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1

Laccase applications in biofuels production: current status and future prospects.  

PubMed

The desire to reduce dependence on the ever diminishing fossil fuel reserves coupled with the impetus towards green energy has seen increased research in biofuels as alternative sources of energy. Lignocellulose materials are one of the most promising feedstocks for advanced biofuels production. However, their utilisation is dependent on the efficient hydrolysis of polysaccharides, which in part is dependent on cost-effective and benign pretreatment of biomass to remove or modify lignin and release or expose sugars to hydrolytic enzymes. Laccase is one of the enzymes that are being investigated not only for potential use as pretreatment agents in biofuel production, mainly as a delignifying enzyme, but also as a biotechnological tool for removal of inhibitors (mainly phenolic) of subsequent enzymatic processes. The current review discusses the major advances in the application of laccase as a potential pretreatment strategy, the underlying principles as well as directions for future research in the search for better enzyme-based technologies for biofuel production. Future perspectives could include synergy between enzymes that may be required for optimal results and the adoption of the biorefinery concept in line with the move towards the global implementation of the bioeconomy strategy. PMID:24841120

Kudanga, Tukayi; Le Roes-Hill, Marilize

2014-08-01

2

LIHD biofuels: toward a sustainable future  

E-print Network

LIHD biofuels: toward a sustainable future 115 Linda Wallace, Department of Botany and Microbiology of America www.frontiersinecology.org Will biofuels help to wean the US off of oil, or at least off simple. First, we need to understand what is meant by the term "biofuel". All biofuels are organic

Palmer, Michael W.

3

iBioSeminar: Technical Issues Associated with Future Large-Scale Cellulosic Biofuels Production  

NSDL National Science Digital Library

This presentation describes the rationale for using plant biomass as a source of fuels and presents information about how much energy could be obtained in this way. Examples of the kinds of plants that are likely to be used are presented along with comments on some of the issues, such as losses to disease and effects of various cropping systems on soil quality, that need additional research. The potential for various types of biofuels are compared and some of the technical challenges in production of cellulosic fuels are outlined.

Chris Somerville (Carnegie Institution for Science; )

2007-05-01

4

Cyanobacterial biofuel production.  

PubMed

The development of new technologies for production of alternative fuel became necessary to circumvent finite petroleum resources, associate rising costs, and environmental concerns due to rising fossil fuel CO? emissions. Several alternatives have been proposed to develop a sustainable industrial society and reduce greenhouse emissions. The idea of biological conversion of CO? to fuel and chemicals is receiving increased attention. In particular, the direct conversion of CO? with solar energy to biofuel by photosynthetic microorganisms such as microalgae and cyanobacteria has several advantages compared to traditional biofuel production from plant biomass. Photosynthetic microorganisms have higher growth rates compared with plants, and the production systems can be based on non-arable land. The advancement of synthetic biology and genetic manipulation has permitted engineering of cyanobacteria to produce non-natural chemicals typically not produced by these organisms in nature. This review addresses recent publications that utilize different approaches involving engineering cyanobacteria for production of high value chemicals including biofuels. PMID:22446641

Machado, Iara M P; Atsumi, Shota

2012-11-30

5

The Economics of Current and Future Biofuels  

Microsoft Academic Search

\\u000a This work presents detailed comparative analysis on the production economics of both current and future biofuels, including\\u000a ethanol, biodiesel, and butanol. Our objectives include demonstrating the impact of key parameters on the overall process\\u000a economics (e.g., plant capacity, raw material pricing, and yield) and comparing how next-generation technologies and fuels\\u000a will differ from today’s technologies. The commercialized processes and corresponding

Ling Tao; Andy Aden

6

The economics of current and future biofuels  

Microsoft Academic Search

This work presents detailed comparative analysis on the production economics of both current and future biofuels, including\\u000a ethanol, biodiesel, and butanol. Our objectives include demonstrating the impact of key parameters on the overall process\\u000a economics (e.g., plant capacity, raw material pricing, and yield) and comparing how next-generation technologies and fuels\\u000a will differ from today’s technologies. The commercialized processes and corresponding

Ling Tao; Andy Aden

2009-01-01

7

The Ecology of Algal Biofuel Production  

NSDL National Science Digital Library

Algae offer a promising alternative to terrestrially grown vascular plants as a future source of biofuel (feedstock). Doing so would decrease the worldâ??s dependence on petroleum fuels, reduce the diversion of edible agricultural crops from food production to energy production, reduce fertilizer use, environmental contamination, and water demands associated with terrestrial biofuel crop cultivation. Combining facilities for the production of algae with sources of domestic or agricultural wastewater would greatly reduce the amount of nitrogen and phosphorus polluting surface waters, and the scientific principles of ecology provide valuable guidance for the design and stable operation of large-scale algal biofuel production facilities.

Val Smith (University of Kansas; )

2011-03-15

8

Spatial Modeling of Geographic Patterns in Biodiversity and Biofuel Production  

E-print Network

Spatial Modeling of Geographic Patterns in Biodiversity and Biofuel Production How can the US of biodiversity. The future of the biofuel industry will depend on public investment and trust that industry for increasing biofuel production have already come under fire because of real and perceived threats

9

Biofuels and biodiversity: principles for creating better policies for biofuel production.  

PubMed

Biofuels are a new priority in efforts to reduce dependence on fossil fuels; nevertheless, the rapid increase in production of biofuel feedstock may threaten biodiversity. There are general principles that should be used in developing guidelines for certifying biodiversity-friendly biofuels. First, biofuel feedstocks should be grown with environmentally safe and biodiversity-friendly agricultural practices. The sustainability of any biofuel feedstock depends on good growing practices and sound environmental practices throughout the fuel-production life cycle. Second, the ecological footprint of a biofuel, in terms of the land area needed to grow sufficient quantities of the feedstock, should be minimized. The best alternatives appear to be fuels of the future, especially fuels derived from microalgae. Third, biofuels that can sequester carbon or that have a negative or zero carbon balance when viewed over the entire production life cycle should be given high priority. Corn-based ethanol is the worst among the alternatives that are available at present, although this is the biofuel that is most advanced for commercial production in the United States. We urge aggressive pursuit of alternatives to corn as a biofuel feedstock. Conservation biologists can significantly broaden and deepen efforts to develop sustainable fuels by playing active roles in pursuing research on biodiversity-friendly biofuel production practices and by helping define biodiversity-friendly biofuel certification standards. PMID:18261147

Groom, Martha J; Gray, Elizabeth M; Townsend, Patricia A

2008-06-01

10

Environmental impacts of biofuel production and use  

EPA Science Inventory

The 2007 Energy Independence and Security Act (EISA) required a significant increase in the production and use of renewable fuels. Given the current state of technology and infrastructure, nearly all of the projected volume of biofuel consumption over the foreseeable future is ex...

11

Invitation/Program Technology Watch Day on Future Biofuels  

E-print Network

Invitation/Program Technology Watch Day on Future Biofuels and 4. TMFB International Workshop;International Research Centers Focussing on Future Biofuels are Presenting Their Research Approaches and Current Concerning Future Biofuels DBFZ ­ Deutsches Biomasseforschungszentrum M. Seiffert, F. Mueller-Langer German

12

Growing duckweed for biofuel production: a review.  

PubMed

Duckweed can be utilised to produce ethanol, butanol and biogas, which are promising alternative energy sources to minimise dependence on limited crude oil and natural gas. The advantages of this aquatic plant include high rate of nutrient (nitrogen and phosphorus) uptake, high biomass yield and great potential as an alternative feedstock for the production of fuel ethanol, butanol and biogas. The objective of this article is to review the published research on growing duckweed for the production of the biofuels, especially starch enrichment in duckweed plants. There are mainly two processes affecting the accumulation of starch in duckweed biomass: photosynthesis for starch generation and metabolism-related starch consumption. The cost of stimulating photosynthesis is relatively high based on current technologies. Considerable research efforts have been made to inhibit starch degradation. Future research need in this area includes duckweed selection, optimisation of duckweed biomass production, enhancement of starch accumulation in duckweeds and use of duckweeds for production of various biofuels. PMID:24985498

Cui, W; Cheng, J J

2015-01-01

13

Biofuels and bio-products derived from  

E-print Network

NEED Biofuels and bio- products derived from lignocellulosic biomass (plant materials) are part improve the energy and carbon efficiencies of biofuels production from a barrel of biomass using chemical and thermal catalytic mechanisms. The Center for Direct Catalytic Conversion of Biomass to Biofuels IMPACT

Ginzel, Matthew

14

Land availability for biofuel production.  

PubMed

Marginal agricultural land is estimated for biofuel production in Africa, China, Europe, India, South America, and the continental United States, which have major agricultural production capacities. These countries/regions can have 320-702 million hectares of land available if only abandoned and degraded cropland and mixed crop and vegetation land, which are usually of low quality, are accounted. If grassland, savanna, and shrubland with marginal productivity are considered for planting low-input high-diversity (LIHD) mixtures of native perennials as energy crops, the total land availability can increase from 1107-1411 million hectares, depending on if the pasture land is discounted. Planting the second generation of biofuel feedstocks on abandoned and degraded cropland and LIHD perennials on grassland with marginal productivity may fulfill 26-55% of the current world liquid fuel consumption, without affecting the use of land with regular productivity for conventional crops and without affecting the current pasture land. Under the various land use scenarios, Africa may have more than one-third, and Africa and Brazil, together, may have more than half of the total land available for biofuel production. These estimations are based on physical conditions such as soil productivity, land slope, and climate. PMID:21142000

Cai, Ximing; Zhang, Xiao; Wang, Dingbao

2011-01-01

15

Towards Sustainable Production of Biofuels from Microalgae  

PubMed Central

Renewable and carbon neutral biofuels are necessary for environmental and economic sustainability. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Microalgal biofuels are a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. This paper aims to analyze and promote integration approaches for sustainable microalgal biofuel production to meet the energy and environmental needs of the society. The emphasis is on hydrothermal liquefaction technology for direct conversion of algal biomass to liquid fuel. PMID:19325798

Patil, Vishwanath; Tran, Khanh-Quang; Giselrød, Hans Ragnar

2008-01-01

16

Towards sustainable production of biofuels from microalgae.  

PubMed

Renewable and carbon neutral biofuels are necessary for environmental and economic sustainability. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Microalgal biofuels are a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. This paper aims to analyze and promote integration approaches for sustainable microalgal biofuel production to meet the energy and environmental needs of the society. The emphasis is on hydrothermal liquefaction technology for direct conversion of algal biomass to liquid fuel. PMID:19325798

Patil, Vishwanath; Tran, Khanh-Quang; Giselrød, Hans Ragnar

2008-06-01

17

Multiphase Flow Modeling of Biofuel Production Processes  

SciTech Connect

As part of the Idaho National Laboratory's (INL's) Secure Energy Initiative, the INL is performing research in areas that are vital to ensuring clean, secure energy supplies for the future. The INL Hybrid Energy Systems Testing (HYTEST) Laboratory is being established to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. HYTEST involves producing liquid fuels in a Hybrid Energy System (HES) by integrating carbon-based (i.e., bio-mass, oil-shale, etc.) with non-carbon based energy sources (i.e., wind energy, hydro, geothermal, nuclear, etc.). Advances in process development, control and modeling are the unifying vision for HES. This paper describes new modeling tools and methodologies to simulate advanced energy processes. Needs are emerging that require advanced computational modeling of multiphase reacting systems in the energy arena, driven by the 2007 Energy Independence and Security Act, which requires production of 36 billion gal/yr of biofuels by 2022, with 21 billion gal of this as advanced biofuels. Advanced biofuels derived from microalgal biomass have the potential to help achieve the 21 billion gal mandate, as well as reduce greenhouse gas emissions. Production of biofuels from microalgae is receiving considerable interest due to their potentially high oil yields (around 600 gal/acre). Microalgae have a high lipid content (up to 50%) and grow 10 to 100 times faster than terrestrial plants. The use of environmentally friendly alternatives to solvents and reagents commonly employed in reaction and phase separation processes is being explored. This is accomplished through the use of hydrothermal technologies, which are chemical and physical transformations in high-temperature (200-600 C), high-pressure (5-40 MPa) liquid or supercritical water. Figure 1 shows a simplified diagram of the production of biofuels from algae. Hydrothermal processing has significant advantages over other biomass processing methods with respect to separations. These 'green' alternatives employ a hybrid medium that, when operated supercritically, offers the prospect of tunable physicochemical properties. Solubility can be rapidly altered and phases partitioned selectively to precipitate or dissolve certain components by altering temperature or pressure in the near-critical region. The ability to tune the solvation properties of water in the highly compressible near-critical region facilitates partitioning of products or by-products into separate phases to separate and purify products. Since most challenges related to lipid extraction are associated with the industrial scale-up of integrated extraction systems, the new modeling capability offers the prospect of addressing previously untenable scaling issues.

D. Gaston; D. P. Guillen; J. Tester

2011-06-01

18

Coupling of algal biofuel production with wastewater.  

PubMed

Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area. PMID:24982930

Bhatt, Neha Chamoli; Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

2014-01-01

19

The California Biomass Crop Adoption Model estimates biofuel feedstock crop production across diverse agro-ecological zones within the state, under different future climates  

NASA Astrophysics Data System (ADS)

Both regulators and businesses need realistic estimates for the potential production of biomass feedstocks for biofuels and bioproducts. This includes the need to understand how climate change will affect mid-tem and longer-term crop performance and relative advantage. The California Biomass Crop Adoption Model is a partial mathematical programming optimization model that estimates the profit level needed for new crop adoption, and the crop(s) displaced when a biomass feedstock crop is added to the state's diverse set of cropping systems, in diverse regions of the state. Both yield and crop price, as elements of profit, can be varied. Crop adoption is tested against current farmer preferences derived from analysis of 10 years crop production data for all crops produced in California, collected by the California Department of Pesticide Regulation. Analysis of this extensive data set resulted in 45 distinctive, representative farming systems distributed across the state's diverse agro-ecological regions. Estimated yields and water use are derived from field trials combined with crop simulation, reported elsewhere. Crop simulation is carried out under different weather and climate assumptions. Besides crop adoption and displacement, crop resource use is also accounted, derived from partial budgets used for each crop's cost of production. Systematically increasing biofuel crop price identified areas of the state where different types of crops were most likely to be adopted. Oilseed crops like canola that can be used for biodiesel production had the greatest potential to be grown in the Sacramento Valley and other northern regions, while sugar beets (for ethanol) had the greatest potential in the northern San Joaquin Valley region, and sweet sorghum in the southern San Joaquin Valley. Up to approximately 10% of existing annual cropland in California was available for new crop adoption. New crops are adopted if the entire cropping system becomes more profitable. In particular, canola production resulted in less overall water use but increased farm profits. Most crop substitutions were resource neutral. If future climate is drier, more winter annual crops like canola are likely to be adopted. Crop displacement is also important for determining market-mediated effects of biomass crop production. Correctly estimating crop displacement at the local scale greatly improves upon estimates for indirect land use change derived from the macro-scale PE and CGE models currently used by US EPA and the California Air Resources Board.

Kaffka, S.; Jenner, M.; Bucaram, S.; George, N.

2012-12-01

20

Production of first and second generation biofuels: A comprehensive review  

Microsoft Academic Search

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to

S. N. Naik; Vaibhav V. Goud; Prasant K. Rout; Ajay K. Dalai

2010-01-01

21

Modifying plants for biofuel and biomaterial production.  

PubMed

The productivity of plants as biofuel or biomaterial crops is established by both the yield of plant biomass per unit area of land and the efficiency of conversion of the biomass to biofuel. Higher yielding biofuel crops with increased conversion efficiencies allow production on a smaller land footprint minimizing competition with agriculture for food production and biodiversity conservation. Plants have traditionally been domesticated for food, fibre and feed applications. However, utilization for biofuels may require the breeding of novel phenotypes, or new species entirely. Genomics approaches support genetic selection strategies to deliver significant genetic improvement of plants as sources of biomass for biofuel manufacture. Genetic modification of plants provides a further range of options for improving the composition of biomass and for plant modifications to assist the fabrication of biofuels. The relative carbohydrate and lignin content influences the deconstruction of plant cell walls to biofuels. Key options for facilitating the deconstruction leading to higher monomeric sugar release from plants include increasing cellulose content, reducing cellulose crystallinity, and/or altering the amount or composition of noncellulosic polysaccharides or lignin. Modification of chemical linkages within and between these biomass components may improve the ease of deconstruction. Expression of enzymes in the plant may provide a cost-effective option for biochemical conversion to biofuel. PMID:25431201

Furtado, Agnelo; Lupoi, Jason S; Hoang, Nam V; Healey, Adam; Singh, Seema; Simmons, Blake A; Henry, Robert J

2014-12-01

22

Future Testing Opportunities to Ensure Sustainability of the Biofuels Industry  

Microsoft Academic Search

For the soil and plant analysis community, development and expansion of biofuels will create many opportunities to provide a wide variety of analytical services. Our objective is to explore potential areas where those services could be marketed to support sustainable development of biofuels. One of the first is to provide soil fertility and plant nutrition information for sustainable feedstock production.

Douglas L. Karlen; Brian J. Kerr

2012-01-01

23

Is Large-Scale Production of Biofuel Possible?  

NSDL National Science Digital Library

By genetically engineering certain crops, there is potential to produce biofuels commercially. Additionally: 1) Producing biofuels can decrease the worldâ??s dependence on petroleum fuel. 2)Using biofuels can alleviate environmental contamination from fossil fuel production and use. 3)Farming bioenergy crops could improve rural economies. 4)Establishing sustainability for the biofuel sector can avoid costly production processes.

Miriam Sticklen (Michigan State University; )

2010-07-17

24

The Future Role of Biofuels in the Asia-Pacific Region  

Microsoft Academic Search

There is growing interest in agriculture as a source of bio-fuels to replace petroleum-based transportation fuels. Ethanol production has more than doubled from 2000 to 2005 but still accounts for less than two percent of the world?'s transportation petrol supply. The future role of bio-fuels will be determined by continuation of high oil prices, availability of low cost feed stocks

William T. Coyle; Walter J. Armbruster

2007-01-01

25

Developments and perspectives of photobioreactors for biofuel production  

Microsoft Academic Search

The production of biofuels from microalgae requires efficient photobioreactors in order to meet the tight constraints of energy\\u000a efficiency and economic profitability. Current cultivation systems are designed for high-value products rather than for mass\\u000a production of cheap energy carriers. Future bioreactors will imply innovative solutions in terms of energy efficiency, light\\u000a and gas transfer or attainable biomass concentration to lower

Michael Morweiser; Olaf Kruse; Ben Hankamer; Clemens Posten

2010-01-01

26

Health impact assessment of liquid biofuel production.  

PubMed

Bioethanol and biodiesel as potential substitutes for fossil fuels in the transportation sector have been analyzed for environmental suitability. However, there could be impacts on human health during the production, therefore adverse health effects have to be analyzed. The aim of this study is to analyze to what health risk factors humans are exposed to in the production of biofuels and what the size of the health effects is. A health impact assessment expressed as disability adjusted life years (DALYs) was conducted in SimaPro 7.1 software. The results show a statistically significant lower carcinogenic impact of biofuels (p < 0.05) than fossil fuels. Meanwhile, the impact of organic respirable compounds is smaller for fossil fuels (p < 0.05) than for biofuels. Analysis of inorganic compounds like PM??,?.?, SO? or NO(x) shows some advantages of sugar beet bioethanol and soybean biodiesel production (p < 0.05), although production of sugarcane bioethanol shows larger impacts of respirable inorganic compounds than for fossil fuels (p < 0.001). Although liquid biofuels are made of renewable energy sources, this does not necessary mean that they do not represent any health hazards. PMID:22774773

Fink, Rok; Medved, Sašo

2013-01-01

27

RESEARCH ARTICLE A model for improving microbial biofuel production using  

E-print Network

. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuelRESEARCH ARTICLE A model for improving microbial biofuel production using a synthetic feedback loop be compared. We propose a model for microbial biofuel production where a synthetic control system is used

Dunlop, Mary

28

Global Biofuel Production and Food Security: Implications for Asia Pacific  

E-print Network

Global Biofuel Production and Food Security: Implications for Asia Pacific 56th AARES Annual Conference Fremantle, Western Australia 7-10 February 2012 William T. Coyle #12;Global Biofuel Production and Food Security: Making the Connection --Past analysis and the evidence about biofuels and spiking

29

Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production  

E-print Network

Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production Peer M. Schenk fuels make up a much larger share of the global energy demand (66%). Biofuels are therefore rapidly for transport fuels. Increasing biofuel production on arable land could have severe consequences for global food

Kudela, Raphael M.

30

Engineering algae for biohydrogen and biofuel production.  

PubMed

There is currently substantial interest in utilizing eukaryotic algae for the renewable production of several bioenergy carriers, including starches for alcohols, lipids for diesel fuel surrogates, and H2 for fuel cells. Relative to terrestrial biofuel feedstocks, algae can convert solar energy into fuels at higher photosynthetic efficiencies, and can thrive in salt water systems. Recently, there has been considerable progress in identifying relevant bioenergy genes and pathways in microalgae, and powerful genetic techniques have been developed to engineer some strains via the targeted disruption of endogenous genes and/or transgene expression. Collectively, the progress that has been realized in these areas is rapidly advancing our ability to genetically optimize the production of targeted biofuels. PMID:19560336

Beer, Laura L; Boyd, Eric S; Peters, John W; Posewitz, Matthew C

2009-06-01

31

USDA Biofuels Strategic Production Report June 23, 2010  

E-print Network

USDA Biofuels Strategic Production Report June 23, 2010 1 A USDA Regional Roadmap to Meeting the Biofuels Goals of the Renewable Fuels Standard by 2022 I. INTRODUCTION The U.S. Department of Agriculture. The strategy targets barriers to the development of a successful biofuels market that will achieve, or surpass

32

A Survey of Biofuel Production potentials in Russia  

NASA Astrophysics Data System (ADS)

Due to the abundance of fossil fuel resources in Russia, the development of the renewable energy market there was delayed. Recent technological advancement has led to an increasing interest in biofuel production. The aim of research was to evaluate how biofuels are introduced into the current energy scheme of the country. The potential production of biofuels was estimated based on sustainable approaches which provide solution for carbon emission reduction and environmental benefits. Russia still requires biofuel policy to make biofuels compatible with traditional fossil fuels.

Lykova, Natalya; Gustafsson, Jan-Erik

2010-01-01

33

Biofuels Fuels Technology Pathway Options for Advanced Drop-in Biofuels Production  

SciTech Connect

Advanced drop-in hydrocarbon biofuels require biofuel alternatives for refinery products other than gasoline. Candidate biofuels must have performance characteristics equivalent to conventional petroleum-based fuels. The technology pathways for biofuel alternatives also must be plausible, sustainable (e.g., positive energy balance, environmentally benign, etc.), and demonstrate a reasonable pathway to economic viability and end-user affordability. Viable biofuels technology pathways must address feedstock production and environmental issues through to the fuel or chemical end products. Potential end products include compatible replacement fuel products (e.g., gasoline, diesel, and JP8 and JP5 jet fuel) and other petroleum products or chemicals typically produced from a barrel of crude. Considering the complexity and technology diversity of a complete biofuels supply chain, no single entity or technology provider is capable of addressing in depth all aspects of any given pathway; however, all the necessary expert entities exist. As such, we propose the assembly of a team capable of conducting an in-depth technology pathway options analysis (including sustainability indicators and complete LCA) to identify and define the domestic biofuel pathways for a Green Fleet. This team is not only capable of conducting in-depth analyses on technology pathways, but collectively they are able to trouble shoot and/or engineer solutions that would give industrial technology providers the highest potential for success. Such a team would provide the greatest possible down-side protection for high-risk advanced drop-in biofuels procurement(s).

Kevin L Kenney

2011-09-01

34

Cyanobacteria as a Platform for Biofuel Production  

PubMed Central

Cyanobacteria have great potential as a platform for biofuel production because of their fast growth, ability to fix carbon dioxide gas, and their genetic tractability. Furthermore they do not require fermentable sugars or arable land for growth and so competition with cropland would be greatly reduced. In this perspective we discuss the challenges and areas for improvement most pertinent for advancing cyanobacterial fuel production, including: improving genetic parts, carbon fixation, metabolic flux, nutrient requirements on a large scale, and photosynthetic efficiency using natural light. PMID:25022311

Nozzi, Nicole E.; Oliver, John W. K.; Atsumi, Shota

2013-01-01

35

Challenges in Engineering Microbes for Biofuels Production  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Economic and geopolitical factors (high oil prices, environmental concerns, and supply instability) have been prompting policy-makers to put added emphasis on renewable energy sources. For the scientific community, recent advances, embodied in new insights into basic biology and technology that can be applied to metabolic engineering, are generating considerable excitement. There is justified optimism that the full potential of biofuel production from cellulosic biomass will be obtainable in the next 10 to 15 years.

Gregory Stephanopoulos (Massachusetts Institute of Technology; Department of Chemical Engineering)

2007-02-09

36

Water resources under future scenarios of climate change and biofuel development: A case study for Yakima River basin  

NASA Astrophysics Data System (ADS)

In recent years, biofuel has become an important renewable energy source with a potential to help mitigate climate change. However, agriculture productivity and its potential use for sustainable production of biofuel are strongly dependent on climate and water conditions that may change in response to future changes in climate and/or socio-economic conditions. For instant in 2012, the US has experienced the most severe drought that results in a 12% decrease in corn production - the main feedstock used for biofuel in US - indicating the vulnerability of biofuel development and policies to change in climate and associated extreme weather conditions. To understand this interrelationship and the combined effects of increased biofuel production and climate change on regional and local water resources, we have applied a SWAT watershed model which integrates future scenarios of climate change and biofuel development and simulates the associated impacts on watershed hydrology, water quality, soil erosion, and agriculture productivity. The study is applied to the Yakima River basin (YRB), which has higher biomass resources in Washington State and represents a region where forestry and agriculture intersect with considerable water shortage as well as spatial variations in annual precipitation. Unlike earlier studies, which commonly define biofuel and climate change scenarios independently, in this study the decision on alternative biofuel feedstock mixes and associated change in land use and management take into account the anticipated climate change. The resulted spatial and temporal distributions of water budget, nutrient loads, and sediment erosion is analyzed to evaluate the effectiveness of biofuel policies under constraints of climate change and water resources in the region.

Demissie, Y. K.

2013-12-01

37

Limitation of Biofuel Production in Europe from the Forest Market  

NASA Astrophysics Data System (ADS)

The European Union has set a 10% target for the share of biofuel in the transportation sector to be met by 2020. To reach this target, second generation biofuel is expected to replace 3 to 5% of the transport fossil fuel consumption. But the competition on the feedstock is an issue and makes the planning for the second generation biofuel plant a challenge. Moreover, no commercial second generation biofuel production plant is under operation, but if reaching commercial status, this type of production plants are expected to become very large. In order to minimize the tranportation costs and to takle the competetion for the feedstock against the existing woody based industries, the geographical location of biofuel production plants becomes an issue. This study investigates the potential of second generation biofuel economically feasible in Europe by 2020 in regards with the competition for the feedsstock with the existing woody biomass based industries (CHP, pulp and paper mills, sawmills...). To assess the biofuel potential in Europe, a techno-economic, geographically explicit model, BeWhere, is used. It determines the optimal locations of bio-energy production plants by minimizing the costs and CO2 emissions of the entire supply chain. The existing woody based industries have to first meet their wood demand, and if the amount of wood that remains is suficiant, new bio-energy production plants if any can be set up. Preliminary results show that CHP plants are preferably chosen over biofuel production plants. Strong biofuel policy support is needed in order to consequently increase the biofuel production in Europe. The carbon tax influences the emission reduction to a higher degree than the biofuel support. And the potential of second generation biofuel would at most reach 3% of the European transport fuel if the wood demand does not increase from 2010.

Leduc, Sylvain; Wetterlund, Elisabeth; Dotzauer, Erik; Kindermann, Georg

2013-04-01

38

Environmental indicators for sustainable production of algal biofuels  

SciTech Connect

For analyzing sustainability of algal biofuels, we identify 16 environmental indicators that fall into six categories: soil quality, water quality and quantity, air quality, greenhouse gas emissions, biodiversity, and productivity. Indicators are selected to be practical, widely applicable, predictable in response, anticipatory of future changes, independent of scale, and responsive to management. Major differences between algae and terrestrial plant feedstocks, as well as their supply chains for biofuel, are highlighted, for they influence the choice of appropriate sustainability indicators. Algae strain selection characteristics do not generally affect which indicators are selected. The use of water instead of soil as the growth medium for algae determines the higher priority of water- over soil-related indicators. The proposed set of environmental indicators provides an initial checklist for measures of biofuel sustainability but may need to be modified for particular contexts depending on data availability, goals of the stakeholders, and financial constraints. Use of these indicators entails defining sustainability goals and targets in relation to stakeholder values in a particular context and can lead to improved management practices.

Efroymson, Rebecca Ann [ORNL; Dale, Virginia H [ORNL

2014-01-01

39

Fermentative butanol production: bulk chemical and biofuel.  

PubMed

Clostridium acetobutylicum is an anaerobic, spore-forming bacterium with the ability to ferment starch and sugars into solvents. In the past, it has been used for industrial production of acetone and butanol, until cheap crude oil rendered petrochemical synthesis more economically feasible. Both economic (price of crude oil) and environmental aspects (carbon dioxide emissions) have caused the pendulum to swing back again. Molecular biology has allowed a detailed understanding of genes and enzymes, required for solventogenesis. Thus, construction of strains with improved fermentation ability is now possible. Advances in continuous culture technology and improved downstream processing also add to economic advantages of a new biotechnological process. Two major companies have already committed themselves to biobutanol production as a biofuel additive. Thus, butanol fermentation is on the rise again. PMID:18378605

Dürre, Peter

2008-03-01

40

An Overview of Algae Biofuel Production and Potential Environmental Impact  

EPA Science Inventory

Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas)...

41

Directed Evolution of a Cellodextrin Transporter for Improved Biofuel Production Under Anaerobic  

E-print Network

Directed Evolution of a Cellodextrin Transporter for Improved Biofuel Production Under Anaerobic that anaerobic biofuel production could be significantly improved via directed evolution of a sugar transporter: cellodextrin transporter; cellobiose utilization; cellulosic biofuel; anaerobic fermentation; directed

Zhao, Huimin

42

7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.  

Code of Federal Regulations, 2012 CFR

...Succession and loss of control of advanced biofuel facilities and production. 4288.137...AGRICULTURE PAYMENT PROGRAMS Advanced Biofuel Payment Program General Provisions ...Succession and loss of control of advanced biofuel facilities and production. (a)...

2012-01-01

43

7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.  

...Succession and loss of control of advanced biofuel facilities and production. 4288.137...AGRICULTURE PAYMENT PROGRAMS Advanced Biofuel Payment Program General Provisions Payment...Succession and loss of control of advanced biofuel facilities and production. (a)...

2014-01-01

44

7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.  

Code of Federal Regulations, 2013 CFR

...Succession and loss of control of advanced biofuel facilities and production. 4288.137...AGRICULTURE PAYMENT PROGRAMS Advanced Biofuel Payment Program General Provisions ...Succession and loss of control of advanced biofuel facilities and production. (a)...

2013-01-01

45

75 FR 42745 - Production Incentives for Cellulosic Biofuels: Notice of Program Intent  

Federal Register 2010, 2011, 2012, 2013

...Production Incentives for Cellulosic Biofuels: Notice of Program Intent AGENCY: Office...EPAct 2005). Through this notice, biofuels producers and other interested parties...Production Incentives for Cellulosic Biofuels; Reverse Auction Procedures and...

2010-07-22

46

An overview of algae biofuel production and potential environmental impact.  

PubMed

Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas) and produce products with a wide variety of compositions and uses. These products include lipids, which can be processed into biodiesel; carbohydrates, which can be processed into ethanol; and proteins, which can be used for human and animal consumption. Algae are commonly genetically engineered to allow for advantageous process modification or optimization. However, issues remain regarding human exposure to algae-derived toxins, allergens, and carcinogens from both existing and genetically modified organisms (GMOs), as well as the overall environmental impact of GMOs. A literature review was performed to highlight issues related to the growth and use of algal products for generating biofuels. Human exposure and environmental impact issues are identified and discussed, as well as current research and development activities of academic, commercial, and governmental groups. It is hoped that the ideas contained in this paper will increase environmental awareness of issues surrounding the production of algae and will help the algae industry develop to its full potential. PMID:22681590

Menetrez, Marc Y

2012-07-01

47

Integrated microbial processes for biofuels and high value-added products: the way to improve the cost effectiveness of biofuel production.  

PubMed

The production of microbial biofuels is currently under investigation, as they are alternative sources to fossil fuels, which are diminishing and their use has a negative impact on the environment. However, so far, biofuels derived from microbes are not economically competitive. One way to overcome this bottleneck is the use of microorganisms to transform substrates into biofuels and high value-added products, and simultaneously taking advantage of the various microbial biomass components to produce other products of interest, as an integrated process. In this way, it is possible to maximize the economic value of the whole process, with the desired reduction of the waste streams produced. It is expected that this integrated system makes the biofuel production economically sustainable and competitive in the near future. This review describes the investigation on integrated microbial processes (based on bacteria, yeast, and microalgal cultivations) that have been experimentally developed, highlighting the importance of this approach as a way to optimize microbial biofuel production process. PMID:24337249

da Silva, Teresa Lopes; Gouveia, Luísa; Reis, Alberto

2014-02-01

48

Biofuel Production in Microorganisms: From Phototrophs to Obligate Anaerobes  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) provides this presentation on biofuel production in microorganisms. The material would be useful in an advanced course on biofuel technology; it includes advanced biological concepts and includes an in depth analysis of the issue. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

Eckert, Carrie

49

Next-generation biomass feedstocks for biofuel production  

PubMed Central

The development of second-generation biofuels - those that do not rely on grain crops as inputs - will require a diverse set of feedstocks that can be grown sustainably and processed cost-effectively. Here we review the outlook and challenges for meeting hoped-for production targets for such biofuels in the United States. PMID:19133109

Simmons, Blake A; Loque, Dominique; Blanch, Harvey W

2008-01-01

50

Properties of Danish biofuels and the requirements for power production  

Microsoft Academic Search

Owing to government demand, ELSAM (the power pool of the western part of Denmark) obliged to utilize large amounts of biofuels for power production.Straw and wood chips are the most abundant biofuels in Denmark, and an overview of fuel composition in comparison with coal is given. The high content of potassium and chlorine in straw causes a number of serious

Bo Sander

1997-01-01

51

Slab waveguide photobioreactors for microalgae based biofuel production{{ Erica Eunjung Jung,a  

E-print Network

Slab waveguide photobioreactors for microalgae based biofuel production{{ Erica Eunjung Jung are a promising feedstock for sustainable biofuel production. At present, however, there are a number to substantial interest in increasing biofuel production. Biofuels can be produced from a number of different

Erickson, David

52

Questions, Answers and Clarifications Commercial Scale Advanced Biofuels Production Facilities Solicitation  

E-print Network

Questions, Answers and Clarifications Commercial Scale Advanced Biofuels Production Facilities biofuels production facility? A.1 An existing biofuels facility is an existing facility that, as of the application due date of PON-13-601, produces (or did produce) biofuels in California. Q.2 Must an eligible

53

Tree legumes as feedstock for sustainable biofuel production: Opportunities and challenges.  

PubMed

Concerns about future fossil fuel supplies and the environmental effects of their consumption have prompted the search for alternative sources of liquid fuels, specifically biofuels. However, it is important that the sources of such biofuel have minimal impact on global food supplies, land use, and commodity prices. Many legume trees can be grown on so-called marginal land with beneficial effects to the environment through their symbiotic interaction with "Rhizobia" and the associated process of root nodule development and biological nitrogen fixation. Once established legume trees can live for many years and some produce an annual yield of oil-rich seeds. For example, the tropical and sub-tropical legume tree Pongamia pinnata produces large seeds (?1.5-2g) that contain about 40% oil, the quality and composition of which is regarded as highly desirable for sustainable biofuel production. Here we consider the benefits of legume trees as future energy crops, particularly in relation to their impact on nitrogen inputs and the net energy balance for biofuel production, and also ways in which these as yet fully domesticated species may be further improved for optimal use as biofuel feedstock. PMID:21715045

Biswas, Bandana; Scott, Paul T; Gresshoff, Peter M

2011-11-01

54

Future testing opportunities to ensure sustainability of the biofuels industry  

Technology Transfer Automated Retrieval System (TEKTRAN)

For the Soil and Plant Analysis Community, development and expansion of biofuels will create many opportunities to provide a wide variety of analytical services. Our objective is to explore potential areas where those services could be marketed to support sustainable development of biofuels. One of ...

55

Enzymatic deconstruction of xylan for biofuel production  

PubMed Central

The combustion of fossil-derived fuels has a significant impact on atmospheric carbon dioxide (CO2) levels and correspondingly is an important contributor to anthropogenic global climate change. Plants have evolved photosynthetic mechanisms in which solar energy is used to fix CO2 into carbohydrates. Thus, combustion of biofuels, derived from plant biomass, can be considered a potentially carbon neutral process. One of the major limitations for efficient conversion of plant biomass to biofuels is the recalcitrant nature of the plant cell wall, which is composed mostly of lignocellulosic materials (lignin, cellulose, and hemicellulose). The heteropolymer xylan represents the most abundant hemicellulosic polysaccharide and is composed primarily of xylose, arabinose, and glucuronic acid. Microbes have evolved a plethora of enzymatic strategies for hydrolyzing xylan into its constituent sugars for subsequent fermentation to biofuels. Therefore, microorganisms are considered an important source of biocatalysts in the emerging biofuel industry. To produce an optimized enzymatic cocktail for xylan deconstruction, it will be valuable to gain insight at the molecular level of the chemical linkages and the mechanisms by which these enzymes recognize their substrates and catalyze their reactions. Recent advances in genomics, proteomics, and structural biology have revolutionized our understanding of the microbial xylanolytic enzymes. This review focuses on current understanding of the molecular basis for substrate specificity and catalysis by enzymes involved in xylan deconstruction. PMID:20431716

DODD, DYLAN; CANN, ISAAC K. O.

2010-01-01

56

Challenges in Engineering Microbes for Biofuels Production  

Microsoft Academic Search

Economic and geopolitical factors (high oil prices, environmental concerns, and supply instability) have been prompting policy-makers to put added emphasis on renewable energy sources. For the scientific community, recent advances, embodied in new insights into basic biology and technology that can be applied to metabolic engineering, are generating considerable excitement. There is justified optimism that the full potential of biofuel

Gregory Stephanopoulos

2007-01-01

57

Genes related to xylose fermentation and methods of using same for enhanced biofuel production  

DOEpatents

The present invention provides isolated gene sequences involved in xylose fermentation and related recombinant yeast which are useful in methods of enhanced biofuel production, particularly ethanol production. Methods of bioengineering recombinant yeast useful for biofuel production are also provided.

Wohlbach, Dana J.; Gasch, Audrey P.

2014-08-05

58

Biofuel production from microalgae as feedstock: current status and potential.  

PubMed

Abstract Algal biofuel has become an attractive alternative of petroleum-based fuels in the past decade. Microalgae have been proposed as a feedstock to produce biodiesel, since they are capable of mitigating CO2 emission and accumulating lipids with high productivity. This article is an overview of the updated status of biofuels, especially biodiesel production from microalgae including fundamental research, culture selection and engineering process development; it summarizes research on mathematical and life cycle modeling on algae growth and biomass production; and it updates global efforts of research and development and commercialization attempts. The major challenges are also discussed. PMID:24641484

Han, Song-Fang; Jin, Wen-Biao; Tu, Ren-Jie; Wu, Wei-Min

2014-03-18

59

The potential of C4 grasses for cellulosic biofuel production  

PubMed Central

With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulosic feedstock for biofuel production is discussed. These include three important field crops—maize, sugarcane and sorghum—and two undomesticated perennial energy grasses—miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum, and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of biofuel. PMID:23653628

van der Weijde, Tim; Alvim Kamei, Claire L.; Torres, Andres F.; Vermerris, Wilfred; Dolstra, Oene; Visser, Richard G. F.; Trindade, Luisa M.

2013-01-01

60

Limits to biofuels  

NASA Astrophysics Data System (ADS)

Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays' use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years' agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2-6000TWh (biogas from residues and waste and ethanol from woody biomass) in the more optimistic cases.

Johansson, S.

2013-06-01

61

Bioeconomic Sustainability of Cellulosic Biofuel Production on Marginal Lands  

ERIC Educational Resources Information Center

The use of marginal land (ML) for lignocellulosic biofuel production is examined for system stability, resilience, and eco-social sustainability. A North American prairie grass system and its industrialization for maximum biomass production using biotechnology and agro-technical inputs is the focus of the analysis. Demographic models of ML biomass…

Gutierrez, Andrew Paul; Ponti, Luigi

2009-01-01

62

Land substitution effects of biofuel side products and implications on the land area requirement for EU 2020 biofuel targets  

Microsoft Academic Search

The provision of biofuels today is based on energy crops rather than residual biomass, which results in the requirement of agricultural land area. The side products may serve as animal feed and thus prevent cultivation of other feedstock and the use of corresponding land area. These effects of biofuel provision have to be taken into account for a comprising assessment

Enver Doruk Özdemir; Marlies Härdtlein; Ludger Eltrop

2009-01-01

63

Potential Direct and Indirect Effects of Global Cellulosic Biofuel Production on Greenhouse  

E-print Network

Potential Direct and Indirect Effects of Global Cellulosic Biofuel Production on Greenhouse Gas on recycled paper #12;1 Potential Direct and Indirect Effects of Global Cellulosic Biofuel Production. Melillo*, John M. Reilly§ , and Sergey Paltsev§ Abstract The production of cellulosic biofuels may have

64

Will Sulfur Limit Bio-fuel Corn Production?  

Technology Transfer Automated Retrieval System (TEKTRAN)

The short- and long-term effects of striving for higher grain yields and removing crop residues for bio-fuels production on soil-nutrient cycling, physical properties and biological activity must be understood. To provide more quantitative guidelines, soil management studies focusing on tillage, fer...

65

Crop-Based Biofuel Production with Acreage Competition and Uncertainty  

Microsoft Academic Search

This paper examines the role of uncertaincrude oil prices, uncertain crop yields, andcompetition for acreage on corn, soybean, andswitchgrass prices under biofuel production mandates.We find enforcement of the cellulosic mandateis costly in that it raises equilibrium prices of all threecrops through competition for acreage. However,crude oil prices largely determine industry profitabilityeven in the face of high crop prices. Further wefind

M. Mallory; Dermot J. Hayes; Bruce A. Babcock

2011-01-01

66

Spatially Explicit Life Cycle Assessment of Biofuel Feedstock Production  

EPA Science Inventory

Biofuels derived from renewable resources have gained increased research and development priority due to increasing energy demand and national security concerns. In the US, the Energy Independence and Security Act (EISA) of 2007 mandated the annual production of 56.8 billion L of...

67

Crop-Based Biofuel Production with Acreage Competition and Uncertainty  

Microsoft Academic Search

This paper examines the role of uncertain crude oil prices, uncertain crop yields, and competition for acreage on corn, soybean, and switchgrass prices under biofuel production mandates. We find enforcement of the cellulosic mandate is costly in that it raises equilibrium prices of all three crops through competition for acreage. However, crude oil prices largely determine industry profitability even in

Mindy L. Mallory; Dermot J. Hayes; Bruce A. Babcock

2012-01-01

68

Crop-Based Biofuel Production with Acreage Competition and Uncertainty  

Microsoft Academic Search

This paper examines the role of uncertain crude oil prices, uncertain crop yields, and competition for acreage on corn, soybean, and switchgrass prices under biofuel production mandates. We find enforcement of the cellulosic mandate is costly in that it raises equilibrium prices of all three crops through competition for acreage. However, crude oil prices largely determine industry profitability even in

Mindy L. Mallory; Dermot J. Hayes; Bruce A. Babcock

2011-01-01

69

Watershed scale environmental sustainability analysis of biofuel production in changing land use and climate scenarios  

NASA Astrophysics Data System (ADS)

One of the grand challenges in meeting the US biofuel goal is producing large quantities of cellulosic biofeedstock materials for the production of biofuels in an environmentally sustainable and economically viable manner. The possible land use and land management practice changes induce concerns over the environmental impacts of these bioenergy crop production scenarios both in terms of water availability and water quality, and these impacts may be exacerbated by climate variability and change. This study aims to evaluate environmental sustainability of various plausible land and crop management scenarios for biofuel production under changing climate scenarios for a Midwest US watershed. The study considers twelve environmental sustainability indicators related hydrology and water quality with thirteen plausible biofuels scenarios in the watershed under nine climate change scenarios. The land use change scenarios for evaluation includes, (1) bioenergy crops in highly erodible soils (3) bioenergy crops in low row crop productive fields (marginal lands); (3) bioenergy crops in pasture and range land use areas and (4) combinations of these scenarios. Future climate data bias corrected and downscaled to daily values from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset were used in this study. The distributed hydrological model SWAT (Soil and Water Assessment Tool) was used to simulate bioenergy crops growth, hydrology and water quality. The watershed scale sustainability analysis was done in Wildcat Creek basin, which is located in North-Central Indiana, USA.

RAJ, C.; Chaubey, I.; Cherkauer, K. A.; Brouder, S. M.; Volenec, J. J.

2013-12-01

70

The Role of Synthetic Biology in the Design of Microbial Cell Factories for Biofuel Production  

PubMed Central

Insecurity in the supply of fossil fuels, volatile fuel prices, and major concerns regarding climate change have sparked renewed interest in the production of fuels from renewable resources. Because of this, the use of biodiesel has grown dramatically during the last few years and is expected to increase even further in the future. Biodiesel production through the use of microbial systems has marked a turning point in the field of biofuels since it is emerging as an attractive alternative to conventional technology. Recent progress in synthetic biology has accelerated the ability to analyze, construct, and/or redesign microbial metabolic pathways with unprecedented precision, in order to permit biofuel production that is amenable to industrial applications. The review presented here focuses specifically on the role of synthetic biology in the design of microbial cell factories for efficient production of biodiesel. PMID:22028591

Colin, Verónica Leticia; Rodríguez, Analía; Cristóbal, Héctor Antonio

2011-01-01

71

Biological pretreatment for production of lignocellulosic biofuel.  

PubMed

Lignocellulosic biomass was submitted to a biological pretreatment prior to a catalytic hydroliquefaction in order to produce biofuel. The biodegradation process was conducted over 3 months in a reactor under controlled conditions. During the biodegradation process the organic matter was characterised and its evolution was correlated with physico-chemical parameters. In parallel with the analysis of the lipidic fraction, analytical pyrolysis was used to monitor bacterial activity. The alterations of branched to linear fatty acids ratio and of mono- to diacids ratio were compared when determined by thermochemolysis and observed in the directly extractable lipids. The evolution of the phytol to the corresponding isoprenoic ketone ratio was observed to be dependent on the desorption technique since it decreases using headspace while it increases using pyrolysis. "Humic"/"fulvic acids" ratio, infrared spectroscopy and thermodifferential analysis were used to determine the degree of OM complexification. PMID:22617032

Lemée, L; Kpogbemabou, D; Pinard, L; Beauchet, R; Laduranty, J

2012-08-01

72

Photobioreactor Design for Commercial Biofuel Production from Microalgae Aditya M. Kunjapur* and R. Bruce Eldridge  

E-print Network

Photobioreactor Design for Commercial Biofuel Production from Microalgae Aditya M. Kunjapur* and R This review paper describes systems used to cultivate microalgae for biofuel production. It addresses general of biofuel. This paper also highlights the concept of combining open and closed systems and concludes

Eldridge, R. Bruce

73

Comparative genomics of xylose-fermenting fungi for enhanced biofuel production  

E-print Network

Comparative genomics of xylose-fermenting fungi for enhanced biofuel production Dana J. Wohlbacha for review February 24, 2011) Cellulosic biomass is an abundant and underused substrate for biofuel creates specific challenges for microbial biofuel production from cellulosic material. Although engineered

Gasch, Audrey P.

74

Tappable Pine Trees: Commercial Production of Terpene Biofuels in Pine  

SciTech Connect

PETRO Project: The University of Florida is working to increase the amount of turpentine in harvested pine from 4% to 20% of its dry weight. While enhanced feedstocks for biofuels have generally focused on fuel production from leafy plants and grasses, the University of Florida is experimenting with enhancing fuel production in a species of pine that is currently used in the paper pulping industry. Pine trees naturally produce around 3-5% terpene content in the wood—terpenes are the energy-dense fuel molecules that are the predominant components of turpentine. The team aims to increase the terpene storage potential and production capacity while improving the terpene composition to a point at which the trees could be tapped while alive, like sugar maples. Growth and production from these trees will take years, but this pioneering technology could have significant impact in making available an economical and domestic source of aviation and diesel biofuels.

None

2012-01-01

75

Turning Bacteria into Biofuel: Development of an Integrated Microbial Electrocatalytic (MEC) System for Liquid Biofuel Production from CO2  

SciTech Connect

Electrofuels Project: LBNL is improving the natural ability of a common soil bacteria called Ralstonia eutropha to use hydrogen and carbon dioxide for biofuel production. First, LBNL is genetically modifying the bacteria to produce biofuel at higher concentrations. Then, LBNL is using renewable electricity obtained from solar, wind, or wave power to produce high amounts of hydrogen in the presence of the bacteria—increasing the organism’s access to its energy source and improving the efficiency of the biofuel-creation process. Finally, LBNL is tethering electrocatalysts to the bacteria’s surface which will further accelerate the rate at which the organism creates biofuel. LBNL is also developing a chemical method to transform the biofuel that the bacteria produce into ready-to-use jet fuel.

None

2010-08-01

76

Sequencing of Multiple Clostridial Genomes Related to Biomass Conversion and Biofuel Production  

SciTech Connect

Modern methods to develop microbe-based biomass conversion processes require a system-level understanding of the microbes involved. Clostridium species have long been recognized as ideal candidates for processes involving biomass conversion and production of various biofuels and other industrial products. To expand the knowledge base for clostridial species relevant to current biofuel production efforts, we have sequenced the genomes of 20 species spanning multiple genera. The majority of species sequenced fall within the class III cellulosome-encoding Clostridium and the class V saccharolytic Thermoanaerobacteraceae. Species were chosen based on representation in the experimental literature as model organisms, ability to degrade cellulosic biomass either by free enzymes or by cellulosomes, ability to rapidly ferment hexose and pentose sugars to ethanol, and ability to ferment synthesis gas to ethanol. The sequenced strains significantly increase the number of noncommensal/nonpathogenic clostridial species and provide a key foundation for future studies of biomass conversion, cellulosome composition, and clostridial systems biology.

Hemme, Christopher [University of Oklahoma; Mouttaki, Housna [University of Oklahoma; Lee, Yong-Jin [University of Oklahoma, Norman; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; He, Zhili [University of Oklahoma; Wu, Liyou [University of Oklahoma, Norman; Van Nostrand, Joy [University of Oklahoma, Norman; Henrissat, Bernard [Universite d'Aix-Marseille I & II; HE, Qiang [ORNL; Lawson, Paul A. [University of Oklahoma, Norman; Tanner, Ralph S. [University of Oklahoma, Norman; Lynd, Lee R [Thayer School of Engineering at Dartmouth; Wiegel, Juergen [University of Georgia, Athens, GA; Fields, Dr. Matthew Wayne [Montana State University; Arkin, Adam [Lawrence Berkeley National Laboratory (LBNL); Schadt, Christopher Warren [ORNL; Stevenson, Bradley S. [University of Oklahoma, Norman; McInerney, Michael J. [University of Oklahoma, Norman; Yang, Yunfeng [ORNL; Dong, Hailiang [Miami University, Oxford, OH; Xing, Defeng [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology; Ren, Nanqi [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology; Wang, Aijie [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology; Ding, Shi-You [National Energy Renewable Laboratory; Himmel, Michael E [National Renewable Energy Laboratory (NREL); Taghavi, Safiyh [Brookhaven National Laboratory (BNL)/U.S. Department of Energy; Van Der Lelie, Daniel [Brookhaven National Laboratory (BNL); Rubin, Edward M. [U.S. Department of Energy, Joint Genome Institute; Zhou, Jizhong [University of Oklahoma

2010-01-01

77

Molecular Breeding of Advanced Microorganisms for Biofuel Production  

PubMed Central

Large amounts of fossil fuels are consumed every day in spite of increasing environmental problems. To preserve the environment and construct a sustainable society, the use of biofuels derived from different kinds of biomass is being practiced worldwide. Although bioethanol has been largely produced, it commonly requires food crops such as corn and sugar cane as substrates. To develop a sustainable energy supply, cellulosic biomass should be used for bioethanol production instead of grain biomass. For this purpose, cell surface engineering technology is a very promising method. In biobutanol and biodiesel production, engineered host fermentation has attracted much attention; however, this method has many limitations such as low productivity and low solvent tolerance of microorganisms. Despite these problems, biofuels such as bioethanol, biobutanol, and biodiesel are potential energy sources that can help establish a sustainable society. PMID:21318120

Sakuragi, Hiroshi; Kuroda, Kouichi; Ueda, Mitsuyoshi

2011-01-01

78

Piedmont Biofuels Homepage  

NSDL National Science Digital Library

The Piedmont Biofuels homepage provides access to information about small industrial production of biodiesel, biofuels educational programs at Cental Carolina Community College, and volunteer opportunities in biofuels.

79

Genetic Engineering of Algae for Enhanced Biofuel Production ?  

PubMed Central

There are currently intensive global research efforts aimed at increasing and modifying the accumulation of lipids, alcohols, hydrocarbons, polysaccharides, and other energy storage compounds in photosynthetic organisms, yeast, and bacteria through genetic engineering. Many improvements have been realized, including increased lipid and carbohydrate production, improved H2 yields, and the diversion of central metabolic intermediates into fungible biofuels. Photosynthetic microorganisms are attracting considerable interest within these efforts due to their relatively high photosynthetic conversion efficiencies, diverse metabolic capabilities, superior growth rates, and ability to store or secrete energy-rich hydrocarbons. Relative to cyanobacteria, eukaryotic microalgae possess several unique metabolic attributes of relevance to biofuel production, including the accumulation of significant quantities of triacylglycerol; the synthesis of storage starch (amylopectin and amylose), which is similar to that found in higher plants; and the ability to efficiently couple photosynthetic electron transport to H2 production. Although the application of genetic engineering to improve energy production phenotypes in eukaryotic microalgae is in its infancy, significant advances in the development of genetic manipulation tools have recently been achieved with microalgal model systems and are being used to manipulate central carbon metabolism in these organisms. It is likely that many of these advances can be extended to industrially relevant organisms. This review is focused on potential avenues of genetic engineering that may be undertaken in order to improve microalgae as a biofuel platform for the production of biohydrogen, starch-derived alcohols, diesel fuel surrogates, and/or alkanes. PMID:20139239

Radakovits, Randor; Jinkerson, Robert E.; Darzins, Al; Posewitz, Matthew C.

2010-01-01

80

Genetic engineering of algae for enhanced biofuel production.  

PubMed

There are currently intensive global research efforts aimed at increasing and modifying the accumulation of lipids, alcohols, hydrocarbons, polysaccharides, and other energy storage compounds in photosynthetic organisms, yeast, and bacteria through genetic engineering. Many improvements have been realized, including increased lipid and carbohydrate production, improved H(2) yields, and the diversion of central metabolic intermediates into fungible biofuels. Photosynthetic microorganisms are attracting considerable interest within these efforts due to their relatively high photosynthetic conversion efficiencies, diverse metabolic capabilities, superior growth rates, and ability to store or secrete energy-rich hydrocarbons. Relative to cyanobacteria, eukaryotic microalgae possess several unique metabolic attributes of relevance to biofuel production, including the accumulation of significant quantities of triacylglycerol; the synthesis of storage starch (amylopectin and amylose), which is similar to that found in higher plants; and the ability to efficiently couple photosynthetic electron transport to H(2) production. Although the application of genetic engineering to improve energy production phenotypes in eukaryotic microalgae is in its infancy, significant advances in the development of genetic manipulation tools have recently been achieved with microalgal model systems and are being used to manipulate central carbon metabolism in these organisms. It is likely that many of these advances can be extended to industrially relevant organisms. This review is focused on potential avenues of genetic engineering that may be undertaken in order to improve microalgae as a biofuel platform for the production of biohydrogen, starch-derived alcohols, diesel fuel surrogates, and/or alkanes. PMID:20139239

Radakovits, Randor; Jinkerson, Robert E; Darzins, Al; Posewitz, Matthew C

2010-04-01

81

Production of biofuels from synthesis gas using microbial catalysts.  

PubMed

World energy consumption is expected to increase 44% in the next 20 years. Today, the main sources of energy are oil, coal, and natural gas, all fossil fuels. These fuels are unsustainable and contribute to environmental pollution. Biofuels are a promising source of sustainable energy. Feedstocks for biofuels used today such as grain starch are expensive and compete with food markets. Lignocellulosic biomass is abundant and readily available from a variety of sources, for example, energy crops and agricultural/industrial waste. Conversion of these materials to biofuels by microorganisms through direct hydrolysis and fermentation can be challenging. Alternatively, biomass can be converted to synthesis gas through gasification and transformed to fuels using chemical catalysts. Chemical conversion of synthesis gas components can be expensive and highly susceptible to catalyst poisoning, limiting biofuel yields. However, there are microorganisms that can convert the CO, H(2), and CO(2) in synthesis gas to fuels such as ethanol, butanol, and hydrogen. Biomass gasification-biosynthesis processing systems have shown promise as some companies have already been exploiting capable organisms for commercial purposes. The discovery of novel organisms capable of higher product yield, as well as metabolic engineering of existing microbial catalysts, makes this technology a viable option for reducing our dependency on fossil fuels. PMID:20359454

Tirado-Acevedo, Oscar; Chinn, Mari S; Grunden, Amy M

2010-01-01

82

Comparative cost analysis of algal oil production for biofuels  

Microsoft Academic Search

Economic analysis is an essential evaluation for considering feasibility and viability of large-scale, photoautotrophic algae-based, biofuel production. Thus far, economic analysis has been conducted on a scenario-by-scenario basis which does not allow for cross-comparisons. In 2008, a comparative study was carried out using a cross-section of cost analyses consisting of 12 public studies. The resulting triacylglyceride cost had a spread

Amy Sun; Ryan Davis; Meghan Starbuck; Ami Ben-Amotz; Ron Pate; Philip T. Pienkos

2011-01-01

83

Diagram of the Biofuel Production Process (SPORL -Alcohol Production):Introduction: The Northwest Advanced Renewables Alliance (NARA) is an organization  

E-print Network

Diagram of the Biofuel Production Process (SPORL - Alcohol Production):Introduction: The Northwest Advanced Renewables Alliance (NARA) is an organization that aims to create a sustainable aviation biofuels to determine the atmospheric emissions and emission sources that may be released from proposed NARA biofuels

Collins, Gary S.

84

Fatty acid alkyl esters: perspectives for production of alternative biofuels.  

PubMed

The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis. PMID:20033403

Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

2010-02-01

85

The US Ethanol and Biofuels Boom: Its Origins, Current Status, and Future Prospects  

NSDL National Science Digital Library

This article explains why we are experiencing a boom in ethanol and other biofuels, the current status of biofuels, and prospects for the future under different policy regimes. I argue that today's boom is in a sense an unintended consequence of a fixed ethanol subsidy that was keyed to $20-per-barrel crude oil, combined with a surge in crude oil pricesinitially to $60 per barrel, and later doubling to $120 per barrel. Future prospects for corn ethanol depend on the crude oil price, the price of corn and distillers' grains, the market value of ethanol, plant capital and operating costs, and federal ethanol and biofuels policies. I examine the impacts of a wide range of policies for subsidies and renewable fuels standards. Policy choices will be absolutely critical in determining the extent to which biofuels targets are achieved and at what cost. However, if the price of oil remains above $100 per barrel, biofuels will continue to be produced even without government interventions.

Wallace E. Tyner (Purdue University;)

2008-08-01

86

Tailoring lignin biosynthesis for efficient and sustainable biofuel production.  

PubMed

Increased global interest in a bio-based economy has reinvigorated the research on the cell wall structure and composition in plants. In particular, the study of plant lignification has become a central focus, with respect to its intractability and negative impact on the utilization of the cell wall biomass for producing biofuels and bio-based chemicals. Striking progress has been achieved in the last few years both on our fundamental understanding of lignin biosynthesis, deposition and assembly, and on the interplay of lignin synthesis with the plant growth and development. With the knowledge gleaned from basic studies, researchers are now able to invent and develop elegant biotechnological strategies to sophisticatedly manipulate the quantity and structure of lignin and thus to create economically viable bioenergy feedstocks. These concerted efforts open an avenue for the commercial production of cost-competitive biofuel to meet our energy needs. PMID:25209835

Liu, Chang-Jun; Cai, Yuanheng; Zhang, Xuebin; Gou, Mingyue; Yang, Huijun

2014-12-01

87

Downgrading recent estimates of land available for biofuel production.  

PubMed

Recent estimates of additional land available for bioenergy production range from 320 to 1411 million ha. These estimates were generated from four scenarios regarding the types of land suitable for bioenergy production using coarse-resolution inputs of soil productivity, slope, climate, and land cover. In this paper, these maps of land availability were assessed using high-resolution satellite imagery. Samples from these maps were selected and crowdsourcing of Google Earth images was used to determine the type of land cover and the degree of human impact. Based on this sample, a set of rules was formulated to downward adjust the original estimates for each of the four scenarios that were previously used to generate the maps of land availability for bioenergy production. The adjusted land availability estimates range from 56 to 1035 million ha depending upon the scenario and the ruleset used when the sample is corrected for bias. Large forest areas not intended for biofuel production purposes were present in all scenarios. However, these numbers should not be considered as definitive estimates but should be used to highlight the uncertainty in attempting to quantify land availability for biofuel production when using coarse-resolution inputs with implications for further policy development. PMID:23308357

Fritz, Steffen; See, Linda; van der Velde, Marijn; Nalepa, Rachel A; Perger, Christoph; Schill, Christian; McCallum, Ian; Schepaschenko, Dmitry; Kraxner, Florian; Cai, Ximing; Zhang, Xiao; Ortner, Simone; Hazarika, Rubul; Cipriani, Anna; Di Bella, Carlos; Rabia, Ahmed H; Garcia, Alfredo; Vakolyuk, Mar'yana; Singha, Kuleswar; Beget, Maria E; Erasmi, Stefan; Albrecht, Franziska; Shaw, Brian; Obersteiner, Michael

2013-02-01

88

PETRO: Higher Productivity Crops for Biofuels  

SciTech Connect

PETRO Project: The 10 projects that comprise ARPA-E’s PETRO Project, short for “Plants Engineered to Replace Oil,” aim to develop non-food crops that directly produce transportation fuel. These crops can help supply the transportation sector with agriculturally derived fuels that are cost-competitive with petroleum and do not affect U.S. food supply. PETRO aims to redirect the processes for energy and carbon dioxide (CO2) capture in plants toward fuel production. This would create dedicated energy crops that serve as a domestic alternative to petroleum-based fuels and deliver more energy per acre with less processing prior to the pump.

None

2012-01-01

89

A model for improving microbial biofuel production using a synthetic feedback loop.  

PubMed

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straightforward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates. PMID:20805930

Dunlop, Mary J; Keasling, Jay D; Mukhopadhyay, Aindrila

2010-06-01

90

An integrative modeling framework to evaluate the productivity and sustainability of biofuel crop production systems  

SciTech Connect

The potential expansion of biofuel production raises food, energy, and environmental challenges that require careful assessment of the impact of biofuel production on greenhouse gas (GHG) emissions, soil erosion, nutrient loading, and water quality. In this study, we describe a spatially explicit integrative modeling framework (SEIMF) to understand and quantify the environmental impacts of different biomass cropping systems. This SEIMF consists of three major components: (1) a geographic information system (GIS)-based data analysis system to define spatial modeling units with resolution of 56 m to address spatial variability, (2) the biophysical and biogeochemical model Environmental Policy Integrated Climate (EPIC) applied in a spatially-explicit way to predict biomass yield, GHG emissions, and other environmental impacts of different biofuel crops production systems, and (3) an evolutionary multiobjective optimization algorithm for exploring the trade-offs between biofuel energy production and unintended ecosystem-service responses. Simple examples illustrate the major functions of the SEIMF when applied to a nine-county Regional Intensive Modeling Area (RIMA) in SW Michigan to (1) simulate biofuel crop production, (2) compare impacts of management practices and local ecosystem settings, and (3) optimize the spatial configuration of different biofuel production systems by balancing energy production and other ecosystem-service variables. Potential applications of the SEIMF to support life cycle analysis and provide information on biodiversity evaluation and marginal-land identification are also discussed. The SEIMF developed in this study is expected to provide a useful tool for scientists and decision makers to understand sustainability issues associated with the production of biofuels at local, regional, and national scales.

Zhang, X [University of Maryland; Izaurralde, R. C. [University of Maryland; Manowitz, D. [University of Maryland; West, T. O. [University of Maryland; Thomson, A. M. [University of Maryland; Post, Wilfred M [ORNL; Bandaru, Vara Prasad [ORNL; Nichols, Jeff [ORNL; Williams, J. [AgriLIFE, Temple, TX

2010-10-01

91

An Integrative Modeling Framework to Evaluate the Productivity and Sustainability of Biofuel Crop Production Systems  

SciTech Connect

The potential expansion of biofuel production raises food, energy, and environmental challenges that require careful assessment of the impact of biofuel production on greenhouse gas (GHG) emissions, soil erosion, nutrient loading, and water quality. In this study, we describe a spatially-explicit integrative modeling framework (SEIMF) to understand and quantify the environmental impacts of different biomass cropping systems. This SEIMF consists of three major components: 1) a geographic information system (GIS)-based data analysis system to define spatial modeling units with resolution of 56 m to address spatial variability, 2) the biophysical and biogeochemical model EPIC (Environmental Policy Integrated Climate) applied in a spatially-explicit way to predict biomass yield, GHG emissions, and other environmental impacts of different biofuel crops production systems, and 3) an evolutionary multi-objective optimization algorithm for exploring the trade-offs between biofuel energy production and unintended ecosystem-service responses. Simple examples illustrate the major functions of the SEIMF when applied to a 9-county Regional Intensive Modeling Area (RIMA) in SW Michigan to 1) simulate biofuel crop production, 2) compare impacts of management practices and local ecosystem settings, and 3) optimize the spatial configuration of different biofuel production systems by balancing energy production and other ecosystem-service variables. Potential applications of the SEIMF to support life cycle analysis and provide information on biodiversity evaluation and marginal-land identification are also discussed. The SEIMF developed in this study is expected to provide a useful tool for scientists and decision makers to understand sustainability issues associated with the production of biofuels at local, regional, and national scales.

Zhang, Xuesong; Izaurralde, Roberto C.; Manowitz, David H.; West, T. O.; Post, W. M.; Thomson, Allison M.; Bandaru, V. P.; Nichols, J.; Williams, J.R.

2010-09-08

92

Integrated biorefineries with engineered microbes and high-value co-products for profitable biofuels production  

Microsoft Academic Search

Corn-based fuel ethanol production processes provide several advantages which could be synergistically applied to overcome\\u000a limitations of biofuel processes based on lignocellulose. These include resources such as equipment, manpower, nutrients,\\u000a water, and heat. The fact that several demonstration-scale biomass ethanol processes are using corn as a platform supports\\u000a this viewpoint. This report summarizes the advantages of first-generation corn-based biofuel processes

W. R. Gibbons; S. R. Hughes

2009-01-01

93

Integrated Biorefineries with Engineered Microbes and High-value Co-products for Profitable Biofuels Production  

Microsoft Academic Search

\\u000a Corn-based fuel ethanol production processes provide several ­advantages which could be synergistically applied to overcome\\u000a limitations of biofuel processes based on lignocellulose. These include resources such as equipment, manpower, nutrients,\\u000a water, and heat. The fact that several demonstration-scale biomass ethanol processes are using corn as a platform supports\\u000a this viewpoint. This report summarizes the advantages of first-generation corn-based biofuel processes

William Gibbons; Stephen Hughes

94

The impact of extreme drought on the biofuel feedstock production  

NASA Astrophysics Data System (ADS)

Miscanthus (Miscanthus x giganteus) and Switchgrass (Panicum virgatum) have been identified as the primary targets for second-generation cellulosic biofuel crops. Prairie managed for biomass is also considered as one of the alternative to conventional biofuel and promised to provide ecosystem services, including carbon sequestration. These perennial grasses possess a number of traits that make them desirable biofuel crops and can be cultivated on marginal lands or interspersed with maize and soybean in the Corn Belt region. The U.S. Corn Belt region is the world's most productive and expansive maize-growing region, approximately 20% of the world's harvested corn hectares are found in 12 Corn Belt states. The introduction of a second generation cellulosic biofuels for biomass production in a landscape dominated by a grain crop (maize) has potential implications on the carbon and water cycles of the region. This issue is further intensified by the uncertainty in the response of the vegetation to the climate change induced drought periods, as was seen during the extreme droughts of 2011 and 2012 in the Midwest. The 2011 and 2012 growing seasons were considered driest since the 1932 dust bowl period; temperatures exceeded 3.0 °C above the 50- year mean and precipitation deficit reached 50 %. The major objective of this study was to evaluate the drought responses (2011 and 2012) of corn and perennial species at large scale, and to determine the seasonability of carbon and water fluxes in the response of controlling factors. We measured net CO2 ecosystem exchange (NEE) and water fluxes of maize-maize-soybean, and perennial species such as miscanthus, switchgrass and mixture of prairie grasses, using eddy covariance in the University of Illinois energy farm at Urbana, IL. The data presented here were for 5 years (2008- 2012). In the first two years, higher NEE in maize led to large CO2 sequestration. NEE however, decreased in dry years, particularly in 2012. On the other hand, miscanthus, switchgrass, and to a lesser extent, prairie showed higher NEE and gross primary production (GPP) - a partitioned NEE component - than maize during 2012. Although miscanthus uses more water relative to maize (consumed 30 % more water), Net Ecosystem Carbon Balance (NECB) results show that it provides the greatest net benefits of sequestering atmospheric CO2 during drought. Our findings highlight the important role of perennial species in sustaining productivity and sequestering CO2 during drought, as compared to maize. We conclude that changing land use from row crops to perennial species will result in more sequestered carbon, even with drought stress, and will be more resilient to prolonged dry periods.

hussain, M.; Zeri, M.; Bernacchi, C.

2013-12-01

95

Fields of dreams: Agriculture, economy and nature in Midwest United States biofuel production  

NASA Astrophysics Data System (ADS)

This work explores the social and ecological dimensions of recent biofuel production increases in the United States (US), focusing on the case of Iowa. Biofuels are proposed to mitigate the greenhouse gas emissions that cause climate change, improve US energy security, and support rural economies. Little research has examined how increased US Midwestern biofuels production will change social and ecological outcomes at farm and regional levels or interact with broader governance processes at the nexus of agriculture, energy and environment. These broad questions guide my research: (1) How does biofuel production reconfigure agricultural practice and landscapes in Iowa? (2) What are the costs, benefits and risks of increased biofuels production as seen by farmers and rural residents, and how do these factors influence farmer decisions about agriculture and conservation practice? (3) How and with what effects are biofuels initiatives constituted as a form of environmental governance through scientific knowledge and practice and political economic dynamics? To address these questions, this research integrates both qualitative and quantitative methods, drawing on a political ecological approach complemented by agroecological analysis and theoretical insights from geographical analyses of nature-society relations. Quantitative analysis focuses on changing land use patterns in agriculture and conservation practice in Iowa. Qualitative methods include extensive interviews, participant observation, and policy and document analyses. Fieldwork focused on Northeastern Iowa to understand regional changes in agricultural and conservation practice, the renegotiated position of farmers in agriculture and biofuel production, and biofuel industry development. I find that biofuel production presents significant social and ecological challenges for rural places of production. Longstanding, unequal political economic relations in industrialized agriculture limit rural economic benefits. I describe how biofuel governance focuses on scientific practices that legitimize biofuel production for their capacity to marginally reduce greenhouse gas emissions, despite biofuels' agroecological consequences outside this regulatory purview. These consequences include pressure on conservation and agrienvironmental practice, which could be better supported through existing, highly effective, place-based, democratic institutions dedicated to stewarding the resources upon which agricultural livelihoods depend.

Gillon, Sean Thomas

96

Greenhouse Gas Mitigation on Marginal Land: A Quantitative Review of the Relative Benefits of Forest Recovery versus Biofuel Production.  

PubMed

Decisions concerning future land-use/land cover change stand at the forefront of ongoing debates on how to best mitigate climate change. In this study, we compare the greenhouse gas (GHG) mitigation value over a 30-year time frame for a range of forest recovery and biofuel production scenarios on abandoned agricultural land. Carbon sequestration in recovering forests is estimated based on a statistical analysis of tropical and temperate studies on marginal land. GHGs offset by biofuel production are analyzed for five different production pathways. We find that forest recovery is superior to low-yielding biofuel production scenarios such as oil palm and corn. Biofuel production scenarios with high yields, such as sugarcane or high-yielding energy grasses, can be comparable or superior to natural forest succession and to reforestation in some cases. This result stands in contrast to previous research suggesting that restoring degraded ecosystems to their native state is generally superior to agricultural production in terms of GHG mitigation. Further work is needed on carbon stock changes in forests, soil carbon dynamics, and bioenergy crop production on degraded/abandoned agricultural land. This finding also emphasizes the need to consider the full range of social, economic, and ecological consequences of land-use policies. PMID:25582654

Evans, Samuel G; Ramage, Benjamin S; DiRocco, Tara L; Potts, Matthew D

2015-02-17

97

Biofuel Database  

National Institute of Standards and Technology Data Gateway

Biofuel Database (Web, free access)   This database brings together structural, biological, and thermodynamic data for enzymes that are either in current use or are being considered for use in the production of biofuels.

98

Biofuel Production Initiative at Claflin University Final Report  

SciTech Connect

For US transportation fuel independence or reduced dependence on foreign oil, the Federal Government has mandated that the country produce 36 billion gallons (bg) of renewable transportation fuel per year for its transportation fuel supply by 2022. This can be achieved only if development of efficient technology for second generation biofuel from ligno-cellulosic sources is feasible. To be successful in this area, development of a widely available, renewable, cost-effective ligno-cellulosic biomass feedstock that can be easily and efficiently converted biochemically by bacteria or other fast-growing organisms is required. Moreover, if the biofuel type is butanol, then the existing infrastructure to deliver fuel to the customer can be used without additional costs and retrofits. The Claflin Biofuel Initiative project is focused on helping the US meet the above-mentioned targets. With support from this grant, Claflin University (CU) scientists have created over 50 new strains of microorganisms that are producing butanol from complex carbohydrates and cellulosic compounds. Laboratory analysis shows that a number of these strains are producing higher percentages of butanol than other methods currently in use. All of these recombinant bacterial strains are producing relatively high concentrations of acetone and numerous other byproducts as well. Therefore, we are carrying out intense mutations in the selected strains to reduce undesirable byproducts and increase the desired butanol production to further maximize the yield of butanol. We are testing the proof of concept of producing pre-industrial large scale biobutanol production by utilizing modifications of currently commercially available fermentation technology and instrumentation. We have already developed an initial process flow diagram (PFD) and selected a site for a biobutanol pilot scale facility in Orangeburg, SC. With the recent success in engineering new strains of various biofuel producing bacteria at CU, it will soon be possible to provide other technical information for the development of process flow diagrams (PFD’s) and piping and instrumentation diagrams (P&ID’s). This information can be used for the equipment layout and general arrangement drawings for the proposed process and eventual plant. An efficient bio-butanol pilot plant to convert ligno-cellulosic biomass feedstock from bagasse and wood chips will create significant number of green jobs for the Orangeburg, SC community that will be environmentally-friendly and generate much-needed income for farmers in the area.

Chowdhury, Kamal

2011-07-20

99

Sustainable multipurpose biorefineries for third-generation biofuels and value-added co-products  

Technology Transfer Automated Retrieval System (TEKTRAN)

Modern biorefinery facilities conduct many types of processes, including those producing advanced biofuels, commodity chemicals, biodiesel, and value-added co-products such as sweeteners and bioinsecticides, with many more co-products, chemicals and biofuels on the horizon. Most of these processes ...

100

Life cycle and landscape impacts of biofuel production  

NASA Astrophysics Data System (ADS)

Achieving the biofuel volumes mandated in the Renewable Fuels Standard of the United States Energy Independence and Security Act of 2007 will require large amounts of biomass such as crop residues and dedicated bioenergy crops. Growing sufficient amounts of these feedstocks would greatly transform the agricultural landscape of the United States, and depending on where and how they are grown, may have vastly different implications for the sustainability of the biofuels industry. This presentation describes ongoing research into how biomass can best be produced on the landscape so as to benefit rural economies and provide ecosystem services such as greenhouse gas mitigation and improved air quality. The focus is on newly developed methods for integrating spatial and temporal information into life cycle assessment so as to both allow for more detailed impact assessment and to provide insight into how to improve efficiency along bioenergy production supply chains. Results will benefit stakeholders both by offering recommendations for guiding sustainable growth of the emerging bioeconomy and by advancing understanding of the inherent tradeoffs among alternate scenarios.

Hill, J.

2012-12-01

101

A Dynamic Simulation of the Indirect Land Use Implications of Recent Biofuel Production and Use in the United States.  

SciTech Connect

The global indirect land use change (ILUC) implications of biofuel use in the United States of America (USA) from 2001 to 2010 are evaluated with a dynamic general equilibrium model. The effects of biofuels production on agricultural land area vary by year; from a net expansion of 0.17 ha per 1000 gallons produced (2002) to a net contraction of 0.13 ha per 1000 gallons (2018) in Case 1 of our simulation. In accordance with the general narrative about the implications of biofuel policy, agricultural land area increased in many regions of the world. However, oil-export dependent economies experienced agricultural land contraction because of reductions in their revenues. Reducing crude oil imports is a major goal of biofuel policy, but the land use change implications have received little attention in the literature. Simulations evaluating the effects of doubling supply elasticities for land and fossil resources show that these parameters can significantly influence the land use change estimates. Therefore, research that provides empirically-based and spatially-detailed agricultural land-supply curves and capability to project future fossil energy prices is critical for improving estimates of the effects of biofuel policy on land use.

Oladosu, Gbadebo A [ORNL] [ORNL; Kline, Keith L [ORNL] [ORNL

2013-01-01

102

Sub-national TIMES model for analyzing regional future use of Biomass and Biofuels in France and  

E-print Network

1 Sub-national TIMES model for analyzing regional future use of Biomass and Biofuels in France, to estimate the possibility of fulfilling national goals concerning the future use of biomass sources and to estimate the future use of biomass sources in the energy sector, the current energy system models needs

Boyer, Edmond

103

Your World Magazine - Biofuels: Energy for Your Future  

SciTech Connect

Policymakers have been talking for years about measures to cut back how much petroleum we use. Interest has spiked recently, with government and private companies coming together to push forward scientific research and development of alternative fuel products such as ethanol. Biotechnology is helping make alternative energy sources easier - and more affordable - to produce. Most of the world's energy needs are met with oil and natural gas, which come from fossil fuel. No one knows how long the supply can last. Biobased fuels come from natural sources that can be replaced quickly. Along with corn, there are many other grains, grasses, trees, and even agricultural wastes being investigated for their usefulness and environmental friendliness as alternative fuel sources. Careers in this emerging new field emphasize chemistry and engineering. Look into it for a potential career - it's definitely a job full of energy.

Biotechnology Institute

2006-10-01

104

Optimization of light use efficiency for biofuel production in algae.  

PubMed

A major challenge for next decades is development of competitive renewable energy sources, highly needed to compensate fossil fuels reserves and reduce greenhouse gas emissions. Among different possibilities, which are currently under investigation, there is the exploitation of unicellular algae for production of biofuels and biodiesel in particular. Some algae species have the ability of accumulating large amount of lipids within their cells which can be exploited as feedstock for the production of biodiesel. Strong research efforts are however still needed to fulfill this potential and optimize cultivation systems and biomass harvesting. Light provides the energy supporting algae growth and available radiation must be exploited with the highest possible efficiency to optimize productivity and make microalgae large scale cultivation energetically and economically sustainable. Investigation of the molecular bases influencing light use efficiency is thus seminal for the success of this biotechnology. In this work factors influencing light use efficiency in algal biomass production are reviewed, focusing on how algae genetic engineering and control of light environment within photobioreactors can improve the productivity of large scale cultivation systems. PMID:23876487

Simionato, Diana; Basso, Stefania; Giacometti, Giorgio M; Morosinotto, Tomas

2013-12-01

105

Perspectives on engineering strategies for improving biofuel production from microalgae - A critical review.  

PubMed

Although the potential for biofuel production from microalgae via photosynthesis has been intensively investigated, information on the selection of a suitable operation strategy for microalgae-based biofuel production is lacking. Many published reports describe competitive strains and optimal culture conditions for use in biofuel production; however, the major impediment to further improvements is the absence of effective engineering strategies for microalgae cultivation and biofuel production. This comprehensive review discusses recent advances in understanding the effects of major environmental stresses and the characteristics of various engineering operation strategies on the production of biofuels (mainly biodiesel and bioethanol) using microalgae. The performances of microalgae-based biofuel-producing systems under various environmental stresses (i.e., irradiance, temperature, pH, nitrogen depletion, and salinity) and cultivation strategies (i.e., fed-batch, semi-continuous, continuous, two-stage, and salinity-gradient) are compared. The reasons for variations in performance and the underlying theories of the various production strategies are also critically discussed. The aim of this review is to provide useful information to facilitate development of innovative and feasible operation technologies for effectively increasing the commercial viability of microalgae-based biofuel production. PMID:25285758

Ho, Shih-Hsin; Ye, Xiaoting; Hasunuma, Tomohisa; Chang, Jo-Shu; Kondo, Akihiko

2014-12-01

106

Integrated Biorefineries with Engineered Microbes and High-value Co-products for Profitable Biofuels Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

First-generation (ie., corn-based) fuel ethanol production processes provide several advantages which could be synergistically applied to overcome limitations of second-generation biofuel processes from lignocellulose. These include resources such as equipment, manpower, nutrients, water, and heat....

107

USING GIS TO DETERMINE PLANTABLE AREA FOR PRAIRIE SWITCHGRASS BIOFUEL PRODUCTION IN KENTUCKY RIGHTS-OF-WAY  

EPA Science Inventory

(1) The United States’ dependence on foreign fuel and other non-renewable resources has implications across disciplines including international relationships, the environment, and economics. Biofuels have been proposed as an alternative; however, land for biofuel product...

108

Trade-offs of water use for hydropower generation and biofuel production in the Zambezi basin in Mozambique  

NASA Astrophysics Data System (ADS)

Hydropower is the most important energy source in Mozambique, as in many other southern African countries. In the Zambezi basin, it is one of the major economic resources, and substantial hydropower development is envisaged for the next decades. In Mozambique, the extension of the large Cahora Bassa hydropower plant and the construction of several new facilities downstream are planned. Irrigated agriculture currently plays a minor role, but has a large potential due to available land and water resources. Irrigation development, especially for the production of biofuels, is an important government policy goal in Mozambique. This contribution assesses interrelations and trade-offs between these two development options with high dependence on water availability. Potential water demand for large-scale irrigated agriculture is estimated for a mix of possible biofuel crops in three scenarios with different irrigated area sizes. Impacts on river discharge and hydropower production in the Lower Zambezi and its tributaries under two projected future climates are simulated with a hydrological model and a reservoir operation and hydropower model. Trade-offs of increasing biofuel production with decreasing hydropower generation due to diminished discharge in the Zambezi River are investigated based on potential energy production, from hydropower and biofuels, and resulting gross revenues and net benefits. Results show that the impact of irrigation withdrawal on hydropower production is rather low due to the generally high water availability in the Zambezi River. In simulations with substantial irrigated areas, hydropower generation decreases by -2% as compared to a scenario with only small irrigated areas. The economic analyses suggest that the use of water for cultivation of biofuel crops in the Zambezi basin can generate higher economic benefits than the use of water for hydroelectric power production. If world oil prices stay at more than about 80 USD/barrel, then the production of biofuels for oil import substitution will yield strong benefits except for the least efficient producers. Producing biofuels for export is more challenging and requires highly efficient production. Generally, investment in irrigated agriculture is expected to have more impact on local economy and therefore poverty reduction than investment in hydropower development.

Stanzel, Philipp; Kling, Harald; Nicholson, Kit

2014-05-01

109

Use of tamarisk as a potential feedstock for biofuel production.  

SciTech Connect

This study assesses the energy and water use of saltcedar (or tamarisk) as biomass for biofuel production in a hypothetical sub-region in New Mexico. The baseline scenario consists of a rural stretch of the Middle Rio Grande River with 25% coverage of mature saltcedar that is removed and converted to biofuels. A manufacturing system life cycle consisting of harvesting, transportation, pyrolysis, and purification is constructed for calculating energy and water balances. On a dry short ton woody biomass basis, the total energy input is approximately 8.21 mmBTU/st. There is potential for 18.82 mmBTU/st of energy output from the baseline system. Of the extractable energy, approximately 61.1% consists of bio-oil, 20.3% bio-char, and 18.6% biogas. Water consumptive use by removal of tamarisk will not impact the existing rate of evapotranspiration. However, approximately 195 gal of water is needed per short ton of woody biomass for the conversion of biomass to biocrude, three-quarters of which is cooling water that can be recovered and recycled. The impact of salt presence is briefly assessed. Not accounted for in the baseline are high concentrations of Calcium, Sodium, and Sulfur ions in saltcedar woody biomass that can potentially shift the relative quantities of bio-char and bio-oil. This can be alleviated by a pre-wash step prior to the conversion step. More study is needed to account for the impact of salt presence on the overall energy and water balance.

Sun, Amy Cha-Tien; Norman, Kirsten

2011-01-01

110

Biofuels from Microalgae: Review of Products, Processes and Potential, with Special Focus on Dunaliella sp.  

SciTech Connect

There is currently great interest in using microalgae for the production of biofuels, mainly due to the fact that microalgae can produce biofuels at a much higher productivity than conventional plants and that they can be cultivated using water, in particular seawater, and land not competing for resources with conventional agriculture. However, at present such microalgae-based technologies are not yet developed and the economics of such processes are uncertain. We review power generation by direct combustion, production of hydrogen and other fuel gases and liquids by gasification and pyrolysis, methane generation by anaerobic digestion, ethanol fermentations, and hydrogen production by dark and light-driven metabolism. We in particular discuss the production of lipids, vegetable oils and hydrocarbons, which could be converted to biodiesel. Direct combustion for power generation has two major disadvantages in that the high N-content of algal biomass causes unacceptably high NOx emissions and losses of nitrogen fertilizer. Thus, the use of sun-dried microalgal biomass would not be cost-competitive with other solid fuels such as coal and wood. Thermochemical conversion processes such as gasification and pyrolysis have been successfully demonstrated in the laboratory but will be difficult to scale up commercially and suffers from similar, though sometimes not as stringent, limitations as combustion. Anaerobic digestion of microalgal cells yields only about 0.3 L methane per g volatile solids destroyed, about half of the maximum achievable, but yields can be increased by adding carbon rich substrates to circumvent ammonia toxicity caused by the N-rich algal biomass. Anaerobic digestion would be best suited for the treatment of algal biomass waste after value-added products have been separated. Algae can also be grown to accumulate starches or similar fermentable products, and ethanol or similar (e.g., butanol) fermentations could be applied to such biomass, but research is required on increasing solvent yields. Dark fermentation of algal biomass can also produce hydrogen, but, as for other fermentations, only at low yields. Hydrogen can also be generated by algae in the light, however, this process has not yet been demonstrated in any way that could be scaled up and, in any event, Dunaliella, is not known to produce hydrogen. In response to nutrient deficiency (nitrogen or silicon), some microalgae accumulate neutral lipids which, after physical extraction, could be converted, via transesterification with methanol, to biodiesel. Nitrogen-limitation does not appear to increase either cellular lipid content or lipid productivity in Dunaliella. Results from life cycle energy analyses indicate that cultivation of microalgal biomass in open raceway ponds has a positive energy output ratio (EOR), approaching up to 10 (i.e., the caloric energy output from the algae is 10 times greater than the fossil energy inputs), but EOR are less than 1 for biomass grown in engineered photobioreactors. Thus, from both an energetic as well as economic perspective, only open ponds systems can be considered. Significant long-term R&D will be required to make microalgal biofuels processes economically competitive. Specifically, future research should focus on (a) the improvement of biomass productivities (i.e., maximizing solar conversion efficiencies), (b) the selection and isolation of algal strains that can be mass cultured and maintained stably for long periods, (c) the production of algal biomass with a high content of lipids, carbohydrates, and co-products, at high productivity, (d) the low cost harvesting of the biomass, and (e) the extraction and conversion processes to actually derive the biofuels. For Dunaliella specifically, the highest potential is in the co-production of biofuels with high-value animal feeds based on their carotenoid content.

Huesemann, Michael H.; Benemann, John R.

2009-12-31

111

Biofuel production: an odyssey from metabolic engineering to fermentation scale-up  

PubMed Central

Metabolic engineering has developed microbial cell factories that can convert renewable carbon sources into biofuels. Current molecular biology tools can efficiently alter enzyme levels to redirect carbon fluxes toward biofuel production, but low product yield and titer in large bioreactors prevent the fulfillment of cheap biofuels. There are three major roadblocks preventing economical biofuel production. First, carbon fluxes from the substrate dissipate into a complex metabolic network. Besides the desired product, microbial hosts direct carbon flux to synthesize biomass, overflow metabolites, and heterologous enzymes. Second, microbial hosts need to oxidize a large portion of the substrate to generate both ATP and NAD(P)H to power biofuel synthesis. High cell maintenance, triggered by the metabolic burdens from genetic modifications, can significantly affect the ATP supply. Thereby, fermentation of advanced biofuels (such as biodiesel and hydrocarbons) often requires aerobic respiration to resolve the ATP shortage. Third, mass transfer limitations in large bioreactors create heterogeneous growth conditions and micro-environmental fluctuations (such as suboptimal O2 level and pH) that induce metabolic stresses and genetic instability. To overcome these limitations, fermentation engineering should merge with systems metabolic engineering. Modern fermentation engineers need to adopt new metabolic flux analysis tools that integrate kinetics, hydrodynamics, and 13C-proteomics, to reveal the dynamic physiologies of the microbial host under large bioreactor conditions. Based on metabolic analyses, fermentation engineers may employ rational pathway modifications, synthetic biology circuits, and bioreactor control algorithms to optimize large-scale biofuel production. PMID:25071754

Hollinshead, Whitney; He, Lian; Tang, Yinjie J.

2014-01-01

112

Assessing regional hydrology and water quality implications of large-scale biofuel feedstock production in the Upper Mississippi River Basin.  

PubMed

A recent U.S. Department of Energy study estimated that more than one billion tons of biofuel feedstock could be produced by 2030 in the United States from increased corn yield, and changes in agricultural and forest residue management and land uses. To understand the implications of such increased production on water resources and stream quality at regional and local scales, we have applied a watershed model for the Upper Mississippi River Basin, where most of the current and future crop/residue-based biofuel production is expected. The model simulates changes in water quality (soil erosion, nitrogen and phosphorus loadings in streams) and resources (soil-water content, evapotranspiration, and runoff) under projected biofuel production versus the 2006 baseline year and a business-as-usual scenario. The basin average results suggest that the projected feedstock production could change the rate of evapotranspiration in the UMRB by approximately +2%, soil-water content by about -2%, and discharge to streams by -5% from the baseline scenario. However, unlike the impacts on regional water availability, the projected feedstock production has a mixed effect on water quality, resulting in 12% and 45% increases in annual suspended sediment and total phosphorus loadings, respectively, but a 3% decrease in total nitrogen loading. These differences in water quantity and quality are statistically significant (p < 0.05). The basin responses are further analyzed at monthly time steps and finer spatial scales to evaluate underlying physical processes, which would be essential for future optimization of environmentally sustainable biofuel productions. PMID:22827327

Demissie, Yonas; Yan, Eugene; Wu, May

2012-08-21

113

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels  

SciTech Connect

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.

Kuk Lee, Sung; Chou, Howard; Ham, Timothy S.; Soon Lee, Taek; Keasling, Jay D.

2009-12-02

114

"Trojan Horse" strategy for deconstruction of biomass for biofuels production.  

SciTech Connect

Production of renewable biofuels to displace fossil fuels currently consumed in the transportation sector is a pressing multi-agency national priority. Currently, nearly all fuel ethanol is produced from corn-derived starch. Dedicated 'energy crops' and agricultural waste are preferred long-term solutions for renewable, cheap, and globally available biofuels as they avoid some of the market pressures and secondary greenhouse gas emission challenges currently facing corn ethanol. These sources of lignocellulosic biomass are converted to fermentable sugars using a variety of chemical and thermochemical pretreatments, which disrupt cellulose and lignin cross-links, allowing exogenously added recombinant microbial enzymes to more efficiently hydrolyze the cellulose for 'deconstruction' into glucose. This process is plagued with inefficiencies, primarily due to the recalcitrance of cellulosic biomass, mass transfer issues during deconstruction, and low activity of recombinant deconstruction enzymes. Costs are also high due to the requirement for enzymes and reagents, and energy-intensive and cumbersome pretreatment steps. One potential solution to these problems is found in synthetic biology; they propose to engineer plants that self-produce a suite of cellulase enzymes targeted to the apoplast for cleaving the linkages between lignin and cellulosic fibers; the genes encoding the degradation enzymes, also known as cellulases, are obtained from extremophilic organisms that grow at high temperatures (60-100 C) and acidic pH levels (<5). These enzymes will remain inactive during the life cycle of the plant but become active during hydrothermal pretreatment i.e., elevated temperatures. Deconstruction can be integrated into a one-step process, thereby increasing efficiency (cellulose-cellulase mass-transfer rates) and reducing costs. The proposed disruptive technologies address biomass deconstruction processes by developing transgenic plants encoding a suite of enzymes used in cellulosic deconstruction. The unique aspects of this technology are the rationally engineered, highly productive extremophilic enzymes, targeted to specific cellular locations (apoplast) and their dormancy during normal plant proliferation, which become Trojan horses during pretreatment conditions. They have been leveraging established Sandia's enzyme-engineering and imaging capabilities. Their technical approach not only targets the recalcitrance and mass-transfer problem during biomass degradation but also eliminates the costs associated with industrial-scale production of microbial enzymes added during processing.

Sinclair, Michael B.; Hadi, Masood Z.; Timlin, Jerilyn Ann; Thomson, James (USDA, Albany, CA); Whalen, Maureen (USDA, Albany, CA); Thilmony, Roger (USDA, Albany, CA); Tran-Gyamfi, Mary; Simmons, Blake Alexander; Sapra, Rajat

2008-08-01

115

Water use impacts of future transport fuels: role of California's climate policy & National biofuel policies (Invited)  

NASA Astrophysics Data System (ADS)

In the coming decades, growing demand for energy and water and the need to address climate change will create huge challenges for energy policy and natural resource management. Synergistic strategies must be developed to conserve and use both resources more efficiently. California (CA) is a prime example of a region where policymakers have began to incorporate water planning in energy infrastructure development. But more must be done as CA transforms its energy system to meet its climate target. We analyze lifecycle water use of current and future transport fuel consumption to evaluate impacts & formulate mitigation strategies for the state at the watershed scale. Four 'bounding cases' for CA's future transportation demand to year 2030 are projected for analysis: two scenarios that only meet the 2020 climate target (business-as-usual, BAU) with high / low water use intensity, and two that meet long-term climate target with high / low water use intensity (Fig 1). Our study focuses on the following energy supply chains: (a) liquid fuels from conventional/unconventional oil & gas, (b) thermoelectric and renewable generation technologies, and (c) biofuels (Fig 2-3). We develop plausible siting scenarios that bound the range of possible water sources, impacts, and dispositions to provide insights into how to best allocate water and limit water impacts of energy development. We further identify constraints & opportunities to improve water use efficiency and highlight salient policy relevant lessons. For biofuels we extend our scope to the entire US as most of the biofuels consumed in California are and will be produced from outside of the state. We analyze policy impacts that capture both direct & indirect land use effects across scenarios, thus addressing the major shortcomings of existing studies, which ignore spatial heterogeneity as well as economic effects of crop displacement and the effects of crop intensification and extensification. We use the agronomic-hydrologic model EPIC to capture both green water (GW) and blue water (BW) use at a ~10 square km resolution among three scenarios: (1) a counterfactual scenario with no national biofuel policy, (2) current Renewable Fuels Standard (RFS) mandates, and (3) a proposed national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. Inputs to EPIC are spatially explicit: (a) cropping areas and yields as projected by a partial equilibrium economic model, (b) daily weather data, (c) soil properties (d) N fertilizer application, and (e) irrigation sources and volumes, by crop (Fig 4-5). We assess the differences among biofuel scenarios from 2007-2035 along the following metrics: (1) crop area expansion on prime & marginal lands (Fig 6), (2) Crop-specific & overall annual/seasonal water balances including (2a) water inflows (irrigation & precipitation), (2b) crop-atmosphere interactions: (evaporation & transpiration) and (2c) soil-water flows (runoff & soil infiltration), in mm3 /acre. We found differential water use impacts among biofuel scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes (2) irrigation practices, (3) feedstock water use efficiency, and (4) the longer growing season and a predominance of rainfed cultivation of dedicated biofuel feedstocks. Fig 1-6 available at the linked urls.

Teter, J.; Yeh, S.; Mishra, G. S.; Tiedeman, K.; Yang, C.

2013-12-01

116

Protein engineering in designing tailored enzymes and microorganisms for biofuels production  

PubMed Central

Summary Lignocellulosic biofuels represent a sustainable, renewable, and the only foreseeable alternative energy source to transportation fossil fuels. However, the recalcitrant nature of lignocellulose poses technical hurdles to an economically viable biorefinery. Low enzymatic hydrolysis efficiency and low productivity, yield, and titer of biofuels are among the top cost contributors. Protein engineering has been used to improve the performances of lignocellulose-degrading enzymes, as well as proteins involved in biofuel synthesis pathways. Unlike its great success seen in other industrial applications, protein engineering has achieved only modest results in improving the lignocellulose-to-biofuels efficiency. This review will discuss the unique challenges that protein engineering faces in the process of converting lignocellulose to biofuels and how they are addressed by recent advances in this field. PMID:19660930

Wen, Fei; Nair, Nikhil U; Zhao, Huimin

2009-01-01

117

Quantifying the climate impacts of albedo changes due to biofuel production: a comparison with biogeochemical effects  

E-print Network

Lifecycle analysis is a tool widely used to evaluate the climate impact of greenhouse gas emissions attributable to the production and use of biofuels. In this paper we employ an augmented lifecycle framework that includes ...

Caiazzo, Fabio

118

BIOWINOL TECHNOLOGIES: A HYBRID GREEN PROCESS FOR BIOFUEL PRODUCTION ? PHASE 2  

EPA Science Inventory

The development of hollow fiber membrane (HFM) reactor will result in improved gas utilization that will positively impact overall process efficiencies. Successful completion of this project could result in the development of many decentralized biofuel production systems near ...

119

at Western University From the production of biofuels, fuel cells and alternative forms of energy,  

E-print Network

at Western University From the production of biofuels, fuel cells and alternative forms of energy tailored nanotube- based materials for applications in such areas as fuel cells, batteries and sensing

Denham, Graham

120

The economic prospects of cellulosic biomass for biofuel production  

NASA Astrophysics Data System (ADS)

Alternative fuels for transportation have become the focus of intense policy debate and legislative action due to volatile oil prices, an unstable political environment in many major oil producing regions, increasing global demand, dwindling reserves of low-cost oil, and concerns over global warming. A major potential source of alternative fuels is biofuels produced from cellulosic biomass, which have a number of potential benefits. Recognizing these potential advantages, the Energy Independence and Security Act of 2007 has mandated 21 billion gallons of cellulosic/advanced biofuels per year by 2022. The United States needs 220-300 million tons of cellulosic biomass per year from the major sources such as agricultural residues, forestry and mill residues, herbaceous resources, and waste materials (supported by Biomass Crop Assistance Program) to meet these biofuel targets. My research addresses three key major questions concerning cellulosic biomass supply. The first paper analyzes cellulosic biomass availability in the United States and Canada. The estimated supply curves show that, at a price of 100 per ton, about 568 million metric tons of biomass is available in the United States, while 123 million metric tons is available in Canada. In fact, the 300 million tons of biomass required to meet EISA mandates can be supplied at a price of 50 per metric ton or lower. The second paper evaluates the farmers' perspective in growing new energy crops, such as switchgrass and miscanthus, in prime cropland, in pasture areas, or on marginal lands. My analysis evaluates how the farmers' returns from energy crops compare with those from other field crops and other agricultural land uses. The results suggest that perennial energy crops yielding at least 10 tons per acre annually will be competitive with a traditional corn-soybean rotation if crude oil prices are high (ranging from 88-178 per barrel over 2010-2019). If crude oil prices are low, then energy crops will not be competitive with existing crops, and additional subsidy support would be required. Among the states in the eastern half of US, the states of Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia are found to be economically more suitable to cultivate perennial energy crops. The third paper estimates the optimal feedstock composition of annual and perennial feedstocks from a biorefinery's perspective. The objective function of the optimization model is to minimize the cumulative costs covering harvesting, transport, storage, and GHG costs, of biomass procurement over a biorefinery's productive period of 20 years subject to various constraints on land availability, feedstock availability, processing capacity, contracting needs and storage. The results suggest that the economic tradeoff is between higher production costs for dedicated energy crops and higher collection and transport costs for agricultural residues; the delivered costs of biomass drives the results. These tradeoffs are reflected in optimal spatial planting pattern as preferred by the biorefinery: energy crops are grown in fields closer to the biorefinery and agricultural residues can be sourced from fields farther away from the biorefinery. The optimization model also provides useful insights into the price premiums paid for annual and perennial feedstocks. For the parameters used in the case study, the energy crop price premium ranges from 2 to 8 per ton for fields located within a 10 mile radius. For agricultural residues, the price premiums range from 5 to 16 per ton within a 10-20 mile radius.

Kumarappan, Subbu

121

Techno-economical analysis of a thermo-chemical biofuel plant with feedstock and product flexibility under external disturbances  

Microsoft Academic Search

Biofuel is one candidate that can address the global warming and energy security challenges faced by the transportation sector. However, biofuel production is subject to unpredictable external disturbances caused by demand variation, regional instability and extreme weather. It is highly desired to design a biofuel plant such that it has operational flexibility to survive through these disturbances. Gasification based thermo-chemical

Nannan Kou; Fu Zhao

122

The impact of co-occurring tree and grassland species on carbon sequestration and potential biofuel production  

E-print Network

The impact of co-occurring tree and grassland species on carbon sequestration and potential biofuel for terrestrial carbon sequestration and potential biofuel production. For P. strobus, above- ground plant carbon harvest for biofuel would result in no net carbon sequestration as declines in soil carbon offset plant

Weiblen, George D

123

Natural Oil Production from Microorganisms: Bioprocess and Microbe Engineering for Total Carbon Utilization in Biofuel Production  

SciTech Connect

Electrofuels Project: MIT is using carbon dioxide (CO2) and hydrogen generated from electricity to produce natural oils that can be upgraded to hydrocarbon fuels. MIT has designed a 2-stage biofuel production system. In the first stage, hydrogen and CO2 are fed to a microorganism capable of converting these feedstocks to a 2-carbon compound called acetate. In the second stage, acetate is delivered to a different microorganism that can use the acetate to grow and produce oil. The oil can be removed from the reactor tank and chemically converted to various hydrocarbons. The electricity for the process could be supplied from novel means currently in development, or more proven methods such as the combustion of municipal waste, which would also generate the required CO2 and enhance the overall efficiency of MIT’s biofuel-production system.

None

2010-07-15

124

Defossiling Fuel: How Synthetic Biology Can Transform Biofuel Production  

E-print Network

production is pre- dicted to peak soon, it is reason- able to assume that unconventional fossil fuel sources and economic energy volatility, and smoothing the transition from fossil fuels in the distant future energy economy that is largely independent of fossil fuels. Indeed, such an approach has been underway

125

[FeFe]-hydrogenase-catalyzed H2 production in a photoelectrochemical biofuel cell.  

PubMed

The Clostridium acetobutylicum [FeFe]-hydrogenase HydA has been investigated as a hydrogen production catalyst in a photoelectrochemical biofuel cell. Hydrogenase was adsorbed to pyrolytic graphite edge and carbon felt electrodes. Cyclic voltammograms of the immobilized hydrogenase films reveal cathodic proton reduction and anodic hydrogen oxidation, with a catalytic bias toward hydrogen evolution. When corrected for the electrochemically active surface area, the cathodic current densities are similar for both carbon electrodes, and approximately 40% of those obtained with a platinum electrode. The high surface area carbon felt/hydrogenase electrode was subsequently used as the cathode in a photoelectrochemical biofuel cell. Under illumination, this device is able to oxidize a biofuel substrate and reduce protons to hydrogen. Similar photocurrents and hydrogen production rates were observed in the photoelectrochemical biofuel cell using either hydrogenase or platinum cathodes. PMID:18205358

Hambourger, Michael; Gervaldo, Miguel; Svedruzic, Drazenka; King, Paul W; Gust, Devens; Ghirardi, Maria; Moore, Ana L; Moore, Thomas A

2008-02-13

126

[FeFe]-Hydrogenase-Catalyzed H2 Production in a Photoelectrochemical Biofuel Cell  

SciTech Connect

The Clostridium acetobutylicum [FeFe]-hydrogenase HydA has been investigated as a hydrogen production catalyst in a photoelectrochemical biofuel cell. Hydrogenase was adsorbed to pyrolytic graphite edge and carbon felt electrodes. Cyclic voltammograms of the immobilized hydrogenase films reveal cathodic proton reduction and anodic hydrogen oxidation, with a catalytic bias toward hydrogen evolution. When corrected for the electrochemically active surface area, the cathodic current densities are similar for both carbon electrodes, and 40% of those obtained with a platinum electrode. The high surface area carbon felt/hydrogenase electrode was subsequently used as the cathode in a photoelectrochemical biofuel cell. Under illumination, this device is able to oxidize a biofuel substrate and reduce protons to hydrogen. Similar photocurrents and hydrogen production rates were observed in the photoelectrochemical biofuel cell using either hydrogenase or platinum cathodes.

Hambourger, M.; Gervaldo, M.; Svedruzic, D.; King, P. W.; Gust, D.; Ghirardi, M.; Moore, A. L.; Moore, T. A.

2008-01-01

127

Sustainability standards for biofuels : analyses of the current standards and recommendations of the future direction  

E-print Network

Past decades have seen development and expansion of biofuels industry around the world thanks to the environmental and economic contribution that biofuels have promised. As more and more people became concerned about the ...

Lee, Leebong

2014-01-01

128

Energy Policy 36 (2008) 15771583 Towards a sustainably certifiable futures contract for biofuels  

E-print Network

for biofuels John A. MathewsÃ? Macquarie Graduate School of Management, Macquarie University, Sydney, NSW 2109 are biofuels to be certified as produced in a sustainable and responsible fashion? In the global debate over through which a global biofuels market is being created. In this contribution, I propose a solution

129

Selection, breeding and engineering of microalgae for bioenergy and biofuel production.  

PubMed

Microalgal production technologies are seen as increasingly attractive for bioenergy production to improve fuel security and reduce CO(2) emissions. Photosynthetically derived fuels are a renewable, potentially carbon-neutral and scalable alternative reserve. Microalgae have particular promise because they can be produced on non-arable land and utilize saline and wastewater streams. Furthermore, emerging microalgal technologies can be used to produce a range of products such as biofuels, protein-rich animal feeds, chemical feedstocks (e.g. bioplastic precursors) and higher-value products. This review focuses on the selection, breeding and engineering of microalgae for improved biomass and biofuel conversion efficiencies. PMID:22178650

Larkum, Anthony W D; Ross, Ian L; Kruse, Olaf; Hankamer, Ben

2012-04-01

130

Cost structures and life cycle impacts of algal biomass and biofuel production  

Microsoft Academic Search

Development and extraction of energy sources, energy production and energy use have huge economic, environmental and geopolitical impacts. Increasing energy demands in tandem with reductions in fossil fuel production has led to significant investments in research into alternative forms of energy. One that is promising but yet not commercially established is the production of biofuel from algae. This research quantitatively

Katrina Lea Christiansen

2011-01-01

131

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production  

E-print Network

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production Transportation Energy algae life cycle studies and compare new analyses of multiple production scenarios and process the life cycle greenhouse gas emissions, net energy consumption, and net liquid fuels production

132

Alternative and Renewable fuels and Vehicle Technology Program Subject Area: Biofuels production Facilities  

E-print Network

production plant, with a lower carbon footprint, while creating jobs, improving air quality, and improvingAlternative and Renewable fuels and Vehicle Technology Program Subject Area: Biofuels production for stormwater runoff. These upgrades are complimentary to process improvements that validate production

133

The effect of biofuel production on swine farm methane and ammonia emissions.  

PubMed

Methane (CH) and ammonia (NH3) are emitted to the atmosphere during anaerobic processing of organic matter, and both gases have detrimental environmental effects. Methane conversion to biofuel production has been suggested to reduce CH4 emissions from animal manure processing systems. The purpose of this research is to evaluate the change in CH4 and NH3 emissions in an animal feeding operation due to biofuel production from the animal manure. Gas emissions were measured from swine farms differing only in their manure-management treatment systems (conventional vs. biofuel). By removing organic matter (i.e., carbon) from the biofuel farms' manure-processing lagoons, average annual CH4 emissions were decreased by 47% compared with the conventional farm. This represents a net 44% decrease in global warming potential (CO2 equivalent) by gases emitted from the biofuel farms compared with conventional farms. However, because of the reduction of methanogenesis and its reduced effect on the chemical conversion of ammonium (NH4+) to dinitrogen (N2) gas, NH3 emissions in the biofuel farms increased by 46% over the conventional farms. These studies show that what is considered an environmentally friendly technology had mixed results and that all components of a system should be studied when making changes to existing systems. PMID:21284295

Harper, Lowry A; Flesch, Thomas K; Weaver, Kim H; Wilson, John D

2010-01-01

134

Lifecycle Assessment of Biofuel Production from Wood Pyrolysis Technology  

ERIC Educational Resources Information Center

Due to a stronger dependency on biomass for energy, there is a need for improved technologies in biomass-to-energy conversion in Tanzania. This paper presents a life cycle assessment (LCA) of pyrolysis technology used for conversion of wood and wood waste to liquid biofuel. In particular, a survey of environmental impacts of the process is…

Manyele, S. V.

2007-01-01

135

BIOWINOL TECHNOLOGIES: A HYBRID GREEN PROCESS FOR BIOFUEL PRODUCTION  

EPA Science Inventory

The ability of the unique bacteria to produce ethanol by utilizing H2 and CO2 will be determined. The project will be used to educate the community about advances and importance of bioenergy while building consumer confidence in biofuels in addressing...

136

Unraveling water quality and quantity effects of biofuels production  

Technology Transfer Automated Retrieval System (TEKTRAN)

Developing a sustainable biofuels industry is crucial for several reasons, but what impact will it have on soil water quantity and quality? This popular press article for ISU alumni, teachers, middle/high school students and others is written to help them understand the complexity of this seemingly ...

137

Catalytic processes towards the production of biofuels in a palm oil and oil palm biomass-based biorefinery  

Microsoft Academic Search

In Malaysia, there has been interest in the utilization of palm oil and oil palm biomass for the production of environmental friendly biofuels. A biorefinery based on palm oil and oil palm biomass for the production of biofuels has been proposed. The catalytic technology plays major role in the different processing stages in a biorefinery for the production of liquid

Thiam Leng Chew; Subhash Bhatia

2008-01-01

138

Biofuel production system with operation flexibility: Evaluation of economic and environmental performance under external disturbance  

NASA Astrophysics Data System (ADS)

Biomass derived liquid hydrocarbon fuel (biofuel) has been accepted as an effective way to mitigate the reliance on petroleum and reduce the greenhouse gas emissions. An increasing demand for second generation biofuels, produced from ligno-cellulosic feedstock and compatible with current infrastructure and vehicle technologies, addresses two major challenges faced by the current US transportation sector: energy security and global warming. However, biofuel production is subject to internal disturbances (feedstock supply and commodity market) and external factors (energy market). The biofuel industry has also heavily relied on government subsidy during the early development stages. In this dissertation, I investigate how to improve the economic and environmental performance of biorefineries (and biofuel plant), as well as enhance its survivability under the external disturbances. Three types of disturbance are considered: (1) energy market fluctuation, (2) subsidy policy uncertainty, and (3) extreme weather conditions. All three factors are basically volatile, dynamic, and even unpredictable, which makes them difficult to model and have been largely ignored to date. Instead, biofuel industry and biofuel research are intensively focused on improving feedstock conversion efficiency and capital cost efficiency while assuming these advancements alone will successfully generate higher profit and thus foster the biofuel industry. The collapse of the largest corn ethanol biofuel company, Verasun Energy, in 2008 calls into question this efficiency-driven approach. A detailed analysis has revealed that although the corn ethanol plants operated by Verasun adopted the more efficient (i.e. higher ethanol yield per bushel of corn and lower capital cost) dry-mill technology, they could not maintain a fair profit margin under fluctuating market condition which made ethanol production unprofitable. This is because dry-mill plant converts a single type of biomass feedstock (corn grain) into a single primary product (ethanol). The traditional lower efficient (i.e. lower ethanol yield per bushel of corn and higher capital cost) wet-mill plant has a more diverse and adjustable product portfolio i.e. corn syrup, starch, and ethanol. The fact that only the dry-mill corn ethanol plants have bankrupted while the wet-mill corn ethanol plants have survived the late 2000s economy recession suggests that the higher conversion efficiency achieved by the dry-mill production mode has jeopardized operational flexibility, a design operational feature I agree that is indispensable for the biofuel plant's long term profit and viability. Based on the analysis of corn ethanol production, operational flexibility has been proposed as a key strategy for the next generation biofuel plants to improve its lifetime economic performance, as well as to enhance its survivability under external disturbances. This strategy requires the biofuel plant to adopt a flexible feedstock management, making it possible to utilize alternative types of biomass feedstock when the primary feedstock supply is disturbed. Biofuel plants also need to produce a wider range of final products that could meet the preference variation that either comes from the energy market or from the subsidy policy. Aspen Plus model based numerical simulations have been carried out for a thermochemical ethanol plant and a Fischer Tropsch plant (both are assumed to be located in southwest Indiana) to test this strategy under the external disturbances of extreme weather impact, different energy price projections and various subsidy policy combinations. For the thermochemical ethanol plant, effects of extreme weather conditions are mainly evaluated. It has been shown that this strategy could effectively increase the net present value of the biofuel plant and significantly decrease the GHG emission comparing with the traditional single-feedstock strategy, when the extreme weather conditions are considered. It has also been demonstrated that this strategy could significantly decrease the possibility for the bio

Kou, Nannan

139

Determining the global maximum biofuel production potential without conflicting with food and feed consumption  

NASA Astrophysics Data System (ADS)

This study tries to resolve the competition between food and biofuel by balancing the allocation between food and feed areas and biofuel areas for the entire world. The maximum energy production is calculated by determining the theoretical amount of energy that can be grown, once food and feed consumption is taken into account, based on the assumption that unprotected grass and woody lands and forest lands can be converted into cultivated lands. The total optimum land area for biofuel energy, 4,926.49 Mha, consists of corn, rapeseed, sugar beet, sugar cane, and grasses. When considering energy conversion efficiency, the maximum energy production is 520.5 EJ. Of this amount, 5.9 EJ can be identified with food and feed energy and 514.6 EJ can be identified with biofuel energy. This result is a theoretical value to illustrate the potential global land area for biofuel. The biofuel energy production per area of land in this study is calculated to be 0.12 EJ/Mha. With regards to the limitation in the degree of invasion by grass and woody land and forest land areas, if it is not more than 10 percent, the biofuel energy production can serve about 76 percent of energy demand for transportation in 2009. The total optimum land area is about 45 percent of global cultivated land area. Sensitivity analysis shows that the land area of corn, sweet sorghum, sugarcane, grass, and woody crops is sensitive to energy content. The land area of sweet sorghum and soybeans is sensitive to the land area for food and feed consumption. Also, the land area of corn, sugar beet, and sugarcane is sensitive to the potential crop land area. This study, done at the global level, can also apply in a local area by using local constraints.

Pumkaew, Watcharapol

140

Biofuels from Pyrolysis: Catalytic Biocrude Production in a Novel, Short-Contact Time Reactor  

SciTech Connect

Broad Funding Opportunity Announcement Project: RTI is developing a new pyrolysis process to convert second-generation biomass into biofuels in one simple step. Pyrolysis is the decomposition of substances by heating—the same process used to render wood into charcoal, caramelize sugar, and dry roast coffee and beans. RTI’s catalytic biomass pyrolysis differs from conventional flash pyrolysis in that its end product contains less oxygen, metals, and nitrogen—all of which contribute to corrosion, instability, and inefficiency in the fuel-production process. This technology is expected to easily integrate into the existing domestic petroleum refining infrastructure, making it an economically attractive option for biofuels production.

None

2010-01-01

141

Catalytic Oxidation of Biorefinery Lignin to Value-added Chemicals to Support Sustainable Biofuel Production.  

PubMed

Transforming plant biomass to biofuel is one of the few solutions that can truly sustain mankind's long-term needs for liquid transportation fuel with minimized environmental impact. However, despite decades of effort, commercial development of biomass-to-biofuel conversion processes is still not an economically viable proposition. Identifying value-added co-products along with the production of biofuel provides a key solution to overcoming this economic barrier. Lignin is the second most abundant component next to cellulose in almost all plant biomass; the emerging biomass refinery industry will inevitably generate an enormous amount of lignin. Development of selective biorefinery lignin-to-bioproducts conversion processes will play a pivotal role in significantly improving the economic feasibility and sustainability of biofuel production from renewable biomass. The urgency and importance of this endeavor has been increasingly recognized in the last few years. This paper reviews state-of-the-art oxidative lignin depolymerization chemistries employed in the papermaking process and oxidative catalysts that can be applied to biorefinery lignin to produce platform chemicals including phenolic compounds, dicarboxylic acids, and quinones in high selectivity and yield. The potential synergies of integrating new catalysts with commercial delignification chemistries are discussed. We hope the information will build on the existing body of knowledge to provide new insights towards developing practical and commercially viable lignin conversion technologies, enabling sustainable biofuel production from lignocellulosic biomass to be competitive with fossil fuel. PMID:25272962

Ma, Ruoshui; Xu, Yan; Zhang, Xiao

2015-01-01

142

The National Biofuels Strategy - Importance of sustainable feedstock production systems in regional-based supply chains  

Technology Transfer Automated Retrieval System (TEKTRAN)

Region-based production systems are needed to produce the feedstocks that will be turned into the biofuels required to meet Federal mandated targets. Executive and Legislative actions have put into motion significant government responses designed to advance the development and production of domestic...

143

Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels  

PubMed Central

A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

2012-01-01

144

The current status and perspectives of biofuel production via catalytic cracking of edible and non-edible oils  

Microsoft Academic Search

Biofuel development has gained the attention of researchers in recent years owing to the rate of depletion of fossil fuels. Several processes are currently employed in the conventional production of different biofuels: the production of biodiesel is catalytically performed either through the transesterification of triglycerides using alcohol or the deoxygenative ecofining of triglycerides in a non-alcohol environment; bio-oil is produced

Yee Kang Ong; Subhash Bhatia

2010-01-01

145

Microalgae to biofuels: life cycle impacts of methane production of anaerobically digested lipid extracted algae.  

PubMed

This study presents experimental measurements of the biochemical methane production for whole and lipid extracted Nannochloropsis salina. Results show whole microalgae produced 430 cm(3)-CH4 g-volatile solids(-1) (g-VS) (?=60), 3 times more methane than was produced by the LEA, 140 cm(3)-CH4 g-VS(-1) (?=30). Results illustrate current anaerobic modeling efforts in microalgae to biofuel assessments are not reflecting the impact of lipid removal. On a systems level, the overestimation of methane production is shown to positively skew the environmental impact of the microalgae to biofuels process. Discussion focuses on a comparison results to those of previous anaerobic digestion studies and quantifies the corresponding change in greenhouse gas emissions of the microalgae to biofuels process based on results from this study. PMID:25181698

Quinn, Jason C; Hanif, Asma; Sharvelle, Sybil; Bradley, Thomas H

2014-11-01

146

Process modeling and supply chain design for advanced biofuel production based on bio-oil gasification  

NASA Astrophysics Data System (ADS)

As a potential substitute for petroleum-based fuel, second generation biofuels are playing an increasingly important role due to their economic, environmental, and social benefits. With the rapid development of biofuel industry, there has been an increasing literature on the techno-economic analysis and supply chain design for biofuel production based on a variety of production pathways. A recently proposed production pathway of advanced biofuel is to convert biomass to bio-oil at widely distributed small-scale fast pyrolysis plants, then gasify the bio-oil to syngas and upgrade the syngas to transportation fuels in centralized biorefinery. This thesis aims to investigate two types of assessments on this bio-oil gasification pathway: techno-economic analysis based on process modeling and literature data; supply chain design with a focus on optimal decisions for number of facilities to build, facility capacities and logistic decisions considering uncertainties. A detailed process modeling with corn stover as feedstock and liquid fuels as the final products is presented. Techno-economic analysis of the bio-oil gasification pathway is also discussed to assess the economic feasibility. Some preliminary results show a capital investment of 438 million dollar and minimum fuel selling price (MSP) of $5.6 per gallon of gasoline equivalent. The sensitivity analysis finds that MSP is most sensitive to internal rate of return (IRR), biomass feedstock cost, and fixed capital cost. A two-stage stochastic programming is formulated to solve the supply chain design problem considering uncertainties in biomass availability, technology advancement, and biofuel price. The first-stage makes the capital investment decisions including the locations and capacities of the decentralized fast pyrolysis plants and the centralized biorefinery while the second-stage determines the biomass and biofuel flows. The numerical results and case study illustrate that considering uncertainties can be pivotal in this supply chain design and optimization problem. Also, farmers' participation has a significant effect on the decision making process.

Li, Qi

147

A Thermophilic Ionic Liquid-Tolerant Cellulase Cocktail for the Production of Cellulosic Biofuels  

PubMed Central

Generation of biofuels from sugars in lignocellulosic biomass is a promising alternative to liquid fossil fuels, but efficient and inexpensive bioprocessing configurations must be developed to make this technology commercially viable. One of the major barriers to commercialization is the recalcitrance of plant cell wall polysaccharides to enzymatic hydrolysis. Biomass pretreatment with ionic liquids (ILs) enables efficient saccharification of biomass, but residual ILs inhibit both saccharification and microbial fuel production, requiring extensive washing after IL pretreatment. Pretreatment itself can also produce biomass-derived inhibitory compounds that reduce microbial fuel production. Therefore, there are multiple points in the process from biomass to biofuel production that must be interrogated and optimized to maximize fuel production. Here, we report the development of an IL-tolerant cellulase cocktail by combining thermophilic bacterial glycoside hydrolases produced by a mixed consortia with recombinant glycoside hydrolases. This enzymatic cocktail saccharifies IL-pretreated biomass at higher temperatures and in the presence of much higher IL concentrations than commercial fungal cocktails. Sugars obtained from saccharification of IL-pretreated switchgrass using this cocktail can be converted into biodiesel (fatty acid ethyl-esters or FAEEs) by a metabolically engineered strain of E. coli. During these studies, we found that this biodiesel-producing E. coli strain was sensitive to ILs and inhibitors released by saccharification. This cocktail will enable the development of novel biomass to biofuel bioprocessing configurations that may overcome some of the barriers to production of inexpensive cellulosic biofuels. PMID:22649505

Park, Joshua I.; Steen, Eric J.; Burd, Helcio; Evans, Sophia S.; Redding-Johnson, Alyssa M.; Batth, Tanveer; Benke, Peter I.; D'haeseleer, Patrik; Sun, Ning; Sale, Kenneth L.; Keasling, Jay D.; Lee, Taek Soon; Petzold, Christopher J.; Mukhopadhyay, Aindrila; Singer, Steven W.; Simmons, Blake A.; Gladden, John M.

2012-01-01

148

An integrated modeling framework for exploring flow regime and water quality changes with increasing biofuel crop production in the U.S. Corn Belt  

NASA Astrophysics Data System (ADS)

better address the dynamic interactions between human and hydrologic systems, we develop an integrated modeling framework that employs a System of Systems optimization model to emulate human development decisions which are then incorporated into a watershed model to estimate the resulting hydrologic impacts. The two models are run interactively to simulate the coevolution of coupled human-nature systems, such that reciprocal feedbacks between hydrologic processes and human decisions (i.e., human impacts on critical low flows and hydrologic impacts on human decisions on land and water use) can be assessed. The framework is applied to a Midwestern U.S. agricultural watershed, in the context of proposed biofuels development. This operation is illustrated by projecting three possible future coevolution trajectories, two of which use dedicated biofuel crops to reduce annual watershed nitrate export while meeting ethanol production targets. Imposition of a primary external driver (biofuel mandate) combined with different secondary drivers (water quality targets) results in highly nonlinear and multiscale responses of both the human and hydrologic systems, including multiple tradeoffs, impacting the future coevolution of the system in complex, heterogeneous ways. The strength of the hydrologic response is sensitive to the magnitude of the secondary driver; 45% nitrate reduction target leads to noticeable impacts at the outlet, while a 30% reduction leads to noticeable impacts that are mainly local. The local responses are conditioned by previous human-hydrologic modifications and their spatial relationship to the new biofuel development, highlighting the importance of past coevolutionary history in predicting future trajectories of change.

Yaeger, Mary A.; Housh, Mashor; Cai, Ximing; Sivapalan, Murugesu

2014-12-01

149

Biofuel production and climate mitigation potential from marginal lands in US North Central region  

NASA Astrophysics Data System (ADS)

An ever-increasing demand for liquid fuels, amidst concerns of anthropogenic impacts on the environment and fossil fuels availability, has spurred a strong interest in the development of agriculturally-based renewable energy sources. However, increasing demand for food as well as direct and indirect effects on land use, have raised concerns about reliance on grain-based ethanol and shifted research towards the direction of cellulosic feedstocks. In order to understand the future possibility for using agricultural systems for bio-fuel production, we present here a full greenhouse gas (GHG) balance of six potential sources of cellulosic feedstocks production. From 1991 to 2008, we measured GHGs sinks and sources in cropped and nearby unmanaged ecosystems in SW Michigan. The measurements included soil fluxes of GHGs (N2O and CH4), soil organic carbon concentration change, agronomic practices data, and biomass yields. We analyzed two types of intensively managed annual cropping systems under corn-soybean-wheat rotation (conventional tillage and no till), two perennial systems (alfalfa and poplar plantation), and one successional system. The use of agricultural residues for biofuel feedstock from conventionally-tilled crops had the lowest climate stabilization potential (-9 ±13 gCO2e m-2 y-1). In contrast, biomass collected from a successional system fertilized with N at123 kg ha-1y-1 showed the highest climate stabilization potential (-749 ±30 gCO2e m-2 y-1). We used our results to parameterize the EPIC model, which, together with GIS analysis was used to scale up the biomass productivity of the best environmentally performing systems to the marginal lands of the 10-state U.S. North Central region. Assuming 80 km as the maximum distance for road haulage to the biorefinery from the field, we identified 32 potential biorefinery placements each capable of supplying sufficient feedstock to produce at least 133 × 106 L y-1. In total, ethanol production from marginal lands could produce ~29 × 109 L ethanol y-1, or about 48% of the 2007 U.S. Congress legislative mandate.

Gelfand, I.; Sahajpal, R.; Zhang, X.; Izaurralde, R. C.; Robertson, G. P.

2010-12-01

150

Modeling Regional Groundwater Implications of Biofuel Crop Production in the Great Lakes Region  

NASA Astrophysics Data System (ADS)

In response to a growing call for renewable sources of energy that do not compete directly with food resources, the use of second-generation 'cellulosic' biofuel feedstocks has gained much attention in recent years. The push to advance the technologies that would make such a transformation possible is motivated by the United States Renewable Fuel Standard mandate to produce 36 billion gallons of biofuels by 2022, an increase of 334 percent from 2009. Many different crops, including maize, miscanthus, switchgrass, and poplar have shown promise as cellulosic feedstocks, and in an attempt to supply the needed biomass to meet the 2022 mandate, production of these crops have been on the rise. Yet little is known about the sustainability of large-scale conversion of land to cellulosic biofuel crop production; more research is needed to understand the effects that these crops will have on the quality and quantity of groundwater. This study presents a model scale-up approach to address three questions: What are the hydrologic and nutrient demands of the primary biofuel crops? Which biofuel crops are more water efficient in terms of demand verses energy produced? What are the types and availabilities of land to expand production of these biofuel crops? To answer these questions, we apply a point-based crop dynamics model in combination with a regional-scale hydrologic model, parameterized using stream discharge and chemistry data collected from two representative watersheds in Wisconsin. Approximately 17 stream sites in each watershed are selected for data collection for model parameterization, including stream discharge, nutrient concentrations, and basic chemical characteristics. We then use the System Approach to Land Use Sustainability (SALUS) model, which predicts crop growth under varying soil and climate conditions, to drive vegetation dynamics and groundwater transport of nutrients within the Integrated Landscape Hydrology Model (ILHM). ILHM predictions of stream discharge and baseflow delivery of nutrients are then compared to field data to validate model predictions.

Parish, A.; Kendall, A. D.; Basso, B.; Hyndman, D. W.

2013-12-01

151

The current potential of algae biofuels in the United Arab Emirates  

Technology Transfer Automated Retrieval System (TEKTRAN)

In spite of future uncertainties about industrial algae biofuel production, the UAE is planning to become "a world leader in biofuels from the algae industry by 2020;" thus joining major countries which have already started producing renewable energy and biofuels (biodiesel and bioethanol) from rene...

152

Using mobile distributed pyrolysis facilities to deliver a forest residue resource for bio-fuel production  

NASA Astrophysics Data System (ADS)

Distributed mobile conversion facilities using either fast pyrolysis or torrefaction processes can be used to convert forest residues to more energy dense substances (bio-oil, bio-slurry or torrefied wood) that can be transported as feedstock for bio-fuel facilities. All feedstock are suited for gasification, which produces syngas that can be used to synthesise petrol or diesel via Fischer-Tropsch reactions, or produce hydrogen via water gas shift reactions. Alternatively, the bio-oil product of fast pyrolysis may be upgraded to produce petrol and diesel, or can undergo steam reformation to produce hydrogen. Implementing a network of mobile facilities reduces the energy content of forest residues delivered to a bio-fuel facility as mobile facilities use a fraction of the biomass energy content to meet thermal or electrical demands. The total energy delivered by bio-oil, bio-slurry and torrefied wood is 45%, 65% and 87% of the initial forest residue energy content, respectively. However, implementing mobile facilities is economically feasible when large transport distances are required. For an annual harvest of 1.717 million m3 (equivalent to 2000 ODTPD), transport costs are reduced to less than 40% of the total levelised delivered feedstock cost when mobile facilities are implemented; transport costs account for up to 80% of feedstock costs for conventional woodchip delivery. Torrefaction provides the lowest cost pathway of delivering a forest residue resource when using mobile facilities. Cost savings occur against woodchip delivery for annual forest residue harvests above 2.25 million m3 or when transport distances greater than 250 km are required. Important parameters that influence levelised delivered costs of feedstock are transport distances (forest residue spatial density), haul cost factors, thermal and electrical demands of mobile facilities, and initial moisture content of forest residues. Relocating mobile facilities can be optimised for lowest cost delivery as transport distances of raw biomass are reduced. The overall cost of bio-fuel production is determined by the feedstock delivery pathway and also the bio-fuel production process employed. Results show that the minimum cost of petrol and diesel production is 0.86 litre -1 when a bio-oil feedstock is upgraded. This corresponds to a 2750 TPD upgrading facility requiring an annual harvest of 4.30 million m3. The mini?m cost of hydrogen production is 2.92 kg -1, via the gasification of a woodchip feedstock and subsequent water gas shift reactions. This corresponds to a 1100 ODTPD facility and requires an annual harvest of 947,000 m3. The levelised cost of bio-fuel strongly depends on the size of annual harvest required for bio-fuel facilities. There are optimal harvest volumes (bio-fuel facility sizes) for each bio-fuel production route, which yield minimum bio-fuel production costs. These occur as the benefits of economies of scale for larger bio-fuel facilities compete against increasing transport costs for larger harvests. Optimal harvest volumes are larger for bio-fuel production routes that use feedstock sourced from mobile facilities, as mobile facilities reduce total transport requirements.

Brown, Duncan

153

Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes  

E-print Network

Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes November 5, 2008 (received for review May 22, 2008) Increased demand for corn grain as an ethanol feedstock is altering U.S. agricultural landscapes and the ecosystem services they pro- vide. From 2006 to 2007, corn

Landis, Doug

154

Fluid Fertilizer's Role in Sustaining Soils Used for Bio-fuels Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

The short- and long-term effects on soil nutrient cycling, physical properties, and biological activity of striving for higher grain yields and removing crop residues for bio-fuels production must be understood to provide more quantitative crop and soil management guidelines. This study focuses prim...

155

Fluid Fertilizer's Role in Sustainng Soils Used for Bio-Fuels Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

The short- and long-term effects on soil nutrient cycling, physical properties, and biological activity of striving for higher grain yields and removing crop residues for bio-fuels production must be understood to provide more quantitative crop and soil management guidelines. Studies focusing on til...

156

Contract Designs and Participation in the Conservation Reserve Program in the Era of Biofuel Production  

Microsoft Academic Search

This article has presented a farmer decision making model of participation in the Conservation Reserve Program (CRP) under the current rising bio-fuel production. The decision is specified as an optimal stopping problem and farming return is assumed following stochastic process with the uncertainty of growth rate. Nonliear Kalman filter approach is used to continuously upgrade the new information and estimate

Feng Wu; Zhengfei Guan

2009-01-01

157

A model for improving microbial biofuel production using a synthetic feedback loop  

Microsoft Academic Search

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to

Mary Dunlop; Jay Keasling; Aindrila Mukhopadhyay

2011-01-01

158

Impacts of land use change due to biofuel crops on carbon balance, bioenergy production, and agricultural  

E-print Network

from corn, soybean, and wheat to biofuel crops of switchgrass and Miscanthus will occur. We found when a decrease of 14% was observed. Miscanthus is more productive than switchgrass, producing about 2 are changed to switchgrass, and from 0.4 to 6.7 Tg C yrÃ?1 if chan- ged to Miscanthus. The largest loss

Zhuang, Qianlai

159

Using mobile distributed pyrolysis facilities to deliver a forest residue resource for bio-fuel production  

E-print Network

Using mobile distributed pyrolysis facilities to deliver a forest residue resource for bio-fuel production by Duncan Brown BSc (Hons), University of Birmingham, 2009 A Thesis Submitted in Partial Committee Using mobile distributed pyrolysis facilities to deliver a forest residue resource for bio

Victoria, University of

160

Influence of biofuel crops on mosquito production and oviposition site selection  

E-print Network

fossil fuels, many govern- ments, including the U.S., seek increased energy pro- duction from biofuels energy inputs that may limit the desired energetic benefits over fossil fuels (Vadas et al., 2008 2012 Introduction Due to the increasing economic and environmental costs of energy production from

Allan, Brian

161

Computer simulations suggest a new strategy to design enhanced enzymes for biofuels production.  

E-print Network

Computer simulations suggest a new strategy to design enhanced enzymes for biofuels production the activity of cellulase enzymes, which are a key component in the conversion of cellulose to soluble sugars enzymes, which are responsible for decon- structing cellulose found in plant cell walls to glucose

162

Switchgrass Production in Washington – Part II of Biofuel Feedstocks in Washington  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Integrated Cropping Systems group at Prosser, WA made up of WSU and USDA-ARS personnel have been evaluating production aspects of a number of irrigated biofuel crops that can be planted in rotation with high value vegetables: oilseeds for biodiesel (safflower, soybeans, mustard, canola/rapeseed...

163

Industrial-strength ecology: trade-offs and opportunities in algal biofuel production.  

PubMed

Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, several aspects of algal biology present unique challenges to the industrial-scale aquaculture of photosynthetic microorganisms. These include high susceptibility to invading aquatic consumers and weeds, as well as prodigious requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal biofuel technologies approaches these problems from a cellular or genetic perspective, attempting either to engineer or select algal strains with particular traits. However, inherent functional trade-offs may limit the capacity of genetic selection or synthetic biology to simultaneously optimise multiple functional traits for biofuel productivity and resilience. We argue that a community engineering approach that manages microalgal diversity, species composition and environmental conditions may lead to more robust and productive biofuel ecosystems. We review evidence for trade-offs, challenges and opportunities in algal biofuel cultivation with a goal of guiding research towards intensifying bioenergy production using established principles of community and ecosystem ecology. PMID:24015819

Shurin, Jonathan B; Abbott, Rachel L; Deal, Michael S; Kwan, Garfield T; Litchman, Elena; McBride, Robert C; Mandal, Shovon; Smith, Val H

2013-11-01

164

Residues from the production of biofuels for transportation: Characterization and ash sintering tendency  

Microsoft Academic Search

The continuously growing demand for fuels in the transportation sector has led to the increased use of liquid biofuels, with a corresponding increase in the amounts of production residues. With energy recovery, these residues could become a source of biomass fuels. The current work investigated the behaviour of four potential biomass fuels during combustion. Fermented sewage sludge (FSS) is the

Patrycja Piotrowska; Maria Zevenhoven; Mikko Hupa; Jacopo Giuntoli; Wiebren de Jong

165

INCREASED BIOFUEL PRODUCTION IN THE COMING DECADE: TO WHAT EXTENT WILL IT AFFECT GLOBAL FRESHWATER RESOURCES?y  

Microsoft Academic Search

Irrigated agriculture accounts for 70% of global water withdrawals and therefore contributes substantially to global water scarcity. This article focuses on the impact of the increasing demand for biofuel on global water resources in the coming decade. Based on biofuel production projections for 2008 and 2017, it was estimated that currently around 1% of all water withdrawn for irrigation is

JIPPE HOOGEVEEN; JEAN-MARC FAURES; NICK VAN DE GIESSEN

166

Evaluation of technological alternatives for process integration of sugarcane bagasse for sustainable biofuels production—Part 1  

Microsoft Academic Search

Nowadays, there is a tremendous global interest in the biofuels production. However, first generation biofuels have been debated about that energy-crop compete with food crops and thus cause food deficiency and price increases. In this sense, researchers have started looking for potential feedstock for ethanol such as lignocellulosic biomass (e.g., sugarcane bagasse), which does not affect food security. In this

K. Ojeda; O. Ávila; J. Suárez; V. Kafarov

2011-01-01

167

Tradeoffs and synergies between biofuel production and large-scale solar infrastructure in deserts  

NASA Astrophysics Data System (ADS)

Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large scale solar installations. For efficient power generation, solar infrastructures require large amounts of water for operation (mostly for cleaning panels and dust suppression), leading to significant moisture additions to desert soil. A pertinent question is how to use the moisture inputs for sustainable agriculture/biofuel production. We investigated the water requirements for large solar infrastructures in North American deserts and explored the possibilities for integrating biofuel production with solar infrastructure. In co-located systems the possible decline in yields due to shading by solar panels may be offsetted by the benefits of periodic water addition to biofuel crops, simpler dust management and more efficient power generation in solar installations, and decreased impacts on natural habitats and scarce resources in deserts. In particular, we evaluated the potential to integrate solar infrastructure with biomass feedstocks that grow in arid and semi-arid lands (Agave Spp), which are found to produce high yields with minimal water inputs. To this end, we conducted detailed life cycle analysis for these coupled agave biofuel - solar energy systems to explore the tradeoffs and synergies, in the context of energy input-output, water use and carbon emissions.

Ravi, S.; Lobell, D. B.; Field, C. B.

2012-12-01

168

Improving Efficiency of Cellulosic Fermentation via Genetic Engineering to Create “Smart Plants” for Biofuel Production  

Microsoft Academic Search

\\u000a Biomass-based fuel is a near-term alternative to petroleum for powering the global economy in an ecologically sustainable\\u000a fashion while minimizing the carbon footprint by decreasing net greenhouse gas emission. To affect this major shift in energy\\u000a use and fuel source in the near future, dramatic improvement in the efficiency of converting cellulose into biofuels will\\u000a be a key step. Optimization

Zeyu Xin; Naohide Watanabe; Eric Lam

169

Algae as a Feedstock for Transportation Fuels. The Future of Biofuels?  

SciTech Connect

Events in world energy markets over the past several years have prompted many new technical developments as well as political support for alternative transportation fuels, especially those that are renewable. We have seen dramatic rises in the demand for and production of fuel ethanol from sugar cane and corn and biodiesel from vegetable oils. The quantities of these fuels being used continue to rise dramatically, and their use is helping to create a political climate for doing even more. But, the quantities are still far too small to stem the tide of rising crude prices worldwide. In fact, the use of some traditional crops (corn, sugar, soy, etc.) in making fuels instead of food is apparently beginning to impact the cost of food worldwide. Thus, there is considerable interest in developing alternative biofuel feedstocks for use in making fuels -- feedstocks that are not used in the food industries. Of course, we know that there is a lot of work in developing cellulosic-based ethanol that would be made from woody biomass. Process development is the critical path for this option, and the breakthrough in reducing the cost of the process has been elusive thus far. Making biodiesel from vegetable oils is a well-developed and inexpensive process, but to date there have been few reasonable alternatives for making biodiesel, although advanced processes such as gasification of biomass remain an option.

McGill, Ralph [Sentech, Inc., Fuels, Engines, and Emissions Consulting, Knoxville, TN (United States)

2008-05-15

170

Pongamia pinnata : An Untapped Resource for the Biofuels Industry of the Future  

Microsoft Academic Search

Pongamia pinnata (L.) Pierre is a fast-growing leguminous tree with the potential for high oil seed production and the added benefit of the\\u000a ability to grow on marginal land. These properties support the suitability of this plant for large-scale vegetable oil production\\u000a required by a sustainable biodiesel industry. The future success of P. pinnata as a sustainable source of feedstock

Paul T. Scott; Lisette Pregelj; Ning Chen; Johanna S. Hadler; Michael A. Djordjevic; Peter M. Gresshoff

2008-01-01

171

Future U.S. water consumption : The role of energy production.  

SciTech Connect

This study investigates how meeting domestic energy production targets for both fossil and renewable fuels may affect future water demand. It combines projections of energy production developed by the U.S. Department of Energy with estimates of water consumption on a per-unit basis (water-consumption coefficients) for coal, oil, gas, and biofuels production, to estimate and compare the domestic freshwater consumed. Although total domestic freshwater consumption is expected to increase by nearly 7% between 2005 and 2030, water consumed for energy production is expected to increase by nearly 70%, and water consumed for biofuels (biodiesel and ethanol) production is expected to increase by almost 250%. By 2030, water consumed in the production of biofuels is projected to account for nearly half of the total amount of water consumed in the production of all energy fuels. Most of this is for irrigation, and the West North Central Region is projected to consume most of this water in 2030. These findings identify an important potential future conflict between renewable energy production and water availability that warrants further investigation and action to ensure that future domestic energy demand can be met in an economically efficient and environmentally sustainable manner.

Elcock, D.; Environmental Science Division

2010-06-01

172

Algal biofuels.  

PubMed

The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented. PMID:23605290

Razeghifard, Reza

2013-11-01

173

Wastewater treatment high rate algal ponds (WWT HRAP) for low-cost biofuel production.  

PubMed

Growing energy demand and water consumption have increased concerns about energy security and efficient wastewater treatment and reuse. Wastewater treatment high rate algal ponds (WWT HRAPs) are a promising technology that could help solve these challenges concurrently where climate is favorable. WWT HRAPs have great potential for biofuel production as a by-product of WWT, since the costs of algal cultivation and harvest for biofuel production are covered by the wastewater treatment function. Generally, 800-1400GJ/ha/year energy (average biomass energy content: 20GJ/ton; HRAP biomass productivity: 40-70tons/ha/year) can be produced in the form of harvestable biomass from WWT HRAP which can be used to provide community-level energy supply. In this paper the benefits of WWT HRAPs are compared with conventional mass algal culture systems. Moreover, parameters to effectively increase algal energy content and overall energy production from WWT HRAP are discussed including selection of appropriate algal biomass biofuel conversion pathways. PMID:25465780

Mehrabadi, Abbas; Craggs, Rupert; Farid, Mohammed M

2014-11-13

174

Interactions of woody biofuel feedstock production systems with water resources: Considerations for sustainability.  

SciTech Connect

Abstract. Water resources are important for the production of woody biofuel feedstocks. It is necessary to ensure that production systems do not adversely affect the quantity or quality of surface and ground water. The effects of woody biomass plantations on water resources are largely dependent on the prior land use and the management regime. Experience from both irrigated and non-irrigated systems has demonstrated that woody biofuel production systems do not impair water quality. Water quality actually improves from conversion of idle or degraded agricultural lands to woody biomass plantations. Site water balance may be altered by cultivation of woody biomass plantations relative to agricultural use, due to increases in evapostranspiration (ET) and storage. Incorporation of woody biomass production plantations within the landscape provides an opportunity to improve the quality of runoff water and soil conservation. Given the centrality of water resources to the sustainability of ecosystem services and other values derived, the experience with woody biofuels feedstock production systems is positive. Keywords. Short rotation woody crop, forest hydrology, water quality, hardwood plantation.

Trettin, Carl,C.; Amatya, Devendra; Coleman, Mark.

2008-07-01

175

Organisms for biofuel production: natural bioresources and methodologies for improving their biosynthetic potentials.  

PubMed

: In order to relieve the pressure of energy supply and environment contamination that humans are facing, there are now intensive worldwide efforts to explore natural bioresources for production of energy storage compounds, such as lipids, alcohols, hydrocarbons, and polysaccharides. Around the world, many plants have been evaluated and developed as feedstock for bioenergy production, among which several crops have successfully achieved industrialization. Microalgae are another group of photosynthetic autotroph of interest due to their superior growth rates, relatively high photosynthetic conversion efficiencies, and vast metabolic capabilities. Heterotrophic microorganisms, such as yeast and bacteria, can utilize carbohydrates from lignocellulosic biomass directly or after pretreatment and enzymatic hydrolysis to produce liquid biofuels such as ethanol and butanol. Although finding a suitable organism for biofuel production is not easy, many naturally occurring organisms with good traits have recently been obtained. This review mainly focuses on the new organism resources discovered in the last 5 years for production of transport fuels (biodiesel, gasoline, jet fuel, and alkanes) and hydrogen, and available methods to improve natural organisms as platforms for the production of biofuels. PMID:24085385

Hu, Guangrong; Ji, Shiqi; Yu, Yanchong; Wang, Shi'an; Zhou, Gongke; Li, Fuli

2015-01-01

176

Biofuels Issues and Trends  

EIA Publications

This report presents data on biofuels consumption, production, imports and exports, including data collected by others than the U.S. Energy Information Administration. It also discusses important developments in biofuels markets.

2012-01-01

177

Quantitative uncertainty analysis of Life Cycle Assessment for algal biofuel production.  

PubMed

As a result of algae's promise as a renewable energy feedstock, numerous studies have used Life Cycle Assessment (LCA) to quantify the environmental performance of algal biofuels, yet there is no consensus of results among them. Our work, motivated by the lack of comprehensive uncertainty analysis in previous studies, uses a Monte Carlo approach to estimate ranges of expected values of LCA metrics by incorporating parameter variability with empirically specified distribution functions. Results show that large uncertainties exist at virtually all steps of the biofuel production process. Although our findings agree with a number of earlier studies on matters such as the need for wet lipid extraction, nutrients recovered from waste streams, and high energy coproducts, the ranges of reported LCA metrics show that uncertainty analysis is crucial for developing technologies, such as algal biofuels. In addition, the ranges of energy return on (energy) invested (EROI) values resulting from our analysis help explain the high variability in EROI values from earlier studies. Reporting results from LCA models as ranges, and not single values, will more reliably inform industry and policy makers on expected energetic and environmental performance of biofuels produced from microalgae. PMID:23237457

Sills, Deborah L; Paramita, Vidia; Franke, Michael J; Johnson, Michael C; Akabas, Tal M; Greene, Charles H; Tester, Jefferson W

2013-01-15

178

Predicting potential global distributions of two Miscanthus grasses: implications for horticulture, biofuel production, and biological invasions.  

PubMed

In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk. PMID:24945154

Hager, Heather A; Sinasac, Sarah E; Gedalof, Ze'ev; Newman, Jonathan A

2014-01-01

179

Review of environmental, economic and policy aspects of biofuels  

Microsoft Academic Search

The world is witnessing a sudden growth in production of biofuels, especially those suited for replacing oil like ethanol and biodiesel. This paper synthesizes what the environmental, economic, and policy literature predicts about the possible effects of these types of biofuels. Another motivation is to identify gaps in understanding and recommend areas for future work. The analysis finds three key

David Zilberman; Deepak Rajagopal

2007-01-01

180

From fields to fuels: recent advances in the microbial production of biofuels.  

PubMed

Amid grave concerns over global climate change and with increasingly strained access to fossil fuels, the synthetic biology community has stepped up to the challenge of developing microbial platforms for the production of advanced biofuels. The adoption of gasoline, diesel, and jet fuel alternatives derived from microbial sources has the potential to significantly limit net greenhouse gas emissions. In this effort, great strides have been made in recent years toward the engineering of microorganisms to produce transportation fuels derived from alcohol, fatty acid, and isoprenoid biosynthesis. We provide an overview of the biosynthetic pathways devised in the strain development of biofuel-producing microorganisms. We also highlight many of the commonly used and newly devised engineering strategies that have been employed to identify and overcome pathway bottlenecks and problems of toxicity to maximize production titers. PMID:23656227

Kung, Yan; Runguphan, Weerawat; Keasling, Jay D

2012-11-16

181

A model for improving microbial biofuel production using a synthetic feedback loop  

Microsoft Academic Search

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield\\u000a insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation,\\u000a and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic\\u000a control system is used to

Mary J. Dunlop; Jay D. Keasling; Aindrila Mukhopadhyay

2010-01-01

182

Production of advanced biofuels: Coprocessing of upgraded pyrolysis oil in standard refinery units  

Microsoft Academic Search

One of the possible process options for the production of advanced biofuels is the co-processing of upgraded pyrolysis oil in standard refineries. The applicability of hydrodeoxygenation (HDO) was studied as a pyrolysis oil upgrading step to allow FCC co-processing. Different HDO reaction end temperatures (230–340°C) were evaluated in a 5L autoclave, keeping the other process conditions constant (total 290bar, 5wt.%

F. de Miguel Mercader; M. J. Groeneveld; S. R. A. Kersten; C. J. Schaverien; J. A. Hogendoorn

2010-01-01

183

Synergistic temperature and ethanol effect on Saccharomyces cerevisiae dynamic behaviour in ethanol bio-fuel production  

Microsoft Academic Search

The impact of ethanol and temperature on the dynamic behaviour of Saccharomyces cerevisiae in ethanol biofuel production was studied using an isothermal fed-batch process at five different temperatures. Fermentation parameters and kinetics were quantified. The best performances were found at 30 and 33°C around 120 g l -1 ethanol produced in 30 h with a slight benefit for growth at 30°C and for

A. S. Aldiguier; S. Alfenore; X. Cameleyre; G. Goma; J. L. Uribelarrea; S. E. Guillouet; C. Molina-Jouve

2004-01-01

184

Cost structures and life cycle impacts of algal biomass and biofuel production  

NASA Astrophysics Data System (ADS)

Development and extraction of energy sources, energy production and energy use have huge economic, environmental and geopolitical impacts. Increasing energy demands in tandem with reductions in fossil fuel production has led to significant investments in research into alternative forms of energy. One that is promising but yet not commercially established is the production of biofuel from algae. This research quantitatively assessed the potential of algae biofuel production by examining its cost and environmental impacts. First, two models developed by the RAND corporation were employed to assess Cost Growth defined as the ratio of actual costs to estimated costs, and Plant Performance defined as the ratio of actual production levels to design performance, of three algal biofuel production technologies. The three algal biofuel production technologies examined to open raceway ponds (ORPs), photobioreactors (PBRs), and a system that couples PBRs to ORPs (PBR-ORPs). Though these analyses lack precision due to uncertainty, the results highlight the risks associated with implementing algal biofuel systems, as all scenarios examined were predicted to have Cost Growth, ranging from 1.2 to 1.8, and Plant Performance was projected as less than 50% of design performance for all cases. Second, the Framework the Evaluation of Biomass Energy Feedstocks (FEBEF) was used to assess the cost and environmental impacts of biodiesel produced from three algal production technologies. When these results were compared with ethanol from corn and biodiesel from soybeans, biodiesel from algae produced from the different technologies were estimated to be more expensive, suffered from low energy gains, and did not result in lower greenhouse gas emissions. To identify likely routes to making algal biofuels more competitive, a third study was undertaken. In this case, FEBEF was employed to examine pinch-points (defined as the most costly, energy consuming, greenhouse gas producing processes), in three algal production and fuel conversion scenarios, and then to estimate the improvement to cost and environmental impacts of proposed solutions to the pinch-points. These results illuminated significant opportunities to improve the economics and environmental impacts from producing algal biofuels produced in ORP, PBR, and PBR-ORPs. No single solution examined appeared to be sufficient to reduce the cost of fuel energy from algae to a competitive level with current petroleum diesel prices (4.20 /gal, ca. 28/GJ). However, if multiple pinch-points are overcome, e.g., simultaneous increases in (1) radiation use efficiency and (2) oil content or simultaneous decreases in (3) irrigation, (4) harvesting, (5) labor and (6)PBR costs are achieved then low Fuel Energy Costs (the ratio of total production and conversion costs to total energy available in the fuel) and low Total Energy Costs (the ratio of total production and conversion costs to total energy available in the fuel and co-products) are possible; with estimates ranging from 48 to 11 $/GJ.

Christiansen, Katrina Lea

2011-12-01

185

Importance of systems biology in engineering microbes for biofuel production  

SciTech Connect

Microorganisms have been rich sources for natural products, some of which have found use as fuels, commodity chemicals, specialty chemicals, polymers, and drugs, to name a few. The recent interest in production of transportation fuels from renewable resources has catalyzed numerous research endeavors that focus on developing microbial systems for production of such natural products. Eliminating bottlenecks in microbial metabolic pathways and alleviating the stresses due to production of these chemicals are crucial in the generation of robust and efficient production hosts. The use of systems-level studies makes it possible to comprehensively understand the impact of pathway engineering within the context of the entire host metabolism, to diagnose stresses due to product synthesis, and provides the rationale to cost-effectively engineer optimal industrial microorganisms.

Mukhopadhyay, Aindrila; Redding, Alyssa M.; Rutherford, Becky J.; Keasling, Jay D.

2009-12-02

186

Conventional and molecular breeding for improvement of biofuel crops: past, present and future  

Technology Transfer Automated Retrieval System (TEKTRAN)

First-generation biofuels are derived from food and feed crops rich in sugar, starch, or oil, such as sugarcane (Saccharum hyb.), maize (Zea mays), or soybean (Glycine max), as these are easily converted into liquid fuels. However, these crops alone cannot meet the projected demand for fuel, so sec...

187

future science group 5ISSN 1759-726910.4155/BFS.12.76 2013 Future Science Ltd Special FocuS: advanced FeedStockS For advanced bioFuelS  

E-print Network

petroleum consumption with biofuels by 2030 [1­3]. This goal implies that the demand for cellulosic feed of the conversion efficiency. This article summarizes the state-of-the-art in biomass provision and logistics-scale bioenergy production The success and sustainability of the biofuel industry is highly dependent upon

188

The effect of cellulosic biofuel production on water resources at a regional scale  

NASA Astrophysics Data System (ADS)

The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, of which 16 billion gallons are required to be cellulosic biofuels. Production of cellulosic biomass offers a promising alternative to corn-based systems because large-scale production of corn-based ethanol often requires irrigation and is associated with increased erosion, excess sediment export, and enhanced leaching of nitrogen and phosphorus. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water resources impacts associated with annual crops. There are data sets and models that have been used to evaluate effects of agriculturally-based biofuel options on water quantity and quality, but the evaluation - from instrumentation through data analysis - is designed for these more disturbed systems and is not appropriate for the more subtle changes anticipated from a pine/switchgrass systems. Currently, there is no known hydrologic model that can explicitly assess the effect of intercropping on water resources. However, these models can evaluate the effects of growing switchgrass on water resources and would be useful in identifying the "worst case scenario". We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine effects of large scale conversion of pine plantations to switchgrass biofuel production on water resources in the ~ 5 mil ha Tombigbee Watershed in the southeastern U.S. Publically available datasets were used as input to the model and for calibration. To improve calibration statistics, five tree age classes were added to the model to more appropriately represent existing forested systems in the region, which are not included within the standard model set-up. Results suggest land use conversions result in 4 and 28 % increase in mean annual stream discharge and NO3- yield, respectively. Our results will be essential to public policy makers as they plan for large-scale production of cellulosic biofuels, while sustaining water quality and quantity.

Christopher, S. F.; Scheonholtz, S. H.; Nettles, J. E.

2012-12-01

189

Production of biofuels and biochemicals: in need of an ORACLE  

Microsoft Academic Search

The engineering of cells for the production of fuels and chemicals involves simultaneous optimization of multiple objectives, such as specific productivity, extended substrate range and improved tolerance - all under a great degree of uncertainty. The achievement of these objectives under physiological and process con- straints will be impossible without the use of mathemat- ical modeling. However, the limited information

Ljubisa Miskovic; Vassily Hatzimanikatis

2010-01-01

190

Regional Environmental Impacts of Biofuel Feedstock Production--Scaling Biogeochemical Cycles in Space and Time  

NASA Astrophysics Data System (ADS)

Recently there has been increasing socio-economic and scientific interest in the use of alternative sources of energy to offset the negative effects of current fossil fuel dependence and consequent greenhouse gas emissions. Currently, one of the most popular alternatives is to use ethanol produced from domestically grown crops for use as fuel in the transportation sector. In 2007, over 7.5 billion gallons of ethanol were produced in the U.S. from corn, a traditional food crop. Recent research indicates that it may be logistically impractical, ecologically counterproductive (i.e. a net carbon source), and economically devastating to produce ethanol from crops previously grown to produce food. The EBI (Energy Biosciences Institute, at University of California Berkley and University of Illinois Urbana-Champaign) is now conducting research to assess the ability of traditional crops as well as dedicated biofuel feedstocks (e.g. Panicum virgatum (switchgrass), Miscanthus x Giganteus (Miscanthus), and Saccharum spp (sugar cane)) to provide a productive and sustainable alternative to fossil fuel. This is an important step to take before implementing the large-scale growth necessary to meet U.S. energy needs .A process-based terrestrial ecosystem model, Agro-IBIS (Agricultural Integrated Biosphere Simulator) was adapted to simulate the growth of Miscanthus. The model was calibrated using data collected from sites at the University of Illinois south farms. Simulations indicated significant implications on the regional carbon and water budgets. Next this locally validated method will be extrapolated to simulate the regional scale growth of Miscanthus in the Midwestern U.S. and sugarcane in Brazil and a similar analysis will be conducted for switchgrass. The results should provide insight on optimal land-use decisions and legislation that regard meeting energy demands and mitigating climate change in the near future.

Vanloocke, A.; Bernacchi, C.

2008-12-01

191

Development of New Technologies of Solid and Gaseous Biofuel Production  

NASA Astrophysics Data System (ADS)

Perspective direction of complex usage of biomass is connected with technologies of combined processing of organic fossil fuels and biomass with production of energy and carbon materials of high purity which can be used as high-calorific fuel and raw material for industrial technologies. Various directions of combined processing of a biomass are considered. The technology of pyrolysis of wood waste and peat and natural gas with productions of pure carbon materials and power gas with high content of hydrogen is presented. It is shown, that the combined technology of processing of biomass and natural gas is allowed to solve the problems connected with hydrogen production for power use.

Zaichenko, Victor

192

Assessing microalgae biorefinery routes for the production of biofuels via hydrothermal liquefaction.  

PubMed

The interest in third generation biofuels from microalgae has been rising during the past years. Meanwhile, it seems not economically feasible to grow algae just for biofuels. Co-products with a higher value should be produced by extracting a particular algae fraction to improve the economics of an algae biorefinery. The present study aims at analyzing the influence of two main microalgae components (lipids and proteins) on the composition and quantity of biocrude oil obtained via hydrothermal liquefaction of two strains (Nannochloropsis gaditana and Scenedesmus almeriensis). The algae were liquefied as raw biomass, after extracting lipids and after extracting proteins in microautoclave experiments at different temperatures (300-375°C) for 5 and 15min. The results indicate that extracting the proteins from the microalgae prior to HTL may be interesting to improve the economics of the process while at the same time reducing the nitrogen content of the biocrude oil. PMID:25463806

López Barreiro, Diego; Samorì, Chiara; Terranella, Giuseppe; Hornung, Ursel; Kruse, Andrea; Prins, Wolter

2014-12-01

193

The benefits of biofuels  

SciTech Connect

This article discusses the economic, environmental, and national security advantages of using biofuels instead of petroleum products in vehicles. Smog and carbon monoxide, two of the most trouble-some urban air pollutants, are largely caused by combustion of conventional petroleum based fuels. Topics include sustainable transportation fuels, emphasis on ethanol, the process of producing biofuels, and the growing market for biofuels. 1 tab.

Hinman, N.D. [National Renewable Energy Lab., Golden, CO (United States)

1997-07-01

194

Economic Policy and Resource Implications of Biofuel Feedstock Production  

E-print Network

higher costs, highlighting the issue of sustainability related to the economics of renewable fuels. The estimation of the net energy of biomass ethanol accounting for the production input data indicate a greater than one energy return for biomass crops...

Adusumilli, Naveen

2012-10-19

195

Improving Biocatalysts for the Production of Biofuels from Lignocellulosic Feedstocks  

Technology Transfer Automated Retrieval System (TEKTRAN)

Industrial-scale production of fuel ethanol from biomass continues to show promise for relieving dependence upon petroleum-based transportation fuels. The limited range of materials that can be practically converted, however, continues to be an obstacle to the lignocellulosic revolution. Therefore...

196

Production and Characterization of Biofuel from Coconut Oil  

Microsoft Academic Search

The biggest challenge for developing countries in relation to energy consumption is to develop and implement technologies that help reduce the emissions of gases and particulate matter (dust and smoke), which have both local and possible global environmental impacts. In order to be more environmentally conscious, we need to endeavor to use resources that preferentially create fewer pollutants as by-products.

A. S. Abdulkareem; J. O. Odigure; M. B. Kuranga

2010-01-01

197

Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe.  

PubMed

Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed. To this end, scenarios for the year 2050 are analysed, assuming that in the 27 countries of the European Union fossil diesel will be replaced by biodiesel from algae. Estimates are made for the required fertiliser inputs to algae parks, and how this may increase concentrations of nitrogen and phosphorus in coastal waters, potentially leading to eutrophication. The Global NEWS (Nutrient Export from WaterSheds) model has been used to estimate the transport of nitrogen and phosphorus to the European coastal waters. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment. PMID:25058933

Blaas, Harry; Kroeze, Carolien

2014-10-15

198

Synergistic temperature and ethanol effect on Saccharomyces cerevisiae dynamic behaviour in ethanol bio-fuel production.  

PubMed

The impact of ethanol and temperature on the dynamic behaviour of Saccharomyces cerevisiae in ethanol biofuel production was studied using an isothermal fed-batch process at five different temperatures. Fermentation parameters and kinetics were quantified. The best performances were found at 30 and 33 degrees C around 120 g l(-1) ethanol produced in 30 h with a slight benefit for growth at 30 degrees C and for ethanol production at 33 degrees C. Glycerol formation, enhanced with increasing temperatures, was coupled with growth for all fermentations; whereas, a decoupling phenomenon occurred at 36 and 39 degrees C pointing out a possible role of glycerol in yeast thermal protection. PMID:15098119

Aldiguier, A S; Alfenore, S; Cameleyre, X; Goma, G; Uribelarrea, J L; Guillouet, S E; Molina-Jouve, C

2004-07-01

199

Microalgae for high-value compounds and biofuels production: a review with focus on cultivation under stress conditions.  

PubMed

Microalgal biomass as feedstock for biofuel production is an attracting alternative to terrestrial plant utilization for biofuels production. However, today the microalgal cultivation systems for energy production purposes seem not yet to be economically feasible. Microalgae, though cultivated under stress conditions, such as nutrient starvation, high salinity, high temperature etc. accumulate considerable amounts (up to 60-65% of dry weight) of lipids or carbohydrates along with several secondary metabolites. Especially some of the latter are valuable compounds with an enormous range of industrial applications. The simultaneous production of lipids or carbohydrates for biofuel production and of secondary metabolites in a biorefinery concept might allow the microalgal production to be economically feasible. This paper aims to provide a review on the available literature about the cultivation of microalgae for the accumulation of high-value compounds along with lipids or carbohydrates focusing on stress cultivation conditions. PMID:23928208

Markou, Giorgos; Nerantzis, Elias

2013-12-01

200

Water for Food, Energy, and the Environment: Assessing Streamflow Impacts of Increasing Cellulosic Biofuel Crop Production in the Corn Belt  

NASA Astrophysics Data System (ADS)

The recently expanded Renewable Fuel Standard, which now requires 36 billion gallons of renewable fuels by 2022, has increased demand for biofuel refinery feedstocks. Currently, biofuel production consists mainly of corn-based ethanol, but concern over increasing nitrate levels resulting from increased corn crop fertilization has prompted research into alternative biofuel feedstocks. Of these, high-yielding biomass crops such as Miscanthus have been suggested for cellulose-based ethanol production. Because these perennial crops require less fertilization and do not need tilling, increasing land area in the Midwest planted with Miscanthus would result in less nitrate pollution to the Gulf of Mexico. There is a tradeoff, however, as Miscanthus also has higher water requirements than conventional crops in the region. This could pose a serious problem for riparian ecosystems and other streamflow users such as municipalities and biofuel refineries themselves, as the lowest natural flows in this region coincide with the peak of the growing season. Moreover, low flow reduction may eventually cut off the water quality benefit that planting Miscanthus provides. Therefore, for large-scale cellulosic ethanol production to be sustainable, it is important to understand how the watershed will respond to this change in land and water use. To this end a detailed data analysis of current watershed conditions has been combined with hydrologic modeling to gain deeper insights into how catchments in the highly agricultural central IL watershed of the Sangamon River respond to current and future land and water usage, with the focus on the summer low-flow season. In addition, an integrated systems optimization model has been developed that combines hydrologic, agro-biologic, engineering infrastructural, and economic inputs to provide optimal scenarios of crop type and area and corresponding refinery locations and capacities. Through this integrated modeling framework, we address the key hypothesis: what may benefit the human system (farms, refineries, cities) may damage the environment. The hydrological and optimization models will be run interactively, with the optimization model run for 10 years and the resulting land use solution then used in the SWAT hydrologic model to provide more detailed information on river/ecosystem impacts, which are assessed using low flow analysis. Problem areas highlighted by this analysis can be targeted by implementing flow requirements at different locations in the watershed; these constraints are then added to the optimization model which is run for another 10 years, and the new solution again analyzed in more detail to assess the effectiveness of the imposed environmental measures. Preliminary results show that under proposed subsidies and current crop prices, the percentage of land planted with Miscanthus will increase to environmentally unsustainable levels, but that implementing flow and water quality constraints can mitigate the damage to some extent. Moreover, tributary and mainstem subwatersheds in the Sangamon do not respond equally, even in this very homogenous region, and thus the spatial context is important for understanding the tradeoffs between economic and hydrologic benefits, which become increasingly important in creating sustainable biofuel production.

Yaeger, M. A.; Housh, M.; Ng, T.; Cai, X.; Sivapalan, M.

2012-12-01

201

High liquid fuel yielding biofuel processes and a roadmap for the future transportation  

NASA Astrophysics Data System (ADS)

In a fossil-fuel deprived world when crude oil will be scarce and transportation need cannot be met with electricity and transportation liquid fuel must be produced, biomass derived liquid fuels can be a natural replacement. However, the carbon efficiency of the currently known biomass to liquid fuel conversion processes ranges from 35-40%, yielding 90 ethanol gallon equivalents (ege) per ton of biomass. This coupled with the fact that the efficiency at which solar energy is captured by biomass (<1%) is significantly lower than H 2 (10-27%) and electricity (20-42%), implies that sufficient land area is not available to meet the need for the entire transportation sector. To counter this dilemma, a number of processes have been proposed in this work: a hybrid hydrogen-carbon (H2CAR) process based on biomass gasification followed by the Fischer-Tropsch process such that 100% carbon efficiency is achieved yielding 330 ege/ton biomass using hydrogen derived from a carbon-free energy. The hydrogen requirement for the H2CAR process is 0.33 kg/liter of diesel. To decrease the hydrogen requirement associated with the H2CAR process, a hydrogen bio-oil (H2Bioil) process based on biomass fast-hydropyrolysis/hydrodeoxygenation is proposed which can achieve liquid fuel yield of 215 ege/ton consuming 0.11 kg hydrogen per liter of oil. Due to the lower hydrogen consumption of the H2Bioil process, synergistically integrated transition pathways are feasible where hot syngas derived from coal gasification (H2Bioil-C) or a natural gas reformer (H 2Bioil-NG) is used to supply the hydrogen and process heat for the biomass fast-hydropyrolysis/hydrodeoxygenation. Another off-shoot of the H2Bioil process is the H2Bioil-B process, where hydrogen required for the hydropyrolysis is obtained from gasification of a fraction of the biomass. H2Bioil-B achieves the highest liquid fuel yield (126-146 ege/ton of biomass) reported in the literature for any self-contained conversion of biomass to biofuel. Finally, an integration of the H2Bioil process with the H2CAR process is suggested which can achieve 100% carbon efficiency (330 ege/ton of biomass) at the expense of 0.24 kg hydrogen/liter of oil. A sun-to-fuel efficiency analysis shows that extracting CO2 from air and converting it to liquid fuel is at least two times more efficient than growing dedicated fuel crops and converting them to liquid fuel even for the highest biomass growth rates feasible by algae. This implies that liquid fuel should preferably be produced from sustainably available waste (SAW) biomass first and if the SAW biomass is unable to meet the demand for liquid fuel, then, CO2 should be extracted from air and converted to liquid fuel, rather than growing biomass. Furthermore, based on the Sun-to-Wheels recovery for different transportation pathways, synergistic and complementary use of electricity, hydrogen and biomass, all derived from solar energy, is presented in an energy efficient roadmap to successfully propel the entire future transportation sector.

Singh, Navneet R.

202

Projections of Biofuel Growth Patterns Reveal the Potential Importance of Nitrogen Fixation for Miscanthus Productivity  

NASA Astrophysics Data System (ADS)

Demand for liquid biofuels is increasing because of the disparity between fuel demand and supply. Relative to grain crops, the more intensive harvest required for second generation liquid biofuel production leads to the removal of significantly more carbon and nitrogen from the soil. These elements are conventionally litter products of crops that are returned to the soil and can accumulate over time. This loss of organic matter represents a management challenge because the energy cost associated with fertilizers or external sources of organic matter reduce the net energy value of the biofuel crops. Plants that have exceptional strategies for exploiting nutrients may be the most viable options for sustainable biofuel yields because of low management and energy cost. Miscanthus x giganteus has high N retranslocation rates, maintains high photosynthetic rates over a large temperature range, exploits a longer-than-average growing season, and yields at least twice the biomass of other candidate biofuel grass crops (i.e. switchgrass). We employed the DAYCENT model to project potential productivity of Miscanthus, corn, switchgrass, and mixed prairie communities based on our current knowledge of these species. Ecosystem process descriptions that have been validated for many crop species did not accurately predict Miscanthus yields and lead to new hypotheses about unknown N cycling mechanisms for this species. We tested the hypothesis that Miscanthus hosts N-fixing bacteria in several ways. First, we used enrichment culture and molecular methods to detect N-fixing bacteria in Miscanthus. Then, we demonstrated the plant-growth promoting effect of diazotrophs isolated from Miscanthus rhizomes on a model grass. And finally, we applied 15N2 to the soil and rooting zone of field grown Miscanthus plants to determine if atmospheric N2 was incorporated into plant tissue, a process that requires N-fixation. These experiments are the first tests of N-fixation in Miscanthus x giganteus, and the ecosystem model allowed us to project how much nitrogen may be obtained from N-fixation to support sustainable high biomass yields.

Davis, S. C.; Parton, W. J.; Dohleman, F. G.; Gottel, N. R.; Smith, C. M.; Kent, A. D.; Delucia, E. H.

2008-12-01

203

Biofuels from microbes.  

PubMed

Today, biomass covers about 10% of the world's primary energy demand. Against a backdrop of rising crude oil prices, depletion of resources, political instability in producing countries and environmental challenges, besides efficiency and intelligent use, only biomass has the potential to replace the supply of an energy hungry civilisation. Plant biomass is an abundant and renewable source of energy-rich carbohydrates which can be efficiently converted by microbes into biofuels, of which, only bioethanol is produced on an industrial scale today. Biomethane is produced on a large scale, but is not yet utilised for transportation. Biobutanol is on the agenda of several companies and may be used in the near future as a supplement for gasoline, diesel and kerosene, as well as contributing to the partially biological production of butyl-t-butylether, BTBE as does bioethanol today with ETBE. Biohydrogen, biomethanol and microbially made biodiesel still require further development. This paper reviews microbially made biofuels which have potential to replace our present day fuels, either alone, by blending, or by chemical conversion. It also summarises the history of biofuels and provides insight into the actual production in various countries, reviewing their policies and adaptivity to the energy challenges of foreseeable future. PMID:17891391

Antoni, Dominik; Zverlov, Vladimir V; Schwarz, Wolfgang H

2007-11-01

204

Production of biofuels and biochemicals: in need of an ORACLE.  

PubMed

The engineering of cells for the production of fuels and chemicals involves simultaneous optimization of multiple objectives, such as specific productivity, extended substrate range and improved tolerance - all under a great degree of uncertainty. The achievement of these objectives under physiological and process constraints will be impossible without the use of mathematical modeling. However, the limited information and the uncertainty in the available information require new methods for modeling and simulation that will characterize the uncertainty and will quantify, in a statistical sense, the expectations of success of alternative metabolic engineering strategies. We discuss these considerations toward developing a framework for the Optimization and Risk Analysis of Complex Living Entities (ORACLE) - a computational method that integrates available information into a mathematical structure to calculate control coefficients. PMID:20646768

Miskovic, Ljubisa; Hatzimanikatis, Vassily

2010-08-01

205

Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production  

Microsoft Academic Search

The use of fossil fuels is now widely accepted as unsustainable due to depleting resources and the accumulation of greenhouse\\u000a gases in the environment that have already exceeded the “dangerously high” threshold of 450 ppm CO2-e. To achieve environmental and economic sustainability, fuel production processes are required that are not only renewable,\\u000a but also capable of sequestering atmospheric CO2. Currently, nearly

Peer M. Schenk; Skye R. Thomas-Hall; Evan Stephens; Jan H. Mussgnug; Clemens Posten; Olaf Kruse; Ben Hankamer

2008-01-01

206

Techno-Economic Analysis of Biofuels Production Based on Gasification  

SciTech Connect

This study compares capital and production costs of two biomass-to-liquid production plants based on gasification. The first biorefinery scenario is an oxygen-fed, low-temperature (870?C), non-slagging, fluidized bed gasifier. The second scenario is an oxygen-fed, high-temperature (1,300?C), slagging, entrained flow gasifier. Both are followed by catalytic Fischer-Tropsch synthesis and hydroprocessing to naphtha-range (gasoline blend stock) and distillate-range (diesel blend stock) liquid fractions. Process modeling software (Aspen Plus) is utilized to organize the mass and energy streams and cost estimation software is used to generate equipment costs. Economic analysis is performed to estimate the capital investment and operating costs. Results show that the total capital investment required for nth plant scenarios is $610 million and $500 million for high-temperature and low-temperature scenarios, respectively. Product value (PV) for the high-temperature and low-temperature scenarios is estimated to be $4.30 and $4.80 per gallon of gasoline equivalent (GGE), respectively, based on a feedstock cost of $75 per dry short ton. Sensitivity analysis is also performed on process and economic parameters. This analysis shows that total capital investment and feedstock cost are among the most influential parameters affecting the PV.

Swanson, R. M.; Platon, A.; Satrio, J. A.; Brown, R. C.; Hsu, D. D.

2010-11-01

207

An Integrated Assessment of Location-Dependent Scaling for Microalgae Biofuel Production Facilities  

SciTech Connect

Successful development of a large-scale microalgae-based biofuels industry requires comprehensive analysis and understanding of the feedstock supply chain—from facility siting/design through processing/upgrading of the feedstock to a fuel product. The evolution from pilot-scale production facilities to energy-scale operations presents many multi-disciplinary challenges, including a sustainable supply of water and nutrients, operational and infrastructure logistics, and economic competitiveness with petroleum-based fuels. These challenges are addressed in part by applying the Integrated Assessment Framework (IAF)—an integrated multi-scale modeling, analysis, and data management suite—to address key issues in developing and operating an open-pond facility by analyzing how variability and uncertainty in space and time affect algal feedstock production rates, and determining the site-specific “optimum” facility scale to minimize capital and operational expenses. This approach explicitly and systematically assesses the interdependence of biofuel production potential, associated resource requirements, and production system design trade-offs. The IAF was applied to a set of sites previously identified as having the potential to cumulatively produce 5 billion-gallons/year in the southeastern U.S. and results indicate costs can be reduced by selecting the most effective processing technology pathway and scaling downstream processing capabilities to fit site-specific growing conditions, available resources, and algal strains.

Coleman, Andre M.; Abodeely, Jared; Skaggs, Richard; Moeglein, William AM; Newby, Deborah T.; Venteris, Erik R.; Wigmosta, Mark S.

2014-06-19

208

Soil Carbon Change and Net Energy Associated with Biofuel Production on Marginal Lands: A Regional Modeling Perspective  

SciTech Connect

The use of marginal lands (MLs) for biofuel production has been contemplated as a promising solution for meeting biofuel demands. However, there have been concerns with spatial location of MLs, their inherent biofuel potential, and possible environmental consequences with the cultivation of energy crops. Here, we developed a new quantitative approach that integrates high-resolution land cover and land productivity maps and uses conditional probability density functions for analyzing land use patterns as a function of land productivity to classify the agricultural lands. We subsequently applied this method to determine available productive croplands (P-CLs) and non-crop marginal lands (NC-MLs) in a nine-county Southern Michigan. Furthermore, Spatially Explicit Integrated Modeling Framework (SEIMF) using EPIC (Environmental Policy Integrated Climate) was used to understand the net energy (NE) and soil organic carbon (SOC) implications of cultivating different annual and perennial production systems.

Bandaru, Varaprasad; Izaurralde, Roberto C.; Manowitz, David H.; Link, Robert P.; Zhang, Xuesong; Post, W. M.

2013-12-01

209

Impacts of biofuels production alternatives on water quantity and quality in the Iowa River Basin  

USGS Publications Warehouse

Corn stover as well as perennial grasses like switchgrass (Panicum virgatum) and miscanthus are being considered as candidates for the second generation biofuel feedstocks. However, the challenges to biofuel development are its effects on the environment, especially water quality. This study evaluates the long-term impacts of biofuel production alternatives (e.g., elevated corn stover removal rates and the potential land cover change) on an ecosystem with a focus on biomass production, soil erosion, water quantity and quality, and soil nitrate nitrogen concentration at the watershed scale. The Soil and Water Assessment Tool (SWAT) was modified for setting land cover change scenarios and applied to the Iowa River Basin (a tributary of the Upper Mississippi River Basin). Results show that biomass production can be sustained with an increased stover removal rate as long as the crop demand for nutrients is met with appropriate fertilization. Although a drastic increase (4.7–70.6%) in sediment yield due to erosion and a slight decrease (1.2–3.2%) in water yield were estimated with the stover removal rate ranging between 40% and 100%, the nitrate nitrogen load declined about 6–10.1%. In comparison to growing corn, growing either switchgrass or miscanthus can reduce sediment erosion greatly. However, land cover changes from native grass to switchgrass or miscanthus would lead to a decrease in water yield and an increase in nitrate nitrogen load. In contrast to growing switchgrass, growing miscanthus is more productive in generating biomass, but its higher water demand may reduce water availability in the study area.

Wu, Y.; Liu, S.

2012-01-01

210

Catalytic Fast Pyrolysis for the Production of the Hydrocarbon Biofuels  

SciTech Connect

Catalytic fast pyrolysis is a promising technique for conversion of biomass into hydrocarbons for use as transportation fuels. For over 30 years this process has been studied and it has been demonstrated that oils can be produced with high concentrations of hydrocarbons and low levels of oxygen. However, the yields from this type of conversion are typically low and the catalysts, which are often zeolites, are quickly deactivated through coking. In addition, the hydrocarbons produced are primarily aromatic molecules (benzene, toluene, xylene) that not desirable for petroleum refineries and are not well suited for diesel or jet engines. The goals of our research are to develop new multifunction catalysts for the production of gasoline, diesel and jet fuel range molecules and to improve process conditions for higher yields and low coking rates. We are investigating filtration and the use of hydrogen donor molecules to improve catalyst performance.

Nimlos, M. R.; Robichaud, D. J.; Mukaratate, C.; Donohoe, B. S.; Iisa, K.

2013-01-01

211

Biofuel Production Datasets from DOE's Bioenergy Knowledge Discovery Framework (KDF)  

DOE Data Explorer

The Bioenergy Knowledge Discovery Framework invites users to discover the power of bioenergy through an interface that provides extensive access to research data and literature, GIS mapping tools, and collaborative networks. The Bioenergy KDF supports efforts to develop a robust and sustainable bioenergy industry. The KDF facilitates informed decision making by providing a means to synthesize, analyze, and visualize vast amounts of information in a relevant and succinct manner. It harnesses Web 2.0 and social networking technologies to build a collective knowledge system that can better examine the economic and environmental impacts of development options for biomass feedstock production, biorefineries, and related infrastructure. [copied from https://www.bioenergykdf.net/content/about]

Holdings include datasets, models, and maps and the collections arel growing due to both DOE contributions and data uploads from individuals.

212

Impacts of Urbanization and Biofuels Production on The Price of Land in the Corn Belt: A Farm-Level Analysis  

Microsoft Academic Search

This study uses hedonic techniques to estimate the impact of urban influence, increased bio-fuels production, and environmental factors on land prices in the Corn Belt. We hypothesize that urban influence and ethanol production increase land prices on Corn Belt farms. Although not all states in the Corn Belt are entirely subject to urban influence and ethanol production impacts, some states

Richard Nehring; Kenneth Erickson; Vince Breneman; Alexandre Vialou; David Nulph

213

Catalytic processes towards the production of biofuels in a palm oil and oil palm biomass-based biorefinery.  

PubMed

In Malaysia, there has been interest in the utilization of palm oil and oil palm biomass for the production of environmental friendly biofuels. A biorefinery based on palm oil and oil palm biomass for the production of biofuels has been proposed. The catalytic technology plays major role in the different processing stages in a biorefinery for the production of liquid as well as gaseous biofuels. There are number of challenges to find suitable catalytic technology to be used in a typical biorefinery. These challenges include (1) economic barriers, (2) catalysts that facilitate highly selective conversion of substrate to desired products and (3) the issues related to design, operation and control of catalytic reactor. Therefore, the catalytic technology is one of the critical factors that control the successful operation of biorefinery. There are number of catalytic processes in a biorefinery which convert the renewable feedstocks into the desired biofuels. These include biodiesel production from palm oil, catalytic cracking of palm oil for the production of biofuels, the production of hydrogen as well as syngas from biomass gasification, Fischer-Tropsch synthesis (FTS) for the conversion of syngas into liquid fuels and upgrading of liquid/gas fuels obtained from liquefaction/pyrolysis of biomass. The selection of catalysts for these processes is essential in determining the product distribution (olefins, paraffins and oxygenated products). The integration of catalytic technology with compatible separation processes is a key challenge for biorefinery operation from the economic point of view. This paper focuses on different types of catalysts and their role in the catalytic processes for the production of biofuels in a typical palm oil and oil palm biomass-based biorefinery. PMID:18434141

Chew, Thiam Leng; Bhatia, Subhash

2008-11-01

214

Perennial grass production for biofuels: Soil conversion considerations  

SciTech Connect

The increased use of renewable fuels for energy offers the United States a mechanism for significantly reducing national dependency on imported oil, reducing greenhouse gas emissions, and improving regional agricultural economies. As mandated by law, a wide range of issues have been raised regarding the net environmental impacts of implementation of these new technologies. While uncertainties regarding both positive and negative environmental influences still exist in many areas of this new technology, it is now possible to address with substantial certainty the positive aspects of perennial herbaceous energy crops on several important soil conservation issues. Past experience with forage grasses and recent research with switchgrass. A warm season perennial forage grass selected as one of the model bioenergy species, indicates that important benefits will be gained in the area of soil conservation as grasses replace energy-intensive annual row crops. These include reduced erosion, improved conservation of water and nutrients, and increased productivity of soils by the deep and vigorous rooting systems of perennial warm-season gasses.

McLaughlin, S.B. [Oak Ridge National Lab., TN (United States); Bransby, D.I. [Auburn Univ., AL (United States). Dept. of Agronomy and Soils; Parrish, D. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States). Dept. of Crop, Soil, and Environmental Sciences

1994-10-01

215

Understanding and engineering enzymes for enhanced biofuel production.  

SciTech Connect

Today, carbon-rich fossil fuels, primarily oil, coal and natural gas, provide 85% of the energy consumed in the United States. The release of greenhouse gases from these fuels has spurred research into alternative, non-fossil energy sources. Lignocellulosic biomass is renewable resource that is carbon-neutral, and can provide a raw material for alternative transportation fuels. Plant-derived biomass contains cellulose, which is difficult to convert to monomeric sugars for production of fuels. The development of cost-effective and energy-efficient processes to transform the cellulosic content of biomass into fuels is hampered by significant roadblocks, including the lack of specifically developed energy crops, the difficulty in separating biomass components, the high costs of enzymatic deconstruction of biomass, and the inhibitory effect of fuels and processing byproducts on organisms responsible for producing fuels from biomass monomers. One of the main impediments to more widespread utilization of this important resource is the recalcitrance of cellulosic biomass and techniques that can be utilized to deconstruct cellulosic biomass.

Simmons, Blake Alexander; Volponi, Joanne V.; Sapra, Rajat; Faulon, Jean-Loup Michel; Buffleben, George M.; Roe, Diana C.

2009-01-01

216

Quantifying the climate impacts of albedo changes due to biofuel production: a comparison with biogeochemical effects  

NASA Astrophysics Data System (ADS)

Lifecycle analysis is a tool widely used to evaluate the climate impact of greenhouse gas emissions attributable to the production and use of biofuels. In this paper we employ an augmented lifecycle framework that includes climate impacts from changes in surface albedo due to land use change. We consider eleven land-use change scenarios for the cultivation of biomass for middle distillate fuel production, and compare our results to previous estimates of lifecycle greenhouse gas emissions for the same set of land-use change scenarios in terms of CO2e per unit of fuel energy. We find that two of the land-use change scenarios considered demonstrate a warming effect due to changes in surface albedo, compared to conventional fuel, the largest of which is for replacement of desert land with salicornia cultivation. This corresponds to 222 gCO2e/MJ, equivalent to 3890% and 247% of the lifecycle GHG emissions of fuels derived from salicornia and crude oil, respectively. Nine of the land-use change scenarios considered demonstrate a cooling effect, the largest of which is for the replacement of tropical rainforests with soybean cultivation. This corresponds to - 161 gCO2e/MJ, or - 28% and - 178% of the lifecycle greenhouse gas emissions of fuels derived from soybean and crude oil, respectively. These results indicate that changes in surface albedo have the potential to dominate the climate impact of biofuels, and we conclude that accounting for changes in surface albedo is necessary for a complete assessment of the aggregate climate impacts of biofuel production and use.

Caiazzo, Fabio; Malina, Robert; Staples, Mark D.; Wolfe, Philip J.; Yim, Steve H. L.; Barrett, Steven R. H.

2014-01-01

217

[Life cycle assessment on oxygen biofuels].  

PubMed

Life Cycle Assessment (LCA) was used to compare energy consumption and pollutant emissions of two oxygen biofuels, ethanol and methyl ester, which were mixed with gasoline and diesel oil at levels of 10% and 30% of the biofuel. The future of oxygen-containing biofuels was analyzed and forecasted. The results show that the mixture of biofuels and petroleum products can reduce crude oil consumption, but only methyl ester alternative fuel can reduce fossil fuel consumption. Use of methyl ester mixtures would reduce NOx by 50% compared to gasoline or diesel on a life cycle basis; however, NOx would increase using ethanol. Each alternative fuel mixture reduced PM10 emissions from the vehicle and methyl ester decreased VOCs. The SO2 emissions from the fuel production processes, which account for about 80% of SO2 life cycle emissions, must be strictly controlled. PMID:16447424

Yi, Hong-hong; Zhu, Yong-qing; Wang, Jian-xin; Hao, Ji-ming

2005-11-01

218

Soil carbon change and net energy associated with biofuel production on marginal lands: a regional modeling perspective.  

PubMed

The use of marginal lands for biofuel production has been proposed as a promising solution for meeting biofuel demands while avoiding food-feed-fuel conflicts. However, uncertainty surrounds whether marginal lands can be reliably located, as well as their inherent biofuel potential and the possible environmental impacts. We developed a quantitative approach that integrates high-resolution land cover and land productivity to classify productive croplands and nonarable marginal lands in a nine-county region in southern Michigan. The classified lands were then examined with the spatially explicit modeling framework using the Environmental Policy Integrated Climate (EPIC) model to estimate net energy (NE) and soil organic carbon (SOC) changes associated with the cultivation of different annual and perennial production systems. Simulation results suggest that biofuel production systems underperform on marginal lands when compared to productive croplands. However, we found perennial grasses could perform better than annual crops. Hence, when growing perennial bioenergy crops on marginal lands instead of productive croplands, less additional land (about 0.09 ha per each hectare planted) would be needed to achieve the same NE than if growing annual bioenergy crops (additional 0.17 ha per hectare planted). Miscanthus ( × ) and switchgrass ( L.) can produce 112.43 and 74.61 GJ ha yr NE, respectively, and have the potential to sequester, on average, 0.59 and 0.23 Mg C ha yr SOC, respectively. Notably, simulation results indicate substantial variability of the NE and SOC storage potential across the study region. Thus, although perennial energy crops are promising options for biofuel production on marginal lands, given the large spatial variability, regional- and site-specific management strategies are required for sustainable biofuel production. PMID:25602420

Bandaru, Varaprasad; Izaurralde, R César; Manowitz, David; Link, Robert; Zhang, Xuesong; Post, Wilfred M

2013-11-01

219

Electricity production in biofuel cell using modified graphite electrode with Neutral Red  

Microsoft Academic Search

E. coliwas used as a biocatalyst to compare electricity production, substrate consumption and growth in biofuel cells. With the native electrode 1.44 mV cm-2-electrode and 1.41 µA cm-2-electrode electricity were produced and 21 mM acetate was consumed. With the modified electrode with Neutral Red, 3.12 mV cm-2-electrode and 3.1 µA cm-2-electrode electricity were produced and 39 mM acetate was consumed.

Doo Hyun Park; Si Kyoon Kim; In Ho Shin; Yoo Jung Jeong

2000-01-01

220

Versatile microbial surface-display for environmental remediation and biofuels production  

SciTech Connect

Surface display is a powerful technique that utilizes natural microbial functional components to express proteins or peptides on the cell exterior. Since the reporting of the first surface-display system in the mid-1980s, a variety of new systems have been reported for yeast, Gram-positive and Gram-negative bacteria. Non-conventional display methods are emerging, eliminating the generation of genetically modified microorganisms. Cells with surface display are used as biocatalysts, biosorbents and biostimulants. Microbial cell-surface display has proven to be extremely important for numerous applications ranging from combinatorial library screening and protein engineering to bioremediation and biofuels production.

Wu, Cindy H.; Mulchandani, Ashok; Chen, wilfred

2008-02-14

221

Fuel from Tobacco and Arundo Donax: Synthetic Crop for Direct Drop-in Biofuel Production through Re-routing the Photorespiration Intermediates and Engineering Terpenoid Pathways  

SciTech Connect

PETRO Project: Biofuels offer renewable alternatives to petroleum-based fuels that reduce net greenhouse gas emissions to nearly zero. However, traditional biofuels production is limited not only by the small amount of solar energy that plants convert through photosynthesis into biological materials, but also by inefficient processes for converting these biological materials into fuels. Farm-ready, non-food crops are needed that produce fuels or fuel-like precursors at significantly lower costs with significantly higher productivity. To make biofuels cost-competitive with petroleum-based fuels, biofuels production costs must be cut in half.

None

2012-02-15

222

Effects of Escherichia coli on Mixotrophic Growth of Chlorella minutissima and Production of Biofuel Precursors  

PubMed Central

Chlorella minutissima was co-cultured with Escherichia coli in airlift reactors under mixotrophic conditions (glucose, glycerol, and acetate substrates) to determine possible effects of bacterial contamination on algal biofuel production. It was hypothesized that E. coli would compete with C. minutissima for nutrients, displacing algal biomass. However, C. minutissima grew more rapidly and to higher densities in the presence of E. coli, suggesting a symbiotic relationship between the organisms. At an initial 1% substrate concentration, the co-culture produced 200-587% more algal biomass than the axenic C. minutissima cultures. Co-cultures grown on 1% substrate consumed 23–737% more of the available carbon substrate than the sum of substrate consumed by E. coli and C. minutissima alone. At 1% substrate, total lipid and starch productivity were elevated in co-cultures compared to axenic cultures indicating that bacterial contamination was not detrimental to the production of biofuel precursors in this specific case. Bio-fouling of the reactors observed in co-cultures and acid formation in all mixotrophic cultures, however, could present challenges for scale-up. PMID:24805253

Higgins, Brendan T.; VanderGheynst, Jean S.

2014-01-01

223

Integration of microalgae cultivation with industrial waste remediation for biofuel and bioenergy production: opportunities and limitations.  

PubMed

There is currently a renewed interest in developing microalgae as a source of renewable energy and fuel. Microalgae hold great potential as a source of biomass for the production of energy and fungible liquid transportation fuels. However, the technologies required for large-scale cultivation, processing, and conversion of microalgal biomass to energy products are underdeveloped. Microalgae offer several advantages over traditional 'first-generation' biofuels crops like corn: these include superior biomass productivity, the ability to grow on poor-quality land unsuitable for agriculture, and the potential for sustainable growth by extracting macro- and micronutrients from wastewater and industrial flue-stack emissions. Integrating microalgal cultivation with municipal wastewater treatment and industrial CO(2) emissions from coal-fired power plants is a potential strategy to produce large quantities of biomass, and represents an opportunity to develop, test, and optimize the necessary technologies to make microalgal biofuels more cost-effective and efficient. However, many constraints on the eventual deployment of this technology must be taken into consideration and mitigating strategies developed before large scale microalgal cultivation can become a reality. As a strategy for CO(2) biomitigation from industrial point source emitters, microalgal cultivation can be limited by the availability of land, light, and other nutrients like N and P. Effective removal of N and P from municipal wastewater is limited by the processing capacity of available microalgal cultivation systems. Strategies to mitigate against the constraints are discussed. PMID:21461850

McGinn, Patrick J; Dickinson, Kathryn E; Bhatti, Shabana; Frigon, Jean-Claude; Guiot, Serge R; O'Leary, Stephen J B

2011-09-01

224

Utilization of grasses for potential biofuel production and phytoremediation of heavy metal contaminated soils.  

PubMed

This research focuses on investigating the use of common biofuel grasses to assess their potential as agents of long-term remediation of contaminated soils using lead as a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy grass may be potentially useful for long-term phytoremediation of heavy metal contaminated soils and describe novel techniques to track and remove contaminants from inception to useful product. Enzymatic digestion and thermochemical approaches are being used to convert this lignocellulosic feedstock into useful product (sugars, ethanol, biocrude oil + biochar). Preliminary studies on enzymatic hydrolysis and fast pyrolysis of the Switchgrass materials that were grown in heavy metal contaminated soil and non-contaminated soils show that the presence of lead in the Switchgrass material feedstock does not adversely affect the outcomes of the conversion processes. These results indicate that the modest levels of contaminant uptake allow these grass species to serve as phytoremediation agents as well as feedstocks for biofuel production in areas degraded by industrial pollution. PMID:25495935

Balsamo, Ronald A; Kelly, William J; Satrio, Justinus A; Ruiz-Felix, M Nydia; Fetterman, Marisa; Wynn, Rodd; Hagel, Kristen

2015-01-01

225

Spatial forecasting of switchgrass productivity under current and future climate change scenarios.  

PubMed

Evaluating the potential of alternative energy crops across large geographic regions, as well as over time, is a necessary component to determining if biofuel production is feasible and sustainable in the face of growing production demands and climatic change. Switchgrass (Panicum virgatum L.), a native perennial herbaceous grass, is a promising candidate for cellulosic feedstock production. In this study, current and future (from 2080 to 2090) productivity is estimated across the central and eastern United States using ALMANAC, a mechanistic model that simulates plant growth over time. The ALMANAC model was parameterized for representative ecotypes of switchgrass. Our results indicate substantial variation in switchgrass productivity both within regions and over time. States along the Gulf Coast, southern Atlantic Coast, and in the East North Central Midwest have the highest current biomass potential. However, these areas also contain critical wetland habitat necessary for the maintenance of biodiversity and agricultural lands necessary for food production. The southern United States is predicted to have the largest decrease in future biomass production. The Great Plains are expected to experience large increases in productivity by 2080-2090 due to climate change. In general, regions where future temperature and precipitation are predicted to increase are also where larger future biomass production is expected. In contrast, regions that show a future decrease in precipitation are associated with smaller future biomass production. Switchgrass appears to be a promising biofuel crop for the central and eastern United States, with local biomass predicted to be high (>10 Mg/ha) for approximately 50% of the area studied for each climate scenario. In order to minimize land conversion and loss of biodiversity, areas that currently have and maintain high productivity under climate change should be targeted for their long-term growth potential. PMID:23495637

Behrman, Kathrine D; Kiniry, James R; Winchell, Michael; Juenger, Thomas E; Keitt, Timothy H

2013-01-01

226

Biofuel Feedstock Assessment For Selected Countries  

SciTech Connect

Findings from biofuel feedstock production assessments and projections of future supply are presented and discussed. The report aims to improve capabilities to assess the degree to which imported biofuel could contribute to meeting future U.S. targets to reduce dependence on imported oil. The study scope was focused to meet time and resource requirements. A screening process identified Argentina, Brazil, Canada, China, Colombia, India, Mexico, and the Caribbean Basin Initiative (CBI) region for initial analysis, given their likely role in future feedstock supply relevant to U.S. markets. Supply curves for selected feedstocks in these countries are projected for 2012, 2017 and 2027. The supply functions, along with calculations to reflect estimated supplies available for export and/or biofuel production, were provided to DOE for use in a broader energy market allocation study. Potential cellulosic supplies from crop and forestry residues and perennials were also estimated for 2017 and 2027. The analysis identified capacity to potentially double or triple feedstock production by 2017 in some cases. A majority of supply growth is derived from increasing the area cultivated (especially sugarcane in Brazil). This is supplemented by improving yields and farming practices. Most future supplies of corn and wheat are projected to be allocated to food and feed. Larger shares of future supplies of sugarcane, soybean and palm oil production will be available for export or biofuel. National policies are catalyzing investments in biofuel industries to meet targets for fuel blending that generally fall in the 5-10% range. Social and environmental concerns associated with rapid expansion of feedstock production are considered. If the 2017 projected feedstock supply calculated as 'available' for export or biofuel were converted to fuel, it would represent the equivalent of about 38 billion gallons of gasoline. Sugarcane and bagasse dominate the available supply, representing 64% of the total. Among the nations studied, Brazil is the source of about two-thirds of available supplies, followed distantly by Argentina (12%), India and the CBI region.

Kline, Keith L [ORNL; Oladosu, Gbadebo A [ORNL; Wolfe, Amy K [ORNL; Perlack, Robert D [ORNL; Dale, Virginia H [ORNL

2008-02-01

227

Production of algal-based biofuel using non-fresh water sources.  

SciTech Connect

The goal of this LDRD involves development of a system dynamics model to understand the interdependencies between water resource availability and water needs for production of biofuels. Specifically, this model focuses on availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual simulation framework and historical data are based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The overall water balance ignores both transportation options and water chemistry and is broken down by county level. The resulting model contains an algal growth module, a dairy module, an oil production module, and a gas production module. A user interface is also created for controlling the adjustable parameters in the model. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil- and gas-produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

Sun, Amy Cha-Tien; Reno, Marissa Devan

2007-09-01

228

Biofuel Co-products as Swine Feed Ingredients: Combining Distillers Dried Grains with Solubles (DDGS) and Crude Glycerin  

Technology Transfer Automated Retrieval System (TEKTRAN)

Production of biofuels is increasing both the demand for traditional energy feedstuffs for pigs and the availability of co-products, particularly distillers dried grains with solubles (DDGS) and crude glycerin. Oil naturally found in corn grain is concentrated in DDGS generated from ethanol producti...

229

Comparative genomics of xylose-fermenting fungi for enhanced biofuel production  

SciTech Connect

Cellulosic biomass is an abundant and underused substrate for biofuel production. The inability of many microbes to metabolize the pentose sugars abundant within hemicellulose creates specific challenges for microbial biofuel production from cellulosic material. Although engineered strains of Saccharomyces cerevisiae can use the pentose xylose, the fermentative capacity pales in comparison with glucose, limiting the economic feasibility of industrial fermentations. To better understand xylose utilization for subsequent microbial engineering, we sequenced the genomes of two xylose-fermenting, beetle-associated fungi, Spathaspora passalidarum and Candida tenuis. To identify genes involved in xylose metabolism, we applied a comparative genomic approach across 14 Ascomycete genomes, mapping phenotypes and genotypes onto the fungal phylogeny, and measured genomic expression across five Hemiascomycete species with different xylose-consumption phenotypes. This approach implicated many genes and processes involved in xylose assimilation. Several of these genes significantly improved xylose utilization when engineered into S. cerevisiae, demonstrating the power of comparative methods in rapidly identifying genes for biomass conversion while reflecting on fungal ecology.

Wohlbach, Dana J.; Kuo, Alan; Sato, Trey K.; Potts, Katlyn M.; Salamov, Asaf A.; LaButti, Kurt M.; Sun, Hui; Clum, Alicia; Pangilinan, Jasmyn L.; Lindquist, Erika A.; Lucas, Susan; Lapidus, Alla; Jin, Mingjie; Gunawan, Christa; Balan, Venkatesh; Dale, Bruce E.; Jeffries, Thomas W.; Zinkel, Robert; Barry, Kerrie W.; Grigoriev, Igor V.; Gasch, Audrey P.

2011-02-24

230

Comparative Proteomics Analysis of Engineered Saccharomyces cerevisiae with Enhanced Biofuel Precursor Production  

PubMed Central

The yeast Saccharomyces cerevisiae was metabolically modified for enhanced biofuel precursor production by knocking out genes encoding mitochondrial isocitrate dehydrogenase and over-expression of a heterologous ATP-citrate lyase. A comparative iTRAQ-coupled 2D LC-MS/MS analysis was performed to obtain a global overview of ubiquitous protein expression changes in S. cerevisiae engineered strains. More than 300 proteins were identified. Among these proteins, 37 were found differentially expressed in engineered strains and they were classified into specific categories based on their enzyme functions. Most of the proteins involved in glycolytic and pyruvate branch-point pathways were found to be up-regulated and the proteins involved in respiration and glyoxylate pathway were however found to be down-regulated in engineered strains. Moreover, the metabolic modification of S. cerevisiae cells resulted in a number of up-regulated proteins involved in stress response and differentially expressed proteins involved in amino acid metabolism and protein biosynthesis pathways. These LC-MS/MS based proteomics analysis results not only offered extensive information in identifying potential protein-protein interactions, signal pathways and ubiquitous cellular changes elicited by the engineered pathways, but also provided a meaningful biological information platform serving further modification of yeast cells for enhanced biofuel production. PMID:24376832

Tang, Xiaoling; Feng, Huixing; Zhang, Jianhua; Chen, Wei Ning

2013-01-01

231

Combining micro-structures and micro-algae to increase lipid production for bio-fuel  

NASA Astrophysics Data System (ADS)

3rd generation bio-fuels like lipid producing micro-algae are a promising source of energy that could replace our dependence on petroleum. However, until there are improvements in algae oil yields, and a reduction in the energy needed for processing, algae bio-fuels are not economically competitive with petroleum. Here, we describe our work combining micro-fabricated devices with micro-algae Neochloris oleoabundans, a species first isolated on the sand dunes of Saudi Arabia. Inserting micro-algae of varying fitness into a landscape of micro-habitats allows us to evolve and select them based on a variety of conditions like specific gravity, starvation response and Nile Red fluorescence (which is a marker for lipid production). Hence, we can both estimate the production of lipids and generate conditions that allow the creation and isolation of algae which produce higher amounts of lipids, while discarding the rest. Finally, we can use micro-fabricated structures and flocculation to de-water these high lipid producing algae, reducing the need for expensive centrifugation and filtration.

Vyawahare, Saurabh; Zhu, Emilly; Mestler, Troy; Estévez-Torres, André.; Austin, Robert

2011-03-01

232

Outlook for advanced biofuels  

Microsoft Academic Search

To assess which biofuels have the better potential for the short-term or the longer term (2030), and what developments are necessary to improve the performance of biofuels, the production of four promising biofuels—methanol, ethanol, hydrogen, and synthetic diesel—is systematically analysed. This present paper summarises, normalises and compares earlier reported work. First, the key technologies for the production of these fuels,

Carlo N. Hamelinck

2006-01-01

233

Water Resources Implications of Cellulosic Biofuel Production at a Regional Scale  

NASA Astrophysics Data System (ADS)

Recent increases in oil prices, a strong national interest in greater energy independence, and a concern for the role of fossil fuels in global climate change, have led to a dramatic expansion in use of alternative renewable energy sources in the U.S. The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, of which 16 billion gallons are required to be cellulosic biofuels. Production of cellulosic biomass offers a promising alternative to corn-based systems because large-scale production of corn-based ethanol often requires irrigation and is associated with increased erosion, excess sediment export, and enhanced leaching of nitrogen and phosphorus. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water quality impacts associated with annual crops. Catchlight Energy LLC is examining the feasibility and sustainability of intercropping switchgrass in loblolly pine plantations in the southeastern U.S. Ongoing research is determining efficient operational techniques and information needed to evaluate effects of these practices on water resources in small watershed-scale (~25 ha) studies. Three sets of four to five sub-watersheds are fully instrumented and currently collecting calibration data in North Carolina, Alabama, and Mississippi. These watershed studies will provide detailed information to understand processes and guide management decisions. However, environmental implications of cellulosic systems need to be examined at a regional scale. We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine water quantity effects of various land use change scenarios ranging from switchgrass intercropping a small percentage of managed pine forest land to conversion of all managed forested land to switchgrass. The regional-scale SWAT model was successfully run and calibrated on the ~ 5 million ha Tombigbee Watershed located in Mississippi and Alabama. Publically available datasets were used as input to the model and for calibration. To improve calibration statistics, five tree age classes (0-4 yr, 4-10 yr, 10-17 yr, 17-24 yr, 24-30 yr) were added to the model to more appropriately represent existing forested systems in the region, which are not included within the standard SWAT set-up. Our results will be essential to public policy makers as they influence and plan for large-scale production of cellulosic biofuels, while sustaining water quality and quantity.

Christopher, S. F.; Schoenholtz, S. H.; Nettles, J. E.

2011-12-01

234

Effects of future urban and biofuel crop expansions on the riverine export of phosphorus to the Laurentian Great Lakes  

USGS Publications Warehouse

Increased phosphorus (P) loadings threaten the health of the world’s largest freshwater resource, the Laurentian Great Lakes (GL). To understand the linkages between land use and P delivery, we coupled two spatially explicit models, the landscape-scale SPARROW P fate and transport watershed model and the Land Transformation Model (LTM) land use change model, to predict future P export from nonpoint and point sources caused by changes in land use. According to LTM predictions over the period 2010–2040, the GL region of the U.S. may experience a doubling of urbanized areas and agricultural areas may increase by 10%, due to biofuel feedstock cultivation. These land use changes are predicted to increase P loadings from the U.S. side of the GL basin by 3.5–9.5%, depending on the Lake watershed and development scenario. The exception is Lake Ontario, where loading is predicted to decrease by 1.8% for one scenario, due to population losses in the drainage area. Overall, urban expansion is estimated to increase P loadings by 3.4%. Agricultural expansion associated with predicted biofuel feedstock cultivation is predicted to increase P loadings by an additional 2.4%. Watersheds that export P most ef?ciently and thus are the most vulnerable to increases in P sources tend to be found along southern Lake Ontario, southeastern Lake Erie, western Lake Michigan, and southwestern Lake Superior where watershed areas are concentrated along the coastline with shorter ?ow paths. In contrast, watersheds with high soil permeabilities, fractions of land underlain by tile drains, and long distances to the GL are less vulnerable.

LaBeau, Meredith B.; Robertson, Dale M.; Mayer, Alex S.; Pijanowski, Bryan C.; Saad, David A.

2013-01-01

235

Black liquor fractionation for biofuels production - a techno-economic assessment.  

PubMed

The hemicelluloses fraction of black liquor is an underutilized resource in many chemical pulp mills. It is possible to extract and separate the lignin and hemicelluloses from the black liquor and use the hemicelluloses for biochemical conversion into biofuels and chemicals. Precipitation of the lignin from the black liquor would consequently decrease the thermal load on the recovery boiler, which is often referred to as a bottleneck for increased pulp production. The objective of this work is to techno-economically evaluate the production of sodium-free lignin as a solid fuel and butanol to be used as fossil gasoline replacement by fractionating black liquor. The hydrolysis and fermentation processes are modeled in Aspen Plus to analyze energy and material balances as well as to evaluate the plant economics. A mathematical model of an existing pulp and paper mill is used to analyze the effects on the energy performance of the mill subprocesses. PMID:24950095

Mesfun, Sennai; Lundgren, Joakim; Grip, Carl-Erik; Toffolo, Andrea; Nilsson, Rasika Lasanthi Kudahettige; Rova, Ulrika

2014-08-01

236

Fatty Acid-Derived Biofuels and Chemicals Production in Saccharomyces cerevisiae  

PubMed Central

Volatile energy costs and environmental concerns have spurred interest in the development of alternative, renewable, sustainable, and cost-effective energy resources. Environment-friendly processes involving microbes can be used to synthesize advanced biofuels. These fuels have the potential to replace fossil fuels in supporting high-power demanding machinery such as aircrafts and trucks. From an engineering perspective, the pathway for fatty acid biosynthesis is an attractive route for the production of advanced fuels such as fatty acid ethyl esters, fatty alcohols, and alkanes. The robustness and excellent accessibility to molecular genetics make the yeast Saccharomyces cerevisiae a suitable host for the purpose of bio-manufacturing. Recent advances in metabolic engineering, as well as systems and synthetic biology, have now provided the opportunity to engineer yeast metabolism for the production of fatty acid-derived fuels and chemicals. PMID:25225637

Zhou, Yongjin J.; Buijs, Nicolaas A.; Siewers, Verena; Nielsen, Jens

2014-01-01

237

Fatty Acid-Derived Biofuels and Chemicals Production in Saccharomyces cerevisiae.  

PubMed

Volatile energy costs and environmental concerns have spurred interest in the development of alternative, renewable, sustainable, and cost-effective energy resources. Environment-friendly processes involving microbes can be used to synthesize advanced biofuels. These fuels have the potential to replace fossil fuels in supporting high-power demanding machinery such as aircrafts and trucks. From an engineering perspective, the pathway for fatty acid biosynthesis is an attractive route for the production of advanced fuels such as fatty acid ethyl esters, fatty alcohols, and alkanes. The robustness and excellent accessibility to molecular genetics make the yeast Saccharomyces cerevisiae a suitable host for the purpose of bio-manufacturing. Recent advances in metabolic engineering, as well as systems and synthetic biology, have now provided the opportunity to engineer yeast metabolism for the production of fatty acid-derived fuels and chemicals. PMID:25225637

Zhou, Yongjin J; Buijs, Nicolaas A; Siewers, Verena; Nielsen, Jens

2014-01-01

238

Production of Biofuel from Waste Lignocellulosic Biomass Materials Based on Energy Saving Viewpoint  

NASA Astrophysics Data System (ADS)

To develop biofuel production from waste lignocellulosic biomass materials the rice straw was selected one of renewable material and the degradation condition about pretreatment and enzymatic hydrolysis to obtain effectively fermentable sugars was investigated. Rice straw was pretreated by five kinds of methods and then the components ratio of rice straw was examined. First, the steam explosion was selected based on the degradability and the requirement energy. In addition, the best suitable combination of two cellulases to effective and economical hydrolyze was determined from the degradability of these pretreated rice straws. In the simultaneous saccharification and fermentation of the steam explosion rice straw by combining cellulase cocktail and a novel fermenting fungus, 13.2 g/L ethanol was able to product for 96 h.

Takano, Maki; Hoshino, Kazuhiro

239

Comparison of various microalgae liquid biofuel production pathways based on energetic, economic and environmental criteria.  

PubMed

In view of the increasing demand for bioenergy, in this study, the techno-economic viabilities for three emerging pathways to microalgal biofuel production have been evaluated. The three processes evaluated are the hydrothermal liquefaction (HTL), oil secretion and alkane secretion. These three routes differ in their lipid extraction procedure and the end-products produced. This analysis showed that these three processes showed various advantages: possibility to convert the defatted microalgae into bio-crude via HTL thus increasing the total biodiesel yield; better energetic and environmental performance for oil secretion and an even increased net energy ratio (NER) for alkane secretion. However, great technological breakthroughs are needed before planning any scale-up strategy such as continuous wet biomass processing and heat exchange optimization for the HTL pathway and effective and sustainable excretion for both secretion pathways. PMID:23567683

Delrue, F; Li-Beisson, Y; Setier, P-A; Sahut, C; Roubaud, A; Froment, A-K; Peltier, G

2013-05-01

240

A Biophysical Modeling Framework for Assessing the Environmental Impact of Biofuel Production  

NASA Astrophysics Data System (ADS)

Long-term sustainability of a biofuel economy necessitates environmentally friendly biofuel production systems. We describe a biophysical modeling framework developed to understand and quantify the environmental value and impact (e.g. water balance, nutrients balance, carbon balance, and soil quality) of different biomass cropping systems. This modeling framework consists of three major components: 1) a Geographic Information System (GIS) based data processing system, 2) a spatially-explicit biophysical modeling approach, and 3) a user friendly information distribution system. First, we developed a GIS to manage the large amount of geospatial data (e.g. climate, land use, soil, and hydrograhy) and extract input information for the biophysical model. Second, the Environmental Policy Integrated Climate (EPIC) biophysical model is used to predict the impact of various cropping systems and management intensities on productivity, water balance, and biogeochemical variables. Finally, a geo-database is developed to distribute the results of ecosystem service variables (e.g. net primary productivity, soil carbon balance, soil erosion, nitrogen and phosphorus losses, and N2O fluxes) simulated by EPIC for each spatial modeling unit online using PostgreSQL. We applied this framework in a Regional Intensive Management Area (RIMA) of 9 counties in Michigan. A total of 4,833 spatial units with relatively homogeneous biophysical properties were derived using SSURGO, Crop Data Layer, County, and 10-digit watershed boundaries. For each unit, EPIC was executed from 1980 to 2003 under 54 cropping scenarios (eg. corn, switchgrass, and hybrid poplar). The simulation results were compared with historical crop yields from USDA NASS. Spatial mapping of the results show high variability among different cropping scenarios in terms of the simulated ecosystem services variables. Overall, the framework developed in this study enables the incorporation of environmental factors into economic and life-cycle analysis in order to optimize biomass cropping production scenarios.

Zhang, X.; Izaurradle, C.; Manowitz, D.; West, T. O.; Post, W. M.; Thomson, A. M.; Nichols, J.; Bandaru, V.; Williams, J. R.

2009-12-01

241

Biofuels Research at EPA  

EPA Science Inventory

The development of sustainable and clean biofuels is a national priority. To do so requires a life-cycle approach that includes consideration of feedstock production and logistics, and biofuel production, distribution, and end use. The US Environmental Protection Agency is suppor...

242

Educare: new product, new future.  

PubMed

On September 2, 1990, something very informative about the evolution of early childhood programs in the minds of people appeared in The New York Times. Perhaps only another historian of trivia would have noticed it, but it was significant. The Sunday crossword puzzle had the following cue for 4 down: "Places for day-care" (spelled, with the purist's uncertainty, with a hyphen). Even such a cautious horizontal-vertical weaver as I am did not have to wait very long before filling in the correct 10 letters: "preschools." Preschools = day-cares; day-cares = preschools. I am told that actors and authors and scientists know that they have it made when their names are required as solutions in a Times crossword puzzle. If so, perhaps we now have tangible proof that those of us have at last been heard who have urged acceptance of the concept that early childhood education (or preschool education) and child care (or day care) are really one and the same essential service operated for different lengths of time. Day care, the illegitimate child of the scientific field that gave birth to the early childhood movement, has turned out to be the only offspring sufficiently well endowed and robust to make it in the modern world. It is the only one possessing the characteristics that will enable it to take the family enterprise into the future. At this juncture, near the close of the century during which programs for young children multiplied to the point where they cannot be ignored as significant factors in family and public life, we are on the threshold of a new era.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1869626

Caldwell, B

1991-06-01

243

Relative importance of climate and land surface changes on hydrologic changes in the US Midwest since the 1930s: Implications for biofuel production  

NASA Astrophysics Data System (ADS)

The US Midwest is an important area of first generation biofuels, accounting for 80-90% of US corn and soybean production (2009-2011). However, there are potential adverse impacts of biofuel production on water resources in this area. The objective of this study was to assess potential impacts of biofuel production on water resources by exploring relationships between hydrologic changes and climate and land surface changes based on long-term (˜1930s-2010) stream gage and climate data from 55 unregulated watersheds in the US Midwest. Long-term trends in climate (precipitation and potential evapotranspiration) and flow were evaluated. Sensitivity of changes in annual streamflow and baseflow to climate was evaluated using climate elasticity (sensitivity) and the residuals were attributed to land surface changes. Results show that streamflow increased significantly (p < 0.05) in 35% (19/55) of watersheds (median 2.4 ± 0.3 mm/year), baseflow increased in 58% of watersheds (median 1.1 ± 0.4 mm/year), and baseflow index (baseflow/streamflow, BFI) increased in 42% of watersheds (median 0.2 ± 0.1%/year). Overall, climatic variability contributed more than land surface change to streamflow change (61 ± 19% vs. 40 ± 18%), while land surface change contributed much more to baseflow (74 ± 10% vs. 27 ± 10%; 2.7 times higher) and to BFI (119 ± 14% vs. 27 ± 18%; 4.4 times higher) than climate change. Watersheds (25/55, 45%) with no significant trend in climate but with significant flow trends provide direct evidence that the Midwest land surface change (cropping system and related land management) significantly impacted flow processes. Restricting analysis to these watersheds shows that land surface change contributed 2.0 times more than climate variability/change to streamflow change, 3.2 times more to baseflow change, and 7.7 times more to BFI change. The importance of past land surface changes on hydrology suggests that any future land surface changes, such as biofuel expansion or changing biofuel feedstocks, should consider impacts on the hydrology.

Xu, Xianli; Scanlon, Bridget R.; Schilling, Keith; Sun, Alex

2013-08-01

244

Gaining ground in the modeling of land-use change greenhouse gas emissions associated with biofuel production  

NASA Astrophysics Data System (ADS)

Land-use change (LUC) resulting from biofuel feedstock production and the associated greenhouse gas (GHG) emissions are a hotly-debated aspect of biofuels. Certainly, LUC GHG emissions are one of the most uncertain elements in life cycle analyses (LCA) of biofuels. To estimate LUC GHG emissions, two sets of data are necessary. First, information on the amount and type of land that is converted to biofuel feedstock production is required. These data are typically generated through application of computable general equilibrium (CGE) models such as Purdue University's Global Trade Analysis Project (GTAP) model. Second, soil carbon content data for the affected land types is essential. Recently, Argonne National Laboratory's Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) has been updated with CGE modeling results that estimate the amount and type of LUC world-wide from production of ethanol from corn, corn stover, miscanthus, and switchgrass (Mueller et al. 2012). Moreover, we have developed state-specific carbon content data, determined through modeling with CENTURY, for the two most dominant soil types in the conterminous 48 U.S. states (Kwon et al. 2012) to enable finer-resolution results for domestic LUC GHG emissions for these ethanol production scenarios. Of the feedstocks examined, CCLUB estimates that LUC GHG emissions are highest for corn ethanol (9.1 g CO2e/MJ ethanol) and lowest for miscanthus (-12 g CO2e/MJ ethanol). We will present key observations from CCLUB results incorporated into Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model, which is a LCA tool for transportation fuels and advanced vehicle technologies. We will discuss selected issues in this modeling, including the sensitivity of domestic soil carbon emission factors to modeling parameters and assumptions about the fate of harvested wood products. Further, we will discuss efforts to update CCLUB with county-level soil carbon emission factors and updated international soil carbon emission factors. Finally, we will examine data needs for improved LUC GHG calculations in both the modeling of land conversion and soil carbon content. Kwon, H. Y., Wander, M. M., Mueller, S., Dunn, J. B. "Modeling state-level soil carbon emission factors under various scenarios for direct land use change associated with United States biofuel feedstock production." Biomass and Bioenergy. Under Review. Mueller, S., Dunn, J. B., Wang, M. "Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) Users' Manual and Technical Documentation." May 2012. ANL/ESD/12-5. Available at http://greet.es.anl.gov/publication-cclub-manual.

Dunn, J.; Mueller, S.; Kwon, H.; Wang, M.; Wander, M.

2012-12-01

245

Clash of the Titans: Comparing productivity via radiation use efficiency for two grass giants of the biofuel field  

Technology Transfer Automated Retrieval System (TEKTRAN)

The comparative productivity of switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus x giganteus) is of critical importance to the biofuel industry. The radiation use efficiency (RUE), when derived in an environment with non-limiting soil water and soil nutrients, provides one metric of re...

246

Production of Algal-based Biofuel from Non-fresh Water Sources  

NASA Astrophysics Data System (ADS)

A system dynamics model is developed to assess the availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual framework is based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The simulation framework contains an algal growth module, a dairy module, an oil production module, and a gas production module. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil and gas produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

Sun, A. C.; Reno, M. D.

2008-12-01

247

The Role of Symbiotic Nitrogen Fixation in Sustainable Production of Biofuels  

PubMed Central

With the ever-increasing population of the world (expected to reach 9.6 billion by 2050), and altered life style, comes an increased demand for food, fuel and fiber. However, scarcity of land, water and energy accompanied by climate change means that to produce enough to meet the demands is getting increasingly challenging. Today we must use every avenue from science and technology available to address these challenges. The natural process of symbiotic nitrogen fixation, whereby plants such as legumes fix atmospheric nitrogen gas to ammonia, usable by plants can have a substantial impact as it is found in nature, has low environmental and economic costs and is broadly established. Here we look at the importance of symbiotic nitrogen fixation in the production of biofuel feedstocks; how this process can address major challenges, how improving nitrogen fixation is essential, and what we can do about it. PMID:24786096

Biswas, Bandana; Gresshoff, Peter M.

2014-01-01

248

The role of symbiotic nitrogen fixation in sustainable production of biofuels.  

PubMed

With the ever-increasing population of the world (expected to reach 9.6 billion by 2050), and altered life style, comes an increased demand for food, fuel and fiber. However, scarcity of land, water and energy accompanied by climate change means that to produce enough to meet the demands is getting increasingly challenging. Today we must use every avenue from science and technology available to address these challenges. The natural process of symbiotic nitrogen fixation, whereby plants such as legumes fix atmospheric nitrogen gas to ammonia, usable by plants can have a substantial impact as it is found in nature, has low environmental and economic costs and is broadly established. Here we look at the importance of symbiotic nitrogen fixation in the production of biofuel feedstocks; how this process can address major challenges, how improving nitrogen fixation is essential, and what we can do about it. PMID:24786096

Biswas, Bandana; Gresshoff, Peter M

2014-01-01

249

Enzymatic hydrolysis of pretreated waste paper--source of raw material for production of liquid biofuels.  

PubMed

Enzymatic hydrolysis of waste paper is becoming a perspective way to obtain raw material for production of liquid biofuels. Reducing sugars solutions that arise from the process of saccharification are a precursors for following or simultaneous fermentation to ethanol. Different types of waste paper were evaluated, in terms of composition and usability, in order to select the appropriate type of the waste paper for the enzymatic hydrolysis process. Novozymes® enzymes NS50013 and NS50010 were used in a laboratory scale trials. Technological conditions, which seem to be the most suitable for hydrolysis after testing on cellulose pulp and filter paper, were applied to hydrolysis of widely available waste papers - offset paper, cardboard, recycled paper in two qualities, matte MYsol offset paper and for comparison again on model materials. The highest yields were achieved for the cardboard, which was further tested using various pretreatment combinations in purpose of increasing the hydrolysis yields. PMID:24314601

Brummer, Vladimir; Jurena, Tomas; Hlavacek, Viliam; Omelkova, Jirina; Bebar, Ladislav; Gabriel, Petr; Stehlik, Petr

2014-01-01

250

Thermophysical characterization of the seeds of invasive Chinese tallow tree: importance for biofuel production.  

PubMed

The limited supply of traditional fossil based fuels, and increased concern about their environmental impact has driven the interest in the utilization of biomass based energy sources, including those that are underutilized or otherwise nuisance species such as Chinese tallow trees (Triadica sebifera [L.]). This species is a prolific seeds producer, and this paper shows that they contain more than 50% lipids by mass that are suitable for conversion into biodiesel. We present here, for the first time, the seeds' thermophysical properties important for biofuel production. The seeds were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and ultimate analysis; their thermal conductivity, thermal diffusivity, and specific heat were determined. The characterization results were correlated to fatty acid composition and lipid content for whole seeds and individual layers, as well as to the protein, hemicellulose, cellulose, and lignin content. The TGA analysis indicated the presence, in addition to lipids, of hemicellulose, cellulose, lignin, and proteins, depending on the layer analyzed. Thermal conductivity and specific heat were, respectively 0.14 ± 0.007 W/mK and 3843.5 ± 171.16 J/kgK for wax, 0.20 ± 0.002 W/mK and 2018.7 ± 5.18 J/kgK for shells, 0.13 ± 0.0 W/mK and 1237 ± 3.15 J/kgK for internal kernel, and 0.13 ± 0.000 W/mK and 2833.9 ± 104.11 J/kgK for whole seeds. These properties and characterization method can be further used in engineering analysis used to determine the most optimum processing method for production of biofuels from this feedstock. PMID:23013244

Picou, Laura; Boldor, Doran

2012-10-16

251

Genome replication engineering assisted continuous evolution (GREACE) to improve microbial tolerance for biofuels production  

PubMed Central

Background Microbial production of biofuels requires robust cell growth and metabolism under tough conditions. Conventionally, such tolerance phenotypes were engineered through evolutionary engineering using the principle of “Mutagenesis followed-by Selection”. The iterative rounds of mutagenesis-selection and frequent manual interventions resulted in discontinuous and inefficient strain improvement processes. This work aimed to develop a more continuous and efficient evolutionary engineering method termed as “Genome Replication Engineering Assisted Continuous Evolution” (GREACE) using “Mutagenesis coupled-with Selection” as its core principle. Results The core design of GREACE is to introduce an in vivo continuous mutagenesis mechanism into microbial cells by introducing a group of genetically modified proofreading elements of the DNA polymerase complex to accelerate the evolution process under stressful conditions. The genotype stability and phenotype heritability can be stably maintained once the genetically modified proofreading element is removed, thus scarless mutants with desired phenotypes can be obtained. Kanamycin resistance of E. coli was rapidly improved to confirm the concept and feasibility of GREACE. Intrinsic mechanism analysis revealed that during the continuous evolution process, the accumulation of genetically modified proofreading elements with mutator activities endowed the host cells with enhanced adaptation advantages. We further showed that GREACE can also be applied to engineer n-butanol and acetate tolerances. In less than a month, an E. coli strain capable of growing under an n-butanol concentration of 1.25% was isolated. As for acetate tolerance, cell growth of the evolved E. coli strain increased by 8-fold under 0.1% of acetate. In addition, we discovered that adaptation to specific stresses prefers accumulation of genetically modified elements with specific mutator strengths. Conclusions We developed a novel GREACE method using “Mutagenesis coupled-with Selection” as core principle. Successful isolation of E. coli strains with improved n-butanol and acetate tolerances demonstrated the potential of GREACE as a promising method for strain improvement in biofuels production. PMID:24070173

2013-01-01

252

Registration of Three High Fiber Sugar Cane Varieties, L 79-1002, HoCP 91-552 AND Ho 00-961, for Biofuels Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

High fiber sugarcane (Saccharum spp. hybrids) varieties, or energy canes, have been shown to be a viable feedstock for biofuel applications. Three high fiber sugarcane varieties, L 79-1002, HoCP 91-552 and Ho 00-961, were released in April 2007 for commercial biofuel production. L 79-1002 averaged 2...

253

Economic Competitiveness of Biofuel Production from Underutilized Ethanol Feedstock in Sri Lanka  

Microsoft Academic Search

Sri Lanka's agricultural sector has an abundant supply of natural resources that can be further developed and utilized to produce bio-fuels. Transformation of the nation's significant renewable biomass resources into cost-competitive, high-performance bio-fuels could reduce the country's dependence on imported fossil fuels and enhance energy security. However, there is limited understanding of the potential of bio-fuel resources, their utilization, and

Prabodh Illukpitiya; Chennat Gopalakrishnan; R. M. M. B. Ratnayake

2012-01-01

254

Iron oxide filled magnetic carbon nanotube-enzyme conjugates for recycling of amyloglucosidase: toward useful applications in biofuel production process.  

PubMed

Biofuels are fast advancing as a new research area to provide alternative sources of sustainable and clean energy. Recent advances in nanotechnology have sought to improve the efficiency of biofuel production, enhancing energy security. In this study, we have incorporated iron oxide nanoparticles into single-walled carbon nanotubes (SWCNTs) to produce magnetic single-walled carbon nanotubes (mSWCNTs). Our objective is to bridge both nanotechnology and biofuel production by immobilizing the enzyme, Amyloglucosidase (AMG), onto mSWCNTs using physical adsorption and covalent immobilization, with the aim of recycling the immobilized enzyme, toward useful applications in biofuel production processes. We have demonstrated that the enzyme retains a certain percentage of its catalytic efficiency (up to 40%) in starch prototype biomass hydrolysis when used repeatedly (up to ten cycles) after immobilization on mSWCNTs, since the nanotubes can be easily separated from the reaction mixture using a simple magnet. The enzyme loading, activity, and structural changes after immobilization onto mSWCNTs were also studied. In addition, we have demonstrated that the immobilized enzyme retains its activity when stored at 4 °C for at least one month. These results, combined with the unique intrinsic properties of the nanotubes, pave the way for greater efficiency in carbon nanotube-enzyme bioreactors and reduced capital costs in industrial enzyme systems. PMID:23148719

Goh, Wei Jiang; Makam, Venkata S; Hu, Jun; Kang, Lifeng; Zheng, Minrui; Yoong, Sia Lee; Udalagama, Chammika N B; Pastorin, Giorgia

2012-12-11

255

Stimulating learning-by-doing in advanced biofuels: effectiveness of alternative policies  

NASA Astrophysics Data System (ADS)

This letter examines the effectiveness of various biofuel and climate policies in reducing future processing costs of cellulosic biofuels due to learning-by-doing. These policies include a biofuel production mandate alone and supplementing the biofuel mandate with other policies, namely a national low carbon fuel standard, a cellulosic biofuel production tax credit or a carbon price policy. We find that the binding biofuel targets considered here can reduce the unit processing cost of cellulosic ethanol by about 30% to 70% between 2015 and 2035 depending on the assumptions about learning rates and initial costs of biofuel production. The cost in 2035 is more sensitive to the speed with which learning occurs and less sensitive to uncertainty in the initial production cost. With learning rates of 5-10%, cellulosic biofuels will still be at least 40% more expensive than liquid fossil fuels in 2035. The addition of supplementary low carbon/tax credit policies to the mandate that enhance incentives for cellulosic biofuels can achieve similar reductions in these costs several years earlier than the mandate alone; the extent of these incentives differs across policies and different kinds of cellulosic biofuels.

Chen, Xiaoguang; Khanna, Madhu; Yeh, Sonia

2012-12-01

256

Transgenics are imperative for biofuel crops  

Microsoft Academic Search

Petroleum dependency is a challenge that can potentially be partly offset by agricultural production of biofuels, while decreasing net, non-renewable carbon dioxide output. Plants have not been domesticated for modern biofuel production, and the quickest, most efficient, and often, the only way to convert plants to biofuel feedstocks is biotechnologically. First generation biofuel feedstock sources: sugarcane and cereal grains to

Jonathan Gressel

2008-01-01

257

Switchgrass potential on reclaimed surface mines for biofuel production in West Virginia  

NASA Astrophysics Data System (ADS)

The high cost and environmental risks associated with non-renewable energy sources has caused an increased interest in, and development of renewable biofuels. Switchgrass (Panicum virgatum L.), a warm season perennial grass, has been investigated as a source of biofuel feedstock due to its high biomass production on marginal soils, its tolerance of harsh growing conditions, and its ability to provide habitat for wildlife and soil conservation cover. West Virginia contains vast expanses of reclaimed surface mine lands and could potentially benefit from the production of switchgrass as a biofuel feedstock. Furthermore, switchgrass production could satisfy Surface Mining Reclamation and Control Act of 1977 (SMCRA) requirements for reclamation bond release to mine operators. Three separate studies will be discussed in this thesis to determine if switchgrass grown on reclaimed surface mines can produce yields similar to yields from stands grown under normal agronomic conditions and what common surface mining reclamation practices may be most appropriate for growing switchgrass. The first study examined yield production of three commercially-available, upland switchgrass varieties grown on two reclaimed surface mines in production years two, three and four. The Hampshire Hill mine site, which was reclaimed in the late 1990s using top soil and treated municipal sludge, averaged 5,800 kg (ha-yr)-1 of switchgrass compared to 803 kg (ha-yr)-1 at the Hobet 21 site which was reclaimed with crushed, unweathered rock over compacted overburden. Site and variety interacted with Cave-in-Rock as the top performer at the more fertile Hampshire Hill site and Shawnee produced the highest yields at Hobet 21 (7,853 kg ha-1 and 1,086 kg ha-1 averaged across years, respectively). Switchgrass yields increased from 2009 to 2010, but declined from 2010 to 2011. Switchgrass yields from farmlands in this region averaged about 15000 kg (ha-yr)-1 in the research literature, so switchgrass grown on reclaimed lands appears to be about 50% lower. A second study to determine optimal nitrogen and mulch rates for switchgrass establishment began in June 2011 on two newly-reclaimed surface mines. Both sites were seeded at a rate of 11.2 kg pure live seed (PLS) ha-1 of Cave-in-Rock on replicated treatments of 0, 33.6 and 67.0 kg N ha-1, and high and low mulch rates of mulch applied as hydromulch. Switchgrass cover, frequency and yield improved with the addition of any amount of N fertilizer compared to no N application. There was no significant difference in yield associated with high and low levels of N. We also observed that yields were not affected by application of additional mulch. The final study compared a one- and two-harvest system in the fourth year of production at the Hampshire Hill and Hobet 21 sites. There was no increase in yield production utilizing a two-harvest system (2922 kg (ha-yr)-1, averaged across site) compared to a one-harvest system (3029 kg (ha-yr)-1). The data also showed that re-growth collected from July to October in the two-harvest system added negligible yield and that yield collected in July was comparable in one- and two-harvest systems.

Marra, Michael A.

258

Cooking Up More Uses for the Leftovers of Biofuel Production -N... http://www.nytimes.com/2007/08/08/business/08biodiesel.html?ei=... 1 of 3 8/8/07 10:49 AM  

E-print Network

Cooking Up More Uses for the Leftovers of Biofuel Production - N... http://www.nytimes.com/2007 Uses for the Leftovers of Biofuel Production By HILLARY ROSNER The baking tins and muffin cups lining to be true for biofuels," said Kenneth F. Reardon, a professor of chemical and biological engineering

Kimbrough, Steven Orla

259

Addressing the challenges for sustainable production of algal biofuels: I. Algal strains and nutrient supply.  

PubMed

Microalgae hold promise for the production of sustainable replacement of fossil fuels due to their high growth rates, ability to grow on non-arable land and their high content, under the proper conditions, of high energy compounds that can be relatively easily chemically converted to fuels using existing technology. However, projected large-scale algal production raises a number of sustainability concerns concerning land use, net energy return, water use and nutrient supply. The state-of-the-art of algal production of biofuels is presented with emphasis on some possible avenues to provide answers to the sustainability questions that have been raised. Here, issues concerning algal strains and supply of nutrients for large-scale production are discussed. Since sustainability concerns necessitate the use of wastewaters for supply of bulk nutrients, emphasis is placed on the composition and suitability of different wastewater streams. At the same time, algal cultivation has proven useful in waste treatment processes, and thus this aspect is also treated in some detail. PMID:24350435

Abdelaziz, Ahmed E M; Leite, Gustavo B; Hallenbeck, Patrick C

2013-01-01

260

Hydrothermal treatment of oleaginous yeast for the recovery of free fatty acids for use in advanced biofuel production.  

PubMed

Microbial oils hold great potential as a suitable feedstock for the renewable production of biofuels. Specifically, the use of oleaginous yeasts offers several advantages related to cultivation and quality of lipid products. However, one of the major bottlenecks for large-scale production of yeast oils is found in the lipid extraction process. This work investigated the hydrothermal treatment of oleaginous yeast for hydrolysis and lipid extraction resulting in fatty acids used for biofuel production. The oleaginous yeast, Cryptococcus curvatus, was grown in 5 L bioreactors and the biomass slurry with 53±4% lipid content (dry weight basis) was treated at 280 °C for 1h with an initial pressure of 500 psi in batch stainless steel reactors. The hydrolysis product was separated and each of the resulting streams was further characterized. The hexane soluble fraction contained fatty acids from the hydrolysis of yeast triacylglycerides, and was low in nitrogen and minerals and could be directly integrated as feedstock into pyrolysis processing to produce biofuels. The proposed hydrothermal treatment addresses some current technological bottlenecks associated with traditional methodologies such as dewatering, oil extraction and co-product utilization. It also enhances the feasibility of using microbial biomass for production of renewable fuels and chemicals. PMID:25034431

Espinosa-Gonzalez, Isabel; Parashar, Archana; Bressler, David C

2014-10-10

261

%22Trojan Horse%22 strategy for deconstruction of biomass for biofuels production.  

SciTech Connect

Production of renewable biofuels to displace fossil fuels currently consumed in the transportation sector is a pressing multiagency national priority (DOE/USDA/EERE). Currently, nearly all fuel ethanol is produced from corn-derived starch. Dedicated 'energy crops' and agricultural waste are preferred long-term solutions for renewable, cheap, and globally available biofuels as they avoid some of the market pressures and secondary greenhouse gas emission challenges currently facing corn ethanol. These sources of lignocellulosic biomass are converted to fermentable sugars using a variety of chemical and thermochemical pretreatments, which disrupt cellulose and lignin cross-links, allowing exogenously added recombinant microbial enzymes to more efficiently hydrolyze the cellulose for 'deconstruction' into glucose. This process is plagued with inefficiencies, primarily due to the recalcitrance of cellulosic biomass, mass transfer issues during deconstruction, and low activity of recombinant deconstruction enzymes. Costs are also high due to the requirement for enzymes and reagents, and energy-intensive cumbersome pretreatment steps. One potential solution to these problems is found in synthetic biology-engineered plants that self-produce a suite of cellulase enzymes. Deconstruction can then be integrated into a one-step process, thereby increasing efficiency (cellulose-cellulase mass-transfer rates) and reducing costs. The unique aspects of our approach are the rationally engineered enzymes which become Trojan horses during pretreatment conditions. During this study we rationally engineered Cazy enzymes and then integrated them into plant cells by multiple transformation techniques. The regenerated plants were assayed for first expression of these messages and then for the resulting proteins. The plants were then subjected to consolidated bioprocessing and characterized in detail. Our results and possible implications of this work on developing dedicated energy crops and their advantage in a consolidated bioprocessing system.

Simmons, Blake Alexander; Sinclair, Michael B.; Yu, Eizadora; Timlin, Jerilyn Ann; Hadi, Masood Z.; Tran-Gyamfi, Mary

2011-02-01

262

Biofuel production system with operation flexibility: Evaluation of economic and environmental performance under external disturbance  

Microsoft Academic Search

Biomass derived liquid hydrocarbon fuel (biofuel) has been accepted as an effective way to mitigate the reliance on petroleum and reduce the greenhouse gas emissions. An increasing demand for second generation biofuels, produced from ligno-cellulosic feedstock and compatible with current infrastructure and vehicle technologies, addresses two major challenges faced by the current US transportation sector: energy security and global warming.

Nannan Kou

2011-01-01

263

Livestock production: recent trends, future prospects  

PubMed Central

The livestock sector globally is highly dynamic. In developing countries, it is evolving in response to rapidly increasing demand for livestock products. In developed countries, demand for livestock products is stagnating, while many production systems are increasing their efficiency and environmental sustainability. Historical changes in the demand for livestock products have been largely driven by human population growth, income growth and urbanization and the production response in different livestock systems has been associated with science and technology as well as increases in animal numbers. In the future, production will increasingly be affected by competition for natural resources, particularly land and water, competition between food and feed and by the need to operate in a carbon-constrained economy. Developments in breeding, nutrition and animal health will continue to contribute to increasing potential production and further efficiency and genetic gains. Livestock production is likely to be increasingly affected by carbon constraints and environmental and animal welfare legislation. Demand for livestock products in the future could be heavily moderated by socio-economic factors such as human health concerns and changing socio-cultural values. There is considerable uncertainty as to how these factors will play out in different regions of the world in the coming decades. PMID:20713389

Thornton, Philip K.

2010-01-01

264

The significance of nitrous oxide emission due to cropping of grain for biofuel production: a Swedish perspective  

NASA Astrophysics Data System (ADS)

The current regulations governing production of biofuels in the European Union require that they have to mitigate climate change, by producing >35% less greenhouse gases (GHG) than fossil fuels. There is a risk that this may not be achievable, since land use for crop production inevitably emits the potent GHG nitrous oxide (N2O), due to nitrogen fertilisation and cycling in the environment. We analyse first-generation biofuel production on agricultural land and conclude that efficient agricultural crop production resulting in a good harvest and low N2O emission can fulfil the EU standard, and is possible under certain conditions for the Swedish agricultural and bioethanol production systems. However, in years having low crop yields, and where cropping is on organic soils, total GHG emissions per unit of fuel produced can be even higher than those released by burning of fossil fuels. In general, the N2O emission size in Sweden and elsewhere in northern Europe is such that there is a >50% chance that the 35% saving requirement will not be met. Thus ecosystem N2O emissions have to be convincingly assessed. Here we compare Swedish emission data with values estimated by means of statistical models and by a global, top-down, approach; the measurements and the predictions often show higher values that would fail to meet the EU standard and thus prevent biofuel production development.

Kasimir Klemedtsson, Å.; Smith, K. A.

2011-12-01

265

Engineering the push and pull of lipid biosynthesis in oleaginous yeast Yarrowia lipolytica for biofuel production.  

PubMed

Microbial oil production by heterotrophic organisms is a promising path for the cost-effective production of biofuels from renewable resources provided high conversion yields can be achieved. To this end, we have engineered the oleaginous yeast Yarrowia lipolytica. We first established an expression platform for high expression using an intron-containing translation elongation factor-1? (TEF) promoter and showed that this expression system is capable of increasing gene expression 17-fold over the intronless TEF promoter. We then used this platform for the overexpression of diacylglycerol acyltransferase (DGA1), the final step of the triglyceride (TAG) synthesis pathway, which yielded a 4-fold increase in lipid production over control, to a lipid content of 33.8% of dry cell weight (DCW). We also show that the overexpression of acetyl-CoA carboxylase (ACC1), the first committed step of fatty acid synthesis, increased lipid content 2-fold over control, or 17.9% lipid content. Next we combined the two genes in a tandem gene construct for the simultaneous coexpression of ACC1 and DGA1, which further increased lipid content to 41.4%, demonstrating synergistic effects of ACC1+DGA1 coexpression. The lipid production characteristics of the ACC1+DGA1 transformant were explored in a 2-L bioreactor fermentation, achieving 61.7% lipid content after 120h. The overall yield and productivity were 0.195g/g and 0.143g/L/h, respectively, while the maximum yield and productivity were 0.270g/g and 0.253g/L/h during the lipid accumulation phase of the fermentation. This work demonstrates the excellent capacity for lipid production by the oleaginous yeast Y. lipolytica and the effects of metabolic engineering of two important steps of the lipid synthesis pathway, which acts to divert flux towards the lipid synthesis and creates driving force for TAG synthesis. PMID:23026119

Tai, Mitchell; Stephanopoulos, Gregory

2013-01-01

266

A self-sustaining advanced lignocellulosic biofuel production by integration of anaerobic digestion and aerobic fungal fermentation.  

PubMed

High energy demand hinders the development and application of aerobic microbial biofuel production from lignocellulosic materials. In order to address this issue, this study focused on developing an integrated system including anaerobic digestion and aerobic fungal fermentation to convert corn stover, animal manure and food wastes into microbial lipids for biodiesel production. Dairy manure and food waste were first anaerobically digested to produce energy and solid digestate (AD fiber). AD fiber and corn stover were then processed by a combined alkali and acid hydrolysis, followed by fungal lipid accumulation. The integrated process can generate 1L biodiesel and 1.9kg methane from 12.8kg dry dairy manure, 3.1kg dry food wastes and 12.2kg dry corn stover with a positive net energy of 57MJ, which concludes a self-sustaining lignocellulosic biodiesel process and provides a new route to co-utilize corn stover and organic wastes for advanced biofuel production. PMID:25543542

Zhong, Yuan; Ruan, Zhenhua; Zhong, Yingkui; Archer, Steven; Liu, Yan; Liao, Wei

2015-03-01

267

N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels  

NASA Astrophysics Data System (ADS)

The relationship, on a global basis, between the amount of N fixed by chemical, biological or atmospheric processes entering the terrestrial biosphere, and the total emission of nitrous oxide (N2O), has been re-examined, using known global atmospheric removal rates and concentration growth of N2O as a proxy for overall emissions. The relationship, in both the pre-industrial period and in recent times, after taking into account the large-scale changes in synthetic N fertiliser production and deforestation, is consistent, showing an overall conversion factor of 3-5%. This factor is covered only in part by the ~1% of "direct" emissions from agricultural crop lands estimated by IPCC (2006), or the "indirect" emissions cited therein. This means that the extra N2O entering the atmosphere as a result of using N to produce crops for biofuels will also be correspondingly greater than that estimated just on the basis of IPCC (2006). When the extra N2O emission from biofuel production is calculated in "CO2-equivalent" global warming terms, and compared with the quasi-cooling effect of "saving" emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate each other. This needs to be analyzed in a full life cycle assessment.

Crutzen, P. J.; Mosier, A. R.; Smith, K. A.; Winiwarter, W.

2007-08-01

268

Nanocrystalline cellulose extraction process and utilization of the byproduct for biofuels production.  

PubMed

Cellulose consists of amorphous and crystalline regions. It is the crystalline regions which may be exploited to produce nanocrystalline cellulose (NCC). In order to extract nanocrystalline cellulose from native cellulose, sulfuric acid hydrolysis is typically used. The amorphous regions of cellulose are hydrolyzed and degraded into soluble products while the crystalline regions remain intact. In an effort to make the NCC extraction process more feasible, a new process was developed to recover and utilize the hydrolyzed regions of cellulose as a byproduct. The acid hydrolyzed amorphous regions were separated and then recovered (regenerated) into solid particles. XRD data revealed that the recovered material is characteristic of cellulose II. Hydrolysis conditions were optimized to maximize the yield of the recovered material and at the same time produce NCC material. Preliminary experiments showed yield values of approximately 61% for the cellulose I crystalline portions and values of about 21.7% for the recovered material (cellulose II). Enzymatic hydrolysis experiments of the recovered material revealed high susceptibility to enzymatic hydrolysis which makes it a promising source for biofuels production. PMID:23465941

Pirani, Sanaa; Hashaikeh, Raed

2013-03-01

269

Metabolic Engineering of Clostridium thermocellum for Biofuel Production (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)  

SciTech Connect

Adam Guss of Oak Ridge National Lab on "Metabolic engineering of Clostridium thermocellum for biofuel production" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, Calif.

Guess, Adam [ORNL

2013-03-01

270

Biofuels from Microalgae  

Microsoft Academic Search

Microalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simple structure. They can potentially be employed for the production of biofuels in an economically effective and environmentally sustainable manner. Microalgae have been investigated for the production of a number of different biofuels including biodiesel, bio-oil, bio-syngas, and bio-hydrogen. The production of these

Yanqun Li; Mark Horsman; Nan Wu; Christopher Q. Lan; Nathalie Dubois-Calero

2008-01-01

271

Syntrophic co-culture of aerobic Bacillus and anaerobic Clostridium for bio-fuels and bio-hydrogen production  

Microsoft Academic Search

By using brewery yeast waste and microflora from rice straw compost, an anaerobic semi-solid bio-hydrogen-producing system has been established. For the purpose of industrialization, the major players of both aerobic and anaerobic bacterial strains in the system were isolated and their combination for an effective production of bio-hydrogen and other bio-fuels was examined in this study. The phylogenetic analysis found

Jui-Jen Chang; Chia-Hung Chou; Cheng-Yu Ho; Wei-En Chen; Jiunn-Jyi Lay; Chieh-Chen Huang

2008-01-01

272

Fuel for the Future: Development of New Fuels, e.g. Biofuels  

NASA Astrophysics Data System (ADS)

Whether we like it or not, climate change is to some extent affiliated with the emission of green house gasses, and specifically CO2 emissions, which are rising due to the global increased use of fossil fuels. As a result, political enthusiasm is high when it comes to implementing new initiatives aimed at better protection of the global environment. However, environmental concerns are just one aspect of the issues associated with the use of fossil fuels, since fossil fuels are a natural reserve and, therefore, a limited resource. Prognoses vary, but within the next decades the fossil fuel reserves will be exhausted leading to reduced oil production, rising oil prices, and the risk of international bellicose conflicts caused by adverse national interests. Additionally, fossil fuel as a natural reserve is unevenly distributed, meaning that a few countries possess the main energy reserve of the entire world. The incorporation of alternatives to fossil fuel into the existing fuel infrastructure is currently under intense development in the Western world, both to cut the oil dependency and to counter the depletion of oil reserves. This political enthusiasm to decrease the use of fossil fuel is emphasised by the fact that according to the International Energy Agency (IEA) more than 80% of the global primary energy consumption in 2007 accounts from fossil fuels and half of this is oil. More than 60% of the oil is used in the transport sector.

Sørensen, Gitte; Sørensen, Ketil Bernt; Hansen, Hans Ove; Nygaard, Sune D.

273

Exploiting diversity and synthetic biology for the production of algal biofuels.  

PubMed

Modern life is intimately linked to the availability of fossil fuels, which continue to meet the world's growing energy needs even though their use drives climate change, exhausts finite reserves and contributes to global political strife. Biofuels made from renewable resources could be a more sustainable alternative, particularly if sourced from organisms, such as algae, that can be farmed without using valuable arable land. Strain development and process engineering are needed to make algal biofuels practical and economically viable. PMID:22895338

Georgianna, D Ryan; Mayfield, Stephen P

2012-08-16

274

A life cycle assessment of advanced biofuel production from a hectare of corn  

Microsoft Academic Search

Conventional agricultural life cycle assessments (LCAs) measure greenhouse gas (GHG) emissions for biofuel pathways as the amount of carbon dioxide equivalent emitted per unit of energy provided by the pathway (i.e. gCO2e\\/MJ). This measure of GHG emissions, as computed by the Environmental Protection Agency (EPA) is then used to determine the extent to which the corresponding biofuel pathway complies with

Nathan Kauffman; Dermot Hayes; Robert Brown

2011-01-01

275

Liquid biofuels - can they meet our expectations?  

NASA Astrophysics Data System (ADS)

Liquid biofuels are one of the options for reducing the emission of greenhouse gases and the dependence on fossil fuels. This is reflected in the DIRECTIVE 2003/30/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of biofuels or other renewable fuels for transport. The promotion of E10, an automotive fuel containing 10 percent bioethanol, is based on this directive. At present almost all bioethanol is produced from agricultural crops such as maize, corn or sugar beet and sugar cane in suitable climates. In view of shortages and rising prices of food, in particular in developing countries, the use of food and feed crops for biofuel production is increasingly criticized. Alternative sources of biomass are perennial grasses and wood, whose cellulose fraction can be converted to alcohol by the so called "second generation" processes, which seem to be close to commercial deployment. The use of the total plant biomass increases the biofuel yield per hectare as compared to conventional crops. Of special interest for biofuel production is woody biomass from forests as this avoids competition with food production on arable land. Historically woody biomass was for millennia the predominant source of thermal energy. Before fossil fuels came into use, up to 80 percent of a forest was used for fuel wood, charcoal and raw materials such as potash for trade and industry. Now forests are managed to yield up to 80 percent of high grade timber for the wood industry. Replacing sophisticatedly managed forests by fast growing biofuel plantations could make economic sense for land owners when a protected market is guaranteed by politics, because biofuel plantations would be highly mechanized and cheap to operate, even if costs for certified planting material and fertilizer are added. For forest owners the decision to clear existing long rotation forests for biofuel plantations would still be weighty because of the extended time of decades required to rebuild a timber forest if alternative fuel sources would outcompete biofuels in the future. Because second generation bioethanol plants are technically complex and will require substantial amounts of biomass - at least at current perception - the impact of large scale conversion of arable and forests to biofuel plantations on biodiversity, ground water, rural communities, tourism as well as traffic and transport, just to mention a few, must be considered. Another factor is storability of biomass. Whole plant and woody biomass is much more difficult to store than grains and a steady flux from the plantation to the mill might be difficult to sustain under adverse weather conditions.

Glatzel, G.

2012-04-01

276

Measuring and moderating the water resource impact of biofuel production and trade  

NASA Astrophysics Data System (ADS)

Energy systems and water resources are inextricably linked, especially in the case of bioenergy, which can require up to three orders of magnitude more water than other energy carriers. Water scarcity already affects about 1 in 5 people globally, and stands to be exacerbated in many locales by current biofuel expansion plans. This dissertation engages with several of the analytical and governance challenges raised by this connection between bioenergy expansion and global water resources. My examination begins with an overview of important concepts in water resource analysis, followed by a review of current literature on the water impacts of most major energy pathways. I then report on a case study of ethanol fuel in California. This work employed a coupled agro-climatic and life cycle assessment (LCA) model to estimate the water resource impacts of several bioenergy expansion scenarios at a county-level resolution. It shows that ethanol production in California regularly consumes more than 1000 gallons of water per gallon of fuel produced, and that 99% of life-cycle water consumption occurs in the feedstock cultivation phase. This analysis then delves into the complexity of life cycle impact assessment for water resources. Despite improvements in water accounting methods, impact assessment must contend with the fact that different water sources are not necessarily commensurable, and that impacts depend on the state of the resource base that is drawn upon. I adapt water footprinting and LCA techniques to the bioenergy context, describing comprehensive inventory approaches and developing a process for characterizing (weighting) consumption values to enable comparison across resource bases. This process draws on metrics of water stress, accounting for environmental flow requirements, climatic variability, and non-linearity of water stress effects. My assessment framework was developed in hopes that it would be useful in managing the risks and impacts it describes. The primary actors in this governance effort are government regulators, whose policies and incentives continue to drive and to shape the expansion of the bioenergy industry. However, the ability of governments to manage the impacts of biofuels is severely constrained by their obligations under international trade law. This dissertation concludes, therefore, with a detailed investigation into relevant precedents under the General Agreement on Tariffs and Trade (GATT) and the World Trade Organization (WTO). I use these precedents to identify the policy tools that governments would be able to bring to bear in moderating the water resource impacts and myriad other environmental and social concerns raised by bioenergy expansion.

Fingerman, Kevin Robert

277

Genomic Evaluation of Thermoanaerobacter spp. for the Construction of Designer Co-Cultures to Improve Lignocellulosic Biofuel Production  

PubMed Central

The microbial production of ethanol from lignocellulosic biomass is a multi-component process that involves biomass hydrolysis, carbohydrate transport and utilization, and finally, the production of ethanol. Strains of the genus Thermoanaerobacter have been studied for decades due to their innate abilities to produce comparatively high ethanol yields from hemicellulose constituent sugars. However, their inability to hydrolyze cellulose, limits their usefulness in lignocellulosic biofuel production. As such, co-culturing Thermoanaerobacter spp. with cellulolytic organisms is a plausible approach to improving lignocellulose conversion efficiencies and yields of biofuels. To evaluate native lignocellulosic ethanol production capacities relative to competing fermentative end-products, comparative genomic analysis of 11 sequenced Thermoanaerobacter strains, including a de novo genome, Thermoanaerobacter thermohydrosulfuricus WC1, was conducted. Analysis was specifically focused on the genomic potential for each strain to address all aspects of ethanol production mentioned through a consolidated bioprocessing approach. Whole genome functional annotation analysis identified three distinct clades within the genus. The genomes of Clade 1 strains encode the fewest extracellular carbohydrate active enzymes and also show the least diversity in terms of lignocellulose relevant carbohydrate utilization pathways. However, these same strains reportedly are capable of directing a higher proportion of their total carbon flux towards ethanol, rather than non-biofuel end-products, than other Thermoanaerobacter strains. Strains in Clade 2 show the greatest diversity in terms of lignocellulose hydrolysis and utilization, but proportionately produce more non-ethanol end-products than Clade 1 strains. Strains in Clade 3, in which T. thermohydrosulfuricus WC1 is included, show mid-range potential for lignocellulose hydrolysis and utilization, but also exhibit extensive divergence from both Clade 1 and Clade 2 strains in terms of cellular energetics. The potential implications regarding strain selection and suitability for industrial ethanol production through a consolidated bioprocessing co-culturing approach are examined throughout the manuscript. PMID:23555660

Verbeke, Tobin J.; Zhang, Xiangli; Henrissat, Bernard; Spicer, Vic; Rydzak, Thomas; Krokhin, Oleg V.; Fristensky, Brian; Levin, David B.; Sparling, Richard

2013-01-01

278

Developing Research Capabilities in Energy Biosciences: Design principles of photosynthetic biofuel production.  

SciTech Connect

The current fossil fuel-based energy infrastructure is not sustainable. Solar radiation is a plausible alternative, but realizing it as such will require significant technological advances in the ability to harvest light energy and convert it into suitable fuels. The biological system of photosynthesis can carry out these reactions, and in principle could be engineered using the tools of synthetic biology. One desirable implementation would be to rewire the reactions of a photosynthetic bacterium to direct the energy harvested from solar radiation into the synthesis of the biofuel H2. Proposed here is a series of experiments to lay the basic science groundwork for such an attempt. The goal is to elucidate the transcriptional network of photosynthesis using a novel driver-reporter screen, evolve more robust hydrogenases for improved catalysis, and to test the ability of the photosynthetic machinery to directly produce H2 in vivo. The results of these experiments will have broad implications for the understanding of photosynthesis, enzyme function, and the engineering of biological systems for sustainable energy production. The ultimate impact could be a fundamental transformation of the world's energy economy.

Donald D. Brown; David Savage

2012-06-30

279

Optical microplates for photonic high throughput screening of algal photosynthesis and biofuel production.  

PubMed

Biological systems respond not only to chemical stimuli (drugs, proteins) but also to physical stimuli (light, heat, stress). Though there are many high throughput tools for screening chemical stimuli, no such tool exists for screening of physical stimuli. This paper presents a novel instrument for photonic high throughput screening of photosynthesis, a light-driven bioprocess. The optical microplate has a footprint identical to a standard 96 well plate, and it provides temporal and intensity control of light in each individual well. Intensity control provides 128 dimming levels (7-bit resolution), with maximum intensity 120 mE/cm(2). Temporal modulation, used for studying dynamics and regulation of photosynthesis, can be as low as 10 ?s. We used photonic screening for high throughput studies of algal growth rates and photosynthetic efficiency, using the model organism Dunaliella tertiolecta, a lipid producing algae of interest in biofuel production. Due to the ability to conduct 96 studies in parallel, experiments that would require 2 years using conventional tools can be completed in 1 week. This instrument opens up novel high throughput protocols for photobiology and the growing field of phenomics. PMID:22254353

Mertiri, Taulant; Chen, Meng; Holland, Thomas; Basu, Amar S

2011-01-01

280

Agrigenomics for microalgal biofuel production: an overview of various bioinformatics resources and recent studies to link OMICS to bioenergy and bioeconomy.  

PubMed

Microalgal biofuels offer great promise in contributing to the growing global demand for alternative sources of renewable energy. However, to make algae-based fuels cost competitive with petroleum, lipid production capabilities of microalgae need to improve substantially. Recent progress in algal genomics, in conjunction with other "omic" approaches, has accelerated the ability to identify metabolic pathways and genes that are potential targets in the development of genetically engineered microalgal strains with optimum lipid content. In this review, we summarize the current bioeconomic status of global biofuel feedstocks with particular reference to the role of "omics" in optimizing sustainable biofuel production. We also provide an overview of the various databases and bioinformatics resources available to gain a more complete understanding of lipid metabolism across algal species, along with the recent contributions of "omic" approaches in the metabolic pathway studies for microalgal biofuel production. PMID:24044362

Misra, Namrata; Panda, Prasanna Kumar; Parida, Bikram Kumar

2013-11-01

281

Factors Driving Biofuel Crops' Influence on Climate  

NASA Astrophysics Data System (ADS)

Large scale deployment of new biofuel crops has the potential to influence climate through biogeophysical and biogeochemical mechanisms operating at the land surface. In turn, climatic variability influences the productivity of biofuel crops and thus their potential contribution as a source of energy. In order to characterize this two-way interaction between biofuels and climate, we are conducting a series of modeling experiments within the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM). Key questions that this study attempts to address include 1) In what ways (e.g. at what spatial and temporal scales, under what land cover and management scenarios) does a transition to biofuel crops represent a climate stabilizing versus a climate destabilizing endeavor? 2) Which vegetation properties and management choices are most influential in determining key climatic outcomes associated with biofuels? 3) Are biofuel crop yields robust to changing climatic conditions? Our approach is to develop new biofuel plant functional types (PFTs) for the land surface component of CESM - the Community Land Model (CLM) - and to examine climatic implications of future biofuel deployment scenarios within the coupled land-atmosphere framework of CESM. We are focusing initially on c4 grass crops - i.e. switchgrass, miscnathus, sugarcane, and maize. CLM represents plant functional types with more than 50 parameters that describe aerodynamic, physiological, optical, and biogeochemical properties etc. We are also making structural modification to the model in order to represent unique features of biofuel crops and their management, such as changes to the phenology and carbon allocation schema for c4 grasses. Detailed observational data from new biofuel crops such as switchgrass and miscanthus is limited and offers a weak constraint on the full set of PFT parameters. To address this problem, we are conducting systematic sensitivity analysis on the default c4 grass parameters in CLM in order to identify a smaller set of parameters that exerts the most control on climatically relevant terms such as energy and carbon fluxes. By revealing those parameters that are most and least influential in terms of climate forcing, systematic sensitivity analysis helps to prioritize the search for observational data, constrains the process of tuning parameters to limited data, and leads the way to characterizing the uncertainty in biofuel crops’ influence on climate. Furthermore, due to similarities across managed ecosystems, these results offer general insight into those plant physiological properties and management factors that must be well-characterized in order to model changes in energy and carbon fluxes resulting from human land use.

Jones, A.; Torn, M. S.; Riley, W. J.; Collins, W.

2010-12-01

282

Biofuels: balancing risks and rewards.  

PubMed

This paper describes a framework that can be used to evaluate the environmental risks and benefits associated with biofuel production. It uses the example of biodiesel produced from Argentinean soy to show how such a framework can be used to conceptualize trade-offs between different environmental, social and economic impacts of biofuel production. Results showing the greenhouse-gas savings and overall life-cycle impact of different 'soy-biodiesel' production methods are presented. These impacts and the significance of uncertainty in overall assessments of key parameters, such as greenhouse-gas savings, are discussed. It is shown that, even where sufficient knowledge exists to be able to quantify these impacts, the sustainability of supply of a particular biofuel is inextricably linked to values and ethical judgements. However, tailoring certification efforts to the issues that are most likely to make a significant difference to the overall sustainability could improve the effectiveness of certification efforts. The potential for a framework to guide and focus certification efforts is discussed and future research and policy priorities suggested. PMID:24427513

Thornley, Patricia; Gilbert, Paul

2013-02-01

283

Biofuels: balancing risks and rewards  

PubMed Central

This paper describes a framework that can be used to evaluate the environmental risks and benefits associated with biofuel production. It uses the example of biodiesel produced from Argentinean soy to show how such a framework can be used to conceptualize trade-offs between different environmental, social and economic impacts of biofuel production. Results showing the greenhouse-gas savings and overall life-cycle impact of different ‘soy-biodiesel’ production methods are presented. These impacts and the significance of uncertainty in overall assessments of key parameters, such as greenhouse-gas savings, are discussed. It is shown that, even where sufficient knowledge exists to be able to quantify these impacts, the sustainability of supply of a particular biofuel is inextricably linked to values and ethical judgements. However, tailoring certification efforts to the issues that are most likely to make a significant difference to the overall sustainability could improve the effectiveness of certification efforts. The potential for a framework to guide and focus certification efforts is discussed and future research and policy priorities suggested. PMID:24427513

Thornley, Patricia; Gilbert, Paul

2013-01-01

284

Ecopolis: Biofuels  

NSDL National Science Digital Library

This 3-minute video explains how algae, a biofuel, is being developed as an energy source. It also discusses disadvantages of current biofuels and how algae will overcome these disadvantages. The site also provides links to videos about related topics.

Science Channel

285

Biofuel Ethanol Transport Risk  

EPA Science Inventory

Ethanol production has increased rapidly over the last 10 years and many communities lack awareness of the increased and growing extent of biofuel transportation through their jurisdictions. These communities and their emergency responders may not have the information and resour...

286

Biofuels sources, biofuel policy, biofuel economy and global biofuel projections  

Microsoft Academic Search

The term biofuel is referred to liquid, gas and solid fuels predominantly produced from biomass. Biofuels include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. Biofuels include bioethanol, biomethanol, vegetable oils, biodiesel, biogas, bio-synthetic gas (bio-syngas), bio-oil, bio-char, Fischer-Tropsch liquids, and biohydrogen. Most traditional biofuels, such as ethanol from corn, wheat, or

Ayhan Demirbas

2008-01-01

287

Energy crops for biofuel feedstocks: facts and recent patents on genetic manipulation to improve biofuel crops.  

PubMed

Burning fossil-fuels to meet the global energy requirements by human being has intensified the concerns of increasing concentrations of greenhouse gases. Therefore, serious efforts are required to develop nonfossil-based renewable energy sources. Plants are more efficient in utilizing solar energy to convert it into biomass which can be used as feedstocks for biofuel production. Hence with the increasing demands of energy and the needs of cost-effective, sustainable production of fuels, it has become necessary to switch over to plant biomass as a renewable source of energy. Biofuels derived from more sustainable biological materials such as lignocellulosic plant residues, considered as second generation biofuels, are more dependable. However, there are technical challenges such as pretreatment and hydrolysis of lignocellulosic biomass to convert it into fermentable sugars. Plant genetic engineering has already proven its potential in modifying cell wall composition of plants for enhancing the efficiency of biofuel production. Interest and potential in the area are very much evident from the growing number of patents in the recent years on the subject. In this review, recent trends in genetic engineering of energy crops for biofuel production have been introduced, and strategies for the future developments have been discussed. PMID:24456235

Kumar, Suresh

2013-12-01

288

Spatial Optimization of Cropping Pattern in an Agricultural Watershed for Food and Biofuel Production with Minimum Downstream Pollution  

NASA Astrophysics Data System (ADS)

Biofuel is considered to be a viable alternative to meet the increasing fuel demand, and therefore many countries are promoting agricultural activities that help increase production of raw material for biofuel production. Mostly, the biofuel is produced from grain based crops such as Corn, and it apparently create a shortage in food grains. Consequently, there have been regulations to limit the ethanol production from grains, and to use cellulosic crops as raw material for biofuel production. However, cultivation of such cellulosic crops may have different effects on water quality in the watershed. Corn stover, one of the potential cellulosic materials, when removed from the agricultural field for biofuel production, causes a decrease in the organic nutrients in the field. This results in increased use of pesticides and fertilizers which in turn affect the downstream water quality due to leaching of the chemicals. On the contrary, planting less fertilizer-intensive cellulosic crops, like Switch Grass and Miscanthus, is expected to reduce the pollutant loadings from the watershed. Therefore, an ecologically viable land use scenario would be a mixed cropping of grain crops and cellulosic crops, that meet the demand for food and biofuel without compromising on the downstream water quality. Such cropping pattern can be arrived through a simulation-optimization framework. Mathematical models can be employed to evaluate various management scenarios related to crop production and to assess its impact on water quality. Soil and Water Assessment Tool (SWAT) model is one of the most widely used models in this context. SWAT can simulate the water and nutrient cycles, and also quantify the long-term impacts of land management practices, in a watershed. This model can therefore help take decisions regarding the type of cropping and management practices to be adopted in the watershed such that the water quality in the rivers is maintained at acceptable level. In this study, it is proposed to link SWAT model with an optimization algorithm, whose objective is to identify the optimal cropping pattern that results in maximum biomass production for biofuel generation as well as a minimum guaranteed amount of grain production. The optimal allocation ensures that the downstream water quality in the river is within a desirable limit. The study employed probabilistic information in order to address the uncertainty in model simulations. The residual variance of the model is used to transform the deterministic simulations in to probabilistic information. The proposed framework is illustrated using data pertaining to an agricultural watershed in the USA. The preliminary results of the study are encouraging and suggest that an appropriate combination of Corn, Soyabean, Miscanthus, Switch Grass and Pasture land can be arrived at through the developed framework. The placement of Miscanthus and Switch Grass in the watershed help improve the downstream water quality, while Corn and Soyabean makes it deteriorated. The spatial allocation of these crops therefore certainly plays a major role in the downstream water quality.

Pv, F.; Sudheer, K.; Chaubey, I.; RAJ, C.; Her, Y.

2013-05-01

289

Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes  

PubMed Central

Increased demand for corn grain as an ethanol feedstock is altering U.S. agricultural landscapes and the ecosystem services they provide. From 2006 to 2007, corn acreage increased 19% nationally, resulting in reduced crop diversity in many areas. Biological control of insects is an ecosystem service that is strongly influenced by local landscape structure. Here, we estimate the value of natural biological control of the soybean aphid, a major pest in agricultural landscapes, and the economic impacts of reduced biocontrol caused by increased corn production in 4 U.S. states (Iowa, Michigan, Minnesota, and Wisconsin). For producers who use an integrated pest management strategy including insecticides as needed, natural suppression of soybean aphid in soybean is worth an average of $33 ha?1. At 2007–2008 prices these services are worth at least $239 million y?1 in these 4 states. Recent biofuel-driven growth in corn planting results in lower landscape diversity, altering the supply of aphid natural enemies to soybean fields and reducing biocontrol services by 24%. This loss of biocontrol services cost soybean producers in these states an estimated $58 million y?1 in reduced yield and increased pesticide use. For producers who rely solely on biological control, the value of lost services is much greater. These findings from a single pest in 1 crop suggest that the value of biocontrol services to the U.S. economy may be underestimated. Furthermore, we suggest that development of cellulosic ethanol production processes that use a variety of feedstocks could foster increased diversity in agricultural landscapes and enhance arthropod-mediated ecosystem services. PMID:19075234

Landis, Douglas A.; Gardiner, Mary M.; van der Werf, Wopke; Swinton, Scott M.

2008-01-01

290

Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' manual and technical documentation.  

SciTech Connect

The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, miscanthus, and switchgrass. This document discusses the version of CCLUB released May 31, 2012 which includes corn, as did the previous CCLUB version, and three cellulosic feedstocks: corn stover, miscanthus, and switchgrass. CCLUB calculations are based upon two data sets: land change areas and above- and below-ground carbon content. Table 1 identifies where these data are stored and used within the CCLUB model, which is built in MS Excel. Land change area data is from Purdue University's Global Trade Analysis Project (GTAP) model, a computable general equilibrium (CGE) economic model. Section 2 describes the GTAP data CCLUB uses and how these data were modified to reflect shrubland transitions. Feedstock- and spatially-explicit below-ground carbon content data for the United States were generated with a surrogate model for CENTURY's soil organic carbon sub-model (Kwon and Hudson 2010) as described in Section 3. CENTURY is a soil organic matter model developed by Parton et al. (1987). The previous CCLUB version used more coarse domestic carbon emission factors. Above-ground non-soil carbon content data for forest ecosystems was sourced from the USDA/NCIAS Carbon Online Estimator (COLE) as explained in Section 4. We discuss emission factors used for calculation of international greenhouse gas (GHG) emissions in Section 5. Temporal issues associated with modeling LUC emissions are the topic of Section 6. Finally, in Section 7 we provide a step-by-step guide to using CCLUB and obtaining results.

Mueller, S; Dunn, JB; Wang, M (Energy Systems); (Univ. of Illinois at Chicago)

2012-06-07

291

First generation biofuels compete.  

PubMed

Rising petroleum prices during 2005-2008, and passage of the 2007 U.S. Energy Independence and Security Act with a renewable fuel standard of 36 billion gallons of biofuels by 2022, encouraged massive investments in U.S. ethanol plants. Consequently, corn demand increased dramatically and prices tripled. This created a strong positive correlation between petroleum, corn, and food prices resulting in an outcry from U.S. consumers and livestock producers, and food riots in several developing countries. Other factors contributed to higher grain and food prices. Economic growth, especially in Asia, and a weaker U.S. dollar encouraged U.S. grain exports. Investors shifted funds into the commodity's future markets. Higher fuel costs for food processing and transportation put upward pressure on retail food prices. From mid-2008 to mid-2009, petroleum prices fell, the U.S. dollar strengthened, and the world economy entered a serious recession with high unemployment, housing market foreclosures, collapse of the stock market, reduced global trade, and a decline in durable goods and food purchases. Agricultural commodity prices declined about 50%. Biotechnology has had modest impacts on the biofuel sector. Seed corn with traits that help control insects and weeds has been widely adopted by U.S. farmers. Genetically engineered enzymes have reduced ethanol production costs and increased conversion efficiency. PMID:20601265

Martin, Marshall A

2010-11-30

292

Analysis of advanced biofuels.  

SciTech Connect

Long chain alcohols possess major advantages over ethanol as bio-components for gasoline, including higher energy content, better engine compatibility, and less water solubility. Rapid developments in biofuel technology have made it possible to produce C{sub 4}-C{sub 5} alcohols efficiently. These higher alcohols could significantly expand the biofuel content and potentially replace ethanol in future gasoline mixtures. This study characterizes some fundamental properties of a C{sub 5} alcohol, isopentanol, as a fuel for homogeneous-charge compression-ignition (HCCI) engines. Wide ranges of engine speed, intake temperature, intake pressure, and equivalence ratio are investigated. The elementary autoignition reactions of isopentanol is investigated by analyzing product formation from laser-photolytic Cl-initiated isopentanol oxidation. Carbon-carbon bond-scission reactions in the low-temperature oxidation chemistry may provide an explanation for the intermediate-temperature heat release observed in the engine experiments. Overall, the results indicate that isopentanol has a good potential as a HCCI fuel, either in neat form or in blend with gasoline.

Dec, John E.; Taatjes, Craig A.; Welz, Oliver; Yang, Yi

2010-09-01

293

N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels  

NASA Astrophysics Data System (ADS)

The relationship, on a global basis, between the amount of N fixed by chemical, biological or atmospheric processes entering the terrestrial biosphere, and the total emission of nitrous oxide (N2O), has been re-examined, using known global atmospheric removal rates and concentration growth of N2O as a proxy for overall emissions. For both the pre-industrial period and in recent times, after taking into account the large-scale changes in synthetic N fertiliser production, we find an overall conversion factor of 3-5% from newly fixed N to N2O-N. We assume the same factor to be valid for biofuel production systems. It is covered only in part by the default conversion factor for "direct" emissions from agricultural crop lands (1%) estimated by IPCC (2006), and the default factors for the "indirect" emissions (following volatilization/deposition and leaching/runoff of N: 0.35-0.45%) cited therein. However, as we show in the paper, when additional emissions included in the IPCC methodology, e.g. those from livestock production, are included, the total may not be inconsistent with that given by our "top-down" method. When the extra N2O emission from biofuel production is calculated in "CO2-equivalent" global warming terms, and compared with the quasi-cooling effect of "saving" emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), depending on N fertilizer uptake efficiency by the plants, can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species, have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate each other. This needs to be analyzed in a full life cycle assessment.

Crutzen, P. J.; Mosier, A. R.; Smith, K. A.; Winiwarter, W.

2008-01-01

294

Grazing Strategies for Beef Production Escalating energy costs and alternative cropping systems for biofuels production have  

E-print Network

Grazing Strategies for Beef Production Escalating energy costs and alternative cropping systems with pasture-feedlot manage-· ment alternatives. Assess economic implications of beef production using an array character- istics of beef that may provide an alternative lean-to-fat composition for consum- ers. http

295

Viability Studies of Biofuels Though biofuels (like ethanol) promise renewable "green" energy, these  

E-print Network

Viability Studies of Biofuels Though biofuels (like ethanol) promise renewable "green" energy cannot possibly meet U.S. energy demands, and current methods of biofuel production often consume as much energy as they produce. If biofuels are to be viable long-term energy solutions, we need new sources

Hill, Wendell T.

296

Tradeoffs and Synergies between biofuel production and large solar infrastructure in deserts.  

PubMed

Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large solar installations. However, for efficient power generation, solar infrastructures use large amounts of water for construction and operation. We investigated the water use and greenhouse gas (GHG) emissions associated with solar installations in North American deserts in comparison to agave-based biofuel production, another widely promoted potential energy source from arid systems. We determined the uncertainty in our analysis by a Monte Carlo approach that varied the most important parameters, as determined by sensitivity analysis. We considered the uncertainty in our estimates as a result of variations in the number of solar modules ha(-1), module efficiency, number of agave plants ha(-1), and overall sugar conversion efficiency for agave. Further, we considered the uncertainty in revenue and returns as a result of variations in the wholesale price of electricity and installation cost of solar photovoltaic (PV), wholesale price of agave ethanol, and cost of agave cultivation and ethanol processing. The life-cycle analyses show that energy outputs and GHG offsets from solar PV systems, mean energy output of 2405 GJ ha(-1) year(-1) (5 and 95% quantile values of 1940-2920) and mean GHG offsets of 464 Mg of CO2 equiv ha(-1) year(-1) (375-562), are much larger than agave, mean energy output from 206 (171-243) to 61 (50-71) GJ ha(-1) year(-1) and mean GHG offsets from 18 (14-22) to 4.6 (3.7-5.5) Mg of CO2 equiv ha(-1) year(-1), depending upon the yield scenario of agave. Importantly though, water inputs for cleaning solar panels and dust suppression are similar to amounts required for annual agave growth, suggesting the possibility of integrating the two systems to maximize the efficiency of land and water use to produce both electricity and liquid fuel. A life-cycle analysis of a hypothetical colocation indicated higher returns per m(3) of water used than either system alone. Water requirements for energy production were 0.22 L MJ(-1) (0.28-0.19) and 0.42 L MJ(-1) (0.52-0.35) for solar PV-agave (baseline yield) and solar PV-agave (high yield), respectively. Even though colocation may not be practical in all locations, in some water-limited areas, colocated solar PV-agave systems may provide attractive economic incentives in addition to efficient land and water use. PMID:24467248

Ravi, Sujith; Lobell, David B; Field, Christopher B

2014-03-01

297

School of Engineering and Science Algae Biofuels  

E-print Network

School of Engineering and Science Algae Biofuels BY: Alessandro Faldi, Ph.D. Section Head is algae- based biofuels, which we believe could be a meaningful part of the energy mix in the future. Algae biofuels have potential to be an economically viable, low-net carbon transportation fuel

Fisher, Frank

298

Genomics of cellulosic biofuels.  

PubMed

The development of alternatives to fossil fuels as an energy source is an urgent global priority. Cellulosic biomass has the potential to contribute to meeting the demand for liquid fuel, but land-use requirements and process inefficiencies represent hurdles for large-scale deployment of biomass-to-biofuel technologies. Genomic information gathered from across the biosphere, including potential energy crops and microorganisms able to break down biomass, will be vital for improving the prospects of significant cellulosic biofuel production. PMID:18704079

Rubin, Edward M

2008-08-14

299

Soil Nitrous Oxide Emissions with Crop Production for Biofuel: Implications for Greenhouse Gas Mitigation  

Technology Transfer Automated Retrieval System (TEKTRAN)

The growing biofuel commodity market for corn ethanol has the potential to reduce direct greenhouse gas (GHG) emissions associated with fossil fuel combustion in the US. However, projected increases in cropland to accommodate this energy-based commodity will also impact emissions of GHGs from soils...

300

Sustainability of algal biofuel production using integrated renewable energy park (IREP) and algal biorefinery approach  

Microsoft Academic Search

Algal biomass can provide viable third generation feedstock for liquid transportation fuel. However, for a mature commercial industry to develop, sustainability as well as technological and economic issues pertinent to algal biofuel sector must be addressed first. This viewpoint focuses on three integrated approaches laid out to meet these challenges. Firstly, an integrated algal biorefinery for sequential biomass processing for

Bobban G. Subhadra

2010-01-01

301

SYNTHESIS Industrial-strength ecology: trade-offs and opportunities in algal biofuel production  

E-print Network

REVIEW AND SYNTHESIS Industrial-strength ecology: trade-offs and opportunities in algal biofuel plants, easing the competing demands for land with food crops and native ecosystems. However, several requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal

302

Predicting agricultural management influence on long-term soil organic carbon dynamics: implications for biofuel production  

Technology Transfer Automated Retrieval System (TEKTRAN)

Long-term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations,...

303

Production of Advanced Biofuels via Liquefaction - Hydrothermal Liquefaction Reactor Design: April 5, 2013  

SciTech Connect

This report provides detailed reactor designs and capital costs, and operating cost estimates for the hydrothermal liquefaction reactor system, used for biomass-to-biofuels conversion, under development at Pacific Northwest National Laboratory. Five cases were developed and the costs associated with all cases ranged from $22 MM/year - $47 MM/year.

Knorr, D.; Lukas, J.; Schoen, P.

2013-11-01

304

Biological nitrogen fixation in sugar cane: A key to energetically viable biofuel production  

Microsoft Academic Search

The advantages of producing biofuels to replace fossil energy sources are derived from the fact that the energy accumulated in the biomass in captured directly from photosynthesis and is thus renewable, and that the cycle of carbon dioxide fixation by the crop, followed by burning of the fuel makes no overall contribution to atmospheric COâ or, consequently, to global warming.

R. M. Boddey

1995-01-01

305

Microwave pyrolysis of distillers dried grain with solubles (DDGS) for biofuel production  

Microsoft Academic Search

Microwave pyrolysis of distillers dried grain with solubles (DDGS) was investigated to determine the effects of pyrolytic conditions on the yields of bio-oil, syngas, and biochar. Pyrolysis process variables included reaction temperature, time, and power input. Microwave pyrolysis of DDGS was analyzed using response surface methodology to find out the effect of process variables on the biofuel (bio-oil and syngas)

Hanwu Lei; Shoujie Ren; Lu Wang; Quan Bu; James Julson; Johnathan E. Holladay; Roger Ruan

2011-01-01

306

Engineering the Saccharomyces cerevisiae ?-Oxidation Pathway to Increase Medium Chain Fatty Acid Production as Potential Biofuel  

PubMed Central

Fatty acid-derived biofuels and biochemicals can be produced in microbes using ?-oxidation pathway engineering. In this study, the ?-oxidation pathway of Saccharomyces cerevisiae was engineered to accumulate a higher ratio of medium chain fatty acids (MCFAs) when cells were grown on fatty acid-rich feedstock. For this purpose, the haploid deletion strain ?pox1 was obtained, in which the sole acyl-CoA oxidase encoded by POX1 was deleted. Next, the POX2 gene from Yarrowia lipolytica, which encodes an acyl-CoA oxidase with a preference for long chain acyl-CoAs, was expressed in the ?pox1 strain. The resulting ?pox1 [pox2+] strain exhibited a growth defect because the ?-oxidation pathway was blocked in peroxisomes. To unblock the ?-oxidation pathway, the gene CROT, which encodes carnitine O-octanoyltransferase, was expressed in the ?pox1 [pox2+] strain to transport the accumulated medium chain acyl-coAs out of the peroxisomes. The obtained ?pox1 [pox2+, crot+] strain grew at a normal rate. The effect of these genetic modifications on fatty acid accumulation and profile was investigated when the strains were grown on oleic acids-containing medium. It was determined that the engineered strains ?pox1 [pox2+] and ?pox1 [pox2+, crot+] had increased fatty acid accumulation and an increased ratio of MCFAs. Compared to the wild-type (WT) strain, the total fatty acid production of the strains ?pox1 [pox2+] and ?pox1 [pox2+, crot+] were increased 29.5% and 15.6%, respectively. The intracellular level of MCFAs in ?pox1 [pox2+] and ?pox1 [pox2+, crot+] increased 2.26- and 1.87-fold compared to the WT strain, respectively. In addition, MCFAs in the culture medium increased 3.29-fold and 3.34-fold compared to the WT strain. These results suggested that fatty acids with an increased MCFAs ratio accumulate in the engineered strains with a modified ?-oxidation pathway. Our approach exhibits great potential for transforming low value fatty acid-rich feedstock into high value fatty acid-derived products. PMID:24465440

Chen, Liwei; Zhang, Jianhua; Chen, Wei Ning

2014-01-01

307

Regional Algal Biofuel Production Potential in the Coterminous United States as Affected by Resource Availability Trade-offs  

SciTech Connect

The warm sunny climate and unoccupied arid lands in the American southwest are favorable factors for algae cultivation. However, additional resources affect the overall viability of specific sites and regions. We investigated the tradeoffs between growth rate, water, and CO2 availability and costs for two strains: N. salina and Chlorella sp. We conducted site selection exercises (~88,000 US sites) to produce 21 billion gallons yr-1 (BGY) of renewable diesel (RD). Experimental trials from the National Alliance for Advanced Biofuels and Bio-Products (NAABB) team informed the growth model of our Biomass Assessment Tool (BAT). We simulated RD production by both lipid extraction and hydrothermal liquefaction. Sites were prioritized by the net value of biofuel minus water and flue gas costs. Water cost models for N. salina were based on seawater and high salinity groundwater and for Chlorella, fresh and brackish groundwater. CO2 costs were based on a flue gas delivery model. Selections constrained by production and water were concentrated along the Gulf of Mexico and southeast Atlantic coasts due to high growth rates and low water costs. Adding flue gas constraints increased the spatial distribution, but the majority of sites remained in the southeast. The 21 BGY target required ~3.8 million hectares of mainly forest (41.3%) and pasture (35.7%). Exclusion in favor of barren and scrub lands forced most production to the southwestern US, but with increased water consumption (5.7 times) and decreased economic efficiency (-38%).

Venteris, Erik R.; Skaggs, Richard; Wigmosta, Mark S.; Coleman, Andre M.

2014-03-15

308

Fueling the Future with Fungal Genomics  

SciTech Connect

Fungi play important roles across the range of current and future biofuel production processes. From crop/feedstock health to plant biomass saccharification, enzyme production to bioprocesses for producing ethanol, higher alcohols or future hydrocarbon biofuels, fungi are involved. Research and development are underway to understand the underlying biological processes and improve them to make bioenergy production efficient on an industrial scale. Genomics is the foundation of the systems biology approach that is being used to accelerate the research and development efforts across the spectrum of topic areas that impact biofuels production. In this review, we discuss past, current and future advances made possible by genomic analyses of the fungi that impact plant/feedstock health, degradation of lignocellulosic biomass and fermentation of sugars to ethanol, hydrocarbon biofuels and renewable chemicals.

Grigoriev, Igor V.; Cullen, Daniel; Hibbett, David; Goodwin, Stephen B.; Jeffries, Thomas W.; Kubicek, Christian P.; Kuske, Cheryl; Magnuson, Jon K.; Martin, Francis; Spatafora, Joey; Tsang, Adrian; Baker, Scott E.

2011-04-29

309

Back to the future: inhaled drug products.  

PubMed

Inhaled therapeutic aerosols continue to be an important treatment for asthma and pulmonary diseases. A variety of dosage forms are employed for different indications and demographics including pressurized or propellant-driven metered dose inhalers, dry powder inhalers, and nebulizers/nebules. Research and development in this field has shown remarkable innovation in the past decade. Important new drug products for the treatment of asthma, chronic obstructive pulmonary disease, cystic fibrosis, diabetes, and a range of neurological disorders have been developed. New devices in each of the dosage form categories also have been developed, and new formulation technologies have been adopted. Unlike many other dosage forms, as new inhaled products appeared few of the existing products were converted to generic form. This may be explained by the formulation and device complexity, the implications for degree of difficulty in obtaining regulatory approval, and the prevalence of intellectual property in the field. After the setback of the initial approval and subsequent withdrawal of the Exubera®-inhaled insulin, there appeared to be reluctance to consider the pulmonary route of administration for systemically acting agents, particularly peptides and proteins. However, recent product development activities and approvals suggest that attitudes may be changing in favor of systemic delivery following inhaled aerosol administration. The new inhaled drug technologies seem to be driving reconsideration of therapeutic categories for indications that were of interest at the inception of modern inhaled drug therapy in the past century. We should embrace the opportunity to use new drugs and technologies to go back to the future! PMID:23381932

Hickey, Anthony J

2013-04-01

310

Forest Products Industry of the Future  

SciTech Connect

Los Alamos Technical Associates, Inc (LATA) conducted an evaluation of the potential impact and value of a portion of the current portfolio of r&d projects supported by the Office of Industrial Technology and the Forest Products Industry of the Future. The mission of the evaluation was to (a) assess the potential impact of the projects to meet the critical goals of the industry as identified in the vision and roadmapping documents. (b) Evaluate the relationship between the current portfolio of projects and the Agenda 202 Implementation Plan. In addition, evaluate the relationship between the portfolio and the newly revised draft technology strategy being created by the industry. (c) Identify areas where current efforts are making significant progress towards meeting industry goals and identify areas where additional work my be required to meet these goals. (d) Make recommendations to the DOE and the Forest Products Industry on possible improvements in the portfolio and in the current methodology that DOE uses to assess potential impacts on its R&D activities.

Los Alamos Technical Associates, Inc

2002-05-01

311

A New Biofuels Technology Blooms in Iowa  

SciTech Connect

Cellulosic biofuels made from agricultural waste have caught the attention of many farmers and could be the next revolution in renewable biofuels production. This video shows how an innovative technology that converts waste products from the corn harvest into renewable biofuels will help the U.S. produce billions of gallons of cellulosic biofuels over the coming decade. It will also stimulate local economies and reduce U.S. dependence on foreign oil.

Mathisen, Todd; Bruch, Don

2010-01-01

312

An Assessment of Land Availability and Price in the Coterminous United States for Conversion to Algal Biofuel Production  

SciTech Connect

Realistic economic assessment of land-intensive alternative energy sources (e.g., solar, wind, and biofuels) requires information on land availability and price. Accordingly, we created a comprehensive, national-scale model of these parameters for the United States. For algae-based biofuel, a minimum of 1.04E+05 km2 of land is needed to meet the 2022 EISA target of 2.1E+10 gallons year-1. We locate and quantify land types best converted. A data-driven model calculates the incentive to sell and a fair compensation value (real estate and lost future income). 1.02E+6 km2 of low slope, non-protected land is relatively available including croplands, pasture/ grazing, and forests. Within this total there is 2.64E+5 km2 of shrub and barren land available. The Federal government has 7.68E+4 km2 available for lease. Targeting unproductive lands minimizes land costs and impacts to existing industries. However, shrub and barren lands are limited by resources (water) and logistics, so land conversion requires careful consideration.

Venteris, Erik R.; Skaggs, Richard; Coleman, Andre M.; Wigmosta, Mark S.

2012-12-01

313

Turning Bacteria into Fuel: Cyanobacteria Designed for Solar-Powered Highly Efficient Production of Biofuels  

SciTech Connect

Broad Funding Opportunity Announcement Project: ASU is engineering a type of photosynthetic bacteria that efficiently produce fatty acids—a fuel precursor for biofuels. This type of bacteria, called Synechocystis, is already good at converting solar energy and carbon dioxide (CO2) into a type of fatty acid called lauric acid. ASU has modified the organism so it continuously converts sunlight and CO2 into fatty acids—overriding its natural tendency to use solar energy solely for cell growth and maximizing the solar-to-fuel conversion process. ASU’s approach is different because most biofuels research focuses on increasing cellular biomass and not on excreting fatty acids. The project has also identified a unique way to convert the harvested lauric acid into a fuel that can be easily blended with existing transportation fuels.

None

2010-01-01

314

Mass-cultivation of carbohydrate rich macroalgae, a possible solution for sustainable biofuel production  

Microsoft Academic Search

Global demand for bio-fuels continues unabated. Rising concerns over environmental pollution and global warming have encouraged\\u000a the movement to alternate fuels, the world ethanol market is projected to reach 86 billion litres this year. Bioethanol is\\u000a currently produced from land-based crops such as corn and sugar cane. A continued use of these crops drives the food versus\\u000a fuel debate. An

Stefan Kraan

315

Microalgae biofuel potentials (review).  

PubMed

With the decrease of fossil based fuels and the environmental impact of them over the planet, it seems necessary to seek the sustainable sources of clean energy. Biofuels, is becoming a worldwide leader in the development of renewable energy resources. It is worthwhile to say that algal biofuel production is thought to help stabilize the concentration of carbon dioxide in the atmosphere and decrease global warming impacts. Also, among algal fuels' attractive characteristics, algal biodiesel is non toxic, with no sulfur, highly biodegradable and relatively harmless to the environment if spilled. Algae are capable of producing in excess of 30 times more oil per acre than corn and soybean crops. Currently, algal biofuel production has not been commercialized due to high costs associated with production, harvesting and oil extraction but the technology is progressing. Extensive research was conducted to determine the utilization of microalgae as an energy source and make algae oil production commercially viable. PMID:22586908

Ghasemi, Y; Rasoul-Amini, S; Naseri, A T; Montazeri-Najafabady, N; Mobasher, M A; Dabbagh, F

2012-01-01

316

Carbon Cycling from Biofuel Crop Production in the Mid-Continental U. S. Region Predicted from MODIS Satellite Data and Ecosystem Modeling  

NASA Astrophysics Data System (ADS)

The NASA-CASA (Carnegie Ames Stanford Approach) simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate biomass production from croplands across the states of Iowa and Nebraska (United States) over the period 2001-2004. Adjustments for light-use efficiency and water use in biofuel (both corn and perennial grass) crops were carried out across the region, resulting in a new mapping of aboveground and belowground carbon pools based on 500-meter resolution MODIS satellite data. Simulations of plant residue management and soil carbon decomposition were conducted in the NASA-CASA model during and following conversions to biofuel crops to track the fate of carbon pools and the emissions of greenhouse gases. Initial results are being compared to biofuel production reports from southern Iowa for model calibration and validation. The long-term aims of this research are to enhance understanding of the effects of biofuel feedstocks on the biogeochemical cycling of carbon, nitrogen, and water by bringing NASA satellite data sets to bear on the problems of tracking cropland production trends and shifts in different cover areas of native vegetation and biofuel crops.

Hiatt, S.; Potter, C.; Klooster, S.

2008-12-01

317

Engineering an isoprenoid pathway in Escherichia coli for production of 2-methyl-3-buten-2-ol: a potential biofuel.  

PubMed

2-Methyl-3-buten-2-ol (MBO) is a natural volatile 5-carbon alcohol produced by several pine species that have the potential to be used as biofuel. MBO has a high energy content making it superior to ethanol in terms of energy output, and due to its volatility and lower solubility in water, MBO is easier to recover than ethanol. Pine's MBO synthase enzyme utilizes the intermediate dimethylallyl pyrophosphate (DMAPP) produced by the methyl-erythritol-4-phosphate isoprenoid pathway for the production of MBO. In this study, we performed metabolic engineering of Escherichia coli to express an alternate mevalonate dependent pathway for production of DMAPP, along with a codon optimized Pinus sabiniana MBO synthase gene. This heterologous expressed pathway carried out the conversion of an acetyl CoA precursor to DMAPP leading to production of MBO. PMID:24271564

Gupta, Dinesh; Summers, Michael L; Basu, Chhandak

2014-06-01

318

Biofuels: Report to Congress  

EPA Science Inventory

Section 204 of the Energy Independence and Security Act of 2007 (EISA 2007) requires EPA to assess and report to Congress on the impacts to date and likely future impacts of the increased use of biofuels as required by the Clean Air Act, section 211(0). Environmental issues (...

319

Corrosion Considerations for Thermochemical Biomass Liquefaction Process Systems in Biofuel Production  

NASA Astrophysics Data System (ADS)

Thermochemical liquefaction processing of biomass to produce bio-derived fuels (e.g., gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc., to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic oxygenates, including acids, which make the bio-oil a potential source of corrosion issues in transport, storage, and use. Efforts devoted to modified/further processing of bio-oils to make them less corrosive are currently being widely pursued. Another issue that must also be addressed in bio-oil liquefaction is potential corrosion issues in the process equipment. Depending on the specific process, bio-oil liquefaction production temperatures are typically in the 300-600°C range, and the process environment can contain aggressive sulfur and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. This paper summarizes recent, ongoing efforts to assess the extent of corrosion of bio-oil process equipment, with the ultimate goal of providing a basis for the selection of the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.

Brady, M. P.; Keiser, J. R.; Leonard, D. N.; Whitmer, L.; Thomson, J. K.

2014-12-01

320

Comparative energetics and kinetics of autotrophic lipid and starch metabolism in chlorophytic microalgae: implications for biomass and biofuel production.  

PubMed

Due to the growing need to provide alternatives to fossil fuels as efficiently, economically, and sustainably as possible there has been growing interest in improved biofuel production systems. Biofuels produced from microalgae are a particularly attractive option since microalgae have production potentials that exceed the best terrestrial crops by 2 to 10-fold. In addition, autotrophically grown microalgae can capture CO2 from point sources reducing direct atmospheric greenhouse gas emissions. The enhanced biomass production potential of algae is attributed in part to the fact that every cell is photosynthetic. Regardless, overall biological energy capture, conversion, and storage in microalgae are inefficient with less than 8% conversion of solar into chemical energy achieved. In this review, we examine the thermodynamic and kinetic constraints associated with the autotrophic conversion of inorganic carbon into storage carbohydrate and oil, the dominant energy storage products in Chlorophytic microalgae. We discuss how thermodynamic restrictions including the loss of fixed carbon during acetyl CoA synthesis reduce the efficiency of carbon accumulation in lipids. In addition, kinetic limitations, such as the coupling of proton to electron transfer during plastoquinone reduction and oxidation and the slow rates of CO2 fixation by Rubisco reduce photosynthetic efficiency. In some cases, these kinetic limitations have been overcome by massive increases in the numbers of effective catalytic sites, e.g. the high Rubisco levels (mM) in chloroplasts. But in other cases, including the slow rate of plastoquinol oxidation, there has been no compensatory increase in the abundance of catalytically limiting protein complexes. Significantly, we show that the energetic requirements for producing oil and starch relative to the recoverable energy stored in these molecules are very similar on a per carbon basis. Presently, the overall rates of starch and lipid synthesis in microalgae are very poorly characterized. Increased understanding of the kinetic constraints of lipid and starch synthesis, accumulation and turnover would facilitate the design of improved biomass production systems. PMID:24139286

Subramanian, Sowmya; Barry, Amanda N; Pieris, Shayani; Sayre, Richard T

2013-01-01

321

Transporter-mediated biofuel secretion.  

PubMed

Engineering microorganisms to produce biofuels is currently among the most promising strategies in renewable energy. However, harvesting these organisms for extracting biofuels is energy- and cost-intensive, limiting the commercial feasibility of large-scale production. Here, we demonstrate the use of a class of transport proteins of pharmacological interest to circumvent the need to harvest biomass during biofuel production. We show that membrane-embedded transporters, better known to efflux lipids and drugs, can be used to mediate the secretion of intracellularly synthesized model isoprenoid biofuel compounds to the extracellular milieu. Transporter-mediated biofuel secretion sustainably maintained an approximate three- to fivefold boost in biofuel production in our Escherichia coli test system. Because the transporters used in this study belong to the ubiquitous ATP-binding cassette protein family, we propose their use as "plug-and-play" biofuel-secreting systems in a variety of bacteria, cyanobacteria, diatoms, yeast, and algae used for biofuel production. This investigation showcases the potential of expressing desired membrane transport proteins in cell factories to achieve the export or import of substances of economic, environmental, or therapeutic importance. PMID:23613592

Doshi, Rupak; Nguyen, Tuan; Chang, Geoffrey

2013-05-01

322

Biofuels and the need for additional carbon  

Microsoft Academic Search

Use of biofuels does not reduce emissions from energy combustion but may offset emissions by increasing plant growth or by reducing plant residue or other non-energy emissions. To do so, biofuel production must generate and use 'additional carbon', which means carbon that plants would not otherwise absorb or that would be emitted to the atmosphere anyway. When biofuels cause no

Timothy D. Searchinger

2010-01-01

323

Biofuels and the need for additional carbon  

Microsoft Academic Search

Use of biofuels does not reduce emissions from energy combustion but may offset emissions by increasing plant growth or by reducing plant residue or other non-energy emissions. To do so, biofuel production must generate and use ‘additional carbon’, which means carbon that plants would not otherwise absorb or that would be emitted to the atmosphere anyway. When biofuels cause no

Timothy D Searchinger

2010-01-01

324

Factors Driving Biofuel Crops' Influence on Climate  

Microsoft Academic Search

Large scale deployment of new biofuel crops has the potential to influence climate through biogeophysical and biogeochemical mechanisms operating at the land surface. In turn, climatic variability influences the productivity of biofuel crops and thus their potential contribution as a source of energy. In order to characterize this two-way interaction between biofuels and climate, we are conducting a series of

A. Jones; M. S. Torn; W. J. Riley; W. Collins

2010-01-01

325

Assessing the environmental sustainability of biofuels.  

PubMed

Biofuels vary in their potential to reduce greenhouse gas emissions when displacing fossil fuels. Savings depend primarily on the crop used for biofuel production, and on the effect that expanding its cultivation has on land use. Evidence-based policies should be used to ensure that maximal sustainability benefits result from the development of biofuels. PMID:25281367

Kazamia, Elena; Smith, Alison G

2014-10-01

326

Glycogen production for biofuels by the euryhaline cyanobacteria Synechococcus sp. strain PCC 7002 from an oceanic environment  

PubMed Central

Background Oxygenic photosynthetic microorganisms such as cyanobacteria and microalgae have attracted attention as an alternative carbon source for the next generation of biofuels. Glycogen abundantly accumulated in cyanobacteria is a promising feedstock which can be converted to ethanol through saccharification and fermentation processes. In addition, the utilization of marine cyanobacteria as a glycogen producer can eliminate the need for a freshwater supply. Synechococcus sp. strain PCC 7002 is a fast-growing marine coastal euryhaline cyanobacteria, however, the glycogen yield has not yet been determined. In the present study, the effects of light intensity, CO2 concentration, and salinity on the cell growth and glycogen content were investigated in order to maximize glycogen production in Synechococcus sp. strain PCC 7002. Results The optimal culture conditions for glycogen production in Synechococcus sp. strain PCC 7002 were investigated. The maximum glycogen production of 3.5 g L?1 for 7 days (a glycogen productivity of 0.5 g L?1 d?1) was obtained under a high light intensity, a high CO2 level, and a nitrogen-depleted condition in brackish water. The glycogen production performance in Synechococcus sp. strain PCC 7002 was the best ever reported in the ?-polyglucan (glycogen or starch) production of cyanobacteria and microalgae. In addition, the robustness of glycogen production in Synechococcus sp. strain PCC 7002 to salinity was evaluated in seawater and freshwater. The peak of glycogen production of Synechococcus sp. strain PCC 7002 in seawater and freshwater were 3.0 and 1.8 g L?1 in 7 days, respectively. Glycogen production in Synechococcus sp. strain PCC 7002 maintained the same level in seawater and half of the level in freshwater compared with the optimal result obtained in brackish water. Conclusions We conclude that Synechococcus sp. strain PCC 7002 has high glycogen production activity and glycogen can be provided from coastal water accompanied by a fluctuation of salinity. This work supports Synechococcus sp. strain PCC 7002 as a promising carbohydrate source for biofuel production. PMID:24959200

2014-01-01

327

Direct measurement and characterization of active photosynthesis zones inside biofuel producing and wastewater remediating microalgal biofilms  

SciTech Connect

Abstract: Microalgal biofilm based technologies are of keen interest due to their high biomass concentrations and ability to utilize renewable resources, such as light and CO2. While photoautotrophic biofilms have long been used for wastewater remediation applications, biofuel production represents a relatively new and under-represented focus area. However, the direct measurement and characterization of fundamental parameters required for physiological analyses are challenging due to biofilm heterogeneity. This study evaluated oxygenic photosynthesis and biofuel precursor molecule production using a novel rotating algal biofilm reactor (RABR) operated at field- and laboratory-scales for wastewater remediation and biofuel production, respectively. Clear differences in oxygenic-photosynthesis, respiration and biofuel-precursor capacities were observed between the two systems and different conditions based on light and nitrogen availability. Nitrogen depletion was not found to have the same effect on lipid accumulation compared to prior planktonic studies. Physiological characterizations of these microalgal biofilms identify potential areas for future process optimization.

Bernstein, Hans C.; Kesaano, Maureen; Moll, Karen; Smith, Terence; Gerlach, Robin; Carlson, Ross; Miller, Charles D.; Peyton, Brent; Cooksey, Keith; Gardner, Robert D.; Sims, Ronald C.

2014-03-30

328

Tailoring next-generation biofuels and their combustion in next-generation engines.  

SciTech Connect

Increasing energy costs, the dependence on foreign oil supplies, and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. The strategy for producing next-generation biofuels must include efficient processes for biomass conversion to liquid fuels and the fuels must be compatible with current and future engines. Unfortunately, biofuel development generally takes place without any consideration of combustion characteristics, and combustion scientists typically measure biofuels properties without any feedback to the production design. We seek to optimize the fuel/engine system by bringing combustion performance, specifically for advanced next-generation engines, into the development of novel biosynthetic fuel pathways. Here we report an innovative coupling of combustion chemistry, from fundamentals to engine measurements, to the optimization of fuel production using metabolic engineering. We have established the necessary connections among the fundamental chemistry, engine science, and synthetic biology for fuel production, building a powerful framework for co-development of engines and biofuels.

Gladden, John Michael; Wu, Weihua; Taatjes, Craig A.; Scheer, Adam Michael; Turner, Kevin M.; Yu, Eizadora T.; O'Bryan, Greg; Powell, Amy Jo; Gao, Connie W. [Massachusetts Institute of Technology, Cambridge, MA] [Massachusetts Institute of Technology, Cambridge, MA

2013-11-01

329

Assessment of the Projected One Billion Ton Biomass for Cellulosic Biofuel Production and Its Potential Implications on Regional Water Quality and Availability  

NASA Astrophysics Data System (ADS)

The DOE and USDA joint study, also commonly referred as the "Billion-Ton" study, assessed the cellulosic feedstock resources potential in the U.S. for producing second generation biofuel to replace 30 percent of the country's transportation fuels by year 2030. The available resource is expected to come from changing cropping pattern, increasing crop yield, harvesting agricultural and forest wood residues, and developing energy crops. Such large-scale changes in land use and crop managements are likely to affect the associated water quality and resources at both regional and local scales. To address the water sustainability associated with the projected biomass production in the Upper Mississippi River Basin (UMRB), we have developed a SWAT watershed model that simulate the changes in water quality (nitrogen, phosphorus, and soil erosion) and resources (soil water content, evapotranspiration, and runoff) of the region due to future biomass production scenario estimated by the Billion-Ton study. The scenario is implemented by changing the model inputs and parameters at subbasin and hydrologic response unit levels, as well as by improving the SWAT model to represent spatially varying crop properties. The potential impacts on water quality and water availability were compared with the results obtained from a baseline simulation which represents current watershed conditions and existing level of feedstock production. The basin level results suggested mixed effects on the water quality. The projected large-scale biomass production scenario is expected to decrease loadings of total nitrogen and nitrate in the streams while increase total phosphorus and suspended sediment. Results indicate an increase in the rate of evapotranspiration and a decrease in the soil water content and in surface runoff. discharge to the streams. The impacts at the subbasin or local scale varies spatially and temporally depending on the types of land use change, their locations, and crop managements, suggesting needs to further optimize the sustainable biomass production from water resource perspective at both regional and local levels.

Demissie, Y. K.; Yan, E.; Wu, M.

2011-12-01

330

Water use implications of biofuel scenarios  

NASA Astrophysics Data System (ADS)

Existing studies rely upon attributional lifecycle analysis (LCA) approaches to estimate water intensity of biofuels in liters of irrigated/evapotranspiration water consumed for biofuel production. Such approaches can be misleading. From a policy perspective, a better approach is to compare differential water impacts among scenarios on a landscape scale. We address the shortcomings of existing studies by using consequential LCA, and incorporate direct and indirect land use (changes) of biofuel scenarios, marginal vs. average biofuel water use estimates, future climate, and geographic heterogeneity. We use the outputs of a partial equilibrium economic model, climate and soil data, and a process-based crop-soil-climate-water model to estimate differences in green water (GW - directly from precipitation to soil) and blue water (BW - supplied by irrigation) use among three scenarios: (1) business-as-usual (BAU), (2) Renewable Fuels Standard (RFS) mandates, and (3) a national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. We use spatial statistical methods to interpolate key climatic variables using daily climate observations for the contiguous USA. Finally, we use FAO's crop model AquaCrop to estimate the domestic GW and BW impacts of biofuel policies from 2007-2035. We assess the differences among scenarios along the following metrics: (1) crop area expansion at the county level, including prime and marginal lands, (2) crop-specific and overall annual/seasonal water balances including (a) water inflows (irrigation & precipitation), (b) crop-atmosphere interactions: (evaporation & transpiration) and (d) soil-water flows (runoff & soil infiltration), in mm 3 /acre over the relevant time period. The functional unit of analysis is the BW and GW requirements of biofuels (mm3 per Btu biofuel) at the county level. Differential water use impacts among scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes (2) irrigation practices, (3) feedstock water use efficiency, and (4) the longer growing season and a predominance of rainfed cultivation of dedicated biofuel feedstocks. National-level total water use is lowest in the BAU scenario and highest in the RFS2 + LCFS scenario. Figure: Million acres converted to growing miscanthus (top) & switchgrass (bottom) under the RFS + LCFS scenario in 2035. Land use classes are crop pasture (blue), idle cropland (red-purple) & prime cropland (brown).

Teter, J.; Mishra, G. S.; Yeh, S.

2012-12-01

331

Combinatorial Design of a Highly Efficient Xylose-Utilizing Pathway in Saccharomyces cerevisiae for the Production of Cellulosic Biofuels  

PubMed Central

Balancing the flux of a heterologous metabolic pathway by tuning the expression and properties of the pathway enzymes is difficult, but it is critical to realizing the full potential of microbial biotechnology. One prominent example is the metabolic engineering of a Saccharomyces cerevisiae strain harboring a heterologous xylose-utilizing pathway for cellulosic-biofuel production, which remains a challenge even after decades of research. Here, we developed a combinatorial pathway-engineering approach to rapidly create a highly efficient xylose-utilizing pathway for ethanol production by exploring various combinations of enzyme homologues with different properties. A library of more than 8,000 xylose utilization pathways was generated using DNA assembler, followed by multitiered screening, which led to the identification of a number of strain-specific combinations of the enzymes for efficient conversion of xylose to ethanol. The balancing of metabolic flux through the xylose utilization pathway was demonstrated by a complete reversal of the major product from xylitol to ethanol with a similar yield and total by-product formation as low as 0.06 g/g xylose without compromising cell growth. The results also suggested that an optimal enzyme combination depends on not only the genotype/phenotype of the host strain, but also the sugar composition of the fermentation medium. This combinatorial approach should be applicable to any heterologous pathway and will be instrumental in the optimization of industrial production of value-added products. PMID:23183982

Kim, Byoungjin; Du, Jing; Eriksen, Dawn T.

2013-01-01

332

Utilization of Ash Fractions from Alternative Biofuels used in Power Plants  

E-print Network

Utilization of Ash Fractions from Alternative Biofuels used in Power Plants PSO Project No. 6356 July 2008 Renewable Energy and Transport #12;2 Utilization of Ash Fractions from Alternative Biofuels)...............................................................................7 2. Production of Ash Products from Mixed Biofuels

333

75 FR 21191 - Subpart B-Advanced Biofuel Payment Program; Correction  

Federal Register 2010, 2011, 2012, 2013

...4288 RIN 0570-AA75 Subpart B--Advanced Biofuel Payment Program; Correction AGENCY: Rural...a payment program for producers of advanced biofuels to supporting existing advanced biofuel production and to encourage new production...

2010-04-23

334

Favouring butyrate production for a new generation biofuel by acidogenic glucose fermentation using cells immobilised on ?-alumina.  

PubMed

The effect of ?-alumina as a fermentation advancing tool and as carrier for culture immobilisation, regarding VFAs and ethanol production during acidogenic fermentation of glucose, was examined at various process conditions (sugar concentration, pH) and operation modes (continuous with and without effluent recirculation and batch). The results showed that at high initial pH (8.9) the continuous acidogenic fermentation of glucose led to high yields of VFAs and favoured the accumulation of butyric acid. The batch process on the other hand at pH 6.5, favoured the ethanol-type fermentation. The results indicate that in the frame of technology development for new generation biofuels, using ?-alumina as a process advancing tool at optimum process conditions (pH, initial glucose concentration and mode of operation), the produced VFAs profile and ethanol concentration may be manipulated. PMID:24690582

Syngiridis, Kostas; Bekatorou, Argyro; Kandylis, Panagiotis; Larroche, Christian; Kanellaki, Maria; Koutinas, Athanasios A

2014-06-01

335

The Role of Social Constructions and Biophysical Attributes of the Environment in Decision-Making in the Context of Biofuels and Rubber Production Partnership Regimes in Upland Philippines  

NASA Astrophysics Data System (ADS)

Burgeoning attention in biofuels and natural rubber has spurred interest among governments and private companies in integrating marginalized communities into global commodity markets. Upland farmers from diverse cultural backgrounds and biophysical settings today are deciding whether to agree with partnership proposals from governments and private firms to grow biofuels and natural rubber. In this paper, I examine whether upland farmers' socio-environmental constructions (evaluative beliefs, place satisfaction, and ecological worldviews) and the actual biophysical attributes (land cover and soil types) of upland environments, respectively, function as significant predictors of the intent and decisions of indigenous and non-indigenous farmers to cooperate with government and private actors to establish certain biofuel crops and natural rubber production systems in Palawan, Philippines. Drawing from ethnography and statistical analysis of household surveys, I propose that social constructions and the biophysical attributes of the environment are closely related with each other and in turn both influence individual decision-making behavior in resource-based production partnership regimes. This has significant implications on the resilience of socio-ecological systems, particularly agro-ecosystems, as certain upland farmers prefer to engage in intensive, monocrop production of biofuels and natural rubber on relatively more biodiverse areas, such as secondary forests and traditional shifting cultivation lands. The study aims to advance new institutional theories of resource management, particularly Ostrom's Institutional Analysis and Development and Socio-Ecological Systems frameworks, and scholarship on environmental decision-making in the context of collective action.

Montefrio, M. F.

2012-12-01

336

Shifting Lands: Exploring Kansas Farmer Decision-Making in an Era of Climate Change and Biofuels Production  

NASA Astrophysics Data System (ADS)

While farming has been the subject of frequent critical analysis with respect to its environmental impacts, including its greenhouse gas emissions, there has been relatively little consideration of the potentially positive role of agriculture in responding to a future greatly influenced by climate change. One possible realm for agriculture to contribute successfully to this future is through biofuels cultivation. This paper uses the state of Kansas as an example to examine factors that are influencing farmer decision-making during a time of heightened debates about climate and energy. Drawing on interviews with key informants and Kansas farmers, we apply and refine a conceptual model for understanding farmer decisions. We find that farmers have largely positive perceptions of the natural environment. Climate change, especially, is not a salient concern at this time. Factors that appear most likely to influence farmer decisions to adopt a new practice include the relative advantage of that practice and the ability to learn about and discuss it through existing social networks. Successful policy incentives must provide farmers with a continued sense of both independence and contribution to greater societal good.

White, Stacey Swearingen; Selfa, Theresa

2013-02-01

337

Biofuel impacts on water.  

SciTech Connect

Sandia National Laboratories and General Motors Global Energy Systems team conducted a joint biofuels systems analysis project from March to November 2008. The purpose of this study was to assess the feasibility, implications, limitations, and enablers of large-scale production of biofuels. 90 billion gallons of ethanol (the energy equivalent of approximately 60 billion gallons of gasoline) per year by 2030 was chosen as the book-end target to understand an aggressive deployment. Since previous studies have addressed the potential of biomass but not the supply chain rollout needed to achieve large production targets, the focus of this study was on a comprehensive systems understanding the evolution of the full supply chain and key interdependencies over time. The supply chain components examined in this study included agricultural land use changes, production of biomass feedstocks, storage and transportation of these feedstocks, construction of conversion plants, conversion of feedstocks to ethanol at these plants, transportation of ethanol and blending with gasoline, and distribution to retail outlets. To support this analysis, we developed a 'Seed to Station' system dynamics model (Biofuels Deployment Model - BDM) to explore the feasibility of meeting specified ethanol production targets. The focus of this report is water and its linkage to broad scale biofuel deployment.

Tidwell, Vincent Carroll; Malczynski, Leonard A.; Sun, Amy Cha-Tien

2011-01-01

338

Biofuels and Agriculture  

E-print Network

. They include ethanol and biodiesel (a vegetable oil product) made from agricultural crops and residues, forest vegetable oils, such as soybean oil, as well as animal fats, and recycled cooking greases can be chemically Diesel designed his prototype engine to run on peanut oil? Raw materials for making biofuels, now

Pawlowski, Wojtek

339

Enhanced biofuel production from high-concentration bioethanol wastewater by a newly isolated heterotrophic microalga, Chlorella vulgaris LAM-Q.  

PubMed

Microalgal biofuel production from wastewater has economic and environmental advantages. This article investigates the lipid production from high chemical oxygen demand (COD) bioethanol wastewater without dilution or additional nutrients, using a newly isolated heterotrophic microalga, Chlorella vulgaris LAM-Q. To enhance lipid accumulation, the combined effects of important operational parameters were studied via response surface methodology. The optimal conditions were found to be temperature of 22.8?, initial pH of 6.7, and inoculum density of 1.2 × 10(8) cells/ml. Under these conditions, the lipid productivity reached 195.96 mg/l/d, which was markedly higher than previously reported values in similar systems. According to the fatty acid composition, the obtained lipids were suitable feedstock for biodiesel production. Meanwhile, 61.40% of COD, 51.24% of total nitrogen, and 58.76% of total phosphorus were removed from the bioethanol wastewater during microalgal growth. In addition, 19.17% of the energy contained in the wastewater was transferred to the microalgal biomass in the fermentation process. These findings suggest that C. vulgaris LAMQ can efficiently produce lipids from high-concentration bioethanol wastewater, and simultaneously performs wastewater treatment. PMID:23801252

Xie, Tonghui; Liu, Jing; Du, Kaifeng; Liang, Bin; Zhang, Yongkui

2013-10-28

340

Measuring and moderating the water resource impact of biofuel production and trade  

E-print Network

regulating  trade  in  agricultural  products  (including  Trade  Organization  (2006).  European  Communities  —  Protection  of   Trademarks  and  Geographical  Indications  for  Agricultural  Products  

Fingerman, Kevin Robert

2012-01-01

341

Fuel from wastewater : harnessing a potential energy source in Canada through the co-location of algae biofuel production to sources of effluent, heat and CO2.  

SciTech Connect

Sandia National Laboratories is collaborating with the National Research Council (NRC) Canada and the National Renewable Energy Laboratory (NREL) to develop a decision-support model that will evaluate the tradeoffs associated with high-latitude algae biofuel production co-located with wastewater, CO2, and waste heat. This project helps Canada meet its goal of diversifying fuel sources with algae-based biofuels. The biofuel production will provide a wide range of benefits including wastewater treatment, CO2 reuse and reduction of demand for fossil-based fuels. The higher energy density in algae-based fuels gives them an advantage over crop-based biofuels as the 'production' footprint required is much less, resulting in less water consumed and little, if any conversion of agricultural land from food to fuel production. Besides being a potential source for liquid fuel, algae have the potential to be used to generate electricity through the burning of dried biomass, or anaerobically digested to generate methane for electricity production. Co-locating algae production with waste streams may be crucial for making algae an economically valuable fuel source, and will certainly improve its overall ecological sustainability. The modeling process will address these questions, and others that are important to the use of water for energy production: What are the locations where all resources are co-located, and what volumes of algal biomass and oil can be produced there? In locations where co-location does not occur, what resources should be transported, and how far, while maintaining economic viability? This work is being funded through the U.S. Department of Energy (DOE) Biomass Program Office of Energy Efficiency and Renewable Energy, and is part of a larger collaborative effort that includes sampling, strain isolation, strain characterization and cultivation being performed by the NREL and Canada's NRC. Results from the NREL / NRC collaboration including specific productivities of selected algal strains will eventually be incorporated into this model.

Passell, Howard David; Whalen, Jake (SmartWhale Consulting, Dartmouth, NS, CA); Pienkos, Philip P. (National Renewable Energy Laboratory, Golden, CO); O'Leary, Stephen J. (National Research Council Canada, Institute for Marine Biosciences, Halifax, NS, CA); Roach, Jesse Dillon; Moreland, Barbara D.; Klise, Geoffrey Taylor

2010-12-01

342

Agriculture, Land Use, Energy and Carbon Emission Impacts of Global Biofuel Mandates to Mid-Century  

SciTech Connect

Three potential future scenarios of expanded global biofuel production are presented here utilizing the GCAM integrated assessment model. These scenarios span a range that encompasses on the low end a continuation of existing biofuel production policies to two scenarios that would require an expansion of current targets as well as an extension of biofuels targets to other regions of the world. Conventional oil use is reduced by 4-8% in the expanded biofuel scenarios, which results in a decrease of in CO2 emissions on the order of 1-2 GtCO2/year by mid-century from the global transportation sector. The regional distribution of crop production is relatively unaffected, but the biofuels targets do result in a marked increase in the production of conventional crops used for energy. Producer prices of sugar and corn reach levels about 12% and 7% above year 2005 levels, while the increased competition for land causes the price of food crops such as wheat, although not used for bioenergy in this study, to increase by 1 to 2%. The amount of land devoted to growing all food crops and dedicated bioenergy crops is increased by about 10% by 2050 in the High biofuel case, with concurrent decreases in other uses of land such as forest and pasture. In both of the expanded biofuels cases studied, there is an increase in net cumulative carbon emissions for the first couple of decades due to these induced land use changes. However, the difference in net cumulative emissions from the biofuels expansion decline by about 2035 as the reductions in energy system emissions exceed further increases in emissions from land use change. Even in the absence of a policy that would limit emissions from land use change, the differences in net cumulative emissions from the biofuels scenarios reach zero by 2050, and are decreasing further over time in both cases.

Wise, Marshall A.; Dooley, James J.; Luckow, Patrick; Calvin, Katherine V.; Kyle, G. Page

2014-02-01

343

Comparing life cycle assessments of different biofuel options.  

PubMed

Life cycle assessment (LCA) has shown that first generation biofuels provide a little to no benefit for greenhouse gas (GHG) reductions compared to petroleum fuels, particularly when indirect effects are considered. Second generation fuels are intended to achieve greater GHG reductions and avoid other sustainability issues. LCAs of second generation biofuels exhibit great variability and uncertainty, leading to inconclusive results for the performance of particular pathways (combinations of feedstocks and fuels). Variability arises in part because of the prospective nature of LCAs for future fuels; however, a review of recent articles on biofuel LCA methodology indicates two additional sources of variability: real sources such as spatiotemporal heterogeneity, and methodological sources such as choices for co-product allocation methods and system boundary definition. PMID:23490811

Kendall, Alissa; Yuan, Juhong

2013-06-01

344

Systems analysis and futuristic designs of advanced biofuel factory concepts.  

SciTech Connect

The U.S. is addicted to petroleum--a dependency that periodically shocks the economy, compromises national security, and adversely affects the environment. If liquid fuels remain the main energy source for U.S. transportation for the foreseeable future, the system solution is the production of new liquid fuels that can directly displace diesel and gasoline. This study focuses on advanced concepts for biofuel factory production, describing three design concepts: biopetroleum, biodiesel, and higher alcohols. A general schematic is illustrated for each concept with technical description and analysis for each factory design. Looking beyond current biofuel pursuits by industry, this study explores unconventional feedstocks (e.g., extremophiles), out-of-favor reaction processes (e.g., radiation-induced catalytic cracking), and production of new fuel sources traditionally deemed undesirable (e.g., fusel oils). These concepts lay the foundation and path for future basic science and applied engineering to displace petroleum as a transportation energy source for good.

Chianelli, Russ; Leathers, James; Thoma, Steven George; Celina, Mathias Christopher; Gupta, Vipin P.

2007-10-01

345

Third Generation Biofuels via Direct Cellulose Fermentation  

PubMed Central

Consolidated bioprocessing (CBP) is a system in which cellulase production, substrate hydrolysis, and fermentation are accomplished in a single process step by cellulolytic microorganisms. CBP offers the potential for lower biofuel production costs due to simpler feedstock processing, lower energy inputs, and higher conversion efficiencies than separate hydrolysis and fermentation processes, and is an economically attractive near-term goal for “third generation” biofuel production. In this review article, production of third generation biofuels from cellulosic feedstocks will be addressed in respect to the metabolism of cellulolytic bacteria and the development of strategies to increase biofuel yields through metabolic engineering. PMID:19325807

Carere, Carlo R.; Sparling, Richard; Cicek, Nazim; Levin, David B.

2008-01-01

346

Microwave pyrolysis of distillers dried grain with solubles (DDGS) for biofuel production.  

PubMed

Microwave pyrolysis of distillers dried grain with solubles (DDGS) was investigated to determine the effects of pyrolytic conditions on the yields of bio-oil, syngas, and biochar. Pyrolysis process variables included reaction temperature, time, and power input. Microwave pyrolysis of DDGS was analyzed using response surface methodology to find out the effect of process variables on the biofuel (bio-oil and syngas) conversion yield and establish prediction models. Bio-oil recovery was in the range of 26.5-50.3 wt.% of the biomass. Biochar yields were 23.5-62.2% depending on the pyrolysis conditions. The energy content of DDGS bio-oils was 28 MJ/kg obtained at the 650°C and 8 min, which was about 66.7% of the heating value of gasoline. GC/MS analysis indicated that the biooil contained a series of important and useful chemical compounds: aliphatic and aromatic hydrocarbons. At least 13% of DDGS bio-oil was the same hydrocarbon compounds found in regular unleaded gasoline. PMID:21377870

Lei, Hanwu; Ren, Shoujie; Wang, Lu; Bu, Quan; Julson, James; Holladay, John; Ruan, Roger

2011-05-01

347

Biofuels for the gas turbine: A review  

Microsoft Academic Search

Due to depletion of fossil fuel, bio-fuels have generated a significant interest as an alternative fuel for the future. The use of bio-fuels to fuel gas turbine seems a viable solution for the problems of decreasing fossil-fuel reserves and environmental concerns. Bio-fuels are alternative fuels, made from renewable sources and having environmental benefit. In recent years, the desire for energy

K. K. Gupta; A. Rehman; R. M. Sarviya

2010-01-01

348

Plastid biotechnology for crop production: present status and future perspectives  

PubMed Central

The world population is expected to reach an estimated 9.2 billion by 2050. Therefore, food production globally has to increase by 70% in order to feed the world, while total arable land, which has reached its maximal utilization, may even decrease. Moreover, climate change adds yet another challenge to global food security. In order to feed the world in 2050, biotechnological advances in modern agriculture are essential. Plant genetic engineering, which has created a new wave of global crop production after the first green revolution, will continue to play an important role in modern agriculture to meet these challenges. Plastid genetic engineering, with several unique advantages including transgene containment, has made significant progress in the last two decades in various biotechnology applications including development of crops with high levels of resistance to insects, bacterial, fungal and viral diseases, different types of herbicides, drought, salt and cold tolerance, cytoplasmic male sterility, metabolic engineering, phytoremediation of toxic metals and production of many vaccine antigens, biopharmaceuticals and biofuels. However, useful traits should be engineered via chloroplast genomes of several major crops. This review provides insight into the current state of the art of plastid engineering in relation to agricultural production, especially for engineering agronomic traits. Understanding the bottleneck of this technology and challenges for improvement of major crops in a changing climate are discussed. PMID:21437683

Daniell, Henry

2012-01-01

349

Sustainable cement production-present and future  

SciTech Connect

Cement will remain the key material to satisfy global housing and modern infrastructure needs. As a consequence, the cement industry worldwide is facing growing challenges in conserving material and energy resources, as well as reducing its CO{sub 2} emissions. According to the International Energy Agency, the main levers for cement producers are the increase in energy efficiency and the use of alternative materials, be it as fuel or raw materials. Accordingly, the use of alternative fuels has already increased significantly in recent years, but potential for further increases still exists. In cement, the reduction of the clinker factor remains a key priority: tremendous progress has already been made. Nevertheless, appropriate materials are limited in their regional availability. New materials might be able to play a role as cement constituents in the future. It remains to be seen to what extent they could substitute Portland cement clinker to a significant degree.

Schneider, M., E-mail: sch@vdz-online.de [VDZ, Duesseldorf (Germany); Romer, M.; Tschudin, M. [Holcim Group Support Ltd, Holderbank (Switzerland); Bolio, H. [CEMEX, Monterrey (Mexico)

2011-07-15

350

Future crop production threatened by extreme heat  

NASA Astrophysics Data System (ADS)

Heat is considered to be a major stress limiting crop growth and yields. While important findings on the impact of heat on crop yield have been made based on experiments in controlled environments, little is known about the effects under field conditions at larger scales. The study of Deryng et al (2014 Global crop yield response to extreme heat stress under multiple climate change futures Environ. Res. Lett. 9 034011), analysing the impact of heat stress on maize, spring wheat and soya bean under climate change, represents an important contribution to this emerging research field. Uncertainties in the occurrence of heat stress under field conditions, plant responses to heat and appropriate adaptation measures still need further investigation.

Siebert, Stefan; Ewert, Frank

2014-04-01

351

Predicting Agricultural Management Influence on Long-Term Soil Organic Carbon Dynamics: Implications for Biofuel Production  

SciTech Connect

Long-term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations, fertilizer or organic amendments, and crop residue managements using the CQESTR model and (ii) to predict the potential of no-tillage (NT) management to maintain SOC stocks while removing crop residue. Classical LTEs at Champaign, IL (1876), Columbia, MO (1888), Lethbridge, AB (1911), Breton, AB (1930), and Pendleton, OR (1931) were selected for their documented history of management practice and periodic soil organic matter (SOM) measurements. Management practices ranged from monoculture to 2- or 3-yr crop rotations, manure, no fertilizer or fertilizer additions, and crop residue returned, burned, or harvested. Measured and CQESTR predicted SOC stocks under diverse agronomic practices, mean annual temperature (2.1 19 C), precipitation (402 973 mm), and SOC (5.89 33.58 g SOC kg 1) at the LTE sites were significantly related (r 2 = 0.94, n = 186, P < 0.0001) with a slope not significantly different than 1. The simulation results indicated that the quantities of crop residue that can be sustainably harvested without jeopardizing SOC stocks were influenced by initial SOC stocks, crop rotation intensity, tillage practices, crop yield, and climate. Manure or a cover crop/intensified crop rotation under NT are options to mitigate loss of crop residue C, as using fertilizer alone is insufficient to overcome residue removal impact on SOC stocks

Gollany, H. T. [USDA ARS; Rickman, R. W. [USDA ARS; Albrecht, S. L. [USDA ARS; Liang, Y. [University of Arkansas; Kang, Shujiang [ORNL; Machado, S. [Oregon State University, Corvallis

2011-01-01

352

Environmental implications of jatropha biofuel from a silvi-pastoral production system in central-west Brazil.  

PubMed

We present a life cycle assessment of synthetic paraffinic kerosene produced from Jatropha curcas. The feedstock is grown in an intercropping arrangement with pasture grasses so that Jatropha is coproduced with cattle. Additional innovations are introduced including hybrid seeds, detoxification of jatropha seedcake, and cogeneration. Two fuel pathways are examined including a newly developed catalytic decarboxylation process. Sensitivities are examined including higher planting density at the expense of cattle production as well as 50% lower yields. Intercropping with pasture and detoxifying seedcake yield coproducts that are expected to relieve pressure on Brazil's forests and indirectly reduce environmental impacts of biofuel production. Other innovations also reduce impacts. Results of the baseline assessment indicate that innovations would reduce impacts relative to the fossil fuel reference scenario in most categories including 62-75% reduction in greenhouse gas emissions, 64-82% reduction in release of ozone depleting chemicals, 33-52% reduction in smog-forming pollutants, 6-25% reduction in acidification, and 60-72% reduction in use of nonrenewable energy. System expansion, which explicitly accounts for avoided deforestation, results in larger improvements. Results are robust across allocation methodologies, improve with higher planting density, and persist if yield is reduced by half. PMID:23713609

Bailis, Rob; Kavlak, Goksin

2013-07-16

353

Making Photosynthetic Biofuel Renewable: Recovering Phosphorus from Residual Biomass J. M. Gifford and P. Westerhoff  

E-print Network

Making Photosynthetic Biofuel Renewable: Recovering Phosphorus from Residual Biomass J. M. Gifford to global warming. Biofuel from phototrophic microbes like algae and bacteria provides a viable substitute improves biofuel sustainability by refining phosphorus recycling. Biomass Production Residual Biomass

Hall, Sharon J.

354

Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial  

E-print Network

Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial ainsi que des exemples d'applications industrielles. Abstract -- Transformation of Sorbitol to Biofuels and biodiesel production led to first generation biofuels. Nowadays, research is focused on lignocellulosic

Boyer, Edmond

355

Biofuel Residues\\/Wastes: Ban or Boon?  

Microsoft Academic Search

Biofuel production generates significant amounts of low-value residues and wastes. This results in concern over the sustainability of the biofuel industry and its impact on the environment. Bioconversion offers opportunities for the economic utilization of biofuel residues and wastes with concomitant remediation of wastes. Due to their characteristics, these residues\\/wastes can serve as low-cost substrates for bioconversion to high-value products.

SAOHARIT NITAYAVARDHANA; SAMIR KUMAR KHANAL

2012-01-01

356

Biofuel Residues\\/Wastes: Ban or Boon?  

Microsoft Academic Search

Biofuel production generates significant amounts of low-value residues and wastes. This results in concern over sustainability of biofuel industry and its impact on environment. Bioconversion offers opportunities for economic utilization of biofuel residues and wastes with concomitant remediation of wastes. Due to their characteristics, these residues\\/wastes can serve as low-cost substrates for bioconversion to high-value products. Attempts have been made

SAOHARIT NITAYAVARDHANA; SAMIR KUMAR KHANAL

2011-01-01

357

Global Trends on the Processing of Biofuels  

Microsoft Academic Search

The aim of the present paper is to investigate bio-fuels produced from biomass materials by thermochemical and biochemical methods and the utilization trends of the products in the world. Bio-fuels are liquid or gaseous fuels made from plant matter and residues, such as agricultural crops, municipal wastes and agricultural and forestry by-products. Liquid bio-fuels being considered world over fall into

Mustafa Balat

2008-01-01

358

Mitigating Land Use Changes From Biofuel Expansion: An Assessment of Biofuel Feedstock Yield Potential in APEC Economies  

Microsoft Academic Search

The emerging biofuel sector has drawn great interest as an alternative source of fuel for transportation. The expansion of biofuels greatly impacts world agricultural markets, since currently, the primary feedstocks for ethanol and biodiesel production are field crops and their derived products. There is great interest in the potential of countries to expand their biofuel sectors through increased production of

Amani E. Elobeid; Simla Tokgoz; Tun-Hsiang Yu

2009-01-01

359

The Impact of Biofuel and Greenhouse Gas Policies on Land Management, Agricultural Production, and Environmental Quality  

E-print Network

and mitigation, commodity prices, production, net exports, sectoral economic welfare, and shifts in management practices and intensity. Direct and indirect consequences of RFS2 and carbon policy are highlighted, including regional production shifts that can...

Baker, Justin Scott

2012-10-19

360

Algae as a sustainable energy source for biofuel production in Iran: A case study  

Microsoft Academic Search

Algae can be converted directly into energy, such as biodiesel, bioethanol and biomethanol and therefore can be a source of renewable energy. There is a growing interest for biodiesel production from algae because of its higher yield non-edible oil production and its fast growth that does not compete for land with food production. About 50% of algae weight is oil

Gholamhassan Najafi; Barat Ghobadian; Talal F. Yusaf

2011-01-01

361

Fuel from Wastewater - Harnessing a Potential Energy Source in Canada through the Co-location of Algae Biofuel Production to Sources of Effluent, Heat and CO2  

NASA Astrophysics Data System (ADS)

Sandia National Laboratories is collaborating with the National Research Council (NRC) Canada and the National Renewable Energy Laboratory (NREL) to develop a decision-support model that will evaluate the tradeoffs associated with high-latitude algae biofuel production co-located with wastewater, CO2, and waste heat. This project helps Canada meet its goal of diversifying fuel sources with algae-based biofuels. The biofuel production will provide a wide range of benefits including wastewater treatment, CO2 reuse and reduction of demand for fossil-based fuels. The higher energy density in algae-based fuels gives them an advantage over crop-based biofuels as the “production” footprint required is much less, resulting in less water consumed and little, if any conversion of agricultural land from food to fuel production. Besides being a potential source for liquid fuel, algae have the potential to be used to generate electricity through the burning of dried biomass, or anaerobically digested to generate methane for electricity production. Co-locating algae production with waste streams may be crucial for making algae an economically valuable fuel source, and will certainly improve its overall ecological sustainability. The modeling process will address these questions, and others that are important to the use of water for energy production: What are the locations where all resources are co-located, and what volumes of algal biomass and oil can be produced there? In locations where co-location does not occur, what resources should be transported, and how far, while maintaining economic viability? This work is being funded through the U.S. Department of Energy (DOE) Biomass Program Office of Energy Efficiency and Renewable Energy, and is part of a larger collaborative effort that includes sampling, strain isolation, strain characterization and cultivation being performed by the NREL and Canada’s NRC. Results from the NREL / NRC collaboration including specific productivities of selected algal strains will eventually be incorporated into this model. Joint activities in algal biofuel research involving Sandia National Labs, NREL, and Canada’s NRC are supported by the U.S. - Canada Clean Energy Dialogue Secretariat. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Klise, G. T.; Roach, J. D.; Passell, H. D.; Moreland, B. D.; O'Leary, S. J.; Pienkos, P. T.; Whalen, J.

2010-12-01

362

Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production  

PubMed Central

Background Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strain of the genus Monoraphidium (SAG 48.87) was investigated in this work as a potential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated. Results Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category “carbohydrate metabolic process” and in “fatty acid biosynthetic process” in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance. Conclusions The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts. PMID:24373495

2013-01-01

363

Identifying potential areas for biofuel production and evaluating the environmental effects: a case study of the James River Basin in the Midwestern United States  

USGS Publications Warehouse

Biofuels are now an important resource in the United States because of the Energy Independence and Security Act of 2007. Both increased corn growth for ethanol production and perennial dedicated energy crop growth for cellulosic feedstocks are potential sources to meet the rising demand for biofuels. However, these measures may cause adverse environmental consequences that are not yet fully understood. This study 1) evaluates the long-term impacts of increased frequency of corn in the crop rotation system on water quantity and quality as well as soil fertility in the James River Basin and 2) identifies potential grasslands for cultivating bioenergy crops (e.g. switchgrass), estimating the water quality impacts. We selected the soil and water assessment tool, a physically based multidisciplinary model, as the modeling approach to simulate a series of biofuel production scenarios involving crop rotation and land cover changes. The model simulations with different crop rotation scenarios indicate that decreases in water yield and soil nitrate nitrogen (NO3-N) concentration along with an increase in NO3-N load to stream water could justify serious concerns regarding increased corn rotations in this basin. Simulations with land cover change scenarios helped us spatially classify the grasslands in terms of biomass productivity and nitrogen loads, and we further derived the relationship of biomass production targets and the resulting nitrogen loads against switchgrass planting acreages. The suggested economically efficient (planting acreage) and environmentally friendly (water quality) planting locations and acreages can be a valuable guide for cultivating switchgrass in this basin. This information, along with the projected environmental costs (i.e. reduced water yield and increased nitrogen load), can contribute to decision support tools for land managers to seek the sustainability of biofuel development in this region.

Wu, Yiping; Liu, Shuguang; Li, Zhengpeng

2012-01-01

364

Biofuels in Brazil: debates and impacts  

Microsoft Academic Search

This article presents an analysis of the two major components of Brazil's biofuels initiatives – ethanol from sugarcane and biodiesel from a variety of raw material sources. With the crisis unleashed at the end of 2008, huge question marks hang over the timetable and the scope of future investments in the sector. Even prior to the current crisis the biofuels debate was

John Wilkinson; Selena Herrera

2010-01-01

365

Biorefineries for biofuel upgrading: A critical review  

Microsoft Academic Search

This study reviews the biofuel valorization facilities as well as the future importance of biorefineries. Biomass can be converted into useful biofuels and bio-chemicals via biomass upgrading and biorefinery technologies. A biorefinery is a facility that integrates biomass conversion processes to produce fuels, power, and chemicals from biomass. Biomass upgrading processes include fractionation, liquefaction, pyrolysis, hydrolysis, fermentation, and gasification. Upgraded

M. Fatih Demirbas

2009-01-01

366

The Future of Butyric Acid in Industry  

PubMed Central

In this paper, the different applications of butyric acid and its current and future production status are highlighted, with a particular emphasis on the biofuels industry. As such, this paper discusses different issues regarding butyric acid fermentations and provides suggestions for future improvements and their approaches. PMID:22593687

Dwidar, Mohammed; Park, Jae-Yeon; Mitchell, Robert J.; Sang, Byoung-In

2012-01-01

367

Biofuels Overview CLIMATETECHBOOK  

E-print Network

Page | 1 May 2009 Biofuels Overview CLIMATETECHBOOK What are Biofuels? A biofuel is defined as any dependence on petroleum-based fuels, biofuels are gaining increasing attention as one possible solution. Biofuels offer a way to produce transportation fuels from renewable sources or waste materials and to help

368

Predicting the adsorption of second generation biofuels by polymeric resins with applications for in situ product recovery (ISPR)  

E-print Network

The application of hydrophobic polymeric resins as solid-phase adsorbent materials for the recovery and purification of prospective second generation biofuel compounds, including ethanol, iso-propanol, n-propanol, iso-butanol, ...

Nielsen, David R.

369

Some political issues related to future special nuclear materials production  

SciTech Connect

The Federal Government must take action to assure the future adequate supply of special nuclear materials for nuclear weapons. Existing statutes permit the construction of advanced defense production reactors and the reprocessing of commercial spent fuel for the production of special materials. Such actions would not only benefit the US nuclear reactor manufacturers, but also the US electric utilities that use nuclear reactors.

Peaslee, A.T. Jr.

1981-08-01

370

A GIS COST MODEL TO ASSESS THE AVAILABILITY OF FRESHWATER, SEAWATER, AND SALINE GROUNDWATER FOR ALGAL BIOFUEL PRODUCTION IN THE UNITED STATES  

SciTech Connect

A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a limited techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply, and cost models for supplying seawater and saline groundwater. We estimate that combined, within the coterminous US these resources can support production on the order of 9.46E+7 m3 yr-1 (25 billion gallons yr-1) of renewable biodiesel. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Geographically, water availability is most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate and various saline waters are economically available. As a whole, barren and scrub lands of the southwestern US have limited freshwater supplies so accurate assessment of alternative waters is critical.

Venteris, Erik R.; Skaggs, Richard; Coleman, Andre M.; Wigmosta, Mark S.

2013-03-15

371

Agave proves to be a low recalcitrant lignocellulosic feedstock for biofuels production on semi-arid lands  

PubMed Central

Background Agave, which is well known for tequila and other liquor production in Mexico, has recently gained attention because of its attractive potential to launch sustainable bioenergy feedstock solutions for semi-arid and arid lands. It was previously found that agave cell walls contain low lignin and relatively diverse non-cellulosic polysaccharides, suggesting unique recalcitrant features when compared to conventional C4 and C3 plants. Results Here, we report sugar release data from fungal enzymatic hydrolysis of non-pretreated and hydrothermally pretreated biomass that shows agave to be much less recalcitrant to deconstruction than poplar or switchgrass. In fact, non-pretreated agave has a sugar release five to eight times greater than that of poplar wood and switchgrass . Meanwhile, state of the art techniques including glycome profiling, nuclear magnetic resonance (NMR), Simon’s Stain, confocal laser scanning microscopy and so forth, were applied to measure interactions of non-cellulosic wall components, cell wall hydrophilicity, and enzyme accessibility to identify key structural features that make agave cell walls less resistant to biological deconstruction when compared to poplar and switchgrass. Conclusions This study systematically evaluated the recalcitrant features of agave plants towards biofuels applications. The results show that not only does agave present great promise for feeding biorefineries on semi-arid and arid lands, but also show the value of studying agave’s low recalcitrance for developments in improving cellulosic energy crops. PMID:24708685

2014-01-01

372

Development of integrated assessment platform for biofuels production via fast pyrolysis and upgrading pathway.  

E-print Network

??Growing concern over Greenhouse Gas (GHG) emissions from petroleum-based fuel consumption have prompted interest in the production of alternative transportation fuels from biorenewable sources. As… (more)

Zhang, Yanan

2014-01-01

373

Impact of United States biofuels co-products on the feed industry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although 140 biodiesel plants produced 1.2 billion liters of biodiesel in 2010, very little crude glycerol has been used in animal feeds in the U.S. due to relatively low volume produced compared to ethanol industry co-products, and its higher value for consumer products and industrial manufacturing...

374

A ROADMAP FOR SUSTAINABLE ADVANCED BIOFUEL FEEDSTOCK PRODUCTION IN THE MID-SOUTH  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although various studies exist that deal with the production of bioenergy crops, a number of aspects of bioenergy feedstock production (feedstock choice, natural resource availability, available infrastructure, etc.) are strongly influenced by the region in which the feedstock is produced and proces...

375

Production of Butanol (A Biofuel) from Agricultural Residues: Part I - Use of Barley Straw Hydrolysate  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fermentation of dilute sulfuric acid barley straw hydrolyzate (BSH; undiluted/untreated) by Clostridium beijerinckii P260 resulted in the production of 7.09 gL**-1 ABE (acetone butanol ethanol; AB or ABE), an ABE yield of 0.33, and productivity of 0.10 gL**-1h**-1. This level of ABE is much less th...

376

Biofuels generation from sweet sorghum: Fermentative hydrogen production and anaerobic digestion of the remaining biomass  

Microsoft Academic Search

The present study focuses on the exploitation of sweet sorghum biomass as a source for hydrogen and methane. Fermentative hydrogen production from the sugars of sweet sorghum extract was investigated at different hydraulic retention times (HRT). The subsequent methane production from the effluent of the hydrogenogenic process and the methane potential of the remaining solids after the extraction process were

Georgia Antonopoulou; Hariklia N. Gavala; Ioannis V. Skiadas; K. Angelopoulos; Gerasimos Lyberatos

2008-01-01

377

Membrane processes for alcohol-water separation: Improving the energy efficiency of biofuel production  

EPA Science Inventory

The economics and environmental impact of producing fuels and chemicals biologically can be a strong function of the efficiency with which the fermentation products are removed from the biological media. Due to growth inhibition by some fermentation products, including ethanol an...

378

Modification of Lignin by Protein Cross-linking to Facilitate Production of Biofuels From Poplar  

SciTech Connect

The limited supply of fossil fuels and the associated environmental issues associated with their utilization has resulted in much effort put forth to promote renewable resources of energy. Switching to renewable fuels for energy will allow us to become carbon neutral by recycling carbon from plants and reduce carbon from dioxide emissions, which could potentially reduce global warming in future generations and generate new industries with exciting new technologies.

Tien, Ming [The Pennsylvania State University] [The Pennsylvania State University

2013-04-22

379

Biofuel on contaminated land  

NASA Astrophysics Data System (ADS)

Desktop studies of two Swedish contaminated sites has indicated that growing biofuel crops on these sites may be more environmentally beneficial than alternative risk management approaches such as excavation / removal or containment The demand for biofuel increases pressure on the cultivatable soil of the world. While contaminated land is not very suitable for food production, cultivation of low and medium contaminated soil may remove some pressure from agricultural soils. For larger sites, biofuel cultivation may be economically viable without a remediation bonus. Suitable sites have topographic conditions that allow agricultural machinery, are not in urgent need of remediation, and contamination levels are not plant toxic. Life cycle assessment (LCA) was done for two cases. The (desk top) case studies were - Case K, a 5000 m2 site where salix (willow) was cultivated with hand-held machinery and the biofuel harvest was left on site, and - Case F, a 12 ha site were on site ensuring was being considered, and were salix might have rented an economic profit if the remediation had not been urgent due to exploitation pressure. Some selected results for biofuel K; biofuel F; excavation K; and on site ensuring F respectively: Energy: 0,05; 1,4; 3,5; 19 TJ Waste: 1; 9; 1200; 340 ton Land use off-site: 190; 3 500; 200 000; 1 400 000 m² a Global warming: 3; 86; 230; 1 200 ton CO2 eq Acidification: 25; 1 000; 2 600; 14 000 kg SO2 eq Photochemical smog: 10; 180; 410; 2 300 kg ethene eq Human health: 2; 51; 150; 620 index The environmental impact of the traditional remediation methods of excavation and on-site ensuring was mainly due to the transport of contaminated soil and replacement soil, and landfilling of the contaminated soil. Biofuel cultivation avoids these impacts, while fertiliser production and agricultural machinery would have a lower environmental impact than moving large volumes of soil around. Journeys of a controller to check on the groundwater quality also contributed to the biofuel impacts. The net CO2 equivalent emission on a 100 year basis per MJ energy in the Salix Vinimalis was between -0.02 and -0.1 kgCO2e/MJ. The fate of the stubble and roots of the salix was crucial for the carbon footprint. While stubble and roots remain in the soil (as increased soil organic matter), the carbon dioxide they took up while growing is not contributing to global warming. This pool was much larger than the CO2 emissions from soil transport and other processes. Biodiversity was difficult to include, and the results are uncertain. But the results indicated that biodiversity impact of biofuel cultivation may be large compared to "easier" categories like global warming and human health, and the net impact of biofuel cultivation may well be benifical to the environment instead of damaging.

Suer, Pascal; Andersson-Sköld, Yvonne; Blom, Sonja; Bardos, Paul; Polland, Marcel; Track, Thomas

2010-05-01

380

Generating Phenotypic Diversity in a Fungal Biocatalyst to Investigate Alcohol Stress Tolerance Encountered during Microbial Cellulosic Biofuel Production  

PubMed Central

Consolidated bioprocessing (CBP) of lignocellulosic biomass offers an alternative route to renewable energy. The crop pathogen Fusarium oxysporum is a promising fungal biocatalyst because of its broad host range and innate ability to co-saccharify and ferment lignocellulose to bioethanol. A major challenge for cellulolytic CBP-enabling microbes is alcohol inhibition. This research tested the hypothesis that Agrobacterium tumefaciens - mediated transformation (ATMT) could be exploited as a tool to generate phenotypic diversity in F. oxysporum to investigate alcohol stress tolerance encountered during CBP. A random mutagenesis library of gene disruption transformants (n=1,563) was constructed and screened for alcohol tolerance in order to isolate alcohol sensitive or tolerant phenotypes. Following three rounds of screening, exposure of select transformants to 6% ethanol and 0.75% n-butanol resulted respectively in increased (?11.74%) and decreased (?43.01%) growth compared to the wild –type (WT). Principal component analysis (PCA) quantified the level of phenotypic diversity across the population of genetically transformed individuals and isolated candidate strains for analysis. Characterisation of one strain, Tr. 259, ascertained a reduced growth phenotype under alcohol stress relative to WT and indicated the disruption of a coding region homologous to a putative sugar transporter (FOXG_09625). Quantitative PCR (RT-PCR) showed FOXG_09625 was differentially expressed in Tr. 259 compared to WT during alcohol-induced stress (P<0.05). Phylogenetic analysis of putative sugar transporters suggests diverse functional roles in F. oxysporum and other filamentous fungi compared to yeast for which sugar transporters form part of a relatively conserved family. This study has confirmed the potential of ATMT coupled with a phenotypic screening program to select for genetic variation induced in response to alcohol stress. This research represents a first step in the investigation of alcohol tolerance in F. oxysporum and has resulted in the identification of several novel strains, which will be of benefit to future biofuel research. PMID:24147009

Hennessy, Rosanna C.; Doohan, Fiona; Mullins, Ewen

2013-01-01

381

Generating phenotypic diversity in a fungal biocatalyst to investigate alcohol stress tolerance encountered during microbial cellulosic biofuel production.  

PubMed

Consolidated bioprocessing (CBP) of lignocellulosic biomass offers an alternative route to renewable energy. The crop pathogen Fusarium oxysporum is a promising fungal biocatalyst because of its broad host range and innate ability to co-saccharify and ferment lignocellulose to bioethanol. A major challenge for cellulolytic CBP-enabling microbes is alcohol inhibition. This research tested the hypothesis that Agrobacterium tumefaciens--mediated transformation (ATMT) could be exploited as a tool to generate phenotypic diversity in F. oxysporum to investigate alcohol stress tolerance encountered during CBP. A random mutagenesis library of gene disruption transformants (n=1,563) was constructed and screened for alcohol tolerance in order to isolate alcohol sensitive or tolerant phenotypes. Following three rounds of screening, exposure of select transformants to 6% ethanol and 0.75% n-butanol resulted respectively in increased (? 11.74%) and decreased (? 43.01%) growth compared to the wild -type (WT). Principal component analysis (PCA) quantified the level of phenotypic diversity across the population of genetically transformed individuals and isolated candidate strains for analysis. Characterisation of one strain, Tr. 259, ascertained a reduced growth phenotype under alcohol stress relative to WT and indicated the disruption of a coding region homologous to a putative sugar transporter (FOXG_09625). Quantitative PCR (RT-PCR) showed FOXG_09625 was differentially expressed in Tr. 259 compared to WT during alcohol-induced stress (P<0.05). Phylogenetic analysis of putative sugar transporters suggests diverse functional roles in F. oxysporum and other filamentous fungi compared to yeast for which sugar transporters form part of a relatively conserved family. This study has confirmed the potential of ATMT coupled with a phenotypic screening program to select for genetic variation induced in response to alcohol stress. This research represents a first step in the investigation of alcohol tolerance in F. oxysporum and has resulted in the identification of several novel strains, which will be of benefit to future biofuel research. PMID:24147009

Hennessy, Rosanna C; Doohan, Fiona; Mullins, Ewen

2013-01-01

382

Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems  

PubMed Central

Background Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). Methodology/Principal Findings We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements -- biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case – corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. Significance In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens. PMID:21765941

Huang, Wei-Dong; Zhang, Y-H Percival

2011-01-01

383

Engineering microbial biofuel tolerance and export using efflux pumps  

E-print Network

REPORT Engineering microbial biofuel tolerance and export using efflux pumps Mary J Dunlop1 16.9.10; accepted 6.4.11 Many compounds being considered as candidates for advanced biofuels for biofuel production because the engineered microbes must balance production against survival. Cellular

Dunlop, Mary

384

Global Assessments and Guidelines for Sustainable Liquid Biofuel  

E-print Network

Global Assessments and Guidelines for Sustainable Liquid Biofuel Production in Developing Countries Biofuel Production in Developing Countries FINAL REPORT A GEF Targeted Research Project Organized by Bernd for Sustainable Liquid Biofuels. A GEF Targeted Research Project. Heidelberg/Paris/Utrecht/Darmstadt, 29 February

385

A Comprehensive Energy and Economic Assessment of Biofuels: When “Green” Is Not Enough  

Microsoft Academic Search

Referee: Dr. Charles A. S. Hall, Department of Environmental Studies, State University of New York, College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 Biofuel production systems are sometimes claimed to be able to fill in for future fossil fuel shortages as well as to decrease carbon dioxide emissions and global warming. As such, they are often

Sergio Ulgiati

2001-01-01

386

Integration of microalgae cultivation with industrial waste remediation for biofuel and bioenergy production: opportunities and limitations  

Microsoft Academic Search

There is currently a renewed interest in developing microalgae as a source of renewable energy and fuel. Microalgae hold great\\u000a potential as a source of biomass for the production of energy and fungible liquid transportation fuels. However, the technologies\\u000a required for large-scale cultivation, processing, and conversion of microalgal biomass to energy products are underdeveloped.\\u000a Microalgae offer several advantages over traditional

Patrick J. McGinn; Kathryn E. Dickinson; Shabana Bhatti; Jean-Claude Frigon; Serge R. Guiot; Stephen J. B. O’Leary

387

Global Potential of Rice Husk as a Renewable Feedstock for Ethanol Biofuel Production  

Microsoft Academic Search

The production of ethanol for the energy market has traditionally been from corn and sugar cane biomass. The use of such biomass\\u000a as energy feedstocks has recently been criticised as ill-fated due to competitive threat against food supplies. At the same\\u000a time, ethanol production from cellulosic biomass is becoming increasingly popular. In this paper, we analyse rice husk (RH)\\u000a as

Ali Abbas; Santosh Ansumali

2010-01-01

388

The Impact of First and Second Generation Biofuels on Global Agricultural Production, Trade and Land Use  

Microsoft Academic Search

This paper assesses the global and sectoral implications of the growing demand for bio-based inputs for energy and fuel production. More specifically, the purpose of this paper is to assess the global and sectoral implications of policy initiatives in different countries or regions (e.g. the U.S., the EU, Canada, South Africa or Japan) to enhance bioenergy demand and production in

Martin Banse; Hans van Meijl; Geert Woltjer

389

Welfare and Equity Implications of Commercial Biofuel  

Microsoft Academic Search

\\u000a New sources and uses of biofuel energy offer the prospect of climate change mitigation and less reliance on fossil fuels.\\u000a At the same time, biofuel represents an unusual precedent in economics, the possibility of substitution between two essential\\u000a but very different commodities, food and energy. The first characteristic has dramatically heightened interest in biofuel\\u000a production around the world, but particularly

Fredrich Kahrl; David Roland-Holst

390

As corn-based biofuels reach their practical limits, advanced algae-based biofuels are poised to supply  

E-print Network

SEMTE abstract As corn-based biofuels reach their practical limits, advanced algae-based biofuels will be discussed as an economical carbon source for the algae. A highly scalable materials production technique

Reisslein, Martin

391

Time reducing process for biofuel production from non edible oil assisted by ultrasonication.  

PubMed

Limited resources of conventional fuels such as petrodiesel have led to the search for alternative fuels. Various convention batch/continuous processes for the biodiesel production have been developed before the recent year. All processes are time consuming with high labor cost. Thus, we need a new process for biodiesel production which reduces the reaction time and production cost as well as save the energy. In this work, ultrasonic assisted transesterification of Jatrophacurcas oil is carried out in the presence of methanol and potassium hydroxide (KOH) as catalyst, keeping the molar ratio of oil to alcohol 1:5, catalyst concentration 0.75 wt% of oil, ultrasonic amplitude 50% and pulse 0.3 cycle, 7 min reaction time under atmospheric condition. Ultrasonic mixing has increased the rate of transesterification reaction as compare to the mechanical mixing. PMID:24792785

Kumar, Gajendra; Kumar, Dharmendra; Johari, Rajeev

2014-09-01

392

Synergies between bio- and oil refineries for the production of fuels from biomass.  

PubMed

As petroleum prices continue to increase, it is likely that biofuels will play an ever-increasing role in our energy future. The processing of biomass-derived feedstocks (including cellulosic, starch- and sugar-derived biomass, and vegetable fats) by catalytic cracking and hydrotreating is a promising alternative for the future to produce biofuels, and the existing infrastructure of petroleum refineries is well-suited for the production of biofuels, allowing us to rapidly transition to a more sustainable economy without large capital investments for new reaction equipment. This Review discusses the chemistry, catalysts, and challenges involved in the production of biofuels. PMID:17610226

Huber, George W; Corma, Avelino

2007-01-01

393

Potential impacts of cropland biofuel production on the provision of avian habitat  

EPA Science Inventory

Present laws and policies encourage the growth of corn for the production of starch-based and cellulosic ethanol on agricultural lands in the U.S. This has been touted as an environmentally-friendly solution to problems of energy-independence, particularly in the midwestern U.S....

394

Indirect measurements of Brachiaria brizantha cv. Marandu fermentable cell wall sugars for second generation biofuels production.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Results of a study conducted to evaluate the possibility of using IVDMD values of B. brizantha cv. Marandu to predict cell wall sugars that would be available in a biorefinery for ethanol production are reported. The study was conducted based on the similarity between rumen enzymes and those used i...

395

Microbial production of sabinene—a new terpene-based precursor of advanced biofuel  

PubMed Central

Background Sabinene, one kind of monoterpene, accumulated limitedly in natural organisms, is being explored as a potential component for the next generation of aircraft fuels. And demand for advanced fuels impels us to develop biosynthetic routes for the production of sabinene from renewable sugar. Results In this study, sabinene was significantly produced by assembling a biosynthetic pathway using the methylerythritol 4-phosphate (MEP) or heterologous mevalonate (MVA) pathway combining the GPP and sabinene synthase genes in an engineered Escherichia coli strain. Subsequently, the culture medium and process conditions were optimized to enhance sabinene production with a maximum titer of 82.18 mg/L. Finally, the fed-batch fermentation of sabinene was evaluated using the optimized culture medium and process conditions, which reached a maximum concentration of 2.65 g/L with an average productivity of 0.018 g h-1 g-1 dry cells, and the conversion efficiency of glycerol to sabinene (gram to gram) reached 3.49%. Conclusions This is the first report of microbial synthesis of sabinene using an engineered E. coli strain with the renewable carbon source as feedstock. Therefore, a green and sustainable production strategy has been established for sabinene. PMID:24512040

2014-01-01

396

World crop residues production and implications of its use as a biofuel  

Microsoft Academic Search

Reducing and off-setting anthropogenic emissions of CO2 and other greenhouse gases (GHGs) are important strategies of mitigating the greenhouse effect. Thus, the need for developing carbon (C) neutral and renewable sources of energy is more than ever before. Use of crop residue as a possible source of feedstock for bioenergy production must be critically and objectively assessed because of its

R. Lal

2005-01-01

397

Jatropha curcas L. as a source for the production of biofuel in Nicaragua  

Microsoft Academic Search

The development of Jatropha curcas L. as a possible energy crop in Nicaragua is discussed. The energy situation in Nicaragua, the cultivation of Jatropha curcas, the description of the plant, the composition of the seeds, the specification of the oil and the expected yield of oil production is outlined. A technical process for the processing of the seeds and the

N. Foidl; G. Foidl; M. Sanchez; M. Mittelbach; S. Hackel

1996-01-01

398

Particle size characterization of ultrasonic treatment of dry milling coproducts for enhanced biofuel production  

Microsoft Academic Search

This study characterized the use of ultrasonic energy to increase the production of the methane as a biogas from the anaerobic digestion of coproducts of dry milling. Dried distillers grain with solubles (DDGs), solids, thin stillage, and corn syrup were treated with various ultrasonic conditions and compared to untreated (control) samples. The amplitude ranged from 52.8 ympp to 160 ympp

Cody John Hearn

2009-01-01

399

Linking genome content to biofuel production yields: a meta-analysis of major catabolic pathways among select H2 and ethanol-producing bacteria  

PubMed Central

Background Fermentative bacteria offer the potential to convert lignocellulosic waste-streams into biofuels such as hydrogen (H2) and ethanol. Current fermentative H2 and ethanol yields, however, are below theoretical maxima, vary greatly among organisms, and depend on the extent of metabolic pathways utilized. For fermentative H2 and/or ethanol production to become practical, biofuel yields must be increased. We performed a comparative meta-analysis of (i) reported end-product yields, and (ii) genes encoding pyruvate metabolism and end-product synthesis pathways to identify suitable biomarkers for screening a microorganism’s potential of H2 and/or ethanol production, and to identify targets for metabolic engineering to improve biofuel yields. Our interest in H2 and/or ethanol optimization restricted our meta-analysis to organisms with sequenced genomes and limited branched end-product pathways. These included members of the Firmicutes, Euryarchaeota, and Thermotogae. Results Bioinformatic analysis revealed that the absence of genes encoding acetaldehyde dehydrogenase and bifunctional acetaldehyde/alcohol dehydrogenase (AdhE) in Caldicellulosiruptor, Thermococcus, Pyrococcus, and Thermotoga species coincide with high H2 yields and low ethanol production. Organisms containing genes (or activities) for both ethanol and H2 synthesis pathways (i.e. Caldanaerobacter subterraneus subsp. tengcongensis, Ethanoligenens harbinense, and Clostridium species) had relatively uniform mixed product patterns. The absence of hydrogenases in Geobacillus and Bacillus species did not confer high ethanol production, but rather high lactate production. Only Thermoanaerobacter pseudethanolicus produced relatively high ethanol and low H2 yields. This may be attributed to the presence of genes encoding proteins that promote NADH production. Lactate dehydrogenase and pyruvate:formate lyase are not conducive for ethanol and/or H2 production. While the type(s) of encoded hydrogenases appear to have little impact on H2 production in organisms that do not encode ethanol producing pathways, they do influence reduced end-product yields in those that do. Conclusions Here we show that composition of genes encoding pathways involved in pyruvate catabolism and end-product synthesis pathways can be used to approximate potential end-product distribution patterns. We have identified a number of genetic biomarkers for streamlining ethanol and H2 producing capabilities. By linking genome content, reaction thermodynamics, and end-product yields, we offer potential targets for optimization of either ethanol or H2 yields through metabolic engineering. PMID:23249097

2012-01-01

400

Arid Lands Biofuel  

NASA Astrophysics Data System (ADS)

Dependence on imported petroleum, as well as consequences from burning fossil fuels, has increased the demand for biofuel sources in the United States. Competition between food crops and biofuel crops has been an increasing concern, however, since it has the potential to raise prices for US beef and grain products due to land and resource competition. Biofuel crops that can be grown on land not suitable for food crops are thus attractive, but also need to produce biofuels in a financially sustainable manner. In the intermountain west of Nevada, biofuel crops need to survive on low-organic soils with limited precipitation when grown in areas that are not competing with food and feed. The plants must also yield an oil content sufficiently high to allow economically viable fuel production, including growing and harvesting the crop as well as converting the hydrocarbons into a liquid fuel. Gumweed (Grindelia squarrosa) currently appears to satisfy all of these requirements and is commonly observed throughout the west. The plant favors dry, sandy soils and is most commonly found on roadsides and other freshly disturbed land. A warm season biennial, the gumweed plant is part of the sunflower family and normally grows 2-4 feet high with numerous yellow flowers and curly leaves. The gumweed plant contains a large store of diterpene resins—most abundantly grindelic acid— similar to the saps found on pine trees that are used to make inks and adhesives. The dry weight harvest on the experimental field is 5130 lbs/acre. Whole plant biomass yields between 11-15% (average 13%) biocrude when subjected to acetone extraction whereas the buds alone contains up to a maximum of 35% biocrude when harvested in 'white milky' stage. The extract is then converted to basic form (sodium grindelate) followed by extraction of nonpolar constituents (mostly terpenes) with hexane and extracted back to ethyl acetate in acidified condition. Ethyl acetate is removed under vacuum to leave a dark colored viscous gum. At this point, when methylated and the mixture analyzed by gas chromatography, grindelic acid methyl ester composes approximately 60-80% of the hydrocarbons present which is the actual available portion for biodiesel. Based on two years of crop data, we can say that we can produce in between 85-126 gallons of biofuel per acre of land. While agronomic issues remain still to be solved, crops can be grown, harvested and extracted using conventional methods. Further research is being undertaken to select optimal strains of gumweed, as well as methods of conversion of grindelic acid to a diesel fuel directly.

Neupane, B. P.

2013-05-01

401

Regional Impacts of Miscanthus Biofuel Feedstock Production on the Hydrologic Cycle  

NASA Astrophysics Data System (ADS)

Socio-economic and scientific interest toward the use of renewable energy to offset fossil fuel dependence and greenhouse gas emissions is increasing. Currently, the majority of the US renewable energy production is focused on replacing gasoline with corn ethanol. In 2008, 18% of the US corn yield was used to displace ~5% of US gasoline consumption. This represents progress toward meeting the goals of offsetting 30% of liquid fossil fuel consumption by 2030 as established by the US government in the Advanced Energy Initiative (AEI). However, a growing body of research indicates that it may not be beneficial or even possible for corn ethanol alone to meet the AEI goals. Highly productive bioenergy feedstocks requiring fewer inputs such as Miscanthus x Giganteus (Miscanthus) are ideal candidates, relative to maize, to provide a renewable and sustainable alternative to fossil fuel. It is anticipated that Miscanthus is likely to have minimal environmental impacts and could be potentially beneficial to the environment. In order to meet the AEI goals, Miscanthus production on the scale of 1x10<6> ha would be needed. Before this level of production occurs, uncertainty over the environmental impacts of large-scale implementation should be addressed particularly with regards to the hydrologic cycle. We calibrated and evaluated a process-based terrestrial ecosystem model, Agro-IBIS (Integrated Biosphere Simulator, agricultural version), to simulate the impacts of land-use-change from current land-use practices to Miscanthus production on the hydrologic cycle. Simulations for the Midwestern US (0.5°grid cell resolution) were generated using the same climate forcing for current land cover and additional scenarios where Miscanthus was planted in varying densities (10%, 25%, 50%, 75%, and 100%). Analyses indicate that for most of the Midwestern US, large increases in evapotranspiration (~100 to 250 mm/yr) and decreases in drainage (~ -100 to -250 mm/yr) occur when high densities (75-100%) of Miscanthus replace the existing land cover. Analyses of lower densities (10-25%) indicate little to no changes in the same hydrologic cycle components, suggesting that hydrologic impacts could be minimized if Miscanthus production density is moderated.

Vanloocke, A. D.; Twine, T. E.; Bernacchi, C.

2009-12-01

402

Kinetic studies on fermentative production of biofuel from synthesis gas using Clostridium ljungdahlii.  

PubMed

The intrinsic growth, substrate uptake, and product formation biokinetic parameters were obtained for the anaerobic bacterium, Clostridium ljungdahlii, grown on synthesis gas in various pressurized batch bioreactors. A dual-substrate growth kinetic model using Luong for CO and Monod for H2 was used to describe the growth kinetics of the bacterium on these substrates. The maximum specific growth rate (?(max) = 0.195 h(-1)) and Monod constants for CO (K s,CO = 0.855?atm) and H2 (K(s,H2) = 0.412?atm) were obtained. This model also accommodated the CO inhibitory effects on cell growth at high CO partial pressures, where no growth was apparent at high dissolved CO tensions (P(CO)(?) > 0.743 atm). The Volterra model, Andrews, and modified Gompertz were, respectively, adopted to describe the cell growth, substrate uptake rate, and product formation. The maximum specific CO uptake rate (q(max) = 34.364?mmol/g cell/h), CO inhibition constant (K(I) = 0.601 atm), and maximum rate of ethanol (R(max) = 0.172 mmol/L/h at P(CO) = 0.598 atm) and acetate (R(max) = 0.096 mmol/L/h at P(CO) = 0.539 atm) production were determined from the applied models. PMID:24672390

Mohammadi, Maedeh; Mohamed, Abdul Rahman; Najafpour, Ghasem D; Younesi, Habibollah; Uzir, Mohamad Hekarl

2014-01-01

403

Vertical Integration of Biomass Saccharification of Enzymes for Sustainable Cellulosic Biofuel Production in a Biorefinery  

SciTech Connect

Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.

Manoj Kumar, PhD

2011-05-09

404

Kinetic Studies on Fermentative Production of Biofuel from Synthesis Gas Using Clostridium ljungdahlii  

PubMed Central

The intrinsic growth, substrate uptake, and product formation biokinetic parameters were obtained for the anaerobic bacterium, Clostridium ljungdahlii, grown on synthesis gas in various pressurized batch bioreactors. A dual-substrate growth kinetic model using Luong for CO and Monod for H2 was used to describe the growth kinetics of the bacterium on these substrates. The maximum specific growth rate (?max = 0.195?h?1) and Monod constants for CO (Ks,CO = 0.855?atm) and H2 (Ks,H2 = 0.412?atm) were obtained. This model also accommodated the CO inhibitory effects on cell growth at high CO partial pressures, where no growth was apparent at high dissolved CO tensions (PCO? > 0.743?atm). The Volterra model, Andrews, and modified Gompertz were, respectively, adopted to describe the cell growth, substrate uptake rate, and product formation. The maximum specific CO uptake rate (qmax = 34.364?mmol/gcell/h), CO inhibition constant (KI = 0.601?atm), and maximum rate of ethanol (Rmax = 0.172?mmol/L/h at PCO = 0.598?atm) and acetate (Rmax = 0.096?mmol/L/h at PCO = 0.539?atm) production were determined from the applied models. PMID:24672390

Mohamed, Abdul Rahman; Najafpour, Ghasem D.; Younesi, Habibollah; Uzir, Mohamad Hekarl

2014-01-01

405

Mapping grasslands suitable for cellulosic biofuels in the Greater Platte River Basin, United States  

USGS Publications Warehouse

Biofuels are an important component in the development of alternative energy supplies, which is needed to achieve national energy independence and security in the United States. The most common biofuel product today in the United States is corn-based ethanol; however, its development is limited because of concerns about global food shortages, livestock and food price increases, and water demand increases for irrigation and ethanol production. Corn-based ethanol also potentially contributes to soil erosion, and pesticides and fertilizers affect water quality. Studies indicate that future potential production of cellulosic ethanol is likely to be much greater than grain- or starch-based ethanol. As a result, economics and policy incentives could, in the near future, encourage expansion of cellulosic biofuels production from grasses, forest woody biomass, and agricultural and municipal wastes. If production expands, cultivation of cellulosic feedstock crops, such as switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus species), is expected to increase dramatically. The main objective of this study is to identify grasslands in the Great Plains that are potentially suitable for cellulosic feedstock (such as switchgrass) production. Producing ethanol from noncropland holdings (such as grassland) will minimize the effects of biofuel developments on global food supplies. Our pilot study area is the Greater Platte River Basin, which includes a broad range of plant productivity from semiarid grasslands in the west to the fertile corn belt in the east. The Greater Platte River Basin was the subject of related U.S. Geological Survey (USGS) integrated research projects.

Wylie, Bruce K.; Gu, Yingxin

2012-01-01

406

Understanding cost drivers and economic potential of two variants of ionic liquid pretreatment for cellulosic biofuel production  

PubMed Central

Background Ionic liquid (IL) pretreatment could enable an economically viable route to produce biofuels by providing efficient means to extract sugars and lignin from lignocellulosic biomass. However, to realize this, novel IL-based processes need to be developed in order to minimize the overall production costs and accelerate commercial viability. In this study, two variants of IL-based processes are considered: one based on complete removal of the IL prior to hydrolysis using a water-wash (WW) step and the other based on a “one-pot” (OP) process that does not require IL removal prior to saccharification. Detailed techno-economic analysis (TEA) of these two routes was carried out to understand the cost drivers, economic potential (minimum ethanol selling price, MESP), and relative merits and challenges of each route. Results At high biomass loading (50%), both routes exhibited comparable economic performance with an MESP of $6.3/gal. With the possible advances identified (reduced water or acid/base consumption, improved conversion in pretreatment, and lignin valorization), the MESP could be reduced to around $3/gal ($3.2 in the WW route and $2.8 in the OP route). Conclusions It was found that, to be competitive at industrial scale, lowered cost of ILs used and higher biomass loadings (50%) are essential for both routes, and in particular for the OP route. Overall, while the economic potential of both routes appears to be comparable at higher biomass loadings, the OP route showed the benefit of lower water consumption at the plant level, an important cost and sustainability consideration for biorefineries. PMID:24932217

2014-01-01

407

The path to next generation biofuels: successes and challenges in the era of synthetic biology.  

PubMed

Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels. PMID:20089184

Dellomonaco, Clementina; Fava, Fabio; Gonzalez, Ramon

2010-01-01

408

Implications of the Biofuels Boom for the Global Livestock Industry: A Computable General Equilibrium Analysis  

Microsoft Academic Search

In this paper, we offer a general equilibrium analysis of the impacts of US and EU biofuel mandates for the global livestock sector. Our simulation boosts biofuel production in the US and EU from 2006 levels to mandated 2015 levels. We show that mandates will encourage crop production in both biofuel and non biofuel producing regions, while reducing livestock and

Farzad Taheripour; Thomas W. Hertel; Wallace E. Tyner

2009-01-01

409

Production of bio-fuels (hydrogen and lipids) through a photofermentation process.  

PubMed

The purple non-sulfur photosynthetic bacteria Rhodopseudomonas palustris (strain 42OL) was investigated for a co-production of both bio-H(2) and biodiesel (lipids). The investigation was carried out using malic and glutamic acids in a fed-batch cultivation system under continuous irradiances of 36, 56, 75, 151, 320, 500, and 803 W m(-2). Boltzmann's sigmoidal regression model was used to determine growth kinetic parameters during hydrogen photoevolution. The upper limit of volumetric hydrogen photoevolution was 15.5 + or - 0.9 ml l(-1) h(-1). During the entire cultivation period (408 h), the highest average hydrogen production rate (HPR(av)) of 11.1 + or - 3.1 ml l(-1) h(-1) was achieved at an irradiance of 320 W m(-2). Biomasses stored at the end of each experimental set were analyzed in order to determine lipid content, which ranged from a minimum of 22 + or - 1% to a maximum of 39 + or - 2% of biomass dry weight. PMID:20060291

Carlozzi, Pietro; Buccioni, Arianna; Minieri, Sara; Pushparaj, Benjamin; Piccardi, Raffaella; Ena, Alba; Pintucci, Cristina

2010-05-01

410

Effect of operating parameters on bio-fuel production from waste furniture sawdust.  

PubMed

Fast pyrolysis is an effective technology for conversion of biomass into energy and value-added chemicals instead of burning them directly. In this study, fast pyrolysis of waste furniture sawdust (pine sawdust) was investigated under various reaction conditions (reaction time, pyrolysis temperature, heating rate, residence time and particle size) in a tubular reactor. The optimum reaction conditions for bio-oil production was found as reaction time of 5 min, pyrolysis temperature of 500 °C, heating rate of 300 °C min(-1) under nitrogen flow rate of 400 cm(3) min(-1). At these conditions, maximum bio-oil yield was obtained as 42.09%. Pyrolysis oils were characterized by using various elemental analyses, fourier - transformation infrared (FT-IR) spectrometry and gas chromatography-mass spectrometry (GC-MS). The results of the GC-MS showed that cracking of large molecular phenolics was followed by partial conversion into phenol and alkylated phenols (45%) during the pyrolysis. According to the experimental and characterization results; the liquid product could be used as feedstock for the chemical industry or petroleum crude for refinery. PMID:23235998

Uzun, Basak Burcu; Kanmaz, Gülin

2013-04-01

411

Product ecodesign and materials: current status and future prospects  

E-print Network

The aim of this paper is to discuss the current status of ecodesign in the industry and its future implications for materials. There is today more and more focus on the environmental impacts of products during their whole life cycle. In particular, ecodesign aims at integrating environmental aspects during the product's design process as any other criterion, in order to reduce the life cycle impacts. Although a lot of product environmental impact assessment and Design for Environment tools already exist, environmental aspects are unfortunately rarely routinely integrated into product development process in the industry. This is mainly due to the fact that current ecodesign tools are little adapted to designers' practices, requirements and competencies. After the sequential and DfX paradigms, design of products is today maturing into Integrated Design, where multiple points of views and expertise have to be considered at the same time to progressively define the product.

Mathieux, Fabrice; Zwolinski, Peggy

2007-01-01

412

Assessing Habitat for Avian Species in Assessing Habitat for Avian Species in an Integrated Forage/Biofuels an Integrated Forage/Biofuels  

E-print Network

in an Integrated Forage/Biofuels an Integrated Forage/Biofuels Management System Management System in the Midin NWSG mixes beneficial to forage, biofuels production, and wildlife habitatp , 3. identify wildlife habitat benefits associated with varying forage and biofuels management strategies 4. identify optimum

Gray, Matthew

413

Consolidated Bio-Processing of Cellulosic Biomass for Efficient Biofuel Production Using Yeast Consortium  

NASA Astrophysics Data System (ADS)

Fossil fuels have been the major source for liquid transportation fuels for ages. However, decline in oil reserves and environmental concerns have raised a lot of interest in alternative and renewable energy sources. One promising alternative is the conversion of plant biomass into ethanol. The primary biomass feed stocks currently being used for the ethanol industry have been food based biomass (corn and sugar cane). However, interest has recently shifted to replace these traditional feed-stocks with more abundant, non-food based cellulosic biomass such as agriculture wastes (corn stover) or crops (switch grass). The use of cellulosic biomass as feed stock for the production of ethanol via bio-chemical routes presents many technical challenges not faced with the use of corn or sugar-cane as feed-stock. Recently, a new process called consolidated Bio-processing (CBP) has been proposed. This process combines simultaneous saccharification of lignocellulose with fermentation of the resulting sugars into a single process step mediated by a single microorganism or microbial consortium. Although there is no natural microorganism that possesses all properties of lignocellulose utilization and ethanol production desired for CBP, some bacteria and fungi exhibit some of the essential traits. The yeast Saccharomyces cerevisiae is the most attractive host organism for the usage of this strategy due to its high ethanol productivity at close to theoretical yields (0.51g ethanol/g glucose consumed), high osmo- and ethanol- tolerance, natural robustness in industrial processes, and ease of genetic manipulation. Introduction of the cellulosome, found naturally in microorganisms, has shown new directions to deal with recalcitrant biomass. In this case enzymes work in synergy in order to hydrolyze biomass more effectively than in case of free enzymes. A microbial consortium has been successfully developed, which ensures the functional assembly of minicellulosome on the yeast surface composed of four yeast populations. These yeast populations include: one displaying scaffoldin on its surface and three populations secreting three different cellulases in the medium to hydrolyze the cellulose. The modular nature of the consortium system allows for the fine-tuning of each population by changing their initial inoculum ratio, thereby optimizing the cellulose hydrolysis and hence ethanol production. When comparing the optimized consortium with equal ratio consortium, the optimized one produced almost double the amount of ethanol (1.87 g/l) with a yield of 0.475 g ethanol/g cellulose. To further evaluate the feasibility of using consortium for CBP, it was grown at very low optical density (OD) under anaerobic conditions. Under stressful conditions like low OD and no oxygen, the consortium system was proficient in assembling the cellulosome on its surface and growing on the PAS-avicel as sole carbon source and concomitantly producing ethanol with a yield of 87% of the theoretical value. For the dynamic study of yeast consortium system, quantitative real time PCR was used to enumerate the individual yeast population in the mixed culture. At the end of the cultivation, ratios of each population in this consortium maintained similar number as the initial inoculums ratios, which further confirms the consortium system is suitable for the application of CBP.

Goyal, Garima

414

Quantum cascade laser photoacoustic detection of nitrous oxide released from soils for biofuel production  

NASA Astrophysics Data System (ADS)

In order to investigate the generation of greenhouse gases in sugarcane ethanol production chain, a comparative study of N2O emission in artificially fertilized soils and soils free from fertilizers was carried out. Photoacoustic spectroscopy using quantum cascade laser with an emission ranging from 7.71 to 7.88 µm and differential photoacoustic cell were applied to detect nitrous oxide (N2O), an important greenhouse gas emitted from soils cultivated with sugar cane. Owing to calibrate the experimental setup, an initial N2O concentration was diluted with pure nitrogen and detection limit of 50 ppbv was achieved. The proposed methodology was selective and sensitive enough to detect N2O from no fertilized and artificially fertilized soils. The measured N2O concentration ranged from ppmv to ppbv.

Couto, F. M.; Sthel, M. S.; Castro, M. P. P.; da Silva, M. G.; Rocha, M. V.; Tavares, J. R.; Veiga, C. F. M.; Vargas, H.

2014-12-01

415

Biofuel vs. Biodiversity? Integrated Emergy and Economic Cost-Benefit Evaluation of Rice-Ethanol Production in Japan  

EPA Science Inventory

Energy analysis results confirmed that abandoned rice fields provide a good opportunity for Japan to fulfill its E-3 target by producing ethanol from high-yield rice feedstock. However, to be a viable alternative, a biofuel should not only provide a net energy gain and reduce the...

416

Biofuels and Fisheries: Risks and Opportunities .  

EPA Science Inventory

A rapidly developing biofuels industry in the U.S. and around the globe poses novel environmental challenges and opportunities, with implications for teh health and sustainability of fisheries. Changes in land uses and agricultural practices for production of biofuel feedstocks ...

417

Anaerobic gut fungi: Advances in isolation, culture, and cellulolytic enzyme discovery for biofuel production.  

PubMed

Anaerobic gut fungi are an early branching family of fungi that are commonly found in the digestive tract of ruminants and monogastric herbivores. It is becoming increasingly clear that they are the primary colonizers of ingested plant biomass, and that they significantly contribute to the decomposition of plant biomass into fermentable sugars. As such, anaerobic fungi harbor a rich reservoir of undiscovered cellulolytic enzymes and enzyme complexes that can potentially transform the conversion of lignocellulose into bioenergy products. Despite their unique evolutionary history and cellulolytic activity, few species have been isolated and studied in great detail. As a result, their life cycle, cellular physiology, genetics, and cellulolytic metabolism remain poorly understood compared to aerobic fungi. To help address this limitation, this review briefly summarizes the current body of knowledge pertaining to anaerobic fungal biology, and describes progress made in the isolation, cultivation, molecular characterization, and long-term preservation of these microbes. We also discuss recent cellulase- and cellulosome-discovery efforts from gut fungi, and how these interesting, non-model microbes could be further adapted for biotechnology applications. PMID:24788404

Haitjema, Charles H; Solomon, Kevin V; Henske, John K; Theodorou, Michael K; O'Malley, Michelle A

2014-08-01

418

Immobilized anaerobic fermentation for bio-fuel production by Clostridium co-culture.  

PubMed

Clostridium thermocellum/Clostridium thermolacticum co-culture fermentation has been shown to be a promising way of producing ethanol from several carbohydrates. In this research, immobilization techniques using sodium alginate and alkali pretreatment were successfully applied on this co-culture to improve the bio-ethanol fermentation performance during consolidated bio-processing (CBP). The ethanol yield obtained increased by over 60 % (as a percentage of the theoretical maximum) as compared to free cell fermentation. For cellobiose under optimized conditions, the ethanol yields were approaching about 85 % of the theoretical efficiency. To examine the feasibility of this immobilization co-culture on lignocellulosic biomass conversion, untreated and pretreated aspen biomasses were also used for fermentation experiments. The immobilized co-culture shows clear benefits in bio-ethanol production in the CBP process using pretreated aspen. With a 3-h, 9 % NaOH pretreatment, the aspen powder fermentation yields approached 78 % of the maximum theoretical efficiency, which is almost twice the yield of the untreated aspen fermentation. PMID:24488259

Xu, Lei; Tschirner, Ulrike

2014-08-01

419

Vermont Biofuels Initiative: Local Production for Local Use to Supply a Portion of VermontâÂ?Â?s Energy Needs  

SciTech Connect

The Vermont Biofuels initiative (VBI) is the Vermont Sustainable Jobs Fund�s (VSJF) biomass-to-biofuels market development program. Vermont is a small state with a large petroleum dependency for transportation (18th in per capita petroleum consumption) and home heating (55% of all households use petroleum for heating). The VBI marks the first strategic effort to reduce Vermont�s dependency on petroleum through the development of homegrown alternatives. As such, it supports the four key priorities of the U.S. Department of Energy�s Multi-year Biomass Plan: 1.) Dramatically reduce dependence on foreign oil; 2.) Promote the use of diverse, domestic and sustainable energy resources; 3.) Reduce carbon emissions from energy production and consumption; 4.) Establish a domestic bioindustry. In 2005 VSJF was awarded with a $496,000 Congressionally directed award from U.S. Senator Patrick Leahy. This award was administered through the U.S. Department of Energy (DE-FG36- 05GO85017, hereafter referred to as DOE FY05) with $396,000 to be used by VSJF for biodiesel development and $100,000 to be used by the Vermont Department of Public Service for methane biodigester projects. The intent and strategic focus of the VBI is similar to another DOE funded organization� the Biofuels Center of North Carolina�in that it is a nonprofit driven, statewide biofuels market development effort. DOE FY05 funds were expensed from 2006 through 2008 for seven projects: 1) a feedstock production, logistics, and biomass conversion research project conducted by the University of Vermont Extension; 2) technical assistance in the form of a safety review and engineering study of State Line Biofuels existing biodiesel production facility; 3) technical assistance in the form of a safety review and engineering study of Borderview Farm�s proposed biodiesel production facility; 4) technology and infrastructure purchases for capacity expansion at Green Technologies, LLC, a waste vegetable biodiesel producer; 5) technical assistance in the form of feasibility studies for AgNorth Biopower LLC�s proposed multi-feedstock biodigester; 6) technology and infrastructure purchases for the construction of a �Cow Power� biodigester at Gervais Family Farm; and 7) the education and outreach activities of the Vermont Biofuels Association. DOE FY05 funded research, technical assistance, and education and outreach activities have helped to provide Vermont farmers and entrepreneurs with important feedstock production, feedstock logistics, and biomass conversion information that did not exist prior as we work to develop an instate biodiesel sector. The efficacy of producing oilseed crops in New England is now established: Oilseed crops can grow well in Vermont, and good yields are achievable given improved harvesting equipment and techniques. DOE FY05 funds used for technology and infrastructure development have expanded Vermont�s pool of renewable electricity and liquid fuel generation. It is now clear that on-farm energy production provides an opportunity for Vermont farmers and entrepreneurs to reduce on-farm expenditures of feed and fuel while providing for their energy security. Meanwhile they are developing new value-added revenue sources (e.g., locally produced livestock meal), retaining more dollars in the local economy, and reducing greenhouse gas emissions.

Scott Sawyer; Ellen Kahler

2009-05-31

420

Path dependence: Biofuels policy under uncertainty about greenhouse gas emissions  

Microsoft Academic Search

We study the effect of uncertainty about the greenhouse gas emissions arising from the production of biofuels on trade policy, in the presence of lobby groups and two policy instruments, trade policy and biofuels mandates. We show that in the presence of biofuels mandates it would be optimal from a societal point of view to lower the trade tariff on

Johanna Jussila Hammes

2011-01-01

421

Nottingham Business School Biofuels Market and Policy Governance  

E-print Network

Nottingham Business School Biofuels Market and Policy Governance The last decade has seen a dramatic growth in the global production and consumption of biofuels, as a rapidly- rising number triggered growing concerns about the downsides from different types of biofuel. This, in turn, presents

Evans, Paul

422

Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad  

E-print Network

Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad Department of Political Science between media framing and public opinion on the issue of biofuels--transportation fuels made from plants, animal products, or organic waste. First, the paper investigates how media framing of biofuels has

423

FULLY FUNDED DEPARTMENT OF ENERGY BIOFUELS RESEARCH INTERNSHIP  

E-print Network

FULLY FUNDED DEPARTMENT OF ENERGY BIOFUELS RESEARCH INTERNSHIP AT PACIFIC NORTHWEST NATIONAL LABORATORY Position Description The overall project objective is to utilize marine microalgae for biofuels (i.e., lipids for biodiesel or jet biofuel) production. The student will set up a series

Wildermuth, Mary C