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1.
生物燃料最新发展态势分析 总被引:7,自引:1,他引:6
第一代生物燃料的生产工艺已经较为成熟,美国、欧盟和巴西等一些国家已经形成了较完善的产业链。以纤维素乙醇为代表的第二代生物燃料是更有希望的替代燃料,但目前还未获得关键性的技术突破,其大规模的商业化生产还有待时日。目前生物燃料正处于由第一代向第二代发展过渡的初期。各国纷纷将发展第二代生物燃料定为国策,为此制订了长期的发展规划与目标,并为生物燃料发展提供了良好的政策环境和大力的经费支持。各相关研究机构与企业也积极行动,力图解决生物燃料发展的各个关键问题。在此过程中,一些与生物燃料可持续发展有关的重要问题也引起了人们的关注。 相似文献
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Many climate change mitigation strategies rely on strong projected growth in biomass energy, supported by literature estimating high future bioenergy potential. However, expectations to 2050 are highly divergent. Examining the most widely cited studies finds that some assumptions in these models are inconsistent with the best available evidence. By identifying literature‐supported, up‐to‐date assumptions for parameters including crop yields, land availability, and costs, we revise upper‐end estimates of potential biomass availability from dedicated energy crops. Even allowing for the conversion of virtually all ‘unused’ grassland and savannah, we find that the maximum plausible limit to sustainable energy crop production in 2050 would be 40–110 EJ yr?1. Combined with forestry, crop residues, and wastes, the maximum limit to long‐term total biomass availability is 60–120 EJ yr?1 in primary energy. After accounting for current trends in bioenergy allocation and conversion losses, we estimate maximum potentials of 10–20 EJ yr?1 of biofuel, 20–40 EJ yr?1 of electricity, and 10–30 EJ yr?1 of heating in 2050. These findings suggest that many technical projections and aspirational goals for future bioenergy use could be difficult or impossible to achieve sustainably. 相似文献
4.
Irshad Ahmad Anil K. Sharma Henry Daniell Shashi Kumar 《Plant biotechnology journal》2015,13(4):540-550
Higher lipid biosynthesis and accumulation are important to achieve economic viability of biofuel production via microalgae. To enhance lipid content, Chlamydomonas reinhardtii was genetically engineered with a key enzyme diacylglycerol acyltransferase (BnDGAT2) from Brassica napus, responsible for neutral lipid biosynthesis. The transformed colonies harbouring aph7 gene, screened on hygromycin‐supplemented medium, achieved transformation frequency of ~120 ± 10 colonies/1 × 106 cells. Transgene integration and expression were confirmed by PCR, Southern blots, staining lipid droplets, proteins and spectro‐fluorometric analysis of Nile red‐stained cells. The neutral lipid is a major class (over 80% of total lipids) and most significant requirement for biodiesel production; this was remarkably higher in the transformed alga than the untransformed control. The levels of saturated fatty acids in the transformed alga decreased to about 7% while unsaturated fatty acids increased proportionately when compared to wild type cells. Polyunsaturated fatty acids, especially α‐linolenic acid, an essential omega‐3 fatty acid, were enhanced up to 12% in the transformed line. Nile red staining confirmed formation of a large number of lipid globules in the transformed alga. Evaluation of long‐term stability and vitality of the transgenic alga revealed that cryopreservation produced significantly higher quantity of lipid than those maintained continuously over 128 generations on solid medium. The overexpression of BnDGAT2 significantly altered the fatty acids profile in the transformed alga. Results of this study offer a valuable strategy of genetic manipulation for enhancing polyunsaturated fatty acids and neutral lipids for biofuel production in algae. 相似文献
5.
Sierk de Jong Joost van Stralen Marc Londo Ric Hoefnagels André Faaij Martin Junginger 《Global Change Biology Bioenergy》2018,10(9):661-682
This study presents supply scenarios of nonfood renewable jet fuel (RJF) in the European Union (EU) toward 2030, based on the anticipated regulatory context, availability of biomass and conversion technologies, and competing biomass demand from other sectors (i.e., transport, heat, power, and chemicals). A cost optimization model was used to identify preconditions for increased RJF production and the associated emission reductions, costs, and impact on competing sectors. Model scenarios show nonfood RJF supply could increase from 1 PJ in 2021 to 165–261 PJ/year (3.8–6.1 million tonne (Mt)/year) by 2030, provided advanced biofuel technologies are developed and adequate (policy) incentives are present. This supply corresponds to 6%–9% of jet fuel consumption and 28%–41% of total nonfood biofuel consumption in the EU. These results are driven by proposed policy incentives and a relatively high fossil jet fuel price compared to other fossil fuels. RJF reduces aviation‐related combustion emission by 12–19 Mt/year CO2‐eq by 2030, offsetting 53%–84% of projected emission growth of the sector in the EU relative to 2020. Increased RJF supply mainly affects nonfood biofuel use in road transport, which remained relatively constant during 2021–2030. The cost differential of RJF relative to fossil jet fuel declines from 40 €/GJ (1,740 €/t) in 2021 to 7–13 €/GJ (280–540 €/t) in 2030, because of the introduction of advanced biofuel technologies, technological learning, increased fossil jet fuel prices, and reduced feedstock costs. The cumulative additional costs of RJF equal €7.7–11 billion over 2021–2030 or €1.0–1.4 per departing passenger (intra‐EU) when allocated to the aviation sector. By 2030, 109–213 PJ/year (2.5–4.9 Mt/year) RJF is produced from lignocellulosic biomass using technologies which are currently not yet commercialized. Hence, (policy) mechanisms that expedite technology development are cardinal to the feasibility and affordability of increasing RJF production. 相似文献
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Gang Zhao Brett A. Bryan Darran King Zhongkui Luo Enli Wang Qiang Yu 《Global Change Biology Bioenergy》2015,7(3):479-487
The use of crop residues for bioenergy production needs to be carefully assessed because of the potential negative impact on the level of soil organic carbon (SOC) stocks. The impact varies with environmental conditions and crop management practices and needs to be considered when harvesting the residue for bioenergy productions. Here, we defined the sustainable harvest limits as the maximum rates that do not diminish SOC and quantified sustainable harvest limits for wheat residue across Australia's agricultural lands. We divided the study area into 9432 climate‐soil (CS) units and simulated the dynamics of SOC in a continuous wheat cropping system over 122 years (1889 – 2010) using the Agricultural Production Systems sIMulator (APSIM). We simulated management practices including six fertilization rates (0, 25, 50, 75, 100, and 200 kg N ha?1) and five residue harvest rates (0, 25, 50, 75, and 100%). We mapped the sustainable limits for each fertilization rate and assessed the effects of fertilization and three key environmental variables – initial SOC, temperature, and precipitation – on sustainable residue harvest rates. We found that, with up to 75 kg N ha?1 fertilization, up to 75% and 50% of crop residue could be sustainably harvested in south‐western and south‐eastern Australia, respectively. Higher fertilization rates achieved little further increase in sustainable residue harvest rates. Sustainable residue harvest rates were principally determined by climate and soil conditions, especially the initial SOC content and temperature. We conclude that environmental conditions and management practices should be considered to guide the harvest of crop residue for bioenergy production and thereby reduce greenhouse gas emissions during the life cycle of bioenergy production. 相似文献
8.
Linda E. Graham 《Journal of phycology》2019,55(1):1-6
Known Proterozoic algal fossils raise compelling questions about the origin and diversification of cyanobacteria and eukaryotic algae, and their ecological influence in deep time. This Perspectives article describes particular examples of persistent evolutionary and biogeochemical issues whose resolution would be aided by additional algal fossil evidence from Proterozoic deposits, which have been the subjects of recent intensive study. New Proterozoic geosciences literature relevant to the early diversification of algae is surveyed. Previously underappreciated algal traits that might improve taxonomic attributions of fossil remains are highlighted. Processes that phycologists could use to improve detection of algal fossils are recommended. Potential geological sources of new Proterozoic fossils are suggested. 相似文献
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Prachi Nawkarkar Vikas U. Kapase Sarika Chaudhary Sachin Kajla Shashi Kumar 《Global Change Biology Bioenergy》2023,15(10):1240-1254
Algae have been explored for renewable energy, nutraceuticals, and value-added products. However, low lipid yield is a significant impediment to its commercial viability. Genetic engineering can improve the fatty acid profile of algae without compromising its growth. This study introduced the diacylglycerol acyltransferase (BnDGAT) gene from Brassica napus into Chlorella sorokiniana-I, a fast-growing and thermotolerant natural strain isolated from wastewater, which increased its intracellular lipid accumulation. Hygromycin-resistant cells were selected, and enhanced green florescence protein fluorescence was used to distinguish pure transgenic cell lines from mixed cultures. Compared to the wild type, BnDGAT expression in transgenic C. sorokiniana-I caused a threefold increase in non-polar lipid and a twofold increase in polyunsaturated fatty acids. Nile red staining reaffirmed the presence of higher intracellular lipid bodies in transgenic cells. There was a substantial alteration in the fatty acid profile of transgenic alga expressing BnDGAT. The non-essential omega 9 (C18: 1) fatty acid decreased (5%–7% from 18%), while alpha-linolenic acid, an essential omega 3 fatty acid (C18: 3), was increased (23%–24% from 11%). This study substantiates a valuable strategy for enhancing essential omega-3 fatty acids and neutral lipids to improve its nutritional value for animal feed. The increased lipid productivity should reduce the cost of producing fatty acid methyl esters (FAME). Improved FAME quality should address the clouding issues in cold regions. 相似文献
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Robert F. McGuire 《Journal of phycology》1984,20(4):454-460
Thirty characteristics of 14 Nostoc and 10 Anabaena species were analyzed from previously published data. Using standard numerical taxonomic methods, simple matching coefficients were calculated and a phenogram drawn. The analysis revealed that some of the central characteristics of Nostoc are: a punctiforme stage; motile reproductive stage; plant mass with a dull to shiny luster, non-veined surface, and nonfimbriate margin; some spherical vegetative cells; no cylindrical heterocysts; and some spherical, but no cylindrical akinetes. Some of the central characteristics of Anabaena that were revealed are: no punctiforme stage; a motile vegetative stage; plant mass with a shiny luster, veined surface, and fimbriate margin; no spherical vegetative cells; some cylindrical heterocysts; and some cylindrical, but no spherical, akinetes. In general, Anabaena has larger akinetes and vegetative cells than Nostoc. Based on 30 morphological characteristics and the clustering data of the phenogram, keys were constructed for the Nostoc and Anabaena species studied. The data clearly support two separate and distinct, though similar genera and, less sharply, the separation of the 24 species. The more useful characteristics for separation of the species are size and shape of akinetes, vegetative cells, and heterocysts; color and luster of plant mass; veined plant mass surface; margin fimbriate; and shape of plant mass in nature. 相似文献
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Diego F. Correa Hawthorne L. Beyer Hugh P. Possingham Skye R. Thomas‐Hall Peer M. Schenk 《Global Change Biology Bioenergy》2019,11(8):914-929
Sustainable alternatives to fossil fuels are urgently needed to avoid severe climate impacts and further environmental degradation. Microalgae are one of the most productive crops globally and do not need to compete for arable land or freshwater resources. Hence, they may become a promising, more sustainable cultivation alternative for the large‐scale production of biofuels provided that substantial reductions are achieved in their production costs. In this study, we identify the most suitable areas globally for siting microalgal farms for biodiesel production that maximize profitability and minimize direct competition with food production and direct impacts on biodiversity, based on a spatially explicit multiple‐criteria decision analysis. We further explore the relationships between microalgal production, agricultural value, and biodiversity, and propose several solutions for siting microalgal production farms, based on current and future targets in energy production using integer linear programming. If using seawater for microalgal cultivation, biodiesel production could reach 5.85 × 1011 L/year based on top suitable lands (i.e., between 13% and 16% of total transport energy demands in 2030) without directly competing with food production and areas of high biodiversity value. These areas are particularly abundant in the dry coasts of North and East Africa, the Middle East, and western South America. This is the first global analysis that incorporates economic and environmental feasibility for microalgal production sites. Our results can guide the selection of best locations for biofuel production using microalgae while minimizing conflicts with food production and biodiversity conservation. 相似文献
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Wei Jiang Katherine Y. Zipp Matthew H. Langholtz Michael G. Jacobson 《Global Change Biology Bioenergy》2019,11(9):1086-1097
This paper investigates the spatial heterogeneity of landowners’ willingness to supply three bioenergy crops: switchgrass, Miscanthus, and willow, in the northeastern United States. Spatial heterogeneity might arise for several reasons. For example, landowners closer to bioenergy processing plants might be more likely to be willing to supply bioenergy crops, and landowners who are more willing to supply bioenergy crops may be spatially clustered because they share similar land attributes, demographics, experiences, and/or values. Using high‐resolution GIS data related to the location of pellet plants utilizing bioenergy crops and survey data related to landowners’ characteristics including spatial location, we estimate a spatial probit model to explain the variation in individual‐specific reservation prices (RPs)—the feedstock price at which landowners become willing to supply a bioenergy crop. We find that respondents’ RP is lower the closer they live to their nearest pellet plant and spatial dependency is only present for switchgrass supply. We also identify three economic hotspots (areas with high potential supply and low RPs) for each bioenergy crop. We believe that bioenergy supply chains could be developed around these hotspots. 相似文献
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Marcos S. Buckeridge Amanda P. De Souza Rebecca A. Arundale Kristina J. Anderson‐Teixeira Evan DeLucia 《Global Change Biology Bioenergy》2012,4(2):119-126
This article reviews the history and current state of ethanol production from sugarcane in Brazil and presents a strategy for improving ecosystem services and production. We propose that it is possible to produce ethanol from sugarcane while maintaining or even recovering some of Brazil's unique neotropical biodiversity and ecosystem climate services. This approach to the future of sustainable and responsible ethanol production is termed the ‘midway’ strategy. The ‘midway’ strategy involves producing the necessary biotechnology to increase productivity while synergistically protecting and regenerating rainforest. Three main areas of scientific and technological advance that are key to realizing the ‘midway’ strategy are: (i) improving the quality of scientific data on sugarcane biology as pertains to its use as a bioenergy crop; (ii) developing technologies for the use of bagasse for cellulosic ethanol; and (iii) developing policies to improve the ecosystem services associated with sugarcane landscapes. This article discusses these three issues in the general context of biofuels production and highlights examples of scientific achievements that are already leading towards the ‘midway’ strategy. 相似文献
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Evonne P. Y. Tang Warwick F. Vincent Daniel Proulx Paul Lessard Joël de la Noüe 《Journal of applied phycology》1997,9(4):371-381
Forty-nine strains of filamentous, mat-forming cyanobacteria isolated from the Arctic, subarctic and Antarctic environments were screened for their potential use in outdoor waste-water treatment systems designed for cold north-temperate climates. The most promising isolate (strain E18, Phormidium sp. from a high Arctic lake) grew well at low temperatures and formed aggregates (flocs) that could be readily harvested by sedimentation. We evaluated the growth and nutrient uptake abilities of E18 relative to a community of green algae (a Chlorococcalean assemblage, denoted Vc) sampled from a tertiary treatment system in Valcartier, Canada. E18 had superior growth rates below 15°C Canada. (μ = 0.20 d-1 at 10°C under continuous irradiance of 225 μmol photon m-2 s-1) and higher phosphate uptake rates below 10°C (k = 0.050 d-1 at 5°C) relative to Vc (μ=0.087 d-1 at 10°C and k = 0.020 d-1 at 5°C, respectively). The green algal assemblage generally performed better than E18 at high temperatures (at 25°C, μ = 0.39 d-1 and k = 0.34 d-1 for Vc; μ = 0.28 d-1 and k = 0.33 d-1 for E18). However, E18 removed nitrate more efficiently than Vc at most temperatures including 25°C. Polar cyanobacteria such as strain E18 are appropriate species for waste-water treatment in cold climates during spring and autumn. Under warmer summer conditions, fast-growing green algae such as the Vc assemblage are likely to colonize and dominate, but warm-water Phormidium isolates could be used at that time. This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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A laboratory assay (SAGA or Sediment Algal Growth Assay) was developed to assess the potential impact of sediment resuspension
on the structure of phytoplankton communities, and to evaluate the effectiveness of various sediment treatments in decreasing
the abundance of blue-green algae in the event of sediment resuspension during storms. In assays with sediment from eutrophic
Akanoi Bay, Lake Biwa, Japan, 7–11 species of phytoplankton seeded from the sediments grew during the 3-week assay indicating
that sediment resuspension has the potential to increase both phytoplankton biomass and species diversity. Treatment of sediments
with Ca(NO3)2 substantially decreased phytoplankton biomass (measured as chlorophyll concentration) in assays with sediments
from Akanoi Bay and the North Basin of Lake Biwa. Further, among various oxidation treatments of sediments, Ca(NO3)2 was most
effective in decreasing or preventing filamentous blue-green algal growth in N- and P-replete media. In contrast, when sediments
were added to P-limited phytoplankton dominated by green algae and diatoms, no growth of blue-green algae occurred regardless
of sediment treatment.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Nathan M. Tarr Matthew J. Rubino Jennifer K. Costanza Alexa J. McKerrow Jaime A. Collazo Robert C. Abt 《Global Change Biology Bioenergy》2017,9(5):909-923
Domestic and foreign renewable energy targets and financial incentives have increased demand for woody biomass and bioenergy in the southeastern United States. This demand is expected to be met through purpose‐grown agricultural bioenergy crops, short‐rotation tree plantations, thinning and harvest of planted and natural forests, and forest harvest residues. With results from a forest economics model, spatially explicit state‐and‐transition simulation models, and species–habitat models, we projected change in habitat amount for 16 wildlife species caused by meeting a renewable fuel target and expected demand for wood pellets in North Carolina, USA. We projected changes over 40 years under a baseline ‘business‐as‐usual’ scenario without bioenergy production and five scenarios with unique feedstock portfolios. Bioenergy demand had potential to influence trends in habitat availability for some species in our study area. We found variation in impacts among species, and no scenario was the ‘best’ or ‘worst’ across all species. Our models projected that shrub‐associated species would gain habitat under some scenarios because of increases in the amount of regenerating forests on the landscape, while species restricted to mature forests would lose habitat. Some forest species could also lose habitat from the conversion of forests on marginal soils to purpose‐grown feedstocks. The conversion of agricultural lands on marginal soils to purpose‐grown feedstocks increased habitat losses for one species with strong associations with pasture, which is being lost to urbanization in our study region. Our results indicate that landscape‐scale impacts on wildlife habitat will vary among species and depend upon the bioenergy feedstock portfolio. Therefore, decisions about bioenergy and wildlife will likely involve trade‐offs among wildlife species, and the choice of focal species is likely to affect the results of landscape‐scale assessments. We offer general principals to consider when crafting lists of focal species for bioenergy impact assessments at the landscape scale. 相似文献
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Tad W. Patzek 《Critical Reviews in Plant Sciences》2004,23(6):519-567
This article defines sustainability and sustainable cyclic processes, and quantifies the degree of non-renewability of a major biofuel: ethanol produced from industrially grown corn. It demonstrates that more fossil energy is used to produce ethanol from corn than the ethanol's calorific value. Analysis of the carbon cycle shows that all leftovers from ethanol production must be returned back to the fields to limit the irreversible mining of soil humus. Thus, production of ethanol from whole plants is unsustainable. In 2004, ethanol production from corn will generate 8 million tons of incremental CO2, over and above the amount of CO2 generated by burning gasoline with 115% of the calorific value of this ethanol. It next calculates the cumulative exergy (available free energy) consumed in corn farming and ethanol production, and estimates the minimum amount of work necessary to restore the key non-renewable resources consumed by the industrial corn-ethanol cycle. This amount of work is compared with the maximum useful work obtained from the industrial corn-ethanol cycle. It appears that if the corn-ethanol exergy is used to power a car engine, the minimum restoration work is about 6 times the maximum useful work from the cycle. This ratio drops down to 2 if an ideal fuel cell is used to process the ethanol. The article estimates the U.S. taxpayer subsidies of the industrial corn-ethanol cycle at $3.8 billion in 2004. The parallel subsidies by the environment are estimated at $1.8 billion in 2004. The latter estimate will increase manifold when the restoration costs of aquifers, streams, and rivers, and the Gulf of Mexico are also included. Finally, the article estimates that (per year and unit area) the inefficient solar cells produce ~ 100 times more electricity than corn ethanol. There is a need for more reliance on sunlight, the only source of renewable energy on the earth. 相似文献
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Increasingly electronic communication and a variety of electronic resources are accessible to a larger group of people within the scientific community. This paper outlines the range of resources that are available, and comments on their current and future value to the phycological community. Resources discussed include mailing lists and newsgroups. These are useful tools for rapid, informal, targeted communication, although the technology employed places limitations on the type and format of information which may be distributed. The World Wide Web (WWW) has the potential to overcome these limitations, the quality, complexity and value to the phycological community of the sites on the WWW are extremely variable, with some material being of dubious quality. However, it is possible to access high quality resources including culture collection catalogues, high quality images and microbial and molecular databases. As well as some of the current resources, this paper discusses some possible directions for the future of phycology on the internet.http://wiua.nwi.ac.uk/ 相似文献
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Walter Rossi Cervi Rubens Augusto Camargo Lamparelli Joaquim Eugênio Abel Seabra Martin Junginger Sierk de Jong Floor van der Hilst 《Global Change Biology Bioenergy》2020,12(2):136-157
It is expected that Brazil could play an important role in biojet fuel (BJF) production in the future due to the long experience in biofuel production and the good agro‐ecological conditions. However, it is difficult to quantify the techno‐economic potential of BJF because of the high spatiotemporal variability of available land, biomass yield, and infrastructure as well as the technological developments in BJF production pathways. The objective of this research is to assess the recent and future techno‐economic potential of BJF production in Brazil and to identify location‐specific optimal combinations of biomass crops and technological conversion pathways. In total, 13 production routes (supply chains) are assessed through the combination of various biomass crops and BJF technologies. We consider temporal land use data to identify potential land availability for biomass production. With the spatial distribution of the land availability and potential yield of biomass crops, biomass production potential and costs are calculated. The BJF production cost is calculated by taking into account the development in the technological pathways and in plant scales. We estimate the techno‐economic potential by determining the minimum BJF total costs and comparing this with the range of fossil jet fuel prices. The techno‐economic potential of BJF production ranges from 0 to 6.4 EJ in 2015 and between 1.2 and 7.8 EJ in 2030, depending on the reference fossil jet fuel price, which varies from 19 to 65 US$/GJ across the airports. The techno‐economic potential consists of a diverse set of production routes. The Northeast and Southeast region of Brazil present the highest potentials with several viable production routes, whereas the remaining regions only have a few promising production routes. The maximum techno‐economic potential of BJF in Brazil could meet almost half of the projected global jet fuel demand toward 2030. 相似文献