criteria have already been proposed. As of 2015, only forest biomass that achieves at least a 60% reduction in GHG emissions, relative to the EU fossil fuel electricity average, can be used for bioenergy production and proof of SFM is required. In the Netherlands, the energy industry and non-governmental organisations achieved principal agreement on sustainability criteria for solid biomass, but issues of compliance testing and monitoring must still be addressed. In Flemish Belgium, the sustainability requirements for bioliquids may soon be applied to woody biomass. In Denmark, a voluntary industry agreement is set to ensure that all bioenergy production by 2019 is conducted sustainably. At present, internationally traded wood pellets from temperate and boreal biomes originate primarily from the United States, Canada and Russia. Among these, Canada offers large stretches of SFM-certified forests, but the US Southeast has seen the strongest increase in wood pellet production and export in recent years. The expansion of pellet production in the Southeast United States is mainly linked to available forest inventory (pulpwood in particular) and the competitive advantage gained by the relative proximity to demand markets in the EU. In addition to the mobilisation barriers observed in supply chains at the local and national scale, limitations in the supply of forest biomass for international trade will be influenced by regulatory measures that could restrict the trade of specific feedstock fractions.

A variety of feedstock types will be needed to grow the bioeconomy. Respective logistics and market structures will be needed to cope with the spatial, temporal, and compositional variability of these feedstocks. At present, pilot-scale cellulosic biorefineries rely on vertically integrated supply systems designed to support traditional agricultural and forestry industries. The vision of the future feedstock supply system is a network of distributed biomass processing centers (depots) and centralized terminals. This introduces methods to increase feedstock volume while decreasing price and quality supply uncertainties. Depots are located close to the resource, while shipping and blending terminals are located in strategic logistical hubs with access to high bulk transportation systems. The system emulates the current grain commodity supply system, which manages crop diversity at the point of harvest and at the storage elevator, allowing subsequent supply system infrastructure to be similar for all resources. The initiation of depot (pilot) operations is seen as a strategic stepping stone to transition to this logistic system. A fundamental part of initiating (pilot-) depot operations is to establish the value proposition to the biomass grower, as biomass becomes available to the market place only through mobilization. A feedstock supply industry independently mobilizing biomass by producing value-add merchandisable intermediates creates a market push that will derisk and accelerate the deployment of bioenergy technologies. Companion markets can help mobilize biomass without biorefineries. That is, depots produce value-added intermediates that are fully fungible in both a companion and the biorefining market. To achieve this, a separation between feedstock supply and conversion industry may be necessary.

A global bioeconomy requires adequate logistical infrastructure to support trade of biomass feedstock and intermediates. An integration of biomass trade streams with existing supply chain infrastructure, originally constructed for other goods, presents an opportunity to efficiently enable such growth. This chapter examines to what extent existing logistical infrastructure can be used and/or shared with biomass trade streams via specific case studies. It identifies how biomass trade is already or could be integrated into existing supply chains handling infrastructure, and for what kind of biomass specifications a dedicated infrastructure is needed. It finds that the existing solids handling infrastructure is well suited to integrate biomass intermediates such as conventional or torrefied pellets. Liquids with a higher energy density than solids, for example, pyrolysis oil, could potentially realize many opportunities to leverage infrastructure designed for the petroleum industry, and may even enable leveraging home heating infrastructure, for example, in the US northeast, preventing costly modifications. However, high oxygen levels render pyrolysis oil corrosive, requiring investments in stainless steel or other more durable handling equipment. Biomethane injection into natural gas grids is already a common technology in most of Europe, but major hurdles remain, including high production costs, pipeline access, and the lack of quality standards.

Commodities are intermediate goods available in standardized qualities that are traded on competitive and liquid international markets. In this chapter, we analyze the current status and trajectories in biomass markets to discern to what extent solid biomass fuels are becoming commoditized. We present five criteria that are key indicators in the process towards commoditization and market maturity. These indicators are then used as a framework to understand biomass market developments, with particular focus on wood pellet markets, and identify current obstacles to market maturity. We continuously draw comparisons with developments in fossil fuel markets with the dramatic developments in crude oil markets from the late 1960s to the mid-1980s used as a key example. In both the crude oil example and in the wood pellet discussion, the successful establishment of a futures contract is seen as a litmus test of the commoditization process. We find several similarities between historical and current fossil fuel markets and wood pellet markets in the reliance of vertical integration as a risk management tool and in how rigid fuel quality standards are perceived as obstacles to market liquidity. However, biomass markets also have particular characteristics that are not present in fossil fuel markets, especially the need for sustainability and traceability in supply chains. These are essential features of biomass fuels since their attractiveness to a very high degree relies on their being superior to fossil fuels in terms of lifecycle environmental performance. However, they do make the process of commoditization more difficult. For future discussions on biomass market developments, the tension here must be addressed.

This book identifies opportunities and challenges for the mobilisation of sustainable forest biomass from supply chains operating in the boreal and temperate biomes. The respective feedstock plays a critical role in meeting global deployment levels for bioenergy, which in turn are necessary to stabilise global greenhouse gas (GHG) emissions and atmospheric carbon levels. Many aspects of bioenergy supply chains (such as logistics and trade, supply chain variability, technology learning and transfer, governance, organisational structures) present both challenges and opportunities and relate to all three dimensions of sustainability. Energy and forest systems can be integrated across landscapes and organisations to establish attractive solutions guided by good governance of forest management and biomass use (eg, policies, regulations, standards and certification systems). Nevertheless, substantial gains in forest bioenergy mobilisation can only be achieved with an important increase in forest management intensity, causing a larger appropriation of forest net primary production (NPP). Such intensification would likely require fundamental shifts in the forest systems and considerable societal change, in some countries. A multifaceted policy effort to support a broad array of technological, structural and behavioural changes is needed to enable energy and industrial transitions and the development of supply chains that deliver feedstock to a range of conversion and utilisation routes.

The environmental sustainability of forest biomass procurement needs to be well understood, as the capacity of ecosystems to provide biomass, without negative impacts on ecological functioning, limits the biomass potential. Emerging bioenergy markets typically first take advantage of secondary residue streams of various wood processing industries and tertiary end-of-life residues. The use of these secondary and tertiary wood resources is not likely to compromise the environmental sustainability of forests. When these resources, in any region, become scarce or fully utilised, primary residues (ie by-products of forestry harvesting operations and silvicultural practices) such as branches, tops and non-merchantable trees become increasingly targeted as feedstock sources. Forest biomass procurement in the boreal and temperate biomes should therefore not be analysed as a stand-alone activity, but rather as an intensification of land use and of forest management, in which tree parts and trees are harvested, in addition to conventional forest product fractions. Thus, principles of protection and sustainability should remain the same, whether forests are managed for conventional forest products only or also for biomass for energy. Some modifications may be needed to properly identify and find mitigation strategies for sensitive conditions where field evidence suggests that the incremental removal of biomass, or other forms of intensive management, may not be sustainable. Silvicultural practices, such as fertilisation, competition control and soil preparation are options to manage the microenvironment and tree growing conditions, as well to prevent or mitigate negative impacts. Moreover, landscape management regulations should be put in place to ensure that sufficient biodiversity-important features, such as dead wood, aging stands, corridors, etc., are preserved. Special attention should then be directed to trees and stands with high biodiversity values, or those important for maintaining ecosystem services. Applying the concept of adaptive forest management, ecological monitoring following harvesting operations, scientific field testing and modelling should be combined to produce better knowledge that could help improve practices. The forestry sector needs to start adapting to a future situation where it is expected to provide conventional forest products, biomaterials and bioenergy. To achieve this, good governance mechanisms, such as landscape-level land-use planning and science-based improvements of practices, will become increasingly important to ensure sustainable forest product supply chains.

Cascading, or cascade use, is concept that has many different definitions, but a common theme is a sequential use of resources for different purposes. The cascading concept was first presented in the early 1990s but has become an intensively debated topic primarily in the most recent decade. In the available literature on cascading of wood, there are few studies that discuss policy implementation. As this is currently heavily debated, there is an important gap here that we aim to fill. In this paper, we (a) critically review the conceptual history of cascading and (b) highlight the complexities involved in its implementation in policy frameworks. Originally, cascading was discussed as a broad framework for how society better should manage natural resource flows. In more recent debates on woody biomass however, cascading is often presented as simply a hierarchy, wherein material use of wood should hold priority over energy use of wood. This is partly based on an idea that certain forms of wood utilization are inherently more valuable than others, an assumption that becomes problematic when implemented in policy. In reality, how and for what a certain wood resource is used varies with time and place and historical examples of implementation of hierarchical policy frameworks indicate a high risk of unwanted consequences, such as unstable policy structures and tendencies toward a negotiation economy. Cascading of woody biomass can have benefits from both an economical and environmental perspective. However, cascading systems should emerge bottom‐up, not be imposed top‐down through politically determined hierarchies. WIREs Energy Environ 2018, 7:e279. doi: 10.1002/wene.279 This article is categorized under: Energy and Climate > Economics and Policy Energy Policy and Planning > Economics and Policy

While the world's transport energy matrix is still strongly linked to limited and heavily polluting fossil fuels, new markets are appearing for the production and use of alternative transport fuels, such as liquid biofuels. Due to an interconnected global economy, such markets today are developing on a global scale with actors looking to meet local as well as potential international demand. The aim of this paper is to describe and evaluate the emergence of markets for liquid biofuels in Argentina. It reveals that biodiesel production for international supply is likely to emerge in the short run (up to 2010), giving the opportunity to be switched back to local supply in the medium run (post-2010). It also suggests that a bioethanol market (demand and supply) does not seem to be likely in the short run, and it is highly uncertain in the medium run as the most influential actors oppose its development. On the other hand, the current constellations of the biodiesel market appear to leave many uncertainties regarding its sustainability, especially in regard to a limited role of small and medium sized enterprises, and a suitable and diversified biodiesel feedstock. Currently, the focus lies solely on (very) large-scale production of biodiesel derived from soybean oil for the export market.

Logistical barrier are tied to feedstock harvesting, collection, storage and distribution. Current crop harvesting machinery is unable to selectively harvest preferred components of cellulosic biomass while maintaining acceptable levels of soil carbon and minimizing erosion. Actively managing biomass variability imposes additional functional requirements on biomass harvesting equipment. A physiological variation in biomass arises from differences in genetics, degree of crop maturity, geographical location, climatic events, and harvest methods. This variability presents significant cost and performance risks for bioenergy systems. Currently, processing standards and specifications for cellulosic feedstocks are not as well-developed as for mature commodities. Biomass that is stored with high moisture content or exposed to moisture during storage is susceptible to spoilage, rotting, spontaneous combustion, and odor problems. Appropriate storage methods and strategies are needed to better define storage requirements to preserve the volume and quality of harvested biomass over time and maintain its conversion yield. Raw herbaceous biomass is costly to collect, handle, and transport because of its low density and fibrous nature. Existing conventional, bale-based handling equipment and facilities cannot cost-effectively deliver and store high volumes of biomass, even with improved handling techniques. Current handling and transportation systems designed for moving woodchips can be inefficient for bioenergy more » processes due to the costs and challenges of transporting, storing, and drying high-moisture biomass. The infrastructure for feedstock logistics has not been defined for the potential variety of locations, climates, feedstocks, storage methods, processing alternatives, etc., which will occur at a national scale. When setting up biomass fuel supply chains, for large-scale biomass systems, logistics are a pivotal part in the system. Various studies have shown that long-distance international transport by ship is feasible in terms of energy use and transportation costs, but availability of suitable vessels and meteorological conditions (e.g., winter time in Scandinavia and Russia) need to be considered. However, local transportation by truck (both in biomass exporting and importing countries) may be a high-cost factor, which can influence the overall energy balance and total biomass costs. « less

During the transition to a market economy, many countries with a planned economy in Central and Eastern Europe face similar challenges when the established socio-economic systems and infrastructures deemed inefficient in a market economy. Also new issues are being raised by the trends of globalization and the vision of sustainable development. In the energy sector the challenges raised by the Kyoto Protocol and its implementation mechanisms are especially interesting, because they are intertwined with other socio-economic sectors. This paper addresses the challenges in the energy sector for transition countries, taking the case of bio-energy in the Ukraine as a prime example of a country undergoing major changes in its economic structures. Given the large potential for bio-energy development in the Ukraine, the current dependence on imported energy resources which threatens the Ukraine's energy security, and the economic, social and environmental benefits associated with bio-energy, this paper investigates drivers and barriers to an increased use of bio-energy in the Ukraine. The paper was written by a group of MSc students of the International Institute for Industrial Environmental Economics at Lund University during a field trip to Kiev city and the Lviv region in Ukraine. The field trip has been supported by the Swedish Institute. (Less)