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1
van, Slyke Torry. « Fields of Dreams : Scenarios to Produce Selected Biomass and Renewable Jet Fuels that Fulfill European Union Sustainability Criteria ». Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-385902.
Texte intégralRésumé :
Aviation greenhouse gas (GHG) emissions have risen faster than any other transport sector to double between 1990 and 2005. Such emissions from aviation could increase another 700 percent globally, and at least 150 percent in the European Union (EU), by 2050 due to continuously increasing consumer demand. To reverse the trend of rising emissions writ large, the EU has set 2030 climate goals of reducing its GHG emissions by 40 percent (relative to 2005) and having 32 percent of gross final energy consumption from renewables. The EU’s recast Renewable Energy Directive (RED-II) calls for 14 percent of transport energy from renewables, gives multipliers to advanced biofuels, and restricts biomass that is from ecologically valuable lands or that causes land use change. Energy security and energy independence are also long-term EU goals. Many of these goals and targets have also been adopted by the European Free Trade Area (EFTA). Despite these efforts, options are limited to reduce aviation emissions compared to other transport sectors, leaving aviation biofuels, also known as renewable jet fuels (RJFs), as currently the only commercialized option. Against this backdrop, in this thesis scenario analyses were conducted to produce biomass from EU+EFTA lands, project RJF yields from this biomass, and estimate emissions savings of these RJFs compared to petroleum jet fuel. Particular effort was devoted to identifying biomass, biofuels, and EU+EFTA lands that comply with RED-II criteria. The two RJF pathways selected were hydroprocessed esters and fatty acid (HEFA) conversion of Camelina sativa vegetable oil and Fischer-Tropsch (FT) synthesis of forestry residue lignocellulosic biomass. Over 117 million hectares in the EU+EFTA was identified as available for Camelina sativa cultivation, which could yield over 64 Mt of RJF each year, or 113 percent of the total jet fuel consumed in the EU+EFTA in 2017. Conversely, if 50 percent of the forestry residues generated as by-products from EU+EFTA roundwood harvesting operations in 2017 were extracted from harvest sites, 40 Mt of forestry residues would be available as biomass, which would yield almost 7.6 Mt of RJF annually (13% of 2017 jet fuel consumption). If all 144 million hectares of EU+EFTA forest lands deemed available for wood supply were logged, 1,772 Mt of forestry residues would be produced in total (at 50 percent extraction), which could result in almost 337 Mt of RJF, or 590% of the jet fuel consumed in the region in 2017. Hence, RJF can be feasibly produced from biomass from EU+EFTA lands, in amounts that meet or exceed the annual jet fuel consumption of the EU+EFTA, and in ways that meet or exceed RED-II sustainability criteria. However, the proportion of these RJF yields to total annual EU+EFTA jet fuel consumption will decrease over time as the number of flights and their resulting emissions increase. The two RJFs also emit 67 percent and 91 percent fewer GHG emissions, respectively, than petroleum-based jet fuel, showing them to be important tools for the EU to meet its 2030 renewables and emissions reductions targets. Producing the biomass feedstocks and RJFs in these quantities will require the EU to make serious decisions on land use trade-offs, such as whether livestock production is more important than biofuel production.
2
Puy, Marimon Neus. « Integrated sustainability analysis of innovative uses of forest biomass. Bio-oil as an energy vector ». Doctoral thesis, Universitat Autònoma de Barcelona, 2010. http://hdl.handle.net/10803/48708.
Texte intégralRésumé :
Aquesta investigació ofereix un enfocament multidisciplinari, des d’un punt de vista ambiental,
social, econòmic i tecnològic, per a estudiar nous usos de la biomassa forestal utilitzant
diferents metodologies, com són els grups de discussió, l’anàlisi del cicle de vida i experimental
en una planta pilot de piròlisi.
En primer lloc, es realitza una avaluació integrada per mitjà de grups de discussió per a
identificar les barreres polítiques, socials i ambientals que han impedit que els sistemes
integrats de biomassa forestal hagin continuat desenvolupant‐se en el context mediterrani. Els
resultats mostren que, tot i les grans oportunitats i apostes per aquests sistemes, és necessari
considerar factors socioecològics específics, com ara els règims de propietat, la baixa
productivitat dels boscos mediterranis, la feble capacitat institucional, logística i dificultats
d'abastament i la falta de rendibilitat econòmica dels productes forestals, si la biomassa
forestal ha de contribuir decisivament a la producció de fonts d'energia renovables a Europa.
En segon lloc, es duu a terme una anàlisi del cicle de vida d'una planta de gasificació de
biomassa forestal i de fusta de post‐consum. Aquest estudi mostra que la biomassa forestal
necessita majors requeriments d'energia, degut principalment a una fase d'assecatge
addicional que necessita per complir amb els requeriments d’entrada de la gasificació.
Finalment, els aspectes tecnològics s’analitzen estudiant la piròlisi de la biomassa. Primer,
s’aplica el model d'activació d’energies distribuïdes (DAEM) a la desvolatilització de la
biomassa i els seus components. Posteriorment, s’estudia la piròlisi d’estelles de biomassa
forestal en una planta pilot amb un reactor de cargol sense fi (10 kg/h) per a estudiar les
condicions òptimes d'operació (temperatura de reacció, temps de residència de sòlids i flux
màssic) i per a determinar les propietats fisicoquímiques dels productes obtinguts. Els
resultats mostren que es pot aconseguir una piròlisi completa de les estelles de biomassa en
aquest tipus de reactor i que el major rendiment per a la producció de líquid (59%) i les
millors propietats dels productes s’obtenen en la temperatura més baixa estudiada (773 K) i
aplicant temps de residència de sòlids de més de 2 minuts. La caracterització química del biooil
mitjançant GC/MS mostra que els compostos més abundants són compostos polars volàtils,
fenols i benzenediols. Es poden observar molt poques diferències en les propietats físiques de
les diferents mostres de bio‐oil, el qual és similar al bio‐oil obtinguts en reactors semblants. Els
balanços d'energia del procés de piròlisi de la planta pilot i d’una planta escalada (1500 kg/h)
mostren que es necessita una unitat d'assecatge i una cambra de combustió de carbó si la
piròlisi s’ha de realitzar en una planta mòbil, tot i que el procés és autosuficient
energèticament quan el contingut d'humitat de la biomassa és inferior al 6%. L'anàlisi
econòmica demostra que els costos totals de producció de biocombustible a la planta pilot
escalada se situen entre 269 i 289 €/m3, depenent del cost de la biomassa (40‐50 €/tona). El
punt d'equilibri de la planta de piròlisi és de 116 €/barril quan la biomassa es compra a 50
€/tona i 108 €/barril quan el cost de la biomassa és de 40 €/tona. A llarg termini, el bio‐oil
ofereix un gran potencial com a vector energètic i en el futur escenari d’una biorefineria, un
nou enfocament que s'estudia a través de la dissolució de la fusta en líquids iònics mitjançant
microones.
En conjunt, aquests nous usos representen una gran oportunitat per al sector forestal en el
context mediterrani, ja que ofereixen productes d’alt valor afegit com és el bio‐oil. El bio‐oil és
un vector energètic, tan versàtil com el petroli, i que pot ser la base per a una nova generació
de biocombustibles de segona generació i, alhora, matèria primera per a biorefineries. A més,
aquesta tesi també està relacionada amb la sostenibilitat social, suggerint accions i propostes
associades amb el desenvolupament local i l’economia en xarxa i facilitant la presa de
decisions, cosa que ajuda a fer un pas endavant cap a un coneixement global i integral de la
sostenibilitat.This research offers a multidisciplinary approach, from the environmental, social, economic and technological standpoint, to study different novel uses of forest biomass using different methodologies such as IA‐Focus Groups, Life Cycle Assessment and experimental in a pyrolysis pilot plant. First, an integrated assessment of forest biomass systems by focus groups methodology is carried out to identify what political, social and environmental barriers have prevented integrated forest biomass systems to be further developed in the Mediterranean context. Results show that while the opportunities and stakes are high, specific socio‐ecologic factors, such as property regimes, low productivity of Mediterranean forests, weak institutional capacity, logistics and supply difficulties and the lack of economic profitability of forest products, need to be taken into account if forest biomass is to contribute decisively to securing renewable sources of energy in Europe, integrating landscape planning with resource policies or mitigating climate change. Second, a life cycle assessment of a gasification plant using forest biomass and post‐consumer wood is performed. This study shows that forest biomass needs higher energy requirements due to mainly an additional drying stage in order to comply with the gasification demands. Finally, technological aspects are investigated by studying biomass pyrolysis. An application of the Distributed Activation Energy Model (DAEM) to biomass and biomass constituents’ devolatilisation is performed to study the thermal decomposition of biomass. Next, pine woodchips pyrolysis is carried out in an auger reactor pilot plant (10 kg/h) to study the optimal operation conditions (reaction temperature, solid residence time and mass flow rate) and to characterize the properties of the products obtained. Results show that complete woodchip pyrolysis can be achieved in the auger reactor and the greatest yields for liquid production (59%) and optimum product characterisation are obtained at the lowest temperature studied (773 K) applying solid residence times longer than 2 minutes. Bio‐oil GC/MS characterisation shows that the most abundant compounds are volatile polar compounds, phenols and benzenediols. Very few differences can be observed in the physical properties of the bio‐oil samples regardless of the operating conditions, and these properties are similar to bio‐oil obtained in other auger reactors. Energy balances of the pyrolysis process in the pilot plant and in a scaled up auger reactor mobile plant (1500 kg/h) show that a drying unit and a char combustor are needed if the pyrolysis has to be performed in a mobile plant, even though the process is energy‐independent when moisture content is lower than 6%. The economic assessment shows that total costs of producing bio‐oil in the scaled‐up pilot plant is between 269 and 289 €/m3 depending on the biomass cost (40‐50€/ton). The break‐even point of the pyrolysis plant is 116 €/barrel when the biomass is purchased at 50 €/ton and 108 €/barrel when the biomass cost is 40 €/ton. In the long term, bio‐oil offers great potential as an energy vector and in a biorefinery scenario, a novel approach that is studied by performing microwave‐assisted dissolution of wood in ionic liquids. On the whole, these novel uses offer great opportunity for the Mediterranean forestry sector, since they offer value‐added products such as bio‐oil. Bio‐oil represents a new energy carrier, which is as versatile as oil and which may be the basis for a new generation of secondgeneration biofuels and, in turn, raw material for biorefineries. This dissertation is also related to social sustainability by suggesting actions and proposals related to local development and the network economy, as well as facilitating decision‐making processes, which help to make a step forward to a global and integral knowledge of sustainability.
3
Zurba, Kamal. « Is short rotation forestry biomass sustainable ? » Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-212162.
Texte intégralRésumé :
Despite the negative effects of fossil fuels on the environment, these remain as the primary contributors to the energy sector. In order to mitigate global warming risks, many countries aim at reducing greenhouse gas emissions. Bioenergy crops are being used as a substitute for fossil fuels and short rotation forestry is a prime example.
In order to examine the sustainability of energy crops for fuel, typical European short rotation forestry (SRF) biomass, willow (Salix spp.) and poplar (Populus spp.) are examined and compared to rapeseed (Brassica napus L.) in respect to various aspects of soil respiration and combustion heat obtained from the extracted products per hectare.
Various approaches are used to look at an As-contaminated site not only in the field but also in a soil-column experiment that examines the fate of trace elements in SRF soils, and in an analysis using MICMAC to describe the driving factors for SRF crop production. Based on the cause-effect chain, the impacts of land-use change and occupation on ecosystem quality are assessed when land-use is changed from degraded land (grassland) to willow and poplar SRF.
A manual opaque dynamic closed chamber system (SEMACH-FG) was utilized to measure CO2 emissions at a willow/poplar short rotation forest in Krummenhennersdorf, Germany during the years 2013 and 2014, and at a rapeseed site in 2014.
Short rotation forest soils showed higher CO2 emission rates during the growing season than the dormant season – with a CO2 release of 5.62±1.81 m-2 s-1 for willows and 5.08±1.37 µmol CO2 m-2 s-1 for poplars in the growing season. However, during the dormant season the soil sites with willow emitted 2.54±0.81 µmol CO2 m-2 s-1 and with poplar 2.07±0.56 µmol CO2 m-2 s-1. The highest emission rates for the studied plantations were observed in July for both years 2013 and 2014, during which the highest air and soil temperatures were recorded.
Correlations between soil emission of CO2 and some meteorological parameters and leaf characteristics were investigated for the years 2013 and 2014. For example, for the willow clone (Jorr) and poplar clone (Max 3), high correlations were found for each between their soil emission of CO2 and both soil temperature and moisture content. Fitted models can explain about 77 and 75% of the results for Jorr and Max 3 clones, respectively. Moreover, a model of leaf area (LA) can explain about 68.6% of soil CO2 emission for H275. Estimated models can be used as a gap-filling method, when field data is not available.
The ratio between soil respiration and the combustion heat calculated from the extracted products per hectare was evaluated and compared for the study’s willow, poplar and rapeseed crops. The results show that poplar and willow SRF has a very low ratio of 183 kg CO2 GJ 1 compared to rapeseed, 738 kg CO2 GJ 1.
The soil-column experiment showed that by continuing the SRF plantation at the As-contaminated site, remediation would need only about 3% of the time needed if the site was left as a fallow field.
In order to understand the complex willow and poplar short rotation forestry production system, 50 key variables were identified and prioritized to describe the system as a step to enhance the success of such potentially sustainable projects. The MICMAC approach was used in order to find the direct and the indirect relationships between those parameters and to classify them into different clusters depending on their driving force and interdependency. From this, it can be summarized that in order to enhance the success of a SRF system, decision makers should be focussing on: ensuring a developed wood-fuel market, increasing farmers’ experience/training, improving subsidy regulations and recommending a proper harvesting year cycle.
Finally, the impacts of land-use change and occupation on the ecosystem quality were assessed. Results show that establishing SRF plantations on degraded lands improved the ecosystem structural quality (ESQ) by about 43% and ecosystem functional quality (EFQ) by about 12%.
Based on overall results, poplar and willow SRF biomass can be recommended as renewable and sustainable sources for bioenergy.
4
Al-Salloum, Mohammed Y. « Use of Pyrolyzed Soybean Hulls as Filler in Polyamide-6 ». University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1626793395861062.
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Laser, Shelby L. « Exploring the Effects of Biomes on Public Health of Urban Residents ». Kent State University Honors College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1556981191847726.
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Cattelan, Lisa. « Green Reactions and Technologies for Biomass Valorisation ». Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18387.
Texte intégralRésumé :
This research project has focussed on the upgrading of biomass derivatives, particularly glycerol derivatives and lignin, to higher added-value chemicals by means of green and sustainable technologies. The experimental work was divided into three main areas: i) Upgrading of glycerol and furan bio-based derivatives. Continuous-flow alkylation reactions. An innovative alkylation protocol was implemented using dialkyl carbonates as alkylating agents under continuous-flow conditions. In the presence of different classes of catalysts, Na-exchanged Y- and X-faujasites and Mg-Al hydrotalcites, functionalised bio-based alcohols and dialkyl carbonates were activated preferentially towards O-alkylations over the competitive transesterifications and other side-reactions. Synthesis of symmetrical dialkyl carbonates. s-DAlCs are of great interest as eco-friendly solvents and intermediates. Carbonate interchange reaction strategies have been investigated in this Thesis and a CF-protocol for the disproportionation of four different methyl alkyl carbonates was optimised, using Mg-Al hydrotalcites as heterogeneous catalysts. ii) Catalytic depolymerisation of Kraft lignin. Lignocellulosic biomass has been proposed as one renewable feedstock to supplement dwindling fossil reserves. In this Thesis, the catalytic depolymerisation of Kraft lignin, which constitutes 25-30% of lignocellulosic biomass, in supercritical ethanol was explored in the presence of eight Mo2C- and MoS2-based catalysts, affording aromatic yields as high as 506 mg/g lignin, amongst the highest yields reported to date. iii) Cleaning up fuels. Nitrogen-based compounds are commonly found in biocrude oils generated from biomass. Since they interfere with traditional refining methods they need to be removed prior to their integration into the supply chain. In this thesis, twelve ionic liquids based on common cations and anions were synthesised and used for the selective extraction of archetypical N-compounds from a model oil.
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Hallmann, Fanfan Weng. « Uncertainty, Emerging Biomass Markets, and Land Use ». Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/37819.
Texte intégralRésumé :
In this dissertation, we study the effects of emerging biomass markets on land use changes between alternatives of agricultural production, conventional timber production, and forest woody biomass production for energy use. Along with the uncertainty associated with woody biomass prices and rents, transaction costs incurred to land use play an important role in land allocation decisions and make this study distinct from other work. In Chapter 1, we introduce the background and objectives of our study. In Chapter 2, we analyze the behavior of a risk-neutral private landowner and social planner under uncertainty of woody biomass prices, assuming that there is a market emergence at some unknown time point in the future. Market emergence is characterized by a price jump and a certain timing of the price jump. Six different price jumps and five different timings of bioenergy market emergence are adopted to study their collective effects on land use change between agriculture and forestry. Chapter 3 studies this problem for a risk-averse private landowner. Two measures of relative risk aversion are used to examine how a landownerâ s preference may affect his or her land use decision.
In Chapter 2, we find that, for three different quality categories of land, land rents from forestry increase significantly for higher price jumps and decreases in the length of time until bioenergy market emergence. One of the most important results is concerned with the presence of transaction costs. Here, we find that these costs may require unrealistic market emergence scenarios to lead to bioenergy adoption on any large scale.
This result is even more likely with nonlinear transaction costs. Land allocation decisions in Chapter 3 are distinctly different from those in Chapter 2, due to the introduction of landowner risk aversion. In certain market emergence cases, some land units retain in agriculture entirely when the landowner is risk averse .
The Chapter 4 studies a stochastic optimization problem of land use, assuming that woody biomass rents follow a stochastic diffusion called geometric Brownian motion that is later discretized by a binomial option pricing approach. The problems in Chapters 2 and 3 assume that the landowner must make all decisions at the beginning of his or her time horizon. This assumption is relaxed in Chapter 4. Now, the landowner is allowed to revise his or her land allocation decision among three alternatives over time as information about market emergence is collected. We observe that the different forms of transaction costs are not as significant as in Chapters 2 and 3. However, different values of volatility of forest biomass rents give rise to different land allocation decisions, especially for the land of high quality.Ph. D.
8
Zhang, Ou. « Compacting biomass waste materials for use as fuel / ». free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3075412.
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Adesanya, Victoria Oluwatosin. « Investigation into the sustainability and feasibility of potential algal-based biofuel production ». Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708126.
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Walter, Christof. « Sustainability assessment of land use systems ». [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981911935.
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Perry, Miles William Aidan. « The role and sustainability implications of imported biomass for the UK energy sector ». Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538701.
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Perruccio, Deandra Marie. « Using Mutli Criteria Decision Analysis To Develop Sustainability Assessment Tools : Biomass Supply Chains ». ScholarWorks @ UVM, 2015. http://scholarworks.uvm.edu/graddis/445.
Texte intégralRésumé :
Energy access remains a significant challenge in nations lacking access to resources and strong infrastructure systems, creating barriers to economic development and to increased standards of living. Small scale biomass gasification energy (BGE) systems have been developed to meet energy needs in rural areas, creating synergies between agricultural and agro-forestry systems through utilization of biomass feedstock for energy generation. The sustainability of such systems requires sophisticated planning and coordination of the biomass supply chain.
The goal of this thesis is to investigate and improve structural and process related characteristics of sustainability assessments for small scale bio-energy systems, specifically focusing on establishment and management of biomass supply chains through the development and dissemination of a generic sustainability assessment framework for biomass supply chains of small-scale BGE systems in rural East Africa. Building on a preliminary sustainability assessment framework (Christensen, 2013; Joerg, 2013) this research develops an assessment tool designed to capture sustainability requirements of the biomass supply chain in the ecological, social, and economic spheres through testing on three case studies in rural Uganda. Application and analysis of a preliminary framework on pilot projects in a rural east African context using Multi Criteria Decision Analysis (MCDA) methodologies contributes to development of strategies for energy system analysis and building stakeholder capacity to incorporate social, economic, and environmental considerations. The assessment process is outlined, including scoring, data collection, contextual considerations. Model application is discussed, including the impact of weighting on decision outcomes, uncertainty management, sensitivity analysis, and identification of tradeoffs among criteria. Finally, discussion of tool usefulness verses usability contributes to bridging academic research with practitioner priorities.
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Czaika, Ellen Gail. « Model use in sustainability negotiations and decisions ». Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/103566.
Texte intégralRésumé :
Thesis: Ph. D., Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 123-130).
Sustainability negotiations and decisions require the integration of scientific information with stakeholder interests. Mathematical models help elucidate the physical world and therefore may orient the negotiators in a shared understanding of the physical world. Many researchers suggest collaborative modeling to facilitate integrating scientific information and stakeholder interests. In this thesis, I use methods that enable repeated instances of the same decision; the exploration of alternatives to model use (e.g. learning of a model's logic, relevant information, or irrelevant information); and the exploration of alternatives to collaborative modeling (e.g. using an expert model or not using a model). This thesis comprises two studies that use serious game role-play simulations. The first study is a computer-driven role-play simulation of governmental policy creation and the second is a five-party role-play simulation to negotiate a more sustainable end-of-life for used paper coffee cups. In the first study, model users reached the Pareto Frontier-the set of non-dominated points-more readily (13%) than non-model-users (2.5%) and model users discovered the win-win nature of electricity access with higher frequency (63%) than non-model users (9%). Participants who learned of the model's logic through presentation performed nearly as well as model users. In the second study, model use shortened the (mean) duration of the negotiation from 55 minutes to 45 minutes. Negotiating tables that co-created a model had a higher likelihood of reaching favorable agreements (44% compared to 25%). Model use did not significantly alter the value distribution among parties. Tables of negotiators used the model in two predominant manners: to test alternatives as they generated potential agreements and to verify a tentative agreement. The former resulted in higher mean table values than the latter. Together, these studies demonstrate: that mathematical models can be used in sustainability negotiations and decisions with good effect; that learning about the insights of a model is beneficial in decision making-but using a model is more beneficial; and that collaborative model building can provide better negotiation outcomes than using an expert model and can be faster than not using a model.
by Ellen Czaika.
Ph. D.
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Robinson, Kathryn Megan. « Biomass determinants and their use as yield predictors in Salicaceae ». Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414608.
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Cerny, P., P. Cerny et P. Stepanek. « Invasive plants : ecological threat or biomass potential for energy use ? » Thesis, Видавництво СумДУ, 2008. http://essuir.sumdu.edu.ua/handle/123456789/11614.
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Risén, Emma. « Sustainability Aspects of Bioenergy and Nutrient Recovery from Marine Biomass : Baltic Sea case studies ». Doctoral thesis, KTH, Industriell ekologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156377.
Texte intégralRésumé :
Coastal areas around the world are experiencing environmental problems such as climate change and eutrophication. These, in turn, lead to emerging challenges with excessive amounts of biomass that impact coastal communities. Developing utilisation strategies for marine biomass is therefore highly relevant and forms part of the blue growth research field. In response to environmental concerns, as a waste management strategy and as part of blue growth research initiatives, several Baltic Sea coastal projects have been initiated in recent years to study utilisation of maritime biomass. However, the sustainability of these utilisation strategies has not been critically appraised. Therefore, the work presented in this thesis explored some key sustainability aspects of two Baltic Sea case studies utilising common reed (Kalmar, Sweden) and mass-occurring filamentous macroalgae (Trelleborg, Sweden) for biogas and biofertiliser recovery. Energy analyses suggested that both case studies could provide a positive energy balance and have the potential to achieve nutrient recovery. Moreover, a contingent valuation study in Trelleborg demonstrated considerable welfare benefits of biomass utilisation. These findings indicate that marine biomass utilisation strategies highlight potential to contribute to environmental and welfare benefits of these coastal communities.QC 20141126
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Lode, Ben Raymond. « Defining Sustainability : A Case Study of a Woody Biomass Project in the Pacific Northwest ». Thesis, Connect to title online (Scholars' Bank), 2008. http://hdl.handle.net/1794/7777.
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Whiting, Andrew John. « Bioenergy in the United Kingdom : an environmental and economic sustainability assessment ». Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/bioenergy-in-the-united-kingdom-an-environmental-and-economic-sustainability-assessment(d7bb1f06-8775-49f1-a17e-69af935f71ce).html.
Texte intégralRésumé :
In an attempt to meet its ambitious climate change targets, the UK government has decided to incentivise the uptake of bioenergy. However, the full economic costs and environmental impacts of this decision have not yet been quantified at a national level. This is the topic of this research which evaluates the life cycle environmental and economic sustainability of different options for electricity and heat generation using biomass available in the UK, notably waste wood, agricultural residues and wastes, straw, municipal solid waste (MSW), food waste, and energy crops. These results are then used to evaluate the environmental impacts and costs for the whole bioenergy sector in the UK.The results suggest that the environmentally and economically most sustainable electricity generating options are, in descending order: manure/agricultural residue anaerobic digestion (AD) combined heat and power (CHP), Miscanthus co-firing with coal, and chicken litter gasification CHP. The most sustainable heat-generating systems are manure/agricultural residue ADC CHP, waste wood gasification CHP, and chicken litter gasification CHP. However, the use of these technologies is limited by the availability of their respective feedstocks. The research finds that there is currently 30.4 million odt of biomass produced annually in the UK which could be used for electricity and heat generation and that potentially 77.8 million odt could be produced if greater amounts of energy crops are grown. Dry biomass makes up the largest proportion of available biomass, which itself largely consists of wood wastes and energy crops. Dry biomass can therefore make the largest contribution of electricity or heat to potential bioenergy sectors. The electricity-generating biotechnologies identified as those which would make the most sustainable use of wood wastes and energy crops are biomass power plants and co-firing plants. Heat would be most sustainably generated from these feedstocks using biomass gasification CHPs and biomass boilers. According to the results, it is more sustainable to use the UK’s current and potential biomass resources for generating electricity, rather than for producing heat. Electricity from biomass has higher potential for reducing the majority of environmental impacts compared to the current UK electricity grid. Despite this, some impacts are expected to increase, including eutrophication, terrestrial ecotoxicity, depletion of elements and acidification. Furthermore, the economic sustainability of most biomass options is often dependent on subsidies being available, mainly because of the high capital costs. It is recommended that the government look beyond climate change and consider full life cycle impacts when deciding which technologies to incentivise to avoid solving the one problem at the expense of others. It is also advised that subsidies be tied to the sustainability of the feedstock, incentivising the use of waste over energy crops (at least in the short term) and encouraging the displacement of coal and oil. Furthermore, the government should consider scaling the FIT and RHI subsidies smoothly with capacity and consider scaling ROC payments which are currently not linked to capacity at all. Improvements to the environmental sustainability of bioenergy could be gained by funding research into cleaning emissions from biomass combustion, enforcing strict regulation of ash disposal and digestate treatment, and encouraging the reuse and recycling of rare elements.
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Zhou, Rusen. « Low-temperature discharge plasmas in liquids assisted biomass conversion ». Thesis, Queensland University of Technology, 2021.
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This project contributed to the establishment of the plasma-based, sustainable, and energy-efficient biorefinery platform. By introducing in-liquid discharge plasmas and understanding plasma-liquid interactions, this thesis explored the engineering and scientific basis of using such plasmas for bioresource conversion, and developed a “plasma-assisted reforming” process for fast biomass liquefaction and selective ethanol conversion into higher-value products at near-ambient conditions.
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Pinkert, Andre. « Investigations on the use of ionic liquids for superior biomass processing ». Thesis, University of Canterbury. Chemical and Process Engineering, 2011. http://hdl.handle.net/10092/5178.
Texte intégralRésumé :
Biocompatible composites, generated from renewable biomass feedstock, are regarded as promising materials that could replace synthetic polymers and reduce global dependence on fossil fuel sources. Wood cellulose, the most abundant biopolymer on earth, holds great potential as a renewable biomass feedstock. To unlock the entire scope of potential benefits of this feedstock, the wood components - namely cellulose, hemicellulose and lignin - need to be separated and processed individually. Current methods to separate wood components, such as Kraft pulping for example, suffer considerable drawbacks and cannot be considered environmentally benign. This thesis aims to increase our understanding of the interaction between ionic liquids (ILs) and biomass, in order to develop superior biomass processing techniques necessary to ensure a rapid transformation of our society towards full sustainability.
The first part of this work deals with the particular interaction of ILs with cellulose, and aims to investigate the structural requirements of ILs in order to qualify as a cellulose solvent. The cellulose-dissolving behaviour of selected alkanolammonium ILs was studied, and, combined with the results of an extensive literature review, a novel concept for the interaction of cellulose-dissolving ILs with cellulose was developed. It was postulated that efficient cellulose solvents need to position themselves in a distinct manner - with respect to the cellulose chain - in order to offer H-bond interaction sites with enhanced stability. As a result, alternative ions for cellulose-dissolving ILs were proposed, including oxazolium, 1,3-oxaphospholium, dimethylcarbamate, phosphate, nitrate, and nitrite.
The second part of the work investigated the use of food-additive based ILs for the separation of wood lignin, and studied the influence of selected process parameters, such as extraction time, extraction temperature, IL moisture content, wood particle size, wood species, IL cation species, solvent composition, and IL recyclability on the lignin extraction efficiency. The lignin extract and the wood residues were characterised via infrared spectroscopy, elemental analysis, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and gel permeation chromatography. An extraction efficiency of e = 0.43 of wood lignin was achieved in one gentle extraction step ( T = 373 K, t = 2 h), and it was found that the presence of a co-solvent increased the extraction efficiency to e = 0.60. Gentle conditions during IL treatment did not decrease the crystallinity of the wood sample, and the extracted
lignin had both a larger molecular mass and a more uniform molecular mass distribution, compared to commercially available Kraft lignin.
The outcomes of both studies were critically evaluated, addressing existing drawbacks and restrictions that need to be considered, and possibilities for future work were suggested.
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Sattar, Anwar. « Hydrogen production from biomass for use in solid oxide fuel cells ». Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6335/.
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This thesis presents an investigation into the use of four biochars (wood, rapeseed, miscanthus and sewage sludge) to generate a hydrogen-rich syngas that can be utilised in solid oxide fuel cells. Experimental investigations are split into three sections; (i) biochar characterisation, (ii) biochar gasification and (iii) the use of syngas in a single, microtubular solid oxide fuel cell. Characterisation revealed that wood biochar had the highest carbon content at 71.58%, sewage sludge had the lowest at 30% and rapeseed had the highest mineral content. The effects of temperature on gasification were investigated over a temperature range of 650 - 850°C at a steam flow of 172 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar and effects of steam flow at 850°C over a steam flow range of 54 - 277 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar. Results revealed the transient behaviour of the process as well as the effects of temperature and steam flow. Dry gas yield increases with both temperature and steam flow, with wood biochar giving maximum values of 2.58 m\(^3\) kg\(^-\)\(^1\) at 850°C and 277 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar. Hydrogen content decreases at high temperatures and peak hydrogen content, 58.7%, was achieved at 750°C from the rapeseed biochar. Syngas from wood and rapeseed biochars was collected and used in a microtubular solid oxide fuel cell. Gas from rapeseed had a negative effect on the fuel cell performance, leading to a 28% decrease in the performance over the 30 minutes of potentiostatic operation of 0.7 V. Gas from wood biochar was more suitable and was used in the solid oxide fuel cell for approximately 500 minutes, giving an initial electrical efficiency of 16.8% at 0.7 V.
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Falco, Camillo. « Sustainable biomass-derived hydrothermal carbons for energy applications ». Phd thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2012/5978/.
Texte intégralRésumé :
The need to reduce humankind reliance on fossil fuels by exploiting sustainably the planet renewable resources is a major driving force determining the focus of modern material research. For this reason great interest is nowadays focused on finding alternatives to fossil fuels derived products/materials. For the short term the most promising substitute is undoubtedly biomass, since it is the only renewable and sustainable alternative to fossil fuels as carbon source. As a consequence efforts, aimed at finding new synthetic approaches to convert biomass and its derivatives into carbon-based materials, are constantly increasing. In this regard, hydrothermal carbonisation (HTC) has shown to be an effective means of conversion of biomass-derived precursors into functional carbon materials. However the attempts to convert raw biomass, in particular lignocellulosic one, directly into such products have certainly been rarer. Unlocking the direct use of these raw materials as carbon precursors would definitely be beneficial in terms of HTC sustainability. For this reason, in this thesis the HTC of carbohydrate and protein-rich biomass was systematically investigated, in order to obtain more insights on the potentials of this thermochemical processing technique in relation to the production of functional carbon materials from crude biomass.
First a detailed investigation on the HTC conversion mechanism of lignocellulosic biomass and its single components (i.e. cellulose, lignin) was developed based on a comparison with glucose HTC, which was adopted as a reference model. In the glucose case it was demonstrated that varying the HTC temperature allowed tuning the chemical structure of the synthesised carbon materials from a highly cross-linked furan-based structure (T = 180oC) to a carbon framework composed of polyaromatic arene-like domains. When cellulose or lignocellulosic biomass was used as carbon precursor, the furan rich structure could not be isolated at any of the investigated processing conditions. These evidences were indicative of a different HTC conversion mechanism for cellulose, involving reactions that are commonly observed during pyrolytic processes. The evolution of glucose-derived HTC carbon chemical structure upon pyrolysis was also investigated. These studies revealed that upon heat treatment (Investigated temperatures 350 – 900 oC) the furan-based structure was progressively converted into highly curved aromatic pre-graphenic domains. This thermal degradation process was observed to produce an increasingly more hydrophobic surface and considerable microporosity within the HTC carbon structure.
In order to introduce porosity in the HTC carbons derived from lignocellulosic biomass, KOH chemical activation was investigated as an HTC post-synthesis functionalisation step. These studies demonstrated that HTC carbons are excellent precursors for the production of highly microporous activated carbons (ACs) and that the porosity development upon KOH chemical activation is dependent on the chemical structure of the HTC carbon, tuned by employing different HTC temperatures. Preliminary testing of the ACs for CO2 capture or high pressure CH4 storage yielded very promising results, since the measured uptakes of both adsorbates (i.e. CO2 and CH4) were comparable to top-performing and commercially available adsorbents, usually employed for these end-applications.
The combined use of HTC and KOH chemical activation was also employed to produce highly microporous N-doped ACs from microalgae. The hydrothermal treatment of the microalgae substrate was observed to cause the depletion of the protein and carbohydrate fractions and the near complete loss (i.e. 90%) of the microalgae N-content, as liquid hydrolysis/degradation products. The obtained carbonaceous product showed a predominantly aliphatic character indicating the presence of alkyl chains presumably derived from the lipid fractions. Addition of glucose to the initial reaction mixture was found out to be extremely beneficial, because it allowed the fixation of a higher N amount, in the algae derived HTC carbons (i.e. 60%), and the attainment of higher product yields (50%). Both positive effects were attributed to Maillard type cascade reactions taking place between the monosaccharides and the microalgae derived liquid hydrolysis/degradation products, which were in this way recovered from the liquid phase. KOH chemical activation of the microalgae/glucose mixture derived HTC carbons produced highly microporous N-doped carbons. Although the activation process led to a major reduction of the N-content, the retained N-amount in the ACs was still considerable. These features render these materials ideal candidates for supercapacitors electrodes, since they provide extremely high surface areas, for the formation of electric double-layer, coupled to abundant heteroatom doping (i.e. N and O) necessary to obtain a pseudocapacitance contribution.Die Notwendigkeit, die Abhängigkeit der Menschheit von fossilen Brennstoffen zu reduzieren ist die treibende Kraft hinter aktuellen Forschungsanstrengungen in den Materialwissenschaften. Folglich besteht heutzutage ein erhebliches Interesse daran Alternativen zu Materialien, die aus fossilen Resourcen gewonnen werden, zu finden. Kurzfristig ist zweifellos Biomasse die vielversprechendste Alternative, da sie aus heutiger Sicht die einzige nicht-fossile, nachhaltige und nachwachsende Kohlenstoffquelle ist. Konsequenterweise werden die Antrengungen neue Syntheseansätze zur Konvertierung von Biomasse und ihren Derivaten in kohlenstoffbasierten Materialien forwährend erhöht. In diesem Zusammenhang hat sich die Hydrothermalkarbonisierung (HTC) als sehr vielseitiges Werkzeug zur Konvertierung von Biomasse-basierten Ausgangsstoffen in funktionale Kohlenstoffmaterialien herausgestellt. Dennoch gibt es bisher wenige Ansätze um rohe Biomasse, genauer gesagt Lignicellulose, direkt in funktionale Materialien umzusetzen. Könnte der direkte Einsatz von roher Biomasse Verfahren wie der HTC zugänglich gemacht werden, würde dies die Nachhaltigkeit des Verfahrens immens steigern. Daher wurde in dieser Dissertation die Hydrothermalkarbonisierung von kohlenhydratreicher (d. h. Lignicelluse) und proteinreicher (d. h. Microalgae) Biomasse systematisch analysiert. Diese Untersuchung galt dem Ziel einen besseren Einblick in das Potential dieser thermochemischen Verarbeitungsmethode funktionale Kohlenstoffmaterialien aus unverarbeiteter Biomasse hervorzubringen zu gewinnen. Die hergestellten Materialien wurden mittels chemischer Aktivierung nachträglich weiter behandelt. Dieser zusätzliche Verarbeitungsschritt ermöglichte die Herstellung hochporöser aktiverter Kohlenstoffe (AC). Die aus Lignicellulose gewonnenen ACs zeigten exzellente Eigenschaften bei der Aufnahme von CO2 und der Hochdruckspeicherung von CH4 währen die aus Microalgae gewonnen Eigenschaften an den Tag legten (z. B. hohe Oberfläche und N-Dotierung), welche sie zu vielversprechenden Materialien für Superkondensatoren machen. Die in dieser Dissertation präsentierte Arbeit zeigte außergewöhnliche Fortschritte in Richtung der Anwendung von unbehandelter Biomasse als Ausgangsmaterial für die Produktion von funktionalen Kohlenstoffen.
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Scott, Jennifer E. « Integrating sustainability provisions into contemporary decision making / ». View thesis, 2004. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20050609.120022/index.html.
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Guo, Zhimei. « Economic and policy perspectives of biofuel as an emerging use of forest biomass in Mississippi ». Master's thesis, Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-09072007-125135.
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Lo, Enlin. « Sustainable Production of Bio-based Succinic Acid from Plant Biomass ». Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7693.
Texte intégralRésumé :
Succinic acid is a compound used for manufacturing lacquers, resins, and other coating chemicals. It is also used in the food and beverage industry as a flavor additive. It is predominantly manufactured from petrochemicals, but it can also be produced more sustainably by fermentation of sugars from renewable feedstocks (biomass). Bio-based succinic acid has excellent potential for becoming a platform chemical (building block) for commodity and high-value chemicals.
In this study, we focused on the production of bio-based succinic acid from the fiber of sweet sorghum (SS), which has a high fermentable sugar content and can be cultivated in a variety of climates and locations around the world. To avoid competition with food feedstocks, we targeted the non-edible ‘bagasse’, which is the fiber part after extracting the juice. Initially, we studied various conditions of pretreating SS bagasse to remove most of the non-fermentable portions and expose the cellulose fibers containing the fermentable sugars (glucose). Concentrated (83%) phosphoric acid was utilized at mild temperatures of 50-80 °C for 30-60 minutes at various bagasse loadings (10-15%) using a partial factorial experimental design. After pretreatment, the biomass was subjected to enzymatic hydrolysis with commercial cellulase enzyme (Cellic® Ctec2) to identify the pretreatment conditions that lead to the highest glucose yield that is critical for the production of succinic acid via fermentation with the bacterium Actinobacillus succinogenes.
As the pretreatment temperature and duration increased, the bagasse color changed from light brown to dark brown-black, indicating decomposition, which ranged from 15% to 72%. The pretreatment results were fitted with an empirical model that identified 50 °C for 43 min at 13% solids loading as optimal pretreatment conditions that lead to the highest glucose release from sweet sorghum bagasse. Biomass pretreated at those conditions and subjected to separate enzymatic hydrolysis and fermentation with A. succinogenes yielded almost 18 g/L succinic acid, which represented 90% of the theoretical yield, a very promising performance that warranties further investigation of bio-based succinic acid production from sweet sorghum bagasse, as a more sustainable alternative to succinic acid produced from fossil sources, such as oil.
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Scott, Jennifer (Jennifer E. )., University of Western Sydney, of Science Technology and Environment College et School of Environment and Agriculture. « Integrating sustainability provisions into contemporary decision making ». THESIS_CSTE_EAG_Scott_J.xml, 2004. http://handle.uws.edu.au:8081/1959.7/500.
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Sustainable development is a multi-faceted and complex proposition, investigating such a goal required a grounded study capable of analysing real world issues. Managing such a highly diverse region as Western Sydney with its multiple demands is complicated by the plethora of government administration agencies. Contemporary land use planning policies and decisions appear frequently at odds with community values and aspirations for the region. Evidence presented in this research suggests a declining natural resource base that manifests itself in an insidious cost impost to the public sector while the benefits accrue to the private sector.Eventual developments in the resolution and maintenance of the functional integrity of the natural systems in Western Sydney may demand a major paradigm shift in economic and social policy. This research suggests that a precautionary based approach to thresholds of harm in the Western Sydney region is long overdue. Tools developed in this study appear capable of clarifying the evident land use planning paradoxes and may assist in negotiating sustainable outcomes by fostering a collaborative learning process between decision makers, experts and the community.Doctor of Philosophy (PhD)
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Caldini, Nayara Nunes. « Use of bioflocs biomass wet and dry for feeding of Nile tilapia ». Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14408.
Texte intégralRésumé :
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoThis study consisted of two experiments. The first objective was to demonstrate the technical feasibility of separate BFT tank technology in juvenile cultivation of Nile tilapia, for monitoring quality variables of water and productive performance. The fish were fed different combinations of artificial food (balanced diet) and natural food (bioflocs biomass). As the supply of food decreased the tanks increased the biomass supply bioflocs. Bioflocs biomass was produced in an external tank 500 L, separately from the cultivation system (separate tank BFT). You can reduce the regular feeding rates of juvenile Nile tilapia, with artificial diets, 25 %, without losses, if bioflocs to provide wet grown animals, as a food supplement, in equal proportion. The second objective was determine the effects of the provision of dried bioflocs biomass to Nile tilapia juveniles, stocked in experimental rearing tanks for 8 weeks, upon selected variables of water quality, growth performance and effluents quality. Fish was fed with different combinations of artificial diets and bioflocs biomass, in the wet form (in natura) or dried. As the supply of artificial diet was decreased, the provision of bioflocs biomass was increased in the same proportion. The bioflocs biomass was produced in two extra 500-L tanks. The growth performance of fish that were partially fed with dried bioflocs biomass has remained below what was observed in the tanks supplied with the wet bioflocs biomass. Due to the lacking of positive results, there is not any rationale to dry the bacterial bioflocs aiming at the delivery of it as a dried biomass to the cultured fish.
O presente estudo foi constituÃdo por dois experimentos completos e consecutivos. No primeiro, objetivou-se demonstrar a viabilidade tÃcnica da tecnologia do tanque BFT (c/bioflocos) avulso no cultivo de juvenis de tilÃpia do Nilo, pelo monitoramento de variÃveis de qualidade de Ãgua e de desempenho produtivo. Os peixes foram alimentados com diferentes combinaÃÃes de alimento artificial (raÃÃo balanceada) e de alimento natural (biomassa de bioflocos). à medida que diminuÃa o aporte de raÃÃo aos tanques, aumentava o fornecimento de biomassa de bioflocos. A biomassa de bioflocos foi produzida em um tanque externo de 500 L, em separado do sistema de cultivo (tanque BFT avulso). Os tanques de cultivo que receberam aplicaÃÃes diÃrias de bioflocos apresentaram concentraÃÃes de nitrito na Ãgua significativamente menores do que as observadas nos tanques nos quais a Ãnica fonte de alimentaÃÃo dos peixes foi a raÃÃo comercial. Concluiu-se que à possÃvel reduzir as taxas regulares de arraÃoamento de juvenis de tilÃpia do Nilo, com raÃÃes artificiais, em 25%, sem prejuÃzo zootÃcnico, caso se forneÃa bioflocos Ãmidos aos animais cultivados, como suplemento alimentar, em igual proporÃÃo. O segundo experimento teve como objetivo determinar os efeitos do fornecimento de biomassa seca de bioflocos a juvenis de tilÃpia do Nilo, mantidos em tanques experimentais de cultivo por oito semanas, sobre variÃveis selecionadas de qualidade de Ãgua, desempenho zootÃcnico e qualidade de efluentes. Os peixes foram alimentados com diferentes combinaÃÃes de raÃÃo balanceada e biomassa de bioflocos, na forma Ãmida (in natura) ou seca. à medida o aporte de raÃÃo aos tanques foi menor, o fornecimento de biomassa de bioflocos foi proporcionalmente maior. A biomassa de bioflocos foi produzida em dois tanques avulsos de 500 L. O desempenho zootÃcnico dos peixes nos tanques que receberam a suplementaÃÃo de biomassa seca de bioflocos ficou abaixo do observado nos tanques com biomassa Ãmida. Pela ausÃncia de resultados positivos, concluiu-se que nÃo hà justificativa tÃcnica para a secagem dos bioflocos bacterianos com o objetivo de fornecer a biomassa seca aos peixes cultivados
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Souster, Terri A. « Marine biodiversity of Antarctic hard rock communities : species biomass and energy use ». Thesis, Open University, 2018. http://oro.open.ac.uk/53959/.
Texte intégralRésumé :
This thesis presents the first seasonal study in the Antarctic of shallow water hard rock communities, including surveys to quantify biodiversity and biomass (Ash Free Dry Mass, AFDM). In addition temporal changes in biodiversity since 1998 were evaluated in the same location. To do this all benthic organisms greater than 3mm in size were collected at 6m, 12m and 20m depth from three transects near Rothera Point, Adelaide Island (67° 34’ S, 68° 07’ W) in the summer and winter of 2015. Organisms were identified and their wet, dry and ash free dry masses obtained. Benthic community structure did not vary seasonally, low metabolic costs due to slowed growth rates, reproduction, development with the ability to cease feeding for the winter months may explain the lack of change between season. Community structure did, however, vary with depth, which agrees with previous studies of shallow water Antarctic hard substratum communities. Comparisons between the 2015 and 1998 survey showed reductions of both biodiversity and organic biomass at all three depths over the intervening 17 years. The greatest change was at 12m where faunal density, diversity, richness and biomass all declined significantly between 1998 and 2015. Ice scour is thought to be the main driver of this change as previous studies have shown an increase in ice scour frequency around 10m depth. The effects of seasonality on metabolism were also investigated using the five most common marine invertebrates and significant energy transformers Odontaster validus, Sterechinus neumayeri, Nacella concinna, Heterocucumis steineni and Ophionotus victoriae. Measurements of metabolic rates using closed circuit respirometry were carried out across a size range (juveniles to fully reproductive adults), to represent the population of five locally abundant species during the austral summer and winter. Oxygen consumption of Sterechinus neumayeri and Odontaster validus was significantly higher (by 39% & 44% respectively) in summer than winter. However, metabolic rates showed no consistent seasonal trends in Nacella concinna, and in Ophionotus victoriae and Heterocucumis IV steineni were higher in summer than winter, but only in large individuals which could be due to feeding and reproducing during the summer months. Seasonal metabolic changes were in line with previous studies on Antarctic marine invertebrates. Having established the metabolic rates of these species, identifying how much organic carbon there is in each and what they eat (diet), it is possible to estimate the energy required within the ecosystem to meet their metabolic demands long term. Molecular methods were employed to advance our understanding of diet. Gut contents from the same five species were analysed using DNA extraction and molecular techniques. This project forms a baseline to understand future changes in Antarctic benthic biodiversity and to analyse energy flows in these communities.
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Shaheed, Abdul. « Coconut oil and its derivatives as a renewable alternative diesel fuel for use in the Maldives ». Thesis, Loughborough University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299675.
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Homsy, Sally Louis. « Processing Algal Biomass to Renewable Fuel : Oil Extraction and Hydrothermal Liquefaction ». University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343404093.
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Groover, Miles Clark. « A Comparison of Chipper Productivity, Chip Characteristics, and Nutrient Removals from Two Woody Biomass Harvesting Treatments ». Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/36350.
Texte intégralRésumé :
Increased costs of fossil fuels, regulatory policies, and investments by federal and state governments have caused increased interest and incentive for the use of wood as a renewable form of energy. As a result, landowners and forest managers are considering chipping whole trees and harvesting residues as a means to meet increased demand of wood chips as a renewable source of energy. However, the profitability, productivity gains, and sustainability of these alternative harvesting methods continue to be an area of research. The objective of this study was to compare two biomass harvesting treatments with regard to the characteristics of the chips they produced, chipper productivity, nutrient removals, and site disturbance. The first biomass harvesting treatment was an integrated harvest where roundwood was merchandized and hauled to the appropriate mill and limbs, tops, and small stems (residues) were chipped for hog fuel. The second biomass harvesting treatment simulated a scenario where biomass markets were competing with pulpwood markets and landowners could choose to sell wood for energy or pulp wood. In this treatment whole trees and small stems were chipped for hog fuel. A third harvesting treatment was a conventional roundwood harvest where no wood was chipped, and this treatment was used as a control for comparison of nutrient removals and site disturbance. The chips produced from both harvesting treatments were very similar, but those produced from whole trees tended to be slightly smaller than those produced from residues. Chipper productivity was significantly higher when chipping whole trees and it was also much more efficient in terms of fuel use. Estimations of nutrient removals showed that there was very little difference in the amount of nutrient removed from the biomass harvesting treatments, but both treatments removed significantly more N and Ca than the conventional roundwood harvesting treatment. There was significantly more downed and standing material left on the site after harvesting in the conventional treatment, but this did not translate into a large amount of additional nutrients left on the site. There was little difference in soil disturbance between all three treatments, and due to the dry soil conditions during harvesting, there was very little visual soil disturbance at all during harvesting.Master of Science
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Shearer, Christopher R. « The productive reuse of coal, biomass and co-fired fly ash ». Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52298.
Texte intégralRésumé :
Stricter greenhouse gas emission limits and renewable energy requirements are expected to further increase the worldwide practices of firing biomass and co-firing biomass with coal, which are both considered more sustainable energy sources than coal-only combustion. Reuse options for the by-products of these processes -biomass ash and co-fired fly ash -remain limited. Therefore, this research examines their use as supplementary cementitious materials (SCMs) in concrete and as precursors for alkali-activated geopolymers.
Toward their potential use as an SCM, after characterizing these ashes assessing their compliance with ASTM C618 requirements, their impact on early-age hydration kinetics, rheology, setting time and permeability was assessed. Furthermore, the pozzolanic reactivity and the microstructural and hydrated phase development of the cement-ash samples were analyzed. The results show that a wood biomass ash sample was not satisfactory for use as an SCM. On the other hand, the findings demonstrate that co-fired fly ashes can significantly improve the strength and durability properties of concrete compared to ordinary portland cement, in part due to their pozzolanicity. Thus, it is recommended that the ASTM C618 standard be modified to permit co-fired fly ash sources that meet existing requirements and any additional requirements deemed necessary to ensure their satisfactory performance when used in concrete.
Toward their potential use in geopolymers, this study characterized the early-age reaction kinetics and rheological behavior of these materials, showing that their exothermic reactivity, plastic viscosity and yield stress are significantly influenced by the activator solution chemistry and other characteristics of the ash. Two co-fired fly ashes were successfully polymerized, with compressive strengths generally highest for ashes activated with solutions with a molar ratio of SiO₂/(Na₂O + K₂O) = 1. The results show that geopolymerization is a viable beneficial reuse for these emerging by-products. Further characterization of these materials by scanning transmission X-ray microscopy analysis revealed the heterogeneity of the aluminosilicate phase composition of the co-fired fly ash geopolymer gel at the nano- to micro-scale.
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Saphangthong, Thatheva. « Dynamics and sustainability of land use systems in northern Laos ». 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/137059.
Texte intégralRésumé :
Kyoto University (京都大学)0048
新制・課程博士
博士(地域研究)
甲第13191号
地博第41号
新制||地||14(附属図書館)
UT51-2007-H464
京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻
(主査)助教授 竹田 晋也, 教授 河野 泰之, 教授 小林 繁男
学位規則第4条第1項該当
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Raphael, Caroline. « Collaborative sustainability assessment for significant land-use planning and development ». Thesis, Raphael, Caroline (2011) Collaborative sustainability assessment for significant land-use planning and development. PhD thesis, Murdoch University, 2011. https://researchrepository.murdoch.edu.au/id/eprint/6080/.
Texte intégralRésumé :
There is an increasing need to integrate sustainability and deliberation within land-use planning and development. In Western Australia, despite much rhetoric, there are no effective frameworks or guidelines to support their integration. Sustainability assessment is considered one option to integrate greater levels of sustainability within planning and development (see for example, Pope 2007, Gibson et al. 2005). This thesis explores this possibility, asking the question: “how could sustainability assessment and deliberation best be applied for significant land-use planning and development undertakings in Western Australia?”
The thesis first reviews the literature on sustainability assessment and deliberation. This review reveals that existing approaches have substantial limitations. It is argued that a new approach which draws upon the strengths of these approaches and addresses their limitations is needed. The review also reveals that, in respect to deliberation, limited knowledge exists regarding which dimensions of deliberation are more important from the perspective of those involved and how best to link deliberation to sustainability assessment.
In order to seek insights from practice that could address these gaps, a case study methodology is then used. Two Western Australian cases are examined: the Fremantle Harbours Policy process and the ING Commercial Development, which commenced in 2006 and 2003, respectively. Both cases applied various forms of assessment and deliberation at the policy level and the development application level. The case study analysis reveals that the separation of assessment and deliberative processes does not address key issues or areas of concern. Indeed, the outcomes are less than optimal, with harmed and fractured relationships between key parties resulting. With regards to deliberation, for those interviewed, seeking inclusivity and capacity to influence decision-making were the most important dimensions of deliberation. From their perspective and for both cases, the right people were not involved effectively and capacity to influence key decision-making processes was granted superficially. In both cases, understanding of the issues and their implications was hampered by limited time, resources and aids to fully appreciate the impacts/benefits associated. Honesty, trust and respect were not fostered throughout the deliberative and assessment processes, resulting in a lack of honest responses and preferences being revealed. Deliberative events, in particular, were too large to hold intimate conversations and dominant players had the effect of silencing others. Finally, the media limited deliberation in both cases, restricting rather than enhancing communication on the projects.
Both cases reveal that despite rhetoric for sustainability, it is not adequately integrated into the assessment process. None of the processes revealed the divergent frames and supported frame-bridging, frame-shifts, frame-reflection or reframing to the extent which could enable the resolution of controversy surrounding both cases. In the case of the ING Commercial Development, long after the approval for the development, conflict continued about poor design and execution of deliberative events.
Based on these findings, collaborative sustainability assessment is presented as a more suitable approach for significant land-use planning and development undertakings. The emphasis on collaboration is to develop and foster positive and productive relationships with key parties to enable sustainability assessment and deliberation to take place, and help deal with conflict which may arise. The argument is that, had collaborative approaches been undertaken, issues surrounding deliberation and assessment could have been better dealt with in both cases and relationships fostered, not harmed in the process. Better outcomes would also have resulted.
Building on the findings from the literature review and cases, this thesis proposes collaborative sustainability assessment, emphasising the key dimensions of deliberation and sustainability assessment which should be undertaken within this framework. This framework should help practitioners and theorists in devising, implementing and examining collaborative sustainability assessment in practice. The key contribution of this framework is that it intimately links theory and practice on deliberation and sustainability assessment, providing a sense of reality to collaborative sustainability assessment.
This thesis can be seen as a starting point and an important aspect will be to examine how collaborative sustainability assessment should fit into planning and, importantly, help integrate planning into the broader sustainability agenda. This should be the focus of future theoretical and empirical research.
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Coy, Helen S. « The Use of Performance Measurement Data in Nonprofit Organizational Sustainability ». ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/5315.
Texte intégralRésumé :
In the United States, nonprofit organizations (NPOs) face a precarious future because of their heavy reliance on the financial support of government funding, other donor agencies, and philanthropic foundation resources. The purpose of this study is to understand how and to what extent leadership of NPOs can benefit from using funder-required performance data to improve organizational sustainability. Using Pfeffer and Salincik's resource dependency theory to explain organizational sustainability, this qualitative multiple case study of 10 NPOs in a northeastern U.S. state includes 14 interviews with NPO leadership, a document review of NPO 990 tax filings, annual performance reports, and board meeting minutes. All data were inductively coded and then subjected to a thematic analysis procedure. Key findings indicated 6 overarching themes associated with NPO sustainability and funder-required performance measures that impact program sustainability but are mainly used for compliance: (a) NPO adoption and use of performance measures; (b) data collection and evaluation for external compliance; (c) information pertaining to financial, operational, and administrative decision making; (d) NPO leadership decisions regarding internal constructs, operations, and management; (e) resource dependency; and (f) sustainability practices. The implications for positive social change include strategies for NPO leaders to use to ensure survival, continuous community impact, and awareness for policymakers regarding legislative and regulatory developments that may inadvertently harm NPOs.
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Nixon, Jonathan. « Solar thermal collectors for use in hybrid solar-biomass power plants in India ». Thesis, Aston University, 2012. http://publications.aston.ac.uk/18722/.
Texte intégralRésumé :
This thesis examined solar thermal collectors for use in alternative hybrid solar-biomass power plant applications in Gujarat, India. Following a preliminary review, the cost-effective selection and design of the solar thermal field were identified as critical factors underlying the success of hybrid plants. Consequently, the existing solar thermal technologies were reviewed and ranked for use in India by means of a multi-criteria decision-making method, the Analytical Hierarchy Process (AHP). Informed by the outcome of the AHP, the thesis went on to pursue the Linear Fresnel Reflector (LFR), the design of which was optimised with the help of ray-tracing. To further enhance collector performance, LFR concepts incorporating novel mirror spacing and drive mechanisms were evaluated. Subsequently, a new variant, termed the Elevation Linear Fresnel Reflector (ELFR) was designed, constructed and tested at Aston University, UK, therefore allowing theoretical models for the performance of a solar thermal field to be verified. Based on the resulting characteristics of the LFR, and data gathered for the other hybrid system components, models of hybrid LFR- and ELFR-biomass power plants were developed and analysed in TRNSYS®. The techno-economic and environmental consequences of varying the size of the solar field in relation to the total plant capacity were modelled for a series of case studies to evaluate different applications: tri-generation (electricity, ice and heat), electricity-only generation, and process heat. The case studies also encompassed varying site locations, capacities, operational conditions and financial situations. In the case of a hybrid tri-generation plant in Gujarat, it was recommended to use an LFR solar thermal field of 14,000 m2 aperture with a 3 tonne biomass boiler, generating 815 MWh per annum of electricity for nearby villages and 12,450 tonnes of ice per annum for local fisheries and food industries. However, at the expense of a 0.3 ¢/kWh increase in levelised energy costs, the ELFR increased saving of biomass (100 t/a) and land (9 ha/a). For solar thermal applications in areas with high land cost, the ELFR reduced levelised energy costs. It was determined that off-grid hybrid plants for tri-generation were the most feasible application in India. Whereas biomass-only plants were found to be more economically viable, it was concluded that hybrid systems will soon become cost competitive and can considerably improve current energy security and biomass supply chain issues in India.
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Hassan, El Sayed Rabie El Sayed. « Use of Ionic Liquids for the Treatment of Biomass Materials and Biofuel Production ». Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0043/document.
Texte intégralRésumé :
Le remplacement des solvants organiques classiques par une nouvelle génération de solvants moins toxiques et moins polluants est un défi majeur pour l'industrie chimique. Les liquides ioniques (LIs) ont été largement identifiés comme substituts intéressants aux solvants traditionnels. Le but de ce travail est d'étudier la solubilité des sucres ou des constituants issus de la biomasse dans les liquides ioniques afin de pallier au manque de données expérimentales sur les équilibres de phases de systèmes {sucres + LIs} ou {biomasse + LIs}. Les données de solubilité ont été corrélées avec succès en utilisant les modèles thermodynamiques NRTL et UNIQUAC. Cette étude démontre que la méthode de l'antisolvant est une bonne technique pour l'extraction des sucres des LIs. Par conséquent, les liquides ioniques peuvent être facilement recyclés pour être réutilisés. Les natures fondamentales des interactions entre les sucres et les liquides ioniques ont été définies en utilisant le calcul ab initio. Les résultats obtenus par simulation sont en accord avec les données expérimentales et indiquent que les liquides ioniques interagissent avec les sucres par liaisons hydrogène. La seconde partie de ce travail met en évidence que le prétraitement du miscanthus avec les liquides ioniques permet d'obtenir une bonne production d'éthanol (jusqu'à 150 g d'éthanol par kg de miscanthus). Les résultats montrent que les liquides ioniques sont des solvants performants dans le domaine de la conversion des matières premières issues de la biomasse en biocarburant. Ainsi, l'application à l'échelle industrielle de ces procédés d'extraction de la cellulose pourrait être d'un grand intérêtThe replacement of conventional organic solvents by a new generation of solvents less toxic, less flammable and less polluting is a major challenge for the chemical industry. Ionic liquids have been widely promoted as interesting substitutes for traditional solvents. The purpose of this work is to study the solubility of carbohydrates or biomass based materials in ionic liquids in order to overcome the lack of experimental data on phase equilibria of {biomass or carbohydrate-ILs} mixtures. Solubility data were successfully correlated using NRTL and UNIQUAC thermodynamic models. It was found that the antisolvent method is a good technique for the extraction of carbohydrates from ILs. Ionic liquids could be then recycled successfully for reuse. The fundamental natures of the interaction between carbohydrates and ionic liquids were investigated using ab initio calculations. The theoretical results are in good agreement with experimental data. It was concluded that ionic liquids mainly interact with carbohydrates via hydrogen bonding formation. This confirms that the process of dissolution and regeneration of cellulose in ionic liquids is accompanied only with a physical change. The preatreatment of miscanthus with ionic liquids resulted in the regeneration of amorphous, porous cellulose almost free of lignin, which is suitable for enzymatic hydrolysis and fermentation processes. A successful ethanol production was obtained with an overall ethanol yield reached up to 150 g ethanol kg-1 miscanthus. This indicates the high performance of ionic liquids in converting biomass feedstocks into biofuel. Indeed, applying the cellulose extraction processes on the industrial scale could be of great interest
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Boyle, William Antonio. « Development of a computer vision fish biomass measurement procedure for use in aquaculture / ». Thesis, Connect to this title online ; UW restricted, 1994. http://hdl.handle.net/1773/5325.
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Adams, Mark D. « Assessing awareness of Florida homeowners about the use of biomass for electricity production ». [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001483.
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Mwanje, Dianne. « Smokeless homes : Challenges for Increasing Use of Improved Biomass Cookstoves in Kisumu, Kenya ». Thesis, Linköpings universitet, Tema Miljöförändring, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-153781.
Texte intégralRésumé :
In Kenya, 69 percent of populations depend on biomass fuels to meet their cooking needs. The incomplete combustion of biomass is performed in insufficiently ventilated settings thus exposing human health and environment to toxic pollution. To date, women and children in resource limited settings have been most vulnerable to severe respiratory infections. The promotion of the Improved Biomass Cookstoves has become a popular issue in policy, research and practice. Community Based Organizations have however faced serious challenges in increasing sustainable use of the cookstoves among users. This qualitative study investigates the role of Community Based Organizations in promoting the Improved Biomass Cookstoves through women’s empowerment initiatives. It applies focus group interviews, questionnaire and formal interviews. 11 interview forms were administered to 30 women, 2 key informants and 3 implementing Community Based Organization representatives in Dunga wetland community. A combination of previous research and this empirical study show that economic resources, small diameter stove designs as well as insufficient policy support hinder effective stove programmes. While there is general adoption, women lack sufficient income and ownership of land which is a significant resource to empowerment. Women informal financial networks are instrumental in driving behavioral change towards clean cooking in the community. Sufficient gender sensitive policy intervention and support can provide effective channels to ensure sustainable incomes of women, livelihoods and stove use.
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Dianne, Mwanje. « Smokeless homes : Challenges for Increasing Use of Improved Biomass Cookstoves in Kisumu, Kenya ». Thesis, Linköpings universitet, Tema Miljöförändring, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-153789.
Texte intégralRésumé :
In Kenya, 69 percent of populations depend on biomass fuels to meet their cooking needs. The incomplete combustion of biomass is performed in insufficiently ventilated settings thus exposing human health and environment to toxic pollution. To date, women and children in resource limited settings have been most vulnerable to severe respiratory infections. The promotion of the Improved Biomass Cookstoves has become a popular issue in policy, research and practice. Community Based Organizations have however faced serious challenges in increasing sustainable use of the cookstoves among users. This qualitative study investigates the role of Community Based Organizations in promoting the Improved Biomass Cookstoves through women’s empowerment initiatives. It applies focus group interviews, questionnaire and formal interviews. 11 interview forms were administered to 30 women, 2 key informants and 3 implementing Community Based Organization representatives in Dunga wetland community. A combination of previous research and this empirical study show that economic resources, small diameter stove designs as well as insufficient policy support hinder effective stove programmes. While there is general adoption, women lack sufficient income and ownership of land which is a significant resource to empowerment. Women informal financial networks are instrumental in driving behavioral change towards clean cooking in the community. Sufficient gender sensitive policy intervention and support can provide effective channels to ensure sustainable incomes of women, livelihoods and stove use.
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Haji, Esmaeili Seyed Ali. « A Market Incentives Analysis of Sustainable Biomass Bioethanol Supply Chains with Carbon Policies ». Diss., North Dakota State University, 2020. https://hdl.handle.net/10365/31869.
Texte intégralRésumé :
Given the increasing demand for energy, climate change, and environmental concern of fossil fuels, it is becoming increasingly significant to find alternative renewable energy sources. Bioethanol as one sort of cellulosic biofuel produced from lignocellulosic biomass feedstocks has shown great potential as a renewable resource. Delivering a competitive, sustainable biofuel product requires comprehensive supply chain planning and design. Developing economically and environmentally optimal supply chain models is necessary in this context. Also, designing biomass bioethanol supply chain (BBSC) models addressing social issues requires using second-generation biomass which is not a source of food for humans. Currently, corn as a first-generation feedstock is the primary source of bioethanol in the United States which has given growth to new social issues such as the food versus fuel debate. Considering incentives for first-generation bioethanol producers to switch to second-generation biomass and associated production technologies will help to address such social issues.
The scope of this study focuses on analyzing economic and environmental market incentives for second-generation bioethanol producers while considering different carbon policies as penalties and restrictions for emissions coming from BBSC activities. First, we develop an integrated life cycle emission and energy optimization model for analyzing an entire second-generation bioethanol supply chain using switchgrass as the source of biomass while finding the most appropriate potential locations for building new cellulosic biorefineries in North Dakota. Second, we propose a supply chain model by comparing a first-generation (corn) and a second-generation (corn stover) bioethanol supply chain to analyze how policymakers can incentivize first-generation bioethanol producers to switch their technology and biomass supply from first-generation to second-generation biomass. Third, we develop the model further by investigating the impact of four different carbon policies including the carbon tax, carbon cap, carbon cap-and-trade, and carbon offset on the supply chain strategic and operational decisions.
This research will help to design robust BBSCs focused on sustainability in order to optimally utilize second-generation biomass resources in the future. The findings can be utilized by renewable energy policy decision makers, bioethanol producers, and investors to operate in a competitive market while protecting the environment.
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Naqi, Ahmad. « Conversion of Biomass to Liquid Hydrocarbon Fuels via Anaerobic Digestion : A Feasibility Study ». Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7639.
Texte intégralRésumé :
The use of biomass as a potential feedstock for the production of liquid hydrocarbon fuels has been under investigation in the last few decades. This paper discusses a preliminary design and a feasibility study of producing liquid hydrocarbon fuels from biomass through a combined biochemical and thermochemical route. The process involves anaerobic digestion (AD) of the biodegradable portion of the biomass to produce methane rich gas. The methane rich biogas stream is purified by removing contaminants and upgraded to liquid hydrocarbon fuel in a gas to liquid facility (GTL) via thermochemical conversion route. The biogas conversion involves two major steps: tri-reforming step to produce syngas (a mixture of CO and H2), and Fischer-Tropsch Synthesis (FTS) step to convert the syngas to a spectrum of hydrocarbons. Separation and upgrading of the produced hydrocarbon mixture allows production of synthetic transportation fuels. AD is ranked as one of the best waste management options as it allows for: energy recovery, nutrient recovery, and reduction in greenhouse gases emission.
A detailed process modeling of the process was carried out using ASPEN Plus process design software package. Data for the process was based on literature on AD combined with laboratory results on the biogas to liquid conversion process. The composition of the final liquid hydrocarbon from the ASPEN model has been compared to the composition of commercial diesel fuel, and results have shown good agreement. As a result, the most current commercial diesel prices were used to evaluate the potential revenue from selling the product in the open market.
The total capital investment to construct the plant with a capacity of handling 100,000 ton per year of wet biomass is $16.2 million with a potential of producing 2.60 million gallons of diesel. The base case feedstock is corn stover. The annual operating cost to run the plant is estimated to be $8.81 million. An annual revenue from selling the diesel product is estimated to be $14.6 million taking into account a green energy incentive of $3.00/gallon of diesel sold. The net present worth at the end of the plant life is $8.76 million with a discounted cash flow of return of 26.2%. The breakeven cost of diesel is determined to be $4.34/gallon assuming no tipping fees are charged for handling the waste.
Sensitivity analyses results concluded that the profitability of the process is most sensitive to variation in diesel selling price. Based on these results, it can be concluded that the process is profitable only if incentives are provided for renewable fuels due to the current low prices of fossil fuels.
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Slusser, Robert S. « Forage Improvements and Riparian Buffers for Water Quality and Sustainability : A Small Farm Management Plan ». Virginia Tech, 2004. http://hdl.handle.net/10919/37059.
Texte intégralRésumé :
Black Hawk Creek was included in the Iowa Department of Natural Resources (DNR) 303(d) list of impaired waters in 1998 due to non-point sources of fecal coliform bacteria. Water quality degradation in the stream network is also impacted by excess nutrients in surface runoff from cropped fields and pastures, sedimentation erosion of streambanks from the high volume of water flow following storm events, and the pulse of enriched groundwater drained into the streams from the subsurface tile network. Rotational grazing will replace the current continuous grazing management system. Implementation includes controlling both sides of Black Hawk Creek in the permanent pastures with electric fencing, installing reinforced controlled stream crossing sites, establishing a permanent clean water distribution system and enhancing the Kentucky bluegrass dominated pastures with three cool season naturalized grass and three legume species adapted to the north central Iowa loess landscape. Multi-species ripariain buffers based on the Leopold Center for Sustainable Agriculture's model and other models based on simulating the functionality of presettlement ecosystem savannah grassland will be created between monocultures of corn and soybean fields and the stream network. Follow on studies will monitor the effectiveness of a managed forage sward, riparian buffers, and natural healing of streambanks to mitigate excess nutrient movement into the streams.Master of Natural Resources
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Ogola, J. B. Ochanda. « Improving water use efficiency of maize through proper nitrogen management ». Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340024.
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Dixit, Shweta. « Modeling Emission Footprints of Sustainable Land Use Policies at Local Jurisdictional Level ». Thesis, George Mason University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10616646.
Texte intégralRésumé :
Sustainable land use practices are redefining the urban form, mobility and therefore the transportation planning processes. Regional travel demand models are not sensitive to variables associated with land use practices at neighborhood level, such as transit-oriented developments (TOD). The first objective of this research is to quantify and compare land-use specific emission footprints at the household level (grams/household) for TOD and Non-TOD areas. Household travel survey data is used to stratify households into various TOD and Non-TOD zones. A comparison of means for emission footprints between Non-TOD and TOD land uses indicated that Non-TOD emission footprints are much higher than the TOD footprints and the differences are statistically significant. On the other hand, the differences amongst pairs of TODs and pairs of Non-TODs showed no statistical significance.
As its second major objective, the research proposes a disaggregate methodology (the Methodology) that is sensitive enough to sustainable land use policies and allows planners to quantify emission impacts of the policies at sub-regional level. At the center of the Methodology is a sub-regional travel demand model with finer TAZ resolution than what is represented in the regional model for the same sub-region. Different land use scenarios, including TODs, and transit patronages are represented in the experimental implementation of the Methodology for Loudoun County, VA, which is a rapidly growing suburban county in the metropolitan Washington D.C. area. Loudoun County’s brisk growth, its emphasis on sustainable land use and transportation planning, and recent expansion of Metro rail service in to the County presented a unique opportunity to develop and experiment with TOD scenarios in the end-to-end (from planning to modeling) implementation of the Methodology. The effectiveness of the Methodology is demonstrated by the results, which show that emission reductions can be achieved by sustainable land use policy implementation at sub regional level. Furthermore, unlike the regional models, the Methodology is found to adequately model sensitivity of emissions to land use, area type and facility type as established by statistical validation using analysis of variance technique.
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Maddi, Balakrishna. « Pyrolysis Strategies for Effective Utilization of Lignocellulosic and Algal Biomass ». University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418340334.
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Landén, Johannes, et Edvin Malmberg. « Sustainability reports : environmental friendly or a greenwashing tool ? : A study of how global mining companies use sustainability report ». Thesis, Högskolan i Jönköping, Internationella Handelshögskolan, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-30105.
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Maine, Joshua, et Oskar Svensson. « Does an Ambidextrous Use of Sustainability Resources Lead to Sustainability Performance ? : a Survey on Swedish Municipal Housing Organisations ». Thesis, Högskolan Kristianstad, Fakulteten för ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-18286.
Texte intégralRésumé :
An increasing pressure is found on public sector organisations both to be efficient and innovative. Recently ambidexterity has found its ground in the public sector showing significant impact on firm performance. Combined with the increasing pressure from society for conducting sustainable business, we aimed at investigating how structural ambidexterity in regard to sustainability relates to sustainability performance, and how this relationship is moderated by centralisation and connectedness. A quantitative method has been used where the Swedish municipal housing organisations were surveyed. 141 different municipal housing organisations participated in the survey. A content analysis was also done with the help of the TBL to measure the organisations sustainability performance. The results from the dissertation showed that ambidextrous sustainability leads to sustainability performance. No moderating effect from centralisation and connectedness was found on the relationship between ambidextrous sustainability and sustainability performance. This dissertation sets the ground for a new concept of ambidextrous sustainability. Furthermore, contributing to strategic public management as well as further expanding on the stakeholder approach and the moderating effect of stakeholders. The dissertation also contributes methodologically by measuring sustainability performance with the TBL through a content analysis as well as how to measure ambidextrous sustainability.
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Dobbs, Jonathan. « The Potential Use of PEI Modified Biochar for Different Environmental Applications ». Thesis, Mississippi State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10616945.
Texte intégralRésumé :
Man-made pollution is hazardous to both the environment and human health. This study attempts to develop a low-cost, biobased adsorbent for CO2 capture and heavy metal removal. The adsorption behavior of CO2 from air and Pb (II) from aqueous systems onto polyethylenimine (PEI) modified biochar was studied. Chemical and physical pretreatments were performed in an attempt to enhance the adsorption kinetics of biochar. FT-IR and Elemental Analysis were performed to confirm the loading of PEI onto the surface of biochar was achieved. The efficiency of the PEI modified biochar on the removal of Pb (II) from aqueous solutions was determined by Atomic Absorption Spectrometer (AAS). Alkali pretreatment of PEI modified biochar increased CO2 capture and removal of Pb(II). This experiment introduces a new approach to air and water purification by using the combination of an amine with biochar.