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Maslak, Valeria. "Biofuel." Thesis, Київський національний університет технологій та дизайну, 2020. https://er.knutd.edu.ua/handle/123456789/15338.
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Matakala, Litiya. "Biofuel policies : what can Zambia learn from leading biofuel producers." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/5748.
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Thesis (MDF (Development Finance))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: Price volatility and high dependency on imported petroleum fuel has prompted the Zambian government to look into renewable fuels as part of an energy diversification program. With growing global interest in biofuels as a transportation fuel, the Zambian government intends to introduce bioethanol and biodiesel as renewable fuels in the transportation sector. While it seems feasible to produce both the feedstocks and biofuels to meet local demand, a regulatory framework and industry support mechanisms have not yet been formulated. The policy and regulatory frameworks encompass a multitude of actors, networks and institutions all playing distinct and important roles. Incorporating the differing interests of all these stakeholders is an involving process that requires detailed analysis of agriculture, environmental, energy, socioeconomic and taxation policies. This study attempts to contribute to the biofuels policy formulation process in Zambia. It analyses biofuel policies in leading biofuels producing countries and identifies aspects that the Zambian government should consider incorporating in its own policies to ensure a viable biofuels industry. Biofuel policies in Brazil, Germany and the United States of America were analysed using a detailed case study and extensive literature review. Furthermore, a detailed analysis of the Zambian agriculture sector and the demand for petroleum fuel puts into context the potential demand and challenges likely to be faced. By understanding the history and development of biofuels in the case study countries, best practices, problems faced, policy innovations and industry support mechanisms were identified to inform policy formulation in Zambia. This does not only provide valuable insights and lessons but also ensures that time and resources are not wasted by reinventing the wheel. The comparative analysis of policies and support mechanisms in the three case study countries showed that articulating a clear policy objective, government support in the form of subsidies, wide stakeholder involvement and industry regulation have all played a critical role in the development of the industry. However, the extent to which all these factors have helped to shape the industry in Brazil, Germany and the USA is neither equal nor static. Countries are continuously adapting their policies and support mechanisms to environmental, energy and economic conditions.
AFRIKAANSE OPSOMMING: Die onbestendigheid van pryse en die groot mate van afhanklikheid van ingevoerde petroleumbrandstof het die Zambiese regering aangespoor om ondersoek in te stel na hernubare brandstof as deel van 'n energiediversifiseringsprogram. In die lig van die groeiende globale belangstelling in biobrandstof as vervoerbrandstof, beplan die Zambiese regering om bioetanol en biodiesel as hernubare brandstof in die vervoersektor te begin gebruik. Al lyk dit prakties uitvoerbaar om sowel die voerstof as die biobrandstof te vervaardig om in die plaaslike aanvraag te voorsien, is 'n reguleringsraamwerk en ondersteuningsmeganismes vir die industrie nog nie geskep nie. 'n Menigte rolspelers, netwerke en instellings, wat almal verskillende en belangrike rolle speel, sal betrokke wees by die beleidsformulering en reguleringsraamwerk. Om die uiteenlopende belange van al die betrokke partye in ag te neem is 'n ingewikkelde proses wat sal vereis dat 'n uitvoerige analise gemaak word van landbou-, omgewings-, energie-, sosio-ekonomiese en belastingbeleidsrigtings. Die doelwit van hierdie studie is om 'n bydrae te lewer tot die formuleringsproses van die biobrandstofbeleid in Zambie. Dit analiseer die biobrandstofbeleid van die vooraanstaande lande wat biobrandstof vervaardig, en identifiseer aspekte wat die Zambiese regering in sy beleid behoort in te sluit om 'n lewensvatbare biobrandstofindustrie te verseker. Die biobrandstofbeleid van Brasilie, Duitsland en die Verenigde State van Amerika (VSA) is geanaliseer met behulp van uitvoerige gevallestudies en 'n grondige literatuurstudie. Verder plaas 'n noukeurige analise van die Zambiese landbousektor en die aanvraag na petroleumbrandstof die potensiele aanvraag en uitdagings wat waarskynlik hanteer sal meet word in konteks. Deur insig te verkry in die geskiedenis en ontwikkeling van biobrandstof in die lande waar die gevallestudies gedoen is, kon die beste gebruike, moontlike probleme, nuwe beleidsrigtings en ondersteuningsmeganismes in die bedryf geidentifiseer word om die beleid in Zambie te help formuleer. Dit bied nie slegs waardevolle insig en leergeleenthede nie, maar verseker ook dat tyd en hulpbronne nie vermors word deur die wiel van voor af uit te vind nie. Die vergelykende analise van die beleidsrigtings en ondersteuningsmeganismes in die drie lande waar die gevallestudies gedoen is, het getoon dat 'n duidelik geformuleerde beleidsdoelwit, ondersteuning van die regering in die vorm van subsidies, die algemene betrokkenheid van belanghebbendes en die regulering van die industrie alles 'n uiters belangrike rol gespeel het in die ontwikkeling van hierdie industrie. Die mate waarin al hierdie faktore die industrie in Brasilie, Duitsland en die VSA help vorm het, het egter gewissel en was nooit staties nie. Lande pas voortdurend hulle beleid en ondersteuningsmeganismes aan by omgewings-, energie- en ekonomiese toestande.
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Larsson, Mathias. "Environmental assessments and Swedish consumption of biofuels : Review of Swedish biofuel research and aggregated life cycle assessment of Swedish biofuel consumption 2000-2013." Thesis, KTH, Industriell ekologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172050.
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This thesis assesses the potential environmental impacts for Swedish biofuel consumption and evaluates the environmental scope in Swedish biofuel research. The biofuel consumption is portrayed with life cycle assessment methodology and presents the emissions occurring from different feedstock and fuel production regions. The outcome of the biofuel consumption is compared with a fossil fuel scenario in order to put the emissions of biofuels in broader context. A systematic literature review is conducted on the published Swedish environmental system analysis on biofuels, to quantitatively interpret assessed environmental indicators and methods. The findings are that while global warming potential emissions decreased, local environmental impact potentials increases drastically. Most of the environmental burdens from the consumption have occurred in the EU and South America. Results from the systematic literature review shows on a dominating scope towards global warming potential and energy performance of the fuels. The justifications for the low consideration of other impact categories are often without motivation. Implications occurring from the limited scope are discussed in terms of potential problem shifting and its correspondence to Swedish environmental policy. The biofuel policies from the European Union and the Swedish Government are insufficient regarding mitigation of e.g. eutrophication, acidification and toxicity. Impacts from land use change and indirect land use change are also highly important to include in the assessments.I denna masteruppstats bedöms de potentiella miljöeffekterna för Svensk biodrivmedelskonsumtion och analysomfattningen i den Svensk biodrivmedelsforskningen. Sveriges konsumtion av biodrivmedel är miljömässigt bedömd genom livscykelanalys, där emissioner från råvaruframställning och produktion presenteras över uppkomstområde åren 2000-2013. De olika påverkansindikatorerna jämförs med miljöpåverkan från förbränning av fossila drivmedel med samma energiinnehåll. En systematisk litteraturundersökning genomförs över alla svenskpublicerade vetenskapliga artiklar i syfte att kvantitativt bedöma omfattningen av påverkanskategorier. Resultaten visar att samtidigt som växthusgaserna minskat har andra påverkanskategorier ökat dramatiskt. Den bedömda miljöpåverkan till följd av biodrivmedelskonsumtionen skedde till största delen i Europeiska och Sydamerikanska länder. Resultatet från den systematiska litteraturundersökningen visar ett övervägande i miljöpåverkansfokus på växthusgasutsläpp och energiprestanda i forskningen. Valet av påverkanskategorier är ofta undermåligt beskrivet och motivering till de studerade påverkansområdena saknas i majoriteten av rapporterna. Konsekvenserna av denna snäva miljöpåverkanssyn är diskuterad i förhållande till problemförflyttning och svensk miljöpolicy. Biodrivmedels strategier från Europeiska Unionen och den svenska regeringen är bristfälliga för att minska t. ex. övergödning, försurning och toxicitet. Påverkan från förändrad landanvändning och indirekt förändrad landanvändning är även de viktiga att medta i bedömningarna.
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Affandy, Gabriel, Donald Bridges, Quinn Daniels, Drew Janicek, Julia Martin, Edward Poling, Jordan Schmalz, et al. "HAWAII ALGAL BIOFUEL." Monterey, California. Naval Postgraduate School, 2013. http://hdl.handle.net/10945/32891.
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This report investigates the feasibility and affordability of producing algae-derived biofuel in Hawaii for military aviation. The authors evaluated methods for cultivation of algae, investigated the processes necessary to locally refine bio-oil into bio-kerosene, researched the environmental impacts of cultivation and refinement facilities in Hawaii, and studied the resultant cost per gallon of bio-kerosene production. Based on the current state of technology and the proposed system of systems architecture, this report estimates that bio-kerosene can be produced for $8.00 - 22.87/gal, indicating that although this system is technically feasible, it is unlikely to be affordable at current fuel prices without ongoing subsidy or further technical innovation.
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Khor, Adela. "Energy from biofuel." Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/3595/.
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Coal energized the 19"' century while oil worked for the 20"' century. The question that remains pending is the future energy source. With the expanding population and growing demands from industrialization of countries such as India and China, total reliance on fossil fuel is not sustainable. The urgent need for a green and sustainable fuel prompted research into energy crops as an alternative to fossil fuels. There is a need to identify a suitable biomass species, which can provide high-energy outputs in order to replace conventional fossil fuel. The type of biomass used would then depend on the energy conversion process and the form in which the energy is required. Theoretical and experimental studies are also required to investigate the relevant parameters for future process optimisation. In response to this demand, the first part of this PhD study focuses on examining the parameters affecting the behaviour of solid bed combustion in a fixed bed reactor. Extensive experimental investigation aimed at studying the behaviour of various biomass materials in fixed bed combustion was successfully completed. The parameters investigated in this experimental programme were the influence of primary air flow rates and particle sizes. Complementary conversion technology studied in this PhD is the solid bed gasification in a counter-current fixed bed reactor. The proposed gasifier is part of a two-stage integrated unit that ultimately aims to utilise biomass fuel such as wood chips and fuel pellets derived from agricultural waste. Experimental work was carried out to increase the understanding of the underlying principle of the gasification process. Parameters studied were the steam/air ratio, reactor temperature and particle size. The results obtained from the combustion tests showed that the burning rate, ignition velocity and flue gas composition were governed by the primary air flow. Single stage combustion occurred at higher air flow rates. It was also observed that the ignition front speed was inversely proportional to the bulk density. Larger particles have a lower ignition front speed and burning rate. The average burning rates of herbaceous fuels were 3-4 times slower compared to other biomass materials such as willow wood, miscanthus pellets and RDF waste. Channelling occurred around the side wall of the reactor for small miscanthus pellets and at several locations in the bed for larger particles (35mm cube). However, the observed channelling effect is severe in the test cases for uncut straw. The study of the gasification process showed that the hydrogen yield is influenced by the steam/air ratio, total flow rate of reactants, reactor temperature and particle size. The production of methane was negligible and no higher hydrocarbons were detected. A computational code known as the Fluid Dynamics of Incinerator Combustion code (FLIC) was used to interpret the experimental data. In this model, the initial solid waste undergoes step changes in the volume of its components consisting of moisture, volatile, fixed carbon, ash and internal pore space. The code was adapted to incorporate the steam-char reactions and gas phase reactions for the modelling of the gasification process. Comparison between the experimental results and model predictions showed good agreement. The combustion and gasification characteristics such as the burning rate, ignition rate, temperature profiles and gaseous emissions showed similar trends.
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Görling, Martin. "Turbomachinery in Biofuel Production." Licentiate thesis, KTH, Energiprocesser, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-28901.
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The aim for this study has been to evaluate the integration potential of turbo-machinery into the production processes of biofuels. The focus has been on bio-fuel produced via biomass gasification; mainly methanol and synthetic natural gas. The research has been divided into two parts; gas and steam turbine applications. Steam power generation has a given role within the fuel production process due to the large amounts of excess chemical reaction heat. However, large amounts of the steam produced are used within the production process and is thus not available for power production. Therefore, this study has been focused on lowering the steam demand in the production process, in order to increase the power production. One possibility that has been evaluated is humidification of the gasification agent in order to lower the demand for high quality steam in the gasifier and replace it with waste heat. The results show that the power penalty for the gasification process could be lowered by 18-25%, in the specific cases that have been studied. Another step in the process that requires a significant amount of steam is the CO2-removal. This step can be avoided by adding hydrogen in order to convert all carbon into biofuel. This is also a way to store hydrogen (e.g. from wind energy) together with green carbon. The results imply that a larger amount of sustainable fuels can be produced from the same quantity of biomass. The applications for gas turbines within the biofuel production process are less obvious. There are large differences between the bio-syngas and natural gas in energy content and combustion properties which are technical problems when using high efficient modern gas turbines. This study therefore proposes the integration of a natural gas fired gas turbine; a hybrid plant. The heat from the fuel production and the heat recovery from the gas turbine flue gas are used in a joint steam cycle. Simulations of the hybrid cycle in methanol production have shown good improvements. The total electrical efficiency is increased by 1.4-2.4 percentage points, depending on the fuel mix. The electrical efficiency for the natural gas used in the hybrid plant is 56-58%, which is in the same range as in large-scale combined cycle plants. A bio-methanol plant with a hybrid power cycle is consequently a competitive production route for both biomass and natural gas.QC 20110128
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Rasmussen, Michelle. "Trehalose-Based Biofuel Cells." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1321368249.
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Raut, Mahendra. "Characterising cellulolytic and biofuel generating bacteria using proteomics for future implementation as biofuel producers." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/6404/.
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In natural ecosystems, microbes are mostly found in diverse and complex communities or consortia that can live symbiotically and fulfil most important global biogeochemical cycles. These processes are very difficult or impossible to achieve by a single bacterium. At the global level, scientists have come to know the innate capacity of natural microbial consortia and are starting to understand natural communities and to develop recombinant synthetic consortia for future biotechnology application. In order to overcome key challenges arising due to fossil fuel depletion and contribution to global warming, consolidated bioprocessing (CBP) is thought to be a low cost processing scheme for lignocellulosic biofuel production. Consortia of cellulolytic and biofuel producing microorganisms could be an attractive alternative to single organism approaches. However, proper understanding of the biology of native microbes and their implementation in the development of consortia needs rigorous research study at the system-wide level. Given the immense potential in the conversion of lignocellulosic biomass to biofuels, anaerobic microorganisms are of great interest to researchers. Therefore, this research is focussed on two different anaerobic bacteria: Fibrobacter succinogenes S85, which is an efficient cellulose degrader, but cannot produce biofuels; and Clostridium acetobutylicum ATCC 824, a promising solvents (acetone, ethanol, butanol) producing bacterium that cannot degrade cellulose. The study of these microbes at the systems level will help to understand the biological complexity of these microbes and provide valuable information for future CBP development. Based on capabilities of these microbes, two individual aspects have been proposed and investigated. In this thesis, an investigation of the surface colloidal properties and surface-membrane associated proteins of F. succinogenes involved in cellulose degradation by biotin labelling method using two substrate conditions cellulose and glucose (control) is carried out. Further analysis of the F. succinogenes membrane using high throughput quantitative proteomics using isobaric tag for relative and absolute quantitation (iTRAQ) is presented. This iTRAQ study reveals many novel proteins associated with cellulose degradation, adding valuable information on the mechanism of cellulose degradation in this bacterium. In this thesis, a preliminary technical study comparing two digestion systems (in-gel and in-solution) of soluble proteins from C. acetobutylicum and two peptide separation techniques (SCX and HILIC) is presented. Results reveal that in-gel digestion with HILIC separation is superior to SCX for soluble proteomics from this system. Results are further used in a quantitative proteomics study in the presence of cellobiose and lignin and elucidate the effect of lignin on solvent production and various metabolic processes. This thesis demonstrates that both F. succinogenes and C. acetobutylicum can potentially be used in co-culture to utilise cellulose and pre-treated lignocellulosic waste for bio-augmented bioalcohol production in consolidated bioprocess (CBP) development framework.
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Siddiqui, Aamir, Christopher Kading, and Kasey Carter. "Biofuel: a comparative case study." Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/34746.
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Approved for public release; distribution is unlimitedThis project analyzes the governments role in the commercialization of biofuel by comparing biofuel commercialization efforts to those of nuclear power and nanotechnology commercialization. The PESTEL framework is applied to nuclear power and nanotechnology to identify key factors relevant to successful commercialization. These success factors are compared to current government biofuel policies to infer the likelihood of successful biofuel commercialization. In closing we recommend changes to government policy to improve the prospect of biofuel commercialization.
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Ashworth, Kirsti. "Atmospheric impacts of biofuel cultivation." Thesis, Lancaster University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.654455.
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Biogenic volatile organic compounds play a key role in governing the rate of chemical production and loss of tropospheric ozone and formation of secondary organic aerosol, important atmospheric constituents which affect both climate and air quality. Isoprene is the most important of these compounds, both in terms of quantity emitted and subsequent reactions. The effects of changes in isoprene emissions due to land use change driven by the cultivation of biofuel feedstock crops in the near-future (2020s) have been evaluated. Two realistic biofuel cultivation scenarios were developed, based on current government targets for the replacement of transportation fuel with bio-ethanol and biodiesel. A series of simulations, using isoprene emissions, atmospheric chemistry and climate models, were performed to quantify the impacts. The two biofuel cultivation scenarios yield roughly the same quantity of fuel (180 Mt of oil equivalent per year), in line with projected global demands for biofuel in the 2020s. In each case, global annual isoprene emissions rose by around 1 %. The resulting changes in ground-level ozone concentrations were markedly different, with increases of as much as 10 ppbv over parts of Europe as a result of cultivation in the mid-latitudes, but decreases across much of the tropics due to oil palm cultivation. If co-located emissions of NOx from oil palm processing were included, ozone levels rose by up to 5 ppbv over SE Asia, highlighting the importance of controlling NOx emissions. The increases in ozone over Europe are projected to result in 1300 premature deaths and a 4% reduction r III in the wheat harvest. This is the first time that changes in biogenic emissions resulting from realistic land use changes driven by biofuel cultivation have been considered. The projected impacts on air quality and health indicate that such emissions are important in assessing the overall environmental effect of biofuels.
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Macklyne, Heather-Rose Victoria. "Engineering bacteria for biofuel production." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/67293/.
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This thesis addresses the need for environmentally and socially responsible sources of energy. Biofuels, made from organic matter, have recently become a viable alternative to petroleum-based fossil fuel. Sugar and starch make up the majority of feedstock used in biofuel production as it is easily digested. However, the use of these feedstocks is problematic as they consume resources with negative implications. By using a bacterium able to utilise five and six carbon sugars, such as the thermophile Geobacillus thermoglucosidans, organic lignocellulosic waste material can be used as a feedstock. The aim of this project was to investigate and utilise key genetic regulators of fermentation in G. thermoglucosidans and to construct genetic engineering tools that enable strain development for second generation biofuel production. We have focused on the redox-sensing transcriptional regulator Rex, widespread in Grampositive bacteria, which controls the major fermentation pathways in response to changes in cellular NAD+/NADH ratio. Following the identification of several members of the Rex regulon via bioinformatics analysis, ChIP-seq and qRT-PCR experiments were performed to locate genome-wide binding sites and controlled genes in G. thermoglucosidans. Initial electromobility shift assay experiments were performed to demonstrate the potential for use of Rex from Clostridium thermocellum as an orthogonal regulator. To further this research, novel in vivo synthetic regulatory switches were designed and tested with the aim of controlling gene expression in response to changes in cellular redox state. In addition, new tools for the efficient genetic engineering of G. thermoglucosidans were produced and optimised, including an E. coli-G. thermoglucosidans conjugation method for plasmid transfer and gene disruption.
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Kaloudis, Dimitrios. "Improving microalgae for biofuel production." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665443.
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Microalgae are a diverse group of oxygenic photosynthetic microorganisms which show great promise as a source of biofuel. However, significant challenges still remain before microalgae can be considered a viable source of biofuel. The main current challenges are nutrient sourcing and recycling as well as downstream processing. The algal cell wall and especially the presence of an algaenan cell wall in some Chlorophyte algae could be an important variable in determining downstream processing costs but not much comparative research has been done to elucidate this. The first part of the present study focuses on the recently isolated alga Pseudochoricystis ellipsoidea (Trebouxiophyceae) and its improvement and assessment for biofuel production. Random mutagenesis and FACS screening protocols were developed for the isolation of pigment and cell wall mutants but despite considerable efforts no suitable mutants could be identified in the first half of this project. Two 500 L raceway ponds as well as an algal growth room and bubble column bioreactors were set up to facilitate algal research at the University of Bath and assess the performance of P. ellipsoidea in realistic culture conditions. P. ellipsoidea showed a maximum growth of 1.53 divisions day-1 in semi-open raceway ponds, resistance to contamination and a 30% lipid content, making it particularly suitable for raceway pond cultures. In the second part of this project six species of Chlorophyte (“green”) algae, three of which produced algaenan, were compared for suitability to growth in anaerobic digestate and municipal wastewater as well as cell wall strength, permeability and suitability to hydrothermal liquefaction. We found that anaerobic digestate was a good medium for the growth of all species independently of autoclaving and that non-autoclaved wastewater was a very challenging medium. Algaenan production did not affect cell disruption by ultrasonication but growth stage and cell wall thickness did. Lipid extraction kinetics by chloroform/methanol were greatly affected by algaenan, meaning that this material is relatively impermeable to organic solvents. Cell wall thickness, cell volume and lipid content also had an effect on lipid extraction kinetics but this was only measurable after 180 minutes of extraction. 8 Hydrothermal liquefaction showed high solid and low oil yields, very low sulphur (≤0.1 %) as well as a 1.1 % -1.8 % nitrogen content which is significantly lower than most algal HTL studies to date. This suggests that stationary stage algae are more difficult to process but give a cleaner biocrude and reduce the loss of nitrogen through incorporation in the oil. Significant opportunities for optimisation still exist in the HTL process.
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Warrack, Katrina Anne. "Structural studies of biofuel components." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7819/.
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The main aim of this project is to find, solve and characterise polymorphs of methyl stearate and methyl palmitate, which are the two major compounds that have prevented the widespread use of biodiesel. Biodiesel is traditionally derived from biomass containing high percentages of triglycerides, which are converted into fatty acid methyl esters (FAMEs). High melting point saturated FAMEs produce the same poor low temperature flow properties experienced with petroleum diesel. For many years additives have been designed for petroleum diesel to reduce the cold flow problems; however these are not structurally selective for FAMEs. The most common compounds in biodiesel which cause cold flow problems are methyl stearate and methyl palmitate; therefore accurate crystal structures for all polymorphs that may crystallise in the fuel should be found, to design additives which are structurally selective for these compounds. Throughout this thesis powder x-ray and neutron diffraction were used in conjunction with Gaussian dipole calculations, to characterise the polymorphs of methyl stearate and methyl palmitate and their interactions with 5 straight chain n-alkanes. Variable temperature and solvents were used to mimic the conditions that might be experienced in the fuel tank of a car.
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Gelt, Joe. "Wanted: A Viable Biofuel Crop." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/622106.
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Bullen, Richard Andrew. "Biofuel cells and their development." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/65596/.
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A biofuel cell electrochemical system based on the oxidation of glucose by glucose oxidase has been developed. The glucose oxidase was immobilised at the electrode surface by a cast Nafion polymer membrane neutralised and modified by tetrabutylammonium bromide to stabilise the membrane. Electrochemical communication with the electrode was established with ferrocene derivatives in solution or co-cast with the Nafion. The individual and combined properties of the components of the system were investigated to select the best components to create a biofuel cell. After establishing a functioning biofuel cell a scale-up procedure was followed in which the chemical system was transferred to higher area electrodes. A laboratory prototype biofuel cell was designed and used to test larger 3-d electrode materials. Before use as an electrochemical reactor the flow properties of the test cell and electrodes were investigated by pulse injections of concentrated buffer tracked with an inline conductivity probe. The biofuel cell generated a steady state power density of up to 50 μW cm-2 superficial area at a graphite plate electrode or 6 μW cm-2 (actual surface basis) at a reticulated vitreous carbon electrode. The test cell demonstrated high cell potentials for a biofuel cell based on a single enzyme electrode and gave a stable output for several days.
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Berti, Pietro. "Fuelling expectations : UK biofuel policy." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/15278.
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This dissertation analyses the biofuel debate in the UK, focusing on how the UK Government has deployed expectations to legitimise its biofuel policy. The analysis builds on the sociology of expectations, integrated with insights from the multi-level perspective (MLP) on socio-technical transitions. By the end of the 1990s, a sustainable paradigm permeated UK road transport policy opening a space for biofuel policy to emerge. In the second half of the 2000s, disagreements among UK stakeholders over the translation of EU biofuel targets into UK biofuel policy prefigured later EU-wide discussions over limiting targets for first-generation biofuels. Biofuels critics disagreed with the UK Government and biofuels supporters over how to protect a space for future second-generation biofuels, which were expected to overcome the harm caused by currently available, but controversial, first-generation biofuels. The UK Government and biofuels supporters defended rising targets for available biofuels as a necessary stimulus for industry to help fulfil the UK’s EU obligations and eventually develop second-generation biofuels. By contrast, critics opposed biofuels targets on the grounds that these would instead lock-in first-generation biofuels, thus pre-empting second-generation biofuels. I argue that these disagreements can be explained in relation to the UK Government‘s responsibilities relating to “promise-requirement cycles”, whereby technological promises generate future requirements for the actors involved. Further, I claim that the UK Government’s stance reflects what I call a “policy-promise lock-in” – i.e. a situation in which previous policy commitments towards technology innovators of incumbent technologies (currently controversial and potentially driven by several imperatives) are officially justified as necessary for the development of preferable emerging technologies. Finally, my analysis expands the focus of the sociology of expectations, which has hitherto mostly been used to investigate expectations from technology innovators – i.e. scientists or industrialists – by investigating how other types of actor mediate expectations among different parties, in particular, public authorities, industry associations, consultancies, and non-governmental organisations.
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Kikuchi, Yoko. "Miniaturised glucose-oxygen biofuel cells." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5868.
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Miniaturized glucose-oxygen biofuel cells are useful to power implantable medical devices such as biosensors. They are small, more biocompatible and run continuously on glucose and oxygen, providing cleaner energy at neutral environment. A typical glucose-oxygen biofuel cell consists of an anode with glucose oxidase (GOx) and a cathode with various oxygen reducing catalysts. This thesis describes experimental investigations of the major issues of such systems, viz.: complex electrode fabrication, enzyme instability and inefficient oxygen reduction. Electrodes were built using the simple and scaleable bulk modification method, where all the material was simply mixed and bound together into composites with epoxy resin. For the anodes, the composite made of 10% GOx with 7:7 TTF-TCNQ was found optimal. The GOx electrodes were modified with various enzyme stabilisers (PEI, DTT, PEG, GLC, FAD and mixture of PEI:DTT and PEI:FAD) and 2% of PEI-DTT (1:1 w/w) was most effective in the presence of O2. Its maximum output current density was 1.8 x 10-2 ± 9.9 x 10-3 A.m-2. It also showed the resistant against O2 electron deprivation and enzyme inhibition. Its KM.was 5 mM. For the cathodes, various oxygen reducing catalysts (metalised carbon, anthroquinone modified carbon, laccase and bilirubin oxidase) were incorporated into graphite composite and the electrodes were pretreated in different media in order to enhance their catalytic activity. None showed four-electron O2 reduction. NaOH-pretreated cobalt (II) salophen composite electrodes showed two-electron O2 reduction and were most catalytic. Its standard catalytic rate constant was 1.2 x 10-5 ± 1.2 x 10-6 m.s-1. Of the catalysts examined, metal complex composites gave the best results for oxygen-reducing cathodes and their pretreatment led to the synergetic effect because it increased the concentration of catalytic surface oxygen groups and enhanced oxygen reduction.
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Becker, Arno [Verfasser]. "Impacts of European biofuel policies on global biofuel and agricultural markets / Arno Becker. Landwirtschaftliche Fakultät." Bonn : Universitäts- und Landesbibliothek Bonn, 2011. http://d-nb.info/1016987110/34.
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Blaber-Wegg, Tina. "Just biofuels? : mapping dimensions of energy justice in relation to an international liquid biofuel supply chain." Thesis, University of East Anglia, 2016. https://ueaeprints.uea.ac.uk/59398/.
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It is argued in this thesis that it is morally right to identify and address matters of energy justice associated with renewable energy technologies - and thus biofuels. Equity appraisals, as defined in this thesis, can help to identify social and environmental burdens caused by the implementation of these technologies and where they exist, thus helping to understand the extent to which global sustainable development ideals to reduce inequalities are being achieved. This study is the first equity appraisal of an internationally-traded (Brazil-UK) liquid biofuel (sugarcane bioethanol), across both sites of production and consumption, conducted in a manner advocated by energy justice and environmental justice theories. Furthermore, this study provides the first empirical insights in this context of the ways that principal dimensions of energy justice can interrelate and specifically how matters of procedural justice and recognition can drive distributional changes in outcomes amongst people connected and affected to a transnational liquid biofuel supply chain. Primary qualitative data collected from people living in producer and consumption localities revealed that the nature and geographical patterning of issues differed from the views of transnational governance actors and experts. Rather than the majority of burdens lying with those living in Brazil, and UK-based consumers largely indifferent and unaffected, this research found both positive and negative equity issues affecting people at both ends of the supply chain. Matters of recognition and procedural injustice were found to be affecting consumers, affecting their abilities to engage effectively with their liquid biofuels purchases that could help drive the consumption of more sustainable, just and socially acceptable biofuels. Conversely, higher levels of recognition of local communities and associated impacts in this particular Brazilian production locality were found to be improving social and environmental outcomes for residents. This research highlights the importance of situated, contextual, primary qualitative data for equity appraisals of liquid biofuels and other renewable technologies. It is argued that these types of appraisals should be conducted more systematically in the field to supplement existing forms of appraisals, support decision-making processes and improve the chances of achieving energy justice in relation to renewable energy technologies.
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Heger, Sebastian Verfasser], Henner [Akademischer Betreuer] [Hollert, and Andreas [Akademischer Betreuer] Schäffer. "Green toxicology and biofuels : ecotoxicological tools for sustainable biofuel development / Sebastian Heger ; Henner Hollert, Andreas Schäffer." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1181192862/34.
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Heger, Sebastian [Verfasser], Henner [Akademischer Betreuer] Hollert, and Andreas [Akademischer Betreuer] Schäffer. "Green toxicology and biofuels : ecotoxicological tools for sustainable biofuel development / Sebastian Heger ; Henner Hollert, Andreas Schäffer." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1181192862/34.
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Dooley, Scott J. "Management of biofuel sorghums in Kansas." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4122.
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Wright, Mark Mba. "Techno-economic evaluations of biofuel technologies." [Ames, Iowa : Iowa State University], 2008.
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Evans, Rachael. "Evolving microbial communities for biofuel production." Thesis, University of York, 2018. http://etheses.whiterose.ac.uk/22565/.
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Plant lignocellulose is the most abundant raw material on the planet and a promising substrate for biofuel production. While this complex polymer is efficiently degraded by a range of naturally occurring microbial communities, cost- and energy-efficient industrial use is hampered by its recalcitrance to degradation. By gaining a better understanding of how microbial lignocellulose degrading communities function we may be able to improve industrial processes. In this thesis, I used a combination of ecological and evolutionary approaches to uncover the species and functional traits that drive lignocellulolytic microbial community productivity. I found that the presence of key highly active cellulolytic bacteria increased the productivity of microbial consortia. Specifically, we identified two species, Cellulomonas sp. D13 and Paenibacillus sp. A8, with a range of cellulase and hemicellulase enzymes that have potential for application in industrial processes. Experimental evolution revealed that the rate of phenotypic adaptation of a focal bacterial species, Stenotrophomonas sp. D12, to growth on wheat straw was accelerated by the presence of other competing species. The trajectory of focal species evolution was determined by both the identity and the ecological and evolutionary responses of the competing species. Genome sequencing of evolved clones suggested that genetic adaptation by the focal species to degrade wheat straw involved mutations targeting regulatory genes involved in catabolite repression and carbon storage, two systems that may represent promising targets for the improvement of industrial strains. Overall these results suggest the ecological and evolutionary approaches can be used to design and improve microbial consortia for lignocellulose bioconversion.
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Patel, Bhavish. "Wet algae processing for biofuel production." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/62984.
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Microalgae is seen as a sustainable source of chemicals and biofuels, but its processing to low value fuels is expensive, particularly due to drying, and thus the feasibility of a wet processing route is necessary. This thesis presents experimental research and life cycle assessment on the conversion of microalgal biomass to liquid biofuel (precursor) using high temperature and pressure processing technologies. The bulk of the work is related to Hydrothermal Liquefaction of algal biomass at various residence time (0.5 - 60 min) and temperatures within the Hydrothermal regime (275 - 380°C), using both batch and novel in-house built continuous flow reactor systems. Several analytical tools were deployed to assist with analysis of the formed biocrude to help understand the effect of the reaction conditions on the formed products. Having analysed the biocrude, it became apparent that the aqueous phase contained substantial matter and as such an investigation to quantitate the inorganics in the aqueous phase was conducted. As for the biocrude, detailed analysis showed that further treatment was necessary to make it amenable for utility directly or as a blended fuel and thus, Hydrotreatment using commercially available catalyst under H2 in a batch reactor was conducted. Lastly, the conversion of algal lipids to biodiesel as well as other constituents was investigated under Hydrothermal conditions in presence of methanol, leading to in situ Supercritical Transesterification. The reaction conditions used were found to be too severe for stable yield of methyl esters and consequently degradation kinetics of methyl esters was calculated. Lastly, to understand the environmental profile of the investigated processes, a life cycle assessment was conducted based on experimental data combined with literature values for a conceptual biorefinery in 5 different countries with differing energy mixture. The thesis ends with concluding remarks on the investigation and potential direction for future work.
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Chung, Sooduck, and Michael Farrey. "Biofuel supply chain challenges and analysis." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60830.
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Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010.Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 78-86).
Liquid fuels such as gasoline and diesel are traditionally derived from petroleum. Since petroleum has the potential to be exhausted, there is interest in large scale production of fuels from renewable sources. Currently, ethanol and bio diesel are liquid fuels that are mainly derived from field crops. This paper examines the supply chain challenges and issues that exist for bringing biofuel production up to scale. One major challenge that exists is how to transport the feedstock from a farm to a refinery in the most cost efficient manner. One way to improve transportation efficiency of feedstock is to increase the energy density of the feedstock. However, increasing the density of a feedstock comes with a cost. We use switchgrass as a case study and examine the tradeoff between higher transportation costs in transporting a less energy dense feedstock to processing a feedstock to increase its energy density. We show that creating ethanol from switchgrass in the United States is not competitive in price to gasoline without government subsidies, but as the supply chain matures, efficiencies gained will narrow the gap.
by Sooduck Chung [and] Michael Farrey.
M.Eng.in Logistics
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Wen, Dan, and Alexander Eychmüller. "Enzymatic Biofuel Cells on Porous Nanostructures." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-210960.
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Biofuel cells (BFCs) that utilize enzymes as catalysts represent a new sustainable and renewable energy technology. Numerous efforts have been directed to improve the performance of the enzymatic BFCs (EBFCs) with respect to power output and operational stability for further applications in portable power sources, self-powered electrochemical sensing, implantable medical devices, etc. This concept article details the latest advances about the EBFCs based on porous nanoarchitectures over the past 5 years. Porous matrices from carbon, noble metal, and polymer promote the development of EBFCs through the electron transfer and mass transport benefits. We will also discuss some key issues on how these nanostructured porous media improve the performance of EBFCs in the end.
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Nechypurenko, A. "Biofuel as an alternative energy source." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40410.
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Today there is a problem of effective and efficient use of
energy. Back in 1912, Rudolf Diesel expressed his opinion: "The use
of vegetable oil as fuel today is insignificant, but in the future it will
become as important source of motor fuel, as it is now refined
petroleum products and coal." Today on this thesis scientists have
formed the basis of modern energy sectors related to the use of
alternative energy sources.
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Letete, Thapelo Clifford Mohale. "Multiobjective modelling of biofuel supply systems." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/12125.
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Includes summary.Includes bibliographical references (leaves 117-122).
The aim of this thesis is to determine the optimal land use options offered by different bioenergy crops and technologies available to South Africa for the development of the most efficient and sustainable agriculture-based biofuels industry.
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Dick, Ndukwe Agbai. "Analysis of biofuel potential in Nigeria." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2679.
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Energy security is a priority for most countries as a pivot for economic development. However, Nigeria, despite being a major oil producer, is plagued by energy insecurity in addition to long-standing food insecurity. Nigeria spent 4% of its GDP (~ US$5B/year) importing refined petroleum products (RPP) for its transport sector between 2005 and 2009. In addition, an annual average food import of 3 million metric tonnes has existed for almost a decade. To combat these energy and food insecurities, the Nigerian government plans to produce bioethanol from its major staple food (sugar and starch) crops in order to increase its transport fuel supply and ameliorate the negative impacts of the on-going import of motor fuel to its economy; given substantial uncultivated arable land, unemployed labour and suitable climatic and soil conditions. The dilemma between the apparent benefits of biofuels versus its potential impacts on food security needs to be analysed in order to articulate and implement a feasible ethanol policy. This study develops and applies a sectoral Energy-Food Model (EFM) to: 1) analyse the supply capacity of the feedstock and food suppliers (the farmers in Nigeria) for ethanol; 2) estimate the bioethanol production potential in Nigeria; 3) identify the regional potential ‘best’ feedstock; and 4) assess the impacts of the potential feedstock and bioethanol demands and supplies on the national energy and food securities. The programming model is based on farm production data from relevant national agencies and on Nigerian energy supply, food consumption, commodity export and import and commodity prices from international and national official databases such as EIA, FAOSTAT, IMF, World Bank, and Nigerian Bureau of Statistics databases. Results show that Nigeria has the potential to produce sufficient feedstock and food crops required to meet the domestic ethanol and crop consumption requirements without reducing domestic food supply or increasing domestic commodity prices. Further, cassava is identified as the best feedstock for ethanol production in all the regions under current production and price conditions. Domestic ethanol production/supply to the local market for blending would generate and add a gross profit of US$2,725M per annum (including the potential co-products revenue) to national income. Also an annual production of 5.14 billion litres of ethanol from all the regions is feasible, and this can substitute 514 million litres of gasoline (4% of the annual average domestic RPP demand) at 10% ethanol blending, and save about US$36B per annum at US$70.33 per litre of the imported RPP. The changes in labour and land use were substantial, but without associated increase in the prices of labour and land, reflecting existing un- and under-employment and stocks of uncultivated arable land. The impacts of ethanol production from the first generation feedstock on food supply and food prices are practically absent in a country with sufficient land and production resources.
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Roberts, Michael Adrian. "Addressing efficiency in enzyme biofuel cells." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/addressing-efficiency-in-enzyme-biofuel-cells(91027198-5ed8-4f27-9366-e69c44d39eb9).html.
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Biofuel cells (BFCs) use either enzymes or bacteria to catalyse a fuel to generate power. Their advantages over conventional fuels is that they do not use precious metals and the high selectivity of biocatalysts mean that no separation membranes are required between the electrodes. However, the application of BFCs is limited by their low power output and poor enzyme lifetimes. This thesis addresses these limitations by investigating aligned carbon nanotubes (aCNTs) as potential electrode materials. These aCNT electrodes offer high surface areas to increase enzyme coverage and hence power output and their surface topology can stabilise the enzymes to ensure maximum lifetime and current density.A novel BFC half cell was developed using aCNTs and the fungal enzyme, Trametes versicolor laccase which catalyses the four-electron reduction of oxygen to water. Laccase was shown to communicate directly with the nanotubes enabling the oxidant reduction reaction to be monitored without the need for mediators. Initial investigations compared aCNTs with other commonly reported carbon electrodes and found that the current densities were ~30-fold higher on the aCNTs than at pyrolytic graphite edge electrodes. The high surface area of these electrodes contributed to greater electroactive coverage of enzyme and minimal loss of enzyme upon deposition. Cathodic currents increased linearly with geometric electrode area; however they did not scale with actual electrode surface area and the current density was limited to the order of μA cm-2 due to O2-transport limitations. It was also discovered that the porous contribution of these aCNT electrodes could lead to misleading interpretations on nanotube electrochemistry. This effect was observed when increments in electrode area resulted in apparently significantly faster kinetics. This improvement in catalytic behaviour was proposed to be due to a transition from mass diffusion limited to thin layer cell behaviour exhibited by porous materials. Thermal pretreatment of the aCNT electrodes in oxidative and reductive atmospheres were found to improve their performance. These treatments worked by changing the nanotube surface chemistry and purifying the nanotubes, as evidenced by various physical characterisation methods. Furthermore, laccase activity was enhanced significantly after electrodes had been treated under both atmospheres, where it was believed that the removal of contaminant material and higher defect densities increased electrochemical performance.Finally, mass transport limitations were addressed by developing micro-patterned aCNT electrodes which possessed channels in the arrays, allowing better oxygen diffusion. Fundamental studies showed higher current densities per surface area and thus represent a promising electrode for future BFC research.
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Binyamin, Gary Neil. "Glucose electro-oxidizing biofuel cell anodes /." Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992752.
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Interrante, Leonardo. "THERMO-CATALYTIC PROCESSES FOR BIOFUEL PRODUCTION." Doctoral thesis, Università degli Studi di Palermo, 2017. http://hdl.handle.net/10447/239941.
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Ryu, Jong Eun. "Nanomanufacturing processes for biofuel cells and sensors." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1997615321&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Hu, Zhoujian. "Utilization of switchgrass as a biofuel feedstock." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44088.
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Secondary generation biofuels such as cellulosic biofuels rely on large portions of cellulosic bioresources, which may include forests, perennial grasses, wood and agricultural residues. Switchgrass is one promising feedstock for biofuel production. In the present study, thesis work focused on the chemical and structural profiles and hydrothermal pretreatment of switchgrass. Four populations of switchgrass were investigated for their chemical properties among populations and morphological portions, including the compositions of lignin and carbohydrates, extractives content, higher heating value (HHV), and syringyl:guaiacyl (S:G) ratio. The results demonstrate similar chemical profiles and lignin structure among the four populations of switchgrass. Morphological fractions of switchgrass including leaves, internodes, and nodes differ significantly in chemical profiles and S:G ratios of lignin. The structure of isolated cellulose from switchgrass SW9 is similar between leaves and internodes. The structure of isolated lignin from leaves and internodes of switchgrass SW9 differs in S:G ratio and molecular weight. Hydrothermal pretreatment of leaves and internodes indicates that a similar chemical composition and chemical structure for pretreated leaves and internodes. The degree of polymerization (DP) for cellulose of the pretreated internodes is 23.4% greater than that of the pretreated leaves. The accessibility of pretreated leaves measured by Simons' Staining technique is greater than that of pretreated internodes. Pretreated leaves have a 32.5-33.8% greater cellulose-to-glucose conversion yield than do pretreated internodes.
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Song, Yin. "C-MEMS Based Micro Enzymatic Biofuel Cells." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2013.
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Miniaturized, self-sufficient bioelectronics powered by unconventional micropower may lead to a new generation of implantable, wireless, minimally invasive medical devices, such as pacemakers, defibrillators, drug-delivering pumps, sensor transmitters, and neurostimulators. Studies have shown that micro-enzymatic biofuel cells (EBFCs) are among the most intuitive candidates for in vivo micropower.
In the fisrt part of this thesis, the prototype design of an EBFC chip, having 3D intedigitated microelectrode arrays was proposed to obtain an optimum design of 3D microelectrode arrays for carbon microelectromechanical systems (C-MEMS) based EBFCs. A detailed modeling solving partial differential equations (PDEs) by finite element techniques has been developed on the effect of 1) dimensions of microelectrodes, 2) spatial arrangement of 3D microelectrode arrays, 3) geometry of microelectrode on the EBFC performance based on COMSOL Multiphysics.
In the second part of this thesis, in order to investigate the performance of an EBFC, behavior of an EBFC chip performance inside an artery has been studied. COMSOL Multiphysics software has also been applied to analyze mass transport for different orientations of an EBFC chip inside a blood artery. Two orientations: horizontal position (HP) and vertical position (VP) have been analyzed.
The third part of this thesis has been focused on experimental work towards high performance EBFC. This work has integrated graphene/enzyme onto three-dimensional (3D) micropillar arrays in order to obtain efficient enzyme immobilization, enhanced enzyme loading and facilitate direct electron transfer. The developed 3D graphene/enzyme network based EBFC generated a maximum power density of 136.3 μWcm-2 at 0.59 V, which is almost 7 times of the maximum power density of the bare 3D carbon micropillar arrays based EBFC.
To further improve the EBFC performance, reduced graphene oxide (rGO)/carbon nanotubes (CNTs) has been integrated onto 3D mciropillar arrays to further increase EBFC performance in the fourth part of this thesisThe developed rGO/CNTs based EBFC generated twice the maximum power density of rGO based EBFC. Through a comparison of experimental and theoretical results, the cell performance efficiency is noted to be 67%.
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Luo, Dexin. "Design of highly distributed biofuel production systems." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45878.
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This thesis develops quantitative methods for evaluation and design of large-scale biofuel production systems with a particular focus on bioreactor-based fuel systems. In Chapter 2, a lifecycle assessment (LCA) method is integrated with chemical process modeling to select from different process designs the one that maximizes the energy efficiency and minimizes the environmental impact of a production system. An algae-based ethanol production technology, which is in the process of commercialization, is used as a case study. Motivated by this case study, Chapter 3 studies the selection of process designs and production capacity of highly distributed bioreactor-based fuel system from an economic perspective. Nonlinear optimization models based on net present value maximization are developed that aim at selecting the optimal capacities of production equipment for both integrated and distributed-centralized process designs on symmetric production layouts. Global sensitivity analysis based on Monte Carlo estimates is performed to show the impact of different parameters on the optimal capacity decision and the corresponding net present value. Conditional Value at Risk optimization is used to compare the optimal capacity for a risk-neutral planner versus a risk-averse decision maker. Chapter 4 studies mobile distributed processing in biofuel industry as vehicle routing problem and production equipment location with an underlying pipeline network as facility location problem with a focus on general production costs. Formulations and algorithms are developed to explore how fixed cost and concavity in the production cost increases the theoretical complexity of these problems.
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Unosson, Jon. "Acute cardiovascular effects of biofuel exhaust exposure." Doctoral thesis, Umeå universitet, Lungmedicin, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96449.
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Background Anthropogenic air pollution is a global health problem estimated to contribute to millions of premature deaths. Exposure to biomass smoke is common due to varying sources, such as wildfires, indoor cooking over open fires, and residential heating from wood stoves. In urban environments transportation and industry rely heavily on the combustion of fossil fuels yet environmental policies increasingly support a shift to renewable fuels such as biodiesel. It has not been investigated how either wood smoke or biodiesel exhaust affect human health in general or the cardiovascular system in particular. We hypothesized that wood smoke exposure would induce acute cardiovascular impairment via similar underlying mechanisms as have been established for petrodiesel exhaust exposure. We also hypothesized that replacing petrodiesel with biodiesel, as a blend or pure biodiesel, would generate an exhaust profile with a less harmful effect on the cardiovascular system than petrodiesel exhaust. Methods In four separate studies healthy non-smoking subjects were exposed to different air pollutants in controlled exposure chambers followed by clinical investigations of the cardiovascular system. All studies were performed as randomized controlled trials in a crossover fashion with each individual acting as her own control. In study I healthy volunteers were exposed to wood smoke at a target concentration of particulate matter (PM) 300 µg/m3 for three hours followed by measures of blood pressure, heart rate variability and central arterial stiffness. In study II subjects were exposed to wood smoke at a target concentration of PM 1000 µg/m3 for one hour followed by measures of thrombus formation using the Badimon technique and vasomotor function using forearm venous occlusion plethysmography. In study III subjects were exposed to petrodiesel exhaust and a 30% rapeseed methyl ester (RME30) biodiesel blend for one hour at a target concentration of PM 300 µg/m3. Following exposure, thrombus formation and vasomotor function were assessed as in study II. In study IV subjects were exposed to petrodiesel exhaust at a target concentration of PM 300 μg/m3for one hour and pure rapeseed methyl ester (RME100) exhaust generated at identical running conditions of the engine. Following exposure, thrombus formation and vasomotor function were assessed as in study II and III. Results In study I fourteen subjects (8 males) were exposed to wood smoke at P M 294±36 μg/m3. Compared to filtered air exposure, measures of central arterial stiffness were increased and heart rate variability was decreased following wood smoke exposure. No effect was seen on blood pressure. In study II sixteen males were exposed to wood smoke at PM 899±100 μg/m3. We found no evidence of increased thrombus formation or impaired vasomotor function following wood smoke exposure. In study III sixteen subjects (14 males) were exposed to petrodiesel exhaust (PM 314±27 µg/m3) and RME30 exhaust (PM 309±30 µg/m3). Thrombus formation and vasomotor function were equal following either exposure. In study IV nineteen males were exposed to petrodiesel exhaust (PM 310±34 µg/m3, 1.7±0.3 x105 particles/cm3) and RME100 exhaust (PM 165±16 µg/m3, 2.2±0.1 x105 particles/cm3). As in study III, thrombus formation and vasomotor function were identical following both exposures. Conclusions We have for the first time demonstrated that wood smoke exposure can increase central arterial stiffness and decrease heart rate variability in healthy subjects. We did not, however find evidence of increased thrombus formation and impaired vasomotor function following wood smoke exposure at a higher concentration for a shorter time period. We have, for the first time, demonstrated that exhaust from RME biodiesel induced acute adverse cardiovascular effects of increased thrombus formation and impaired vasomotor function in man. These effects are on par with those seen following exposure to petrodiesel exhaust, despite marked physicochemical differences of the exhaust characteristics.
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Mokebo, Kirsty R. "Ultrahigh productivity photobioreactors for algal biofuel production." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589640.
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Algal biodiesel is a biodegradable and sustainable alternative to traditional petroleum fuels. Algal biodiesel is synthesised from algal lipids via transesterification and has many desirable physical properties for fuel use. Current photobioreactors are inefficient. This thesis looks to increase efficiency and reduce energetic running costs. This was undertaken by the design, construction and trialling of an LED photobioreactor. The controlled growth of the algae, specifically Chlorella emersonii, using pulsed monochromatic or bi-chromatic light conditions with comparison to continuous white light to improve light economy is explored in this thesis. The prediction of biodiesel profile from the growth conditions is also investigated for Chlorella emersonii. Chapter 1 is a general introduction to the area of algal biodiesel. This introductory chapter reviews the current literature regarding microalgae growth conditions and control, processing microalgae to produce biodiesel and photobioreactor designs for the controlled growth of algae. The known effects of different light sources and types on algal growth are also reviewed. Chapter 2 concerns the pulsing-LED vertical airlift photobioreactor design, construction and testing, including an overview of the system constructed and the process of design to combat specific issues. Results from the testing of the photobioreactor are reported in this chapter which include analysis of the resultant fatty acid methyl ester (FAME) profile of algae grown under various pulsed mono-chromatic and bi-chromatic light conditions and the comparison to continuous white light. This chapter draws together the hypotheses and stand-alone observations reported in the current literature allowing direct comparisons for different light conditions and conclusions to be reported which include the effect on resultant FAME profile and not just lipid percentage. Chapter 3 explores the effect of environmental factors on the fatty acid methyl ester composition of the algal biodiesel. This chapter describes the effect of carbon dioxide, nitrate, phosphate and iron levels, length of culture and the effect of supplementary carbon sources on Chlorella emersonii growth and resultant FAME composition. The result of synergetic effects of nutrient levels and length of algal cultivation are analysed in addition to the stage of algal growth and its impact on FAME profile. Chapter 4 details the procedures used for the growth of algae, the production of the algal biodiesel and the development of techniques used for analysis of the resultant biodiesel. The techniques and conditions employed for the growth of the algae as well as the extraction and transesterification of the algal lipids are explained.
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Balch, Brian Palmer. "Industrial Transesterification of Cultivated Algae for Biofuel." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/612548.
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The objective of our design was to create a chemical plant that uses cultivated algae grown on site in order to produce a biofuel as an alternative energy source. Currently there is a push for sustainable energy sources and biologically produced fuels are attractive due to their near net-zero carbon emissions. Algae provides a valuable source of energy due to its growth rate and sustainability. Chemical engineering principles were utilized in design; a supercritical carbon dioxide extractor for the triglycerides in the algae cells, base catalyzed transesterification reaction in continuously stirred reactors in series and separation processes at the end in order to produce a high grade biofuel for consumer applications. Emphasis on environmental consideration also went into the design, such as the use of carbon dioxide for both the growth of the algae and solid extraction process and methanol used for the transesterification and liquid extraction, allowing for easy recycle and further reducing the environmental footprint the product fuel will have.
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LaRue, Kate, Brian Balch, Chris Jabczynski, and Connor Swensen. "INDUSTRIAL TRANSESTERIFICATION OF CULTIVATED ALGAE FOR BIOFUEL." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/613238.
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Osman, Mohamad Hussein. "Mathematical modelling and simulation of biofuel cells." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/363762/.
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Bio-fuel cells are driven by diverse and abundant bio-fuels and biological catalysts. The production/consumption cycle of bio-fuels is considered to be carbon neutral and, in principle, more sustainable than that of conventional fuel cells. The cost benefits over traditional precious-metal catalysts, and the mild operating conditions represent further advantages. It is important that mathematical models are developed to reduce the burden on laboratory based testing and accelerate the development of practical systems. In this study, recent key developments in bio-fuel cell technology are reviewed and two different approaches to modelling biofuel cells are presented, a detailed physics-based approach, and a data-driven regression model. The current scientific and engineering challenges involved in developing practical bio-fuel cell systems are described, particularly in relation to a fundamental understanding of the reaction environment, the performance and stability requirements, modularity and scalability. New materials and methods for the immobilization of enzymes and mediators on electrodes are examined, in relation to performance characteristics and stability. Fuels, mediators and enzymes used (anode and cathode), as well as the cell configurations employed are discussed. New developments in microbial fuel cell technologies are reviewed in the context of fuel sources, electron transfer mechanisms, anode materials and enhanced O2 reduction. Multi-dimensional steady-state and dynamic models of two enzymatic glucose/air fuel cells are presented. Detailed mass and charge balances are combined with a model for the reaction mechanism in the electrodes. The models are validated against experimental results. The dynamic performance under different cell voltages is simulated and the evolution of the system is described. Parametric studies are performed to investigate the effect of various operating conditions. A data-driven model, based on a reduced-basis form of Gaussian process regression, is also presented and tested. The improved computational efficiency of data-driven models makes them better candidates for modelling large complex systems.
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Gomez, Franco Weisser. "Determinants for Biofuel Policies in the Americas." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/28358.
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The biofuels market has been increasingly important due to the benefits they provide to society by giving an alternative to fossil fuels. In the Americas, many countries are using biofuel-related policies to incentivize the production of biofuels. Different countries have different reasons to have biofuel policies, among them are variables related to country development, energy security, food security, oil price fluctuation, rural employment, and environmental issues. With the objective of finding determinants for biofuel policies among countries of the Americas, this study conducted a logit regression with panel data using a random effect model, with information from 27 countries of the Americas for a 25-year period, available in the World Bank, FAO, and EIA. Apart from the variables of oil reserves and rural employment, the results were consistent with our expectations. Variables related to food and energy security and country development were found to be highly significant.
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Withers, Jeremy W. "Barriers Impacting United States Advanced Biofuel Projects." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71795.
Full textAbstract:
Although the 2005 EPAct was enacted to help bolster the emerging biofuel industry, 52% of advanced biofuel projects were closed or shut down by 2015. However, there are no complete lists of barriers that impeded these projects. The goal of this study was to develop a framework of barriers impeding success of advanced biofuel projects by conducting a literature review of barriers, spatial analysis of status, survey of barriers, and determination of coproducts and byproducts and their marketing and distribution barriers from the industry stakeholders.
The spatial analysis indicated 59 biofuel projects were attempted, and their Eastern and Western location by status was not a barrier. Using Grounded Theory, nine barriers were derived and aggregated in major categories, including product development, strategy, technology, competition, energy costs, funding, government, suppliers, and third-party relations. A contingency analysis was conducted relating their status to internal and external barriers, indicating no relationship between type of closing and type of barrier. Next, the number of barriers was expanded to 23, and a survey was conducted to gain knowledge on these barriers from industry stakeholders. When comparing the barriers by stakeholders, there were differences based on status, type, and technology of the projects. In addition, the survey and discussion identified 79 barriers different across years, type of industry (pilot, demonstration, or commercial), status (open, closed, or planning), and technology (thermochemical, biochemical, or hybrid). Forty-seven coproducts and byproducts and many unknown barriers to their marketability and distribution were determined and ranked by primary and secondary barriers. These extensive lists of barriers and coproducts will aid future biofuels projects in their planning, research, and development stages.Master of Science
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Palik, Destiny J. "The Invasive Potential of Perennial Biofuel Crops." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503309520467401.
Full text
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Chattha, Muhammad Waqas Alam. "Optimal mix of biofuel crops in Australia." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18810.
Full textAbstract:
This research is proposing a view of a ‘biofuel crops mix’ for Australia. The agronomic, geo-spatial, and economic identification, quantification and evaluation of studied biofuel crops through spatially explicit framework was done to devise a strategically optimal portfolio of biofuels crops and to identify the possible biophysically suitable and economically profitable locations to cultivate biofuel crops. This was pursued by first compiling agronomic requirement and conducting economic assessment of selected biofuel feedstock crops such as sorghum, indian mustard, pongamia, sugarcane and agave. In the absence of observed market prices, the calculated implied prices revealed positive gross margins from the cultivation of the studied biofuel crops. Biophysical suitability analysis suggests that these biofuel crops can be suitably cultivated as biofuel feedstock in many tropical and sub-tropical regions of Australia, including many of the marginal regions. Post suitability analysis suggested 18 crop combinations that were jointly suitable in eastern part of Australia. The results from spatial bio-economic model and biophysical comparison of biofuel crops are indicating the prevalence of these crop combinations in QLD and NSW, which suggests an immense competition for resources with the existing non biofuel crops in these states. Spatial bio-economic model suggesting that pongamia, Indian mustard, sorghum, sugarcane and agave can be profitably cultivated in certain areas where they are profitable and are not in direct competition with existing crops. I concluded that the argument about growing biofuel crops on marginal land is not entirely valid mainly because of their low productivity and profitability on those lands. The outcome of this thesis will help to understand the critical knowledge gaps related to the biofuel expansion and will provide knowledge based informed future pathways to develop a sustainable biofuel industry in Australia.
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Moody, Jeffrey W. "Global Evaluation of Biofuel Potential from Microalgae." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2070.
Full textAbstract:
Traditional terrestrial crops are currently being utilized as a feedstock for biofuels but resource requirements and low yields limit the sustainability and scalability. Comparatively, next generation feedstocks, such as microalgae, have inherent advantages such as higher solar energy efficiencies, larger lipid fractions, utilization of waste carbon dioxide, and cultivation on poor quality land. The assessment of microalgae-based biofuel production systems through lifecycle, technoeconomic, and scalability assessments has been forced to extrapolate laboratory-scale data due to the immaturity of the technology. This type of scaling leads to large uncertainty in the current near-term productivity potential and ultimately the results from modeling work that rely on this type of modeling. This study integrated a large-scale validated outdoor microalgae growth model that utilizes 21 species and reactor-specific inputs that accurately account for biological effects such as nutrient uptake, respiration, and temperature with hourly historical meteorological data from around the world to determine the current global productivity potential. A global map of the microalgae lipid and biomass productivity has been generated based on the results of annual simulations at 4,388 global locations spread over the seven continents. Maximum annual average yields between 24-27 m3·ha-1·yr-1 are found in Australia, Brazil, Colombia, Egypt, Ethiopia, India, Kenya, and Saudi Arabia with the monthly variability (minimum and maximum) yields of these locations ranging between 14 and 33 m3·ha-1·yr-1. A scalability assessment that leverages geographic information systems data to evaluate geographically realized microalgae productivity, energy consumption, and land availability has been performed highlighting the promising potential of microalgae-based biofuels compared to traditional terrestrial feedstocks. Results show many regions can meet their energy requirements through microalgae production without land resource restriction. Discussion focuses on sensitivity of monthly variability in lipid production compared to annual average yields, biomass productivity potential, effects of temperature on lipid production, and a comparison of results to previous published modeling assumptions.
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Blanchard, Ryan. "An assessment of the potential biodiversity impacts from biofuel production in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95933.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Biofuels are being promoted as a global necessity to meet climate change targets through the replacement of fossil fuels. Many countries have identified biofuels as a potential mechanism to meet these challenges, with policy directives driving biofuel production. The South African government has proposed that biofuels form part of the country’s future renewable energy and has proposed a draft biofuel strategy. This study aims to investigate appropriate approaches to determine potential biodiversity impacts from biofuel production. Since biofuels are not currently grown to any large extent in South Africa, impact was modelled using future scenarios of converting available land within the Eastern Cape Province of South Africa. Suitable species were identified using the species distribution modelling programme MaxEnt. Some of the proposed biofuel crops were considered as invasive (i.e. they spread from sites where they are cultivated) or are very likely to be invasive in South Africa. This study also highlighted the considerable overlap between suitable growing areas and areas considered important for future biodiversity conservation. The biodiversity intactness index (BII), a broad based biodiversity indicator, was used to assess the biodiversity implications of transforming available land to biofuels. The BII indicates losses of biodiversity between 17.6% and 42.1% for the land use scenarios identified. An important finding was that excluding important biodiversity areas that occur outside of protected areas can reduce biodiversity losses by as much as 13% and maintain an overall intactness of ~70%. Currently the BII does not account for fragmentation or landscape configuration. This was addressed by developing a revised biodiversity intactness index (R-BII) which included the effect of patch-size and habitat fragmentation on biodiversity intactness. This study found that although the original BII reported on the biodiversity trends of large-scale shifts in land-use across multiple scales it could not detect changes in landscape configuration which was reflected by the R-BII. Land-use change can impact on ecosystem processes that underpin the provisioning of ecosystem services by changing the combinations of species and the plant functional traits within communities. The impacts of cultivating potential biofuel species (Acacia mearnsii, Sorghum halepense and Eucalyptus species) were investigated using a plant functional traits approach. These species were shown to affect the leaf nitrogen content, leaf phosphorous content and leaf dry matter content associated with important ecosystem functions within an ecosystem service hotspot in the Eastern Cape. A decline in functional diversity was reported for all transformed land-uses by as much as ~40%. These shifts may be used to identify potential changes to ecosystem services associated with natural vegetation. The methods used in this thesis highlight the overall relevance of this work and its importance to minimising biodiversity resulting from biofuel production. Some of the key findings address resolving spatial conflict, using biodiversity indicators, assessing impacts of potential invasive species and planning for ecosystem services. New drivers of change to land-use, such as biofuel production, are a major challenge to conservation biologists and planners and the insights derived in from this study can be successfully applied to guide biofuel production.
AFRIKAANSE OPSOMMING: Biobrandstof word internasionaal beskou as 'n noodsaaklike komponent in die bereiking van klimaatsverandering doelwitte deur fossielbrandstowwe daarmee te vervang. Daarom word biobrandstof deur verskeie lande geïmplementeer as 'n potensiële meganisme om aan hierdie uitdaging te voldoen. Die Suid-Afrikaanse regering het voorgestel dat biobrandstof deel vorm van die land se hernubare energie toekoms en het daarom 'n konsep biobrandstofstrategie voorgestel. Die aanvaarding van so 'n strategie sal waarskynlik ‘n aantal verreikende gevolge inhou. Hierdie studie gebruik verskeie benaderings ten einde die impak van biobrandstof produksie op biodiversiteit te bepaal. Aangesien biobrandstof nie tans ‘n beduidende bydra maak tot tradisionele brandstofproduksie in Suid-Afrika nie, word die impak daarvan geskoei op die omskakeling van beskikbare grond. Die Oos-Kaap provinsie van Suid-Afrika speel a sleutelrol in hierdie opsig en vorm daarom die fokus van hierdie analise. Geskikte spesies is geïdentifiseer deur die sagtewareprogram, MaxEnt, waardeur spesiesverspreiding gemodelleer word. Hierdie studie beklemtoon die aansienlike oorvleueling wat daar bestaan tussen geskikte aanplantingsgebiede en belangrike biodiversiteitsareas wat nie tans formeel bewaar word nie. Sommige van die voorgestelde biobrandstofgewasse is tans indringers, of het die potensiaal om indringerplante te word en daarom is daar toenemende kommer oor die kweek van biobrandstof gewasse in Suid-Afrika. Die “Biodiversity Intactness Index” (BII), 'n algemene biodiversiteitsaanwyser, is gebruik om die implikasies van grondomskakeling na biobrandstof op biodiversiteit te evalueer. Die BII dui op verliese van tussen 17,6% en 42,1% vir die grondgebruikscenario's wat geïdentifiseer is. 'n Belangrike bevinding was dat die uitsluiting van belangrike biodiversiteitsareas buite beskermde gebiede die verlies van biodiversiteit met soveel as 13% kan verminder en biodiversiteit eenheid van ~ 70% kan behou. Die BII maak egter nie tans voorsiening vir landskap fragmentasie nie. ‘n “Revised-Biodiversity Intactness Index” (R-BII) is ontwikkel wat die effek van kol-grootte en habitat op biodiversiteit eenheid insluit. Hierdie studie het bevind dat alhoewel die oorspronklike BII grootskaalse verandering in die grondgebruik op verskeie skale aandui, dit egter nie verandering in landskapsamestelling kon opspoor soos die R-BII nie. Ten slotte, die impak van die aanplanting van potensiële biobrandstofspesies (Acacia mearnsii, Sorghum halepense en Eucalyptus spesies) op biodiversiteit is ondersoek deur ‘n plant funksionele eienskappe benadering te gebruik. Daar is bevind dat hierdie spesies die stikstof, fosfor en droë materiaal inhoud van blare verander wat geassosieer word met belangrike ekosisteem funksies binne 'n biodiversiteit brandpunt in die Oos- Kaap. ‘n Vermindering van funksionele diversiteit van soveel as ~ 40% is binne alle omgeskakelde grondgebruike gevind. Hierdie skuiwe kan gebruik word om potensiële veranderinge van ekosisteemdienste te identifiseer en benadruk ook die potensiële impak van uitheemse spesies. Die metodes wat gebruik word in hierdie studie beklemtoon die relevansie van die werk asook die belangrikheid daarvan om die nadelige uitwerking van biobrandstofproduksie op biodiversiteit te minimaliseer. Verskeie benaderings tot die oplossing van ruimtelike konflik, die gebruik van biodiversiteitaanwysers, die beoordeling van die impak van die potensiële indringerspesies en die beplanning vir ekosisteemdienste. Nuwe dryfvere van grondgebruikverandering soos biobrandstof is 'n groot uitdaging en die insigte wat uit hierdie studie verkry is dra by tot die vermindering van die potensiële impak van biobrandstofproduksie op biodiversiteit.
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Haponska, Monika. "Biorefining of microalgae: from harvesting to biofuel production." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/663366.
Full textAbstract:
Aquesta tesi es centra en la modernització del procés de bio-refinat de microalgues mitjançant tecnologia de
membrana. El projecte busca l'optimització de: recol·lecció, ruptura cel·lular, fraccionament de carbohidrats, proteïnes
i lípids i desenvolupament d'un reactor de membrana catalítica per a la transesterificació per obtenir biodièsel. La
reducció de costos es pot aconseguir trobant solucions més barates i millors per a cada pas.
En la primera etapa, es va realitzar la filtració utilitzant membranes polimèriques d'ABS de fabricació pròpia, així com
altres disponibles comercialment, per comprovar el seu rendiment en la deshidratació de microalgues. Aquest estudi
inclou la preparació i caracterització de membranes d'ABS usant diferents tècniques. A més, es va realitzar la
comparació de dos mètodes de filtració, flux creuat i dinàmic per comparar la viabilitat de les membranes afectades
per embrutiment.
En la segona etapa, es va realitzar la deshidratació a escala pilot de dues espècies de microalgues, Chlorella
sorokiniana i Dunaliella tertiolecta per sedimentació i filtració dinàmica. L'objectiu va ser reduir els costos de
deshidratació de microalgues amb un cost menor al de centrifugació. bio-refinat de microalgues aigües avall.
En la quarta etapa, es va realitzar la comparació de nous reactors de membrana catalítica i inert per a la producció de
biodièsel amb òxid d'estronci com a catalitzador heterogeni. Els principals objectius van ser identificar un catalitzador
adequat, triar la tècnica d'immobilització adequada, establir la membrana amb la mida de porus adequat i controlar la
reacció i el procés de separació.microalgues amb diferents característiques de paret cel·lular. L'objectiu d'aquest treball va ser millorar el procés de bio-refinat de microalgues aigües avall.
En la quarta etapa, es va realitzar la comparació de nous reactors de membrana catalítica i inert per a la producció de
biodièsel amb òxid d'estronci com a catalitzador heterogeni. Els principals objectius van ser identificar un catalitzador
adequat, triar la tècnica d'immobilització adequada, establir la membrana amb la mida de porus adequat i controlar la
reacció i el procés de separació.Esta tesis se centra en la modernización del proceso de biorefinado de microalgas mediante tecnología de membrana. El proyecto busca la optimización de: recolección, ruptura celular, fraccionamiento de carbohidratos, proteínas y lípidos y desarrollo de un reactor de membrana catalítica para la transesterificación para obtener biodiesel. La reducción de costos se puede lograr encontrando soluciones más baratas y mejores para cada paso. En la primera etapa, se realizó la filtración utilizando membranas poliméricas de ABS de fabricación propia, así como otras disponibles comercialmente, para comprobar su rendimiento en la deshidratación de microalgas. Este estudio incluye la preparación y caracterización de membranas de ABS usando diferentes técnicas. Además, se realizó la comparación de dos métodos de filtración, flujo cruzado y dinámico para comparar la viabilidad de las membranas afectadas por ensuciamiento. En la segunda etapa, se realizó la deshidratación a escala piloto de dos especies de microalgas, Chlorella sorokiniana y Dunaliella tertiolecta por sedimentación y filtración dinámica. El objetivo fue reducir los costos de deshidratación de microalgas con un costo menor al de centrifugación. En la tercera etapa, se estudió la disrupción celular y el fraccionamiento para la recuperación de lípidos, azúcares y proteínas usando explosión de vapor, flujo cruzado y filtración dinámica de membrana. Se probaron varias especies de microalgas con diferentes características de pared celular. El objetivo de este trabajo fue mejorar el proceso de biorrefinado de microalgas aguas abajo. En la cuarta etapa, se realizó la comparación de nuevos reactores de membrana catalítica e inerte para la producción de biodiesel con óxido de estroncio como catalizador heterogéneo. Los principales objetivos fueron identificar un catalizador adecuado, elegir la técnica de inmovilización adecuada, establecer la membrana con el tamaño de poro adecuado y controlar la reacción y el proceso de separación.
his thesis focuses on the modernization of the downstream process of microalgae biorefining by membrane technology. The project concerns the optimization of: harvesting, cell disruption, carbohydrates, proteins and lipids fractionation and development of catalytic membrane reactor for transesterification to obtain biodiesel. Cost reduction of the overall process can be achieved by finding cheaper solutions for each step. In the first stage the filtration using own-made ABS polymeric membranes as well as the commercially available ones was run to check their performance for microalgae dewatering. This study included ABS membranes preparation and characterization using different techniques. Also, the comparison of two filtration methods, cross-flow and dynamic was performed to compare the viability of membranes affected by a fouling and a cake formation. In a second stage, the pilot scale dewatering of two microalgae specie, Chlorella sorokiniana and Dunaliella tertiolecta by sedimentation followed by dynamic filtration was performed. The objective of the combined process was to reduce microalgae dewatering costs since sedimentation offers a very cheap operation and membrane filtration offers total rejection with high final concentrations at a lower cost than centrifugation. In a third stage cell disruption and fractionation for lipids, sugars and proteins recovery was studied. Acid-catalysedT
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Zhou, Xia. "BIOFUEL AND WATER RESOURCES." 2011. http://trace.tennessee.edu/utk_graddiss/1246.
Full textAbstract:
This dissertation focuses on the economic and environmental benefits of planting switchgrass as a bioenergy feedstock. The first chapter presents a dynamic optimization model of fertilizer and land allocation between switchgrass and corn to estimate economic benefits. Subsequent chapters utilize Geographic Information System (GIS)-based Soil and Water Assessment Tool (SWAT) to be calibrated to evaluate the environmental (nutrient and sediment loading) effects of land use conversion to switchgrass production on water quality and analyze the Water Quality Trading (WQT) program with cost-effectiveness ratios ordered for abatements of nutrient loadings in an East Tennessee watershed.