Search

This note offers a glimpse of the author's PhD thesis on the Limits of Bioenergy, which was defended at Imperial College London in 2014. The thesis was also presented as a conference paper in the 59th Annual Meeting of the International Society for the Systems Sciences in Berlin, 2015, receiving the Sir Geoffrey Vickers Memorial Award. This research note gives a brief overview on the proposed complex systems approach to land use dynamics and constraints, as a contribution to the climate change debate. A full scientific article with the whole methodology and original results is already under publication process by the author and his colleagues. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article offers research news briefs from chemical industry as of January 2015. It discusses development of processes for converting cellulose into n-hexane and other alkanes for using them as biofuels and bio-derived chemical building blocks by M. Dusselier and others, published in the journal "Energy and Environmental Science," and an approach for generating aluminium-aluminium bonding adhesives from waste office paper by Z. Zhang and other, published in the periodical "Green Chemistry."

This paper empirically examines the effect of biomass energy consumption and economic complexity on environmental sustainability in G7 economies. The current study attempts to report a comprehensive analysis of biomass energy and economic complexity on ecological and carbon footprints and carbon emissions. We employ data from 1990 to 2019 and adopt robust panel econometric techniques that account for the analysis's cross‐sectional dependence. We conduct cointegration analysis, pooled ordinary least squares (OLS), system generalized method of moments (GMM) and conditional quantile model for our empirical analysis. The empirical findings show that both biomass energy consumption and economic complexity are detrimental to the ecological footprint and carbon footprint. Additionally, we find that globalization positively affects the environment, while we find some evidence that bureaucratic quality improves environmental quality. Finally, in line with other research, we find that economic growth has detrimental effects on the environment. Our results suggest that policymakers should be more cautious in promoting biomass as a clean energy source and that the G7 economies should take advantage of their leading position in innovation to invest more in sustainable practices and investment. [ABSTRACT FROM AUTHOR]

The article provides information on the undergraduate research papers on agricultural and applied economics that secured second and third place. Zeke Bryant of University of Georgia, secured second place for "An Analysis of U.S. Tariffs on Chinese Solar Cells." Heather Hatzenbuhler of University of Georgia, secured third place for his research on "Biofuels: Rational, Policy Failures and a Way Forward for the State of Georgia."

Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas ( GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are reduced and on what timescale, we construct the GHG balance of wood-pellet electricity. This GHG balance consists of supply chain and combustion GHG emissions, carbon sequestration during biomass growth and avoided GHG emissions through replacing fossil electricity. We investigate wood pellets from four softwood feedstock types: small roundwood, commercial thinnings, harvest residues and mill residues. Per feedstock, the GHG balance of wood-pellet electricity is compared against those of alternative scenarios. Alternative scenarios are combinations of alternative fates of the feedstock materials, such as in-forest decomposition, or the production of paper or wood panels like oriented strand board ( OSB). Alternative scenario composition depends on feedstock type and local demand for this feedstock. Results indicate that the GHG balance of wood-pellet electricity equals that of alternative scenarios within 0-21 years (the GHG parity time), after which wood-pellet electricity has sustained climate benefits. Parity times increase by a maximum of 12 years when varying key variables (emissions associated with paper and panels, soil carbon increase via feedstock decomposition, wood-pellet electricity supply chain emissions) within maximum plausible ranges. Using commercial thinnings, harvest residues or mill residues as feedstock leads to the shortest GHG parity times (0-6 years) and fastest GHG benefits from wood-pellet electricity. We find shorter GHG parity times than previous studies, for we use a novel approach that differentiates feedstocks and considers alternative scenarios based on (combinations of) alternative feedstock fates, rather than on alternative land uses. This novel approach is relevant for bioenergy derived from low-value feedstocks. [ABSTRACT FROM AUTHOR]

Copyright of GCB Bioenergy is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio‐based products. Short rotation coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, easy to manage cultivation system with vegetative propagation of plant material and multiple harvests from the same plantation. The aim of the present paper is to provide an overview of the main challenges and key issues in willow genetic improvement toward sustainable biofuel value chains. Primarily based on results from the research project "Optimized Utilization of Salix" (OPTUS), the influence of Salix wood quality on the potential for biofuel use is discussed, followed by issues related to the conversion of Salix biomass into liquid and gaseous transportation fuels. Thereafter, the studies address genotypic influence on soil carbon sequestration in Salix plantations, as well as on soil carbon dynamics and climate change impacts. Finally, the opportunities for plant breeding are discussed using willow as a resource for sustainable biofuel production. Substantial phenotypic and genotypic variation was reported for different wood quality traits important in biological (i.e., enzymatic and anaerobic) and thermochemical conversion processes, which is a prerequisite for plant breeding. Furthermore, different Salix genotypes can affect soil carbon sequestration variably, and life cycle assessment illustrates that these differences can result in different climate mitigation potential depending on genotype. Thus, the potential of Salix plantations for sustainable biomass production and its conversion into biofuels is shown. Large genetic variation in various wood and biomass traits, important for different conversion processes and carbon sequestration, provides opportunities to enhance the sustainability of the production system via plant breeding. This includes new breeding targets in addition to traditional targets for high yield to improve biomass quality and carbon sequestration potential. [ABSTRACT FROM AUTHOR]

The emission of greenhouse gases from fossil fuels is the main environmental impact of energy resources. Moving toward the use of renewable energy resources is the only solution to tackle these problems. In this paper, a configuration of the hybrid biomass and geothermal energy resource is examined for cooling and electricity generation. In this study, water as a geothermal working fluid is heated up due to combustion of syngas produced in a digester and produce power in a steam turbine. So, the remaining heat of this geofluid runs an absorption chiller for cooling production. The results reveal that the energy and exergy efficiencies of this proposed cycle are 30.8% and 15.5%, respectively. Moreover, the economic analysis of this cycle concludes that the payback period is 2.8 years and the simple payback period for this configuration is 2.6 years. Moreover, the highest exergy destruction rate of 52.4% belongs to the absorption refrigeration cycle. Whereas the lowest exergy destruction of the steam line is the lowest value of 17.4%. [ABSTRACT FROM AUTHOR]

A calendar of international events from October 2009 to May 2010 is presented including the symposium on paper chemistry in Barcelona, Spain, Organic Photovoltaics Summit in Boston, Massachusetts, and Pacific Rim Summit on Industrial Biotechnology and Bioenergy in Honolulu, Hawaii.

Debate continues in this journal on the climate impacts of burning woody biomass from forests. A recent review by Cowie et al. (2021, GCB Bioenergy, 13(8), 1210–1231) addressed what it called 'misconceptions' in papers by us and other authors that examined issues of carbon debt and when burning forest biomass for energy could have a net climate benefit. This letter re‐emphasizes the critical importance of the time dimension in assessing impacts, and takes particular issue with Cowie et al's lack of concern over substantial delays in reducing emissions and increasing the risks of crossing climate tipping points. [ABSTRACT FROM AUTHOR]

The climate impact of bioenergy is commonly quantified in terms of CO2 equivalents, using a fixed 100‐year global warming potential as an equivalency metric. This method has been criticized for the inability to appropriately address emissions timing and the focus on a single impact metric, which may lead to inaccurate or incomplete quantification of the climate impact of bioenergy production. In this study, we introduce Dynamic Relative Climate Impact (DRCI) curves, a novel approach to visualize and quantify the climate impact of bioenergy systems over time. The DRCI approach offers the flexibility to analyze system performance for different value judgments regarding the impact category (e.g., emissions, radiative forcing, and temperature change), equivalency metric, and analytical time horizon. The DRCI curves constructed for fourteen bioenergy systems illustrate how value judgments affect the merit order of bioenergy systems, because they alter the importance of one‐time (associated with land use change emissions) versus sustained (associated with carbon debt or foregone sequestration) emission fluxes and short‐ versus long‐lived climate forcers. Best practices for bioenergy production (irrespective of value judgments) include high feedstock yields, high conversion efficiencies, and the application of carbon capture and storage. Furthermore, this study provides examples of production contexts in which the risk of land use change emissions, carbon debt, or foregone sequestration can be mitigated. For example, the risk of indirect land use change emissions can be mitigated by accompanying bioenergy production with increasing agricultural yields. Moreover, production contexts in which the counterfactual scenario yields immediate or additional climate impacts can provide significant climate benefits. This paper is accompanied by an Excel‐based calculation tool to reproduce the calculation steps outlined in this paper and construct DRCI curves for bioenergy systems of choice. Dynamic Relative Climate Impact (DRCI) curves are a novel approach to quantify the climate impact of bioenergy systems over time. The DRCI approach offers the flexibility to analyze system performance for different value judgments regarding the impact category, equivalency metric, and analytical time horizon. The DRCI curves for four bioenergy systems illustrated in this figure show how the aforementioned value judgments can lead to alternative conclusions about the (relative) performance of bioenergy systems. [ABSTRACT FROM AUTHOR]

This paper describes an economic analysis of the GoBiGas plant, which is a first‐of‐its‐kind industrial installation for advanced biofuel production (ABP) via gasification, in which woody biomass is converted to biomethane. A previous technical evaluation of the demonstration unit confirmed that it is technically feasible to construct advanced biofuel production plants, using commercially available and widely used components. Thus, significant cost reductions for equipment cannot be expected as a consequence of learning effects. However, the equipment itself accounted for <20% of the total investment cost at GoBiGas and there exists the potential to reduce the production cost through learning how to assemble the process and reduce project‐specific costs. The analysis shows that a plant with capacity of 200 MW of biomethane is an attractive scale for future stand‐alone ABP plants with respect to limiting the production cost. For a 200‐MW ABP plant operated using forest residues as fuel, the production cost for biomethane is estimated at approximately 600 SEK/MWh, (60€/MWh, 75US$/MWh), which is equivalent to 5.4 SEK/liter gasoline [0.54 €/liter, or 2.5USD per gallon (9.9 SEK/€, 8 SEK/USD)], where the feedstock accounts for about 36% of the production cost. The most significant uncertainty factors pertaining to the estimated production costs are expected to relate to: trade conditions; the location of the installation; and the local price of feedstock. Thus, there is some potential for implementing cost‐competitive ABP systems of smaller capacity if low‐grade feedstocks (eg, waste‐derived woody biomass) can be utilized, and/or if the unit can be integrated with the already existing infrastructure. In this paper, we describe an economic analysis of the GoBiGas plant, which is a first‐of‐its‐kind industrial installation for advanced biofuel production (ABP) via gasification, in which woody biomass is converted to biomethane. [ABSTRACT FROM AUTHOR]

Lignocellulose is the most abundant biomass on Earth, with an estimated 181.5 billion tonnes produced annually. Of the 8.2 billion tonnes that are currently used, about 7 billion tonnes are produced from dedicated agricultural, grass and forest land and another 1.2 billion tonnes stem from agricultural residues. Economic and environmentally efficient pathways for production and utilization of lignocellulose for chemical products and energy are needed to expand the bioeconomy. This opinion paper arose from the research network "Lignocellulose as new resource platform for novel materials and products" funded by the German federal state of Baden‐Württemberg and summarizes original research presented in this special issue. It first discusses how the supply of lignocellulosic biomass can be organized sustainably and suggests that perennial biomass crops (PBC) are likely to play an important role in future regional biomass supply to European lignocellulosic biorefineries. Dedicated PBC production has the advantage of delivering biomass with reliable quantity and quality. The tailoring of PBC quality through crop breeding and management can support the integration of lignocellulosic value chains. Two biorefinery concepts using lignocellulosic biomass are then compared and discussed: the syngas biorefinery and the lignocellulosic biorefinery. Syngas biorefineries are less sensitive to biomass qualities and are technically relatively advanced, but require high investments and large‐scale facilities to be economically feasible. Lignocellulosic biorefineries require multiple processing steps to separate the recalcitrant lignin from cellulose and hemicellulose and convert the intermediates into valuable products. The refining processes for high‐quality lignin and hemicellulose fractions still need to be further developed. A concept of a modular lignocellulosic biorefinery is presented that could be flexibly adapted for a range of feedstock and products by combining appropriate technologies either at the same location or in a decentralized form. The opinion paper first discusses how the supply of lignocellulosic biomass can be produced sustainably and suggests that perennial biomass crops are expected to play an important role in lignocellulosic biorefineries. For its use, two biorefinery concepts are the compared and discussed. A modular concept for a lignocellulose biorefinery is presented that could be flexible adapted for a range of feedstock and products by selection of appropriate refining modules. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the main experiences gained and conclusions drawn from the demonstration of a first‐of‐its‐kind wood‐based biomethane production plant (20‐MW capacity, 150 dry tonnes of biomass/day) and 10 years of operation of the 2–4‐MW (10–20 dry tonnes of biomass/day) research gasifier at Chalmers University of Technology in Sweden. Based on the experience gained, an elaborated outline for commercialization of the technology for a wide spectrum of applications and end products is defined. The main findings are related to the use of biomass ash constituents as a catalyst for the process and the application of coated heat exchangers, such that regular fluidized bed boilers can be retrofitted to become biomass gasifiers. Among the recirculation of the ash streams within the process, presence of the alkali salt in the system is identified as highly important for control of the tar species. Combined with new insights on fuel feeding and reactor design, these two major findings form the basis for a comprehensive process layout that can support a gradual transformation of existing boilers in district heating networks and in pulp, paper and saw mills, and it facilitates the exploitation of existing oil refineries and petrochemical plants for large‐scale production of renewable fuels, chemicals, and materials from biomass and wastes. The potential for electrification of those process layouts are also discussed. The commercialization route represents an example of how biomass conversion develops and integrates with existing industrial and energy infrastructures to form highly effective systems that deliver a wide range of end products. Illustrating the potential, the existing fluidized bed boilers in Sweden alone represent a jet fuel production capacity that corresponds to 10% of current global consumption. [ABSTRACT FROM AUTHOR]

The article discusses three papers on the effect of land use change in global climate change mitigation. It says that the paper of S. Choi and colleagues presents a sensitivity analysis of forest carbon emissions in relation to crops and livestock. It says that the paper of J. Beckman, C. Jones, and R. Sands presents an equilibrium analysis of biofuel mandates and greenhouse gas (GHG) emissions. Meanwhile, A. Gurgel and colleagues discusses model effects of alternative carbon price policies.

Kraft pulp production generates residues and by‐products of significant importance to the mill. Solid residues from forestry activities are commonly used to generate steam in power boilers. In the recovery cycle, black liquor generates steam (and subsequently energy) by burning in the Tomlinson boiler, while white liquor is regenerated. Well‐developed alternative technologies can use these residues and by‐products to generate different types of biofuels. This review addresses the use of such technologies integrated with Kraft mills, in the concept of biorefineries, showing advantages, disadvantages, and successful examples. Solid residues from forestry can be used to produce bio‐oil through processes such as fast pyrolysis and hydrothermal liquefaction. Bio‐oils are currently used for heating through combustion in commercial/industrial boilers, but greater appreciation occurs if used as biofuels, which is done through catalytic upgrading processes. Black liquor gasification generates synthesis gas, which can be burned for energy co‐generation, used to produce synthetic fuels, or as a hydrogenating agent for bio‐oil or crude tall oil catalytic upgrading. Kraft biorefineries are gradually being implemented, justifying efforts to improve existing and new biomass conversion technologies. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including the bioenergy resources from perennial crops in Europe, the use Miscanthus silvergrass for biogas production and anaerobic digestion, and the environmental impact of energy crops farming.

Energy consumption and CO2 emissions have been increasing continuously over the past few decades in China and there is a pressing need to replace the fossil fuel‐based economy with an efficient low‐carbon system, tailor‐made to future requirements. China is starting an energy transition with the aim of building an energy system for the future. China has made tremendous progress in increasing the amount of renewable energy and reducing the cost of renewable energy over the last 20 years. According to the 14th 5 year plan, China aims to incorporate 20% of renewable energy to the primary energy mix and attain 27% reduction in CO2 emissions. Bioenergy crops constitute a significant proportion of biomass‐based bioenergy and have recently been promoted by the Chinese Government to help overcome food and fuel conflict. Steps are being taken to promote bioenergy crops on marginal lands in China, and various regions across the country with soil marginality have been evaluated for bioenergy crop cultivation. The present paper reviews the status of bioenergy in China and the potential status of marginal lands from different regions of China. It also elaborates on some of the policies, subsidies and incentives allocated by the Chinese Government for the promotion of biomass‐based energy. Land management and plant improvement strategies were discussed, which are effective in making marginal lands suitable for bioenergy crop cultivation. Managing planting strategies, intercropping and crop rotation are effective management practices used in China for the utilization of marginal lands. A national investigation is desirable for creating an inventory of technical and economic potential of biomass feedstocks that could be planted on marginal lands. This would assist with highlighting the pros and cons of using marginal lands for bioenergy production and effective policy making. [ABSTRACT FROM AUTHOR]

Global efforts to develop renewable energy include a focus on biofuels, especially algal‐based biofuels. As the world's largest developing country, China is striving to develop a range of renewable energy sources. Here, we performed an informatics analysis to monitor the development of microalgal biofuels in China by analyzing energy policies related to microalgal biomass and biofuel production and funding inputs and scientific research projects in this field. China has already made substantial contributions to the microalgal biofuel industry worldwide. Despite recent declines in research and investment due to the overall economic environment, microalgal energy research and applications technologies have tremendous prospects. We summarize progress in research on microalgal biomass and biofuel production, focusing on microalgal culture patterns and the production of energy, including efforts in China to promote the industrialization of microalgal biofuels. Finally, we explore possible solutions to bottlenecks that must be overcome before microalgal biofuels can be widely used and discuss future prospects. In addition to serving as a theoretical reference for researchers and decision makers in China and beyond, the information presented in this review article can be used to guide the industrialization of microalgal‐based biofuel production. [ABSTRACT FROM AUTHOR]

Scleractinian corals are colonial animals with a range of life‐history strategies, making up diverse species assemblages that define coral reefs. We tagged and tracked ~30 colonies from each of 11 species during seven trips spanning 6 years (2009–2015) to measure their vital rates and competitive interactions on the reef crest at Trimodal Reef, Lizard Island, Australia. Pairs of species were chosen from five growth forms in which one species of the pair was locally rare (R) and the other common (C). The sampled growth forms were massive (Goniastrea pectinata [R] and G. retiformis [C]), digitate (Acropora humilis [R] and A. cf. digitifera [C]), corymbose (A. millepora [R] and A. nasuta [C]), tabular (A. cytherea [R] and A. hyacinthus [C]) and arborescent (A. robusta [R] and A. intermedia [C]). An extra corymbose species with intermediate abundance, A. spathulata was included when it became apparent that A. millepora was too rare on the reef crest, making the 11 species in total. The tagged colonies were visited each year in the weeks prior to spawning. During visits, two or more observers each took two or three photographs of each tagged colony from directly above and on the horizontal plane with a scale plate to track planar area. Dead or missing colonies were recorded and new colonies tagged to maintain ~30 colonies per species throughout the 6 years of the study. In addition to tracking tagged corals, 30 fragments were collected from neighboring untagged colonies of each species for counting numbers of eggs per polyp (fecundity); and fragments of untagged colonies were brought into the laboratory where spawned eggs were collected for biomass and energy measurements. We also conducted surveys at the study site to generate size structure data for each species in several of the years. Each tagged colony photograph was digitized by at least two people. Therefore, we could examine sources of error in planar area for both photographers and outliners. Competitive interactions were recorded for a subset of species by measuring the margins of tagged colony outlines interacting with neighboring corals. The study was abruptly ended by Tropical Cyclone Nathan (Category 4) that killed all but nine of the more than 300 tagged colonies in early 2015. Nonetheless, these data will be of use to other researchers interested in coral demography and coexistence, functional ecology, and parametrizing population, community, and ecosystem models. The data set is not copyright restricted, and users should cite this paper when using the data. [ABSTRACT FROM AUTHOR]

The article presents a commentary on bioenergy in a global environment. The author mentions some papers focusing on biofuels and the effects of the industry on economic stability, global food prices, and climate change. The author comments on the papers and renders perspectives on the U.S. bioenergy sector and its policies.

Bioethanol has been identified as a renewable product with high potential for application as biofuel. On the other hand, high volumes of agri‐food residues are generated daily. Such residues have potential as raw materials for industrial bioethanol production. There is a significant advance in the synthesis of biofuels from fruit and vegetable residues; however, most of the studies are focused on the conversion of a single type of raw material, limiting the application of the synthesis routes. This work presents a conversion methodology to produce bioethanol from carrot and broccoli residues and from their mixture; the samples of vegetable wastes has been collected in the municipality of Guanajuato, Mexico. Using the 1H NMR technique, the characteristic signals of bioethanol are identified. On the other hand, using the UV–VIS spectrophotometry technique, a maximum of 25.63 mg of total sugar content has been determined for the mixture. Likewise, a maximum bioethanol concentration of 60.6 g/L is obtained. From a refractometry and HPLC study, a conversion to bioethanol of 34.8% is determined for the mixture of residues. This work analyses the potential of broccoli and carrot residues for bioethanol production, either as isolated or as mixed wastes. [ABSTRACT FROM AUTHOR]

Biofuel can be used to abate greenhouse gas emissions in the transport sector, by replacing fossil fuel. To avoid the problem of competition with food production, the use of abandoned agricultural land (AAL) for production of the feedstock for biofuel has been proposed. AAL has generally low productivity but has also low opportunity costs, and production of perennial bioenergy crops on it can lead to carbon sequestration. A spatially explicit optimization model of biofuel production and transport fuel consumption, applied to Sweden, was used for an analysis of how AAL can alter costs for greenhouse gas emissions abatement. Results show that, compared to the case without AAL, AAL could decrease the costs of reducing greenhouse gas emissions by 29%, for emissions reductions equivalent to 50% of current emissions from gasoline in Sweden. The carbon sequestration from establishing perennial bioenergy crops on AAL is the main driver of the positive results. High carbon sequestration on AAL implies larger emissions reduction for a given volume of biofuel, and the results show that the total biofuel production can be both smaller and larger with AAL. The use of arable land for biofuel production is generally smaller with AAL, but larger at some of the highest analyzed target levels. The low AAL feedstock costs contribute to lower costs of the total biofuel production, which pushes for more total biofuel production and less fuel use reduction and therefore counteracts the reduced use of arable land. [ABSTRACT FROM AUTHOR]

The conversion of the biomass into eco‐friendly fuels and chemicals has been extensively recognized as the essential pathway to achieve the sustainable economy and carbon neutral society. Lignin, as a kind of promising biomass energy, has been certified to produce the high‐valued chemicals and fuels. Numerous efforts have been made to develop various catalysts for lignin catalytic conversion. Both metal‐organic frameworks (MOFs) and covalent organic frameworks (COFs) belong to very important heterogeneous porous catalysts due to their regular porous structures, high specific surface area, and precisely tailored diversities. In the review, the first part focused on the catalytic conversion of lignin, lignin model compounds, and lignin derivatives using the pristine MOFs, functional MOF composites, and MOF‐derived materials. The second part summarized the catalytic conversion of lignin model compounds using pristine COFs and functional COF composites. The review here mainly concentrated on the design of the materials, screening of catalytic conditions, and explorations of the corresponded mechanisms. Specifically, (1) we summarized the MOF‐ and COF‐based materials for the effects on the catalytic transformation of lignin‐related substances; (2) we emphasized the catalytic mechanism of C–C and C–O bonds cleavage together with the structure–activity relationships; (3) we in‐depth realized the relationship between the chemical/electronic/structural properties of the MOF‐ and COF‐based catalysts and their catalytic performance for lignin‐related substances. Finally, the challenges and future perspectives were also discussed on the catalytic conversion of lignin‐related substances by MOF‐ and COF‐based catalysts. [ABSTRACT FROM AUTHOR]

Ongoing concern over climate change has led to interest in replacing fossil energy with bioenergy. There are different approaches to quantitatively estimate the climate change effects of bioenergy systems. In the present work, we have focused on a range of published impact assessment methods that vary due to conceptual differences in the treatment of biogenic carbon fluxes, the type of climate change impacts they address and differences in time horizon and time preference. Specifically, this paper reviews fifteen different methods and applies these to three hypothetical bioenergy case studies: (a) woody biomass grown on previously forested land; (b) woody biomass grown on previous pasture land; and (b) annual energy crop grown on previously cropped land. Our analysis shows that the choice of method can have an important influence on the quantification of climate change effects of bioenergy, particularly when a mature forest is converted to bioenergy use as it involves a substantial reduction in biomass carbon stocks. Results are more uniform in other case studies. In general, results are more sensitive to specific impact assessment methods when they involve both emissions and removals at different points in time, such as for forest bioenergy, but have a much smaller influence on agricultural bioenergy systems grown on land previously used for pasture or annual cropping. The development of effective policies for climate change mitigation through renewable energy use requires consistent and accurate approaches to identification of bioenergy systems that can result in climate change mitigation. The use of different methods for the same purpose: estimating the climate change effects of bioenergy systems, can lead to confusing and contradictory conclusions. A full interpretation of the results generated with different methods must be based on an understanding that the different methods focus on different aspects of climate change and represent different time preferences. There are different approaches to quantitatively estimate the climate change effects of bioenergy systems. In the present work, we review fifteen different methods and apply these to three hypothetical bioenergy case studies. Our analysis shows that the choice of method can have an important influence on the quantification of climate change effects of bioenergy. The use of different methods for the same purpose can lead to confusing and contradictory conclusions. [ABSTRACT FROM AUTHOR]

Genetic improvement through breeding is one of the key approaches to increasing biomass supply. This paper documents the breeding progress to date for four perennial biomass crops (PBCs) that have high output–input energy ratios: namely Panicum virgatum (switchgrass), species of the genera Miscanthus (miscanthus), Salix (willow) and Populus (poplar). For each crop, we report on the size of germplasm collections, the efforts to date to phenotype and genotype, the diversity available for breeding and on the scale of breeding work as indicated by number of attempted crosses. We also report on the development of faster and more precise breeding using molecular breeding techniques. Poplar is the model tree for genetic studies and is furthest ahead in terms of biological knowledge and genetic resources. Linkage maps, transgenesis and genome editing methods are now being used in commercially focused poplar breeding. These are in development in switchgrass, miscanthus and willow generating large genetic and phenotypic data sets requiring concomitant efforts in informatics to create summaries that can be accessed and used by practical breeders. Cultivars of switchgrass and miscanthus can be seed‐based synthetic populations, semihybrids or clones. Willow and poplar cultivars are commercially deployed as clones. At local and regional level, the most advanced cultivars in each crop are at technology readiness levels which could be scaled to planting rates of thousands of hectares per year in about 5 years with existing commercial developers. Investment in further development of better cultivars is subject to current market failure and the long breeding cycles. We conclude that sustained public investment in breeding plays a key role in delivering future mass‐scale deployment of PBCs. Plant breeding links the research effort with commercial mass upscaling. The authors' assessment of development status of the four species is shown (poplar having two: one for short rotation coppice (SRC) poplar and one for the more traditional short rotation forestry (SRF)). Mass scale deployment needs developments outside the breeding arenas to drive breeding activities more rapidly and extensively. [ABSTRACT FROM AUTHOR]

The airline industry has a strong interest in developing sustainable aviation fuels, in order to reduce their exposure to increasing oil prices and cost liability for greenhouse gas emissions. The feasibility and cost of producing sustainable biomass-based jet fuels at a sufficient scale to materially address these issues is an enormous challenge. This paper builds directly on the biophysical study by H.T. Murphy, D.A. O'Connell, R.J. Raison, A.C. Warden, T.H. Booth, A. Herr, A.L. Braid, D.F. Crawford, J.A. Hayward, T. Javonovic, J.G. McIvor, M.H. O'Connor, M.L. Poole, D. Prestwidge, N. Raisbeck-Brown & L. Rye, In review, which examined a 25 year scale-up strategy to produce 5% of projected jet fuel demand in Australia in 2020 (470 mL) in the Fitzroy region of Queensland, Australia. The strategy was based on the use of a mixed ligno-cellulosic biomass feedstock and assumed, for the sake of exploring and quantifying the scenario, a simplified two-step conversion process - conversion of biomass to crude bio-oil within the region, and upgrade to jet fuel at a central Brisbane facility. This paper provides details on the costs of production in this scenario, focusing on two different strategies for biomass utilization, and two types of novel small-medium scale conversion technologies. The cost analyses have taken into account technology learning curves, different economies of scale and key cost sensitivities. The cost of biomass-based jet fuels is estimated to be between 0.70 and 1.90 $ L−1 when the efficiency of conversion of biomass to biocrude and subsequently to aviation fuel is varied by ±10% of published values, with an average value of 1.10 $ L−1. This is within the range of the projected 2035 conventional jet fuel price of 1.50 $ L−1. Therefore, biomass-based jet fuel has the potential to contribute to supply of Australia's jet fuel needs in the future. [ABSTRACT FROM AUTHOR]

Recent studies have introduced the metric GWP bio, an indicator of the potential global warming impact of CO2 emissions from biofuels. When a time horizon of 100 years was applied, the studies found the GWP bio of bioenergy from slow-growing forests to be significantly lower than the traditionally calculated GWP of CO2 from fossil fuels. This result means that bioenergy is an attractive energy source from a climate mitigation perspective. The present paper provides an improved method for quantifying GWP bio. The method is based on a model of a forest stand that includes basic dynamics and interactions of the forest's multiple carbon pools, including harvest residues, other dead organic matter, and soil carbon. Moreover, the baseline scenario (with no harvest) takes into account that a mature stand will usually continue to capture carbon if not harvested. With these methodological adjustments, the resulting GWP bio estimates are found to be two to three times as high as the estimates of GWP bio found in other studies, and also significantly higher than the GWP of fossil CO2, when a 100-year time horizon is applied. Hence, the climate impact per unit of CO2 emitted seems to be even higher for the combustion of slow-growing biomass than for the combustion of fossil carbon in a 100-year time frame. [ABSTRACT FROM AUTHOR]

Since the introduction of the European Union's Renewable Energy Directive (RED), biofuel‐producing firms are required to perform life cycle assessment (LCA) based greenhouse gas accounting in order to fulfill part of directive's sustainability criteria. This paper adopts the concepts of "governing by standards" and "governing by numbers" to understand the LCA practices of biofuel‐producing firms and assess the critical moments of friction between these alternative modes of governance. We focus our analysis on the use of LCA in the Swedish biofuel industry, undertaking case studies on the use of LCA in four Swedish biofuel‐producing firms and semistructured interviews with industry associations and governmental bodies. Results indicated that the RED not only influences what biofuel sustainability entails but also structures the calculative practices used to measure it. At the same time, our results point to friction between achieving regulatory compliance and improving biofuel sustainability. [ABSTRACT FROM AUTHOR]

The area of dedicated energy crops is expected to increase in Sweden. This will result in direct land use changes, which may affect the carbon stocks in soil and biomass, as well as yield levels and the use of inputs. Carbon dioxide ( CO2) fluxes of biomass are often not considered when calculating the climate impact in life cycle assessments ( LCA) assuming that the CO2 released at combustion has recently been captured by the biomass in question. With the extended time lag between capture and release of CO2 inherent in many perennial bioenergy systems, the relation between carbon neutrality and climate neutrality may be questioned. In this paper, previously published methodologies and models are combined in a methodological framework that can assist LCA practitioners in interpreting the time-dependent climate impact of a bioenergy system. The treatment of carbon differs from conventional LCA practice in that no distinction is made between fossil and biogenic carbon. A time-dependent indicator is used to enable a representation of the climate impact that is not dependent on the choice of a specific characterization time horizon or time of evaluation and that does not use characterization factors, such as global warming potential and global temperature potential. The indicator used to aid in the interpretation phase of this paper is global mean surface temperature change (Δ Ts( n)). A theoretical system producing willow for district heating was used to study land use change effects depending on previous land use and variations in the standing biomass carbon stocks. When replacing annual crops with willow this system presented a cooling contribution to Δ Ts( n). However, the first years after establishing the willow plantation it presented a warming contribution to Δ Ts( n). This behavior was due mainly to soil organic carbon ( SOC) variation. A rapid initial increase in standing biomass counteracted the initial SOC loss. [ABSTRACT FROM AUTHOR]

Abstract: The increase in greenhouse gases (GHG) emissions in the world has significantly contributed to climate change, prompting an active search for renewable and sustainable biofuels. Sweet sorghum (Sorghum bicolor (L.) Moench) is a leading biofuel feedstock that is produced with minimum inputs and does well even in semi‐arid areas with soils of low fertility. However, a sustainable production system for sweet sorghum is not yet established in South Africa. Lately, conservation agriculture (CA) has gained research focus because of its benefits as a sustainable crop production system. Therefore, CA may offset the negative impacts of intensive agronomic practices during biofuel crop production. This paper reviewed CA as a possible sustainable crop production system for sweet sorghum as a biofuel feedstock. CA enhanced soil quality, reduced carbon dioxide emissions, and increased yield of sorghum and related cereals. It was concluded that CA has potential to enhance sweet sorghum production as a biofuel feedstock under semi‐arid conditions in South Africa. Therefore, local field experiments on sweet sorghum production under CA are desirable in South Africa. [ABSTRACT FROM AUTHOR]

As a renewable energy, biofuel has greatly attracted worldwide attention due to the growing demands for cleaner sources of energy as an intervention to mitigate the serious environmental problems associated with fossil fuel consumption. As an important non‐food biodiesel plant, Pistacia chinensis has a promising prospect for bioenergy development. Based on the principles of multifactor integrated assessment, this paper provides an operational method for comprehensively evaluating the marginal land resources suitable for developing the plantation of Pistacia chinensis in Shaanxi province, China. The results show that the areas of marginal land resources suitable and fairly suitable for growing Pistacia chinensis in Shaanxi province are 1.21 million hectares and 4.45 million hectares, respectively. The suitable land resources are mainly located in Hanzhong (0.44 million hectares), Ankang (0.30 million hectares), and Shangluo (0.31 million hectares), most of which are moderate dense grassland (accounting for 50.65%), dense grassland (accounting for 21.83%), shrub land (accounting for 8.62%), and sparse forest land (accounting for 15.32%). The comparison between the results and field work data suggests that the pixel size of spatial data and soil organic matter content have important impacts on the final results. The outcome of this research can be used to implement specific policies for developing Pistacia chinensis in China and other countries especially the countries along the Silk Road. [ABSTRACT FROM AUTHOR]

Forests of the Midwestern United States are an important source of fiber for the wood and paper products industries. Scientists, land managers, and policy makers are interested in using woody biomass and/or harvest residue for biofuel feedstocks. However, the effects of increased biomass removal for biofuel production on forest production and forest system carbon balance remain uncertain. We modeled the carbon (C) cycle of the forest system by dividing it into two distinct components: (1) biological (net ecosystem production, net primary production, autotrophic and heterotrophic respiration, vegetation, and soil C content) and (2) industrial (harvest operations and transportation, production, use, and disposal of major wood products including biofuel and associated C emissions). We modeled available woody biomass feedstock and whole-system carbon balance of 220 000 km2 of temperate forests in the Upper Midwest, USA by coupling an ecosystem process model to a collection of greenhouse gas life-cycle inventory models and simulating seven forest harvest scenarios in the biological ecosystem and three biofuel production scenarios in the industrial system for 50 years. The forest system was a carbon sink (118 g C m−2 yr−1) under current management practices and forest product production rates. However, the system became a C source when harvest area was doubled and biofuel production replaced traditional forest products. Total carbon stores in the vegetation and soil increased by 5-10% under low-intensity management scenarios and current management, but decreased up to 3% under high-intensity harvest regimes. Increasing harvest residue removal during harvest had more modest effects on forest system C balance and total biomass removal than increasing the rate of clear-cut harvests or area harvested. Net forest system C balance was significantly, and negatively correlated ( R2 = 0.67) with biomass harvested, illustrating the trade-offs between increased C uptake by forests and utilization of woody biomass for biofuel feedstock. [ABSTRACT FROM AUTHOR]

Thermal imagery is among the most promising techniques to assess genotypic variability in crop water status, a factor in yield performance in response to stresses such as water deficit or heat. The paper of Masuka et al. (pp 238-249) reports on novel technologies to evaluate phenotypic performance under different stress conditions together with the use of different phenotyping techniques to handle the problems associated with spatial variability exhibited by field trials. [ABSTRACT FROM AUTHOR]

This paper begins with an introduction to the ancient spiritual tradition of India. The focus is upon aspects of ancient Indian philosophy relevant to modern society. In the Indian context, science and spirituality are complementary. The application of ethical and religious motivations derived from these ideas is delineated with respect to the practical implementation of energy projects. The efforts of religious and social groups in promoting renewable energy in India are included. A few bioenergy technologies relevant to rural communities in developing nations are then described. The paper argues that though scientific research, technology development, community-based efforts, environmental activism, and renewable energy policy making are important elements in dealing with the energy crisis, they are not sufficient to solve the crisis. The paper closes with the premise that the main wisdom to be drawn from the religious, spiritual, and philosophical traditions concerns the inner transformation that is key to meeting today's energy and environmental crisis. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) emissions from biomass combustion are traditionally assumed climate neutral if the bioenergy system is carbon (C) flux neutral, i.e. the CO2 released from biofuel combustion approximately equals the amount of CO2 sequestered in biomass. This convention, widely adopted in life cycle assessment (LCA) studies of bioenergy systems, underestimates the climate impact of bioenergy. Besides CO2 emissions from permanent C losses, CO2 emissions from C flux neutral systems (that is from temporary C losses) also contribute to climate change: before being captured by biomass regrowth, CO2 molecules spend time in the atmosphere and contribute to global warming. In this paper, a method to estimate the climate impact of CO2 emissions from biomass combustion is proposed. Our method uses CO2 impulse response functions (IRF) from C cycle models in the elaboration of atmospheric decay functions for biomass-derived CO2 emissions. Their contributions to global warming are then quantified with a unit-based index, the GWPbio. Since this index is expressed as a function of the rotation period of the biomass, our results can be applied to CO2 emissions from combustion of all the different biomass species, from annual row crops to slower growing boreal forest. [ABSTRACT FROM AUTHOR]

This paper derives a method to quantify the impact of biofuels on fuel markets, assuming that these markets are dominated by a cartel of oil-rich countries and that fuel prices in these countries are significantly lower than those in the rest of the world. We identify large differences between the effects of introducing biofuels using the proposed method (denoted the cartel-of-nations [CON] model), in contrast to the competitive or the standard cartel models. When compared with the CON model, the competitive model overestimates the reduction in fuel prices and underestimates the reduction in fuel consumption, and therefore the impact of biofuels on greenhouse gases. [ABSTRACT FROM AUTHOR]

A large number of proposed biofuel crops share the same traits as known invasive plant species, many of which are already present in Africa and include species such as Prosopis glandulosa Torrey (Mimosaceae), P. juliflora (Sw.) DC, Leucaena leucocephala (Lam.) de Wit (Mimosaceae), Azadirachta indica A. Juss. (Meliaceae), and others. In this paper, we mainly assess the impacts of invasive Prosopis species in Africa, particularly in Kenya and South Africa. Introduced Prosopis species have invaded over 4 million hectares in Africa, threatening crop and pasture production, reducing underground water reserves, and displacing native plant and animal species. This has major implications for millions of people who depend on natural resources for their survival. It is therefore suggested that known invasive or potentially invasive plant species not be introduced to countries or regions for biofuel production. If (after a stringent cost-benefit analysis) the introduction of a potentially invasive species is deemed critical for economic development and the benefits clearly outweigh the potential costs, countries should endeavour to abide by the Principles and Criteria for Sustainable Biofuel Production developed by the Roundtable on Sustainable Biofuels. [ABSTRACT FROM AUTHOR]

It is widely recognized that biofuel production from lignocellulosic materials is limited by inadequate technology to efficiently and economically release fermentable sugars from the complex multi-polymeric raw materials. Therefore, endoglucanases, exoglucanase, pectate lyases, cutinase, swollenin, xylanase, acetyl xylan esterase, beta glucosidase and lipase genes from bacteria or fungi were expressed in Escherichia coli or tobacco chloroplasts. A PCR-based method was used to clone genes without introns from Trichoderma reesei genomic DNA. Homoplasmic transplastomic lines showed normal phenotype and were fertile. Based on observed expression levels, up to 49, 64 and 10, 751 million units of pectate lyases or endoglucanase can be produced annually, per acre of tobacco. Plant production cost of endoglucanase is 3100-fold, and pectate lyase is 1057 or 1480-fold lower than the same recombinant enzymes sold commercially, produced via fermentation. Chloroplast-derived enzymes had higher temperature stability and wider pH optima than enzymes expressed in E. coli. Plant crude-extracts showed higher enzyme activity than E. coli with increasing protein concentration, demonstrating their direct utility without purification. Addition of E. coli extracts to the chloroplast-derived enzymes significantly decreased their activity. Chloroplast-derived crude-extract enzyme cocktails yielded more (up to 3625%) glucose from filter paper, pine wood or citrus peel than commercial cocktails. Furthermore, pectate lyase transplastomic plants showed enhanced resistance to Erwina soft rot. This is the first report of using plant-derived enzyme cocktails for production of fermentable sugars from lignocellulosic biomass. Limitations of higher cost and lower production capacity of fermentation systems are addressed by chloroplast-derived enzyme cocktails. [ABSTRACT FROM AUTHOR]

This paper analyses Brazil's experience with biofuels, focusing on the central role of the federal government as the main force driving the implementation of alternative locally produced ethanol (ethyl alcohol) and biodiesel. The pioneering, large scale ethanol programme that started over 30 years ago can be considered the most successful experience with the use of biofuels to date, as the government was able to rapidly implement the use of ethanol (ethyl alcohol) as a substitute for petrol in the 1970s and 1980s. The work contributes to the general discussion of sustainable and renewable energy sources and sets out the key policy mechanisms used. The paper also innovatively looks at the second large governmental intervention in the renewable fuels market – the biodiesel programme. In addition to the contribution to the debate surrounding command-and-control measures and economic incentive instruments, the paper analyses how lessons learned from the ethanol experiment were taken into consideration in the design and implementation of the biodiesel mandate, including social and environmental facets. It emphasizes the uniqueness of producing sugarcane ethanol in the Brazilian context and how attempts to carry out similar fast growing biofuels programmes may not be possible in other parts of the world. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

The rapid decline in fossil fuel reserves in the world, rising oil prices, and growing concerns about the increase in pollutant gas emissions from this type of energy, have led to the exploration of new energy sources for the production of alternative fuels. The use of vegetable oils as a low-cost raw material for biodiesel production is an effective way to reduce biodiesel costs. This paper reports on the production and biodiesel properties of the seed oils of six native species belonging to different families of plants from the Atlantic Forest in northeast Brazil. The results are compared with those obtained from traditional crops such as soybean and olive. The relative oil content of the seeds ranged from 31.5 to 67.4 %, while the biodiesel yield from these oils ranged from 93.2 to 97.6 wt%. The fatty acid composition is mainly constituted of oleic acid in three species ( Cissampelos andromorpha, Rauwolfia grandiflora, and Tabernaemontana flavicans), eicosenoic acid in two species ( Serjania caracasana and Serjania salzmanniana) and palmitic acid in Protium heptaphyllum. The physicochemical parameters of oil (density, viscosity, % FFA, and % of linolenic acid) and biodiesel (density, viscosity, acid number, copper strip corrosion, flash point, sulfur content, sulfated ash, water, oxidative stability, free and total glycerin) were in agreement with ASTM 6751 and EN 14214 standards. The fatty acid composition, biodiesel yield, oil, and biodiesel properties of the six native species studied demonstrate the high potential for producing alternative fuel in conventional diesel engines. [ABSTRACT FROM AUTHOR]

U.S. forests, particularly in the eastern states, provide an important offset to greenhouse gas (GHG) emissions. Some have proposed that forest‐based natural climate solutions can be strengthened via a number of strategies, including increases in the production of forest biomass energy. We used output from a forest dynamics model (SORTIE‐ND) in combination with a GHG accounting tool (ForGATE) to estimate the carbon consequences of current and intensified timber harvest regimes in the Northeastern United States. We considered a range of carbon pools including forest ecosystem pools, forest product pools, and waste pools, along with different scenarios of feedstock production for biomass energy. The business‐as‐usual (BAU) scenario, which represents current harvest practices derived from the analysis of U.S. Forest Service Forest Inventory and Analysis data, sequestered more net CO2 equivalents than any of the intensified harvest and feedstock utilization scenarios over the next decade, the most important time period for combatting climate change. Increasing the intensity of timber harvest increased total emissions and reduced landscape average forest carbon stocks, resulting in reduced net carbon sequestration relative to current harvest regimes. Net carbon sequestration "parity points," where the regional cumulative net carbon sequestration from alternate intensified harvest scenarios converge with and then exceed the BAU baseline, ranged from 12 to 40 years. A "no harvest" scenario provides an estimate of an upper bound on forest carbon sequestration in the region given the expected successional dynamics of the region's forests but ignores leakage. Regional net carbon sequestration is primarily influenced by (1) the harvest regime and amount of forest biomass removal, (2) the degree to which bioenergy displaces fossil fuel use, and (3) the proportion of biomass diverted to energy feedstocks versus wood products. [ABSTRACT FROM AUTHOR]

Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields and limit negative impacts on plant growth and development including targeting heterologous enzymes into specific subcellular compartments using signal peptides, using tissue-specific or inducible promoters to limit the expression of enzymes to certain portions of the plant or certain times, and fusion of amplification sequences upstream of the coding region to enhance expression. We also summarize methods that have been used to access and maintain activity of plant-generated enzymes when used in conjunction with thermochemical pretreatments for the production of lignocellulosic biofuels. [ABSTRACT FROM AUTHOR]

Grassland agriculture is experiencing a number of threats including declining profitability and loss of area to other land uses including expansion of the built environment as well as from cropland and forestry. The use of grassland as a natural resource either in terms of existing vegetation and land cover or planting of new species for bioenergy and other nonfood applications presents an opportunity, and potential solution, to maintain the broader ecosystem services that perennial grasslands provide as well as to improve the options for grassland farmers and their communities. This paper brings together different grass or grassland-based studies and considers them as part of a continuum of strategies that, when also combined with improvements in grassland production systems, will improve the overall efficiency of grasslands as an important natural resource and enable a greater area to be managed, replanted or conserved. These diversification options relate to those most likely to be available to farmers and land owners in the marginally economic or uneconomic grasslands of middle to northern Europe and specifically in the UK. Grasslands represent the predominant global land use and so these strategies are likely to be relevant to other areas although the grass species used may vary. The options covered include the use of biomass derived from the management of grasses in the urban and semi urban environment, semi-natural grassland systems as part of ecosystem management, pasture in addition to livestock production, and the planting and cropping of dedicated energy grasses. The adoption of such approaches would not only increase income from economically marginal grasslands, but would also mitigate greenhouse gas emissions from livestock production and help fund conservation of these valuable grassland ecosystems and landscapes, which is increasingly becoming a challenge. [ABSTRACT FROM AUTHOR]

Agro-economic modeling studies have shown that indirect land-use change ( iLUC) emissions of first-generation biofuels can be significant, reducing or eliminating the climate change mitigating potential of these fuels. Recognizing this, proposed amendments to the European Union's Renewable Energy Directive ( RED) would require reporting iLUC emissions of biofuels. The objective of this paper was to provide additional evidence of the iLUC emissions of oilseed rape ( OSR) biodiesel using a noneconomic modeling approach called the causal descriptive ( CD) model. The CD model originally developed by E4tech (A Causal Descriptive Approach to Modelling the GHG Emissions Associated with the Indirect Land Use Impacts of Biofuels, 2010, E4tech, London, UK) is one of the first noneconomic modeling approaches used for estimating indirect land-use change ( iLUC). Using the E4tech CD modeling framework, we refine assumptions for key parameters such as yields in marginal land, displacement of OSR oil by palm oil, land availability for OSR expansion in the EU, imports of OSR from Canada and Ukraine, and palm oil expansion on peatland and thereby estimate iLUC GHG emissions for a likely scenario (Central Scenario). We find GHG emissions of OSR biodiesel to be 57 g CO2 eq./ MJ for the Central Scenario. To capture the possible range of iLUC GHG emissions, we calculate iLUC GHG emissions by changing assumptions for the Central Scenario and land-use emission factors. We find that GHG emissions of OSR biodiesel may vary from 18 to 101 CO2 eq./ MJ. The results provide additional evidence supporting the previous conclusions derived from agro-economic modeling studies that iLUC emissions of food-based biofuels can be expected to be significant compared to potential savings. Hence, to achieve meaningful GHG reductions from biofuel use and avoid policy failure, it is important that the EU should take concrete policy action to target support for biofuels toward those with the lowest expected iLUC emissions. [ABSTRACT FROM AUTHOR]

Wood harvesting in boreal forests typically consists of sequential harvesting operations within a rotation: a few thinnings and a final felling. The aim of this paper is to model differentiated relative global warming potential ( GWP) coefficients for stemwood use from different thinnings and final fellings, and correction factors for long-lived wood products, potentially applicable in life cycle assessment studies. All thinnings and final fellings influence the development of forest carbon stocks. The climate impact of a single harvesting operation is generated in comparison with no harvesting, thus encountering a methodological problem on how to handle the subsequent operations. The dynamic forest stand simulator MOTTI was applied in the modelling of evolution of forest carbon stocks at landscape level in Southern Finland. The landscape-level approach for climate impact assessment gave results similar to some stand-level approaches presented in previous literature that included the same forest C pools and also studied the impacts relative to the no-harvest situation. The climate impacts of stemwood use decreased over time. For energy use, the impacts were higher or similar in the short term and 0-50% lower in the midterm in comparison with an identical amount of fossil CO2. The impacts were to some extent (approximately 20-40%) lower for wood from intermediate thinnings than for wood from final fellings or first thinnings. However, the study reveals that product lifetime has higher relative influence on the climate impacts of wood-based value chains than whether the stemwood originates from thinnings or final fellings. Although the evolution of future C stocks in unmanaged boreal forests is uncertain, a sensitivity analysis suggests that landscape-level model results for climate impacts would not be sensitive to the assumptions made on the future evolution of C stocks in unmanaged forest. Energy use of boreal stemwood seems to be far from climate neutral. [ABSTRACT FROM AUTHOR]

The aim of producing sustainable liquid biofuels and chemicals from lignocellulosic biomass remains high on the sustainability agenda, but is challenged by the costs of producing fermentable sugars from these materials. Sugars from plant biomass can be fermented to alcohols or even alkanes, creating a liquid fuel in which carbon released on combustion is balanced by its photosynthetic capture. Large amounts of sugar are present in the woody, nonfood parts of crops and could be used for fuel production without compromising global food security. However, the sugar in woody biomass is locked up in the complex and recalcitrant lignocellulosic plant cell wall, making it difficult and expensive to extract. In this paper,wereview what is known about the major polymeric components of woody plant biomass, with an emphasis on the molecular interactions that contribute to its recalcitrance to enzymatic digestion. In addition, we review the extensive research that has been carried out in order to understand and reduce lignocellulose recalcitrance and enable more cost-effective production of fuel from woody plant biomass. [ABSTRACT FROM AUTHOR]

Growing concerns about energy security and climate change have prompted interest in Australia and worldwide to look for alternatives of fossil fuels. Among the renewable fuel sources, biofuels are one such alternative that have received unprecedented attention in the past decade. Cellulosic biofuels, derived from agricultural and wood biomass, could potentially increase Australia's oil self-sufficiency. In this study, we carry out a hybrid life-cycle assessment ( LCA) of a future cellulose-refining industry located in the Green Triangle region of South Australia. We assess both the upstream and downstream refining stages, and consider as well the life-cycle effects occurring in conventional industries displaced by the proposed biofuel supply chains. We improve on conventional LCA method by utilising multi-region input-output ( IO) analysis that allows a comprehensive appraisal of the industry's supply chains. Using IO-based hybrid LCA, we evaluate the social, economic and environmental impacts of lignocellulosic biofuel production. In particular, we evaluate the employment, economic stimulus, energy consumption and greenhouse gas impacts of the biofuel supply chain and also quantify the loss in economic activity and employment in the paper, pulp and paperboard industry resulting from the diversion of forestry biomass to biofuel production. Our results reveal that the loss in economic activity and employment will only account for 10% of the new jobs and additional stimulus generated in the economy. Lignocellulosic biofuel production will create significant new jobs and enhance productivity and economic growth by initiating the growth of new industries in the economy. The energy return on investment for cellulosic biofuel production lies between 2.7 and 5.2, depending on the type of forestry feedstock and the travel distance between the feedstock industry and the cellulose refinery. Furthermore, the biofuel industry will be a net carbon sequester. [ABSTRACT FROM AUTHOR]

Variation in population size over time can influence our ability to identify landscape-moderated differences in community assembly. To date, however, most studies at the landscape scale only cover snapshots in time, thereby overlooking the temporal dynamics of populations and communities. In this paper, we present data that illustrate how temporal variation in population density at a regional scale can influence landscape-moderated variation in recolonization and population buildup in disturbed habitat patches. Four common insect species, two omnivores and two herbivores, were monitored over 8 years in 10 willow short-rotation coppice bio-energy stands with a four-year disturbance regime (coppice cycle). The population densities in these regularly disturbed stands were compared to densities in 17 undisturbed natural Salix cinerea (grey willow) stands in the same region. A time series approach was used, utilizing the natural variation between years to statistically model recolonization as a function of landscape composition under two different levels of regional density. Landscape composition, i.e. relative amount of forest vs. open agricultural habitats, largely determined the density of re-colonizing populations following willow coppicing in three of the four species. However, the impact of landscape composition was not detectable in years with low regional density. Our results illustrate that landscape-moderated recolonization can change over time and that considering the temporal dynamics of populations may be crucial when designing and evaluating studies at landscape level. [ABSTRACT FROM AUTHOR]

In biomass fired power plants a range of biomass fuels are used to generate electric power. It is desirable to identify the type of biomass fuels on-line continuously in order to achieve an improved combustion efficiency, and reduced pollutant emissions. This paper presents the recent investigations into the on-line identification of biomass fuels based on the combination of flame radical imaging and radical basis function (RBF) neural network (NN) techniques. The characteristic values of flame radicals (OH*, CN*, CH* and C2*), including the intensity ratio, intensity contour, mean intensity, area and eccentricity, are computed to reconstruct two types of RBF NN, that is, accurate and probabilistic RBF networks. Experimental results obtained for three types of biomass fuels (flour, willow sawdust and palm kernel shell) firing on a laboratory-scale combustion test rig are presented to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]