Dissertations / Theses on the topic '850501 Biofuel (Biomass) Energy'
To see the other types of publications on this topic, follow the link: 850501 Biofuel (Biomass) Energy.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic '850501 Biofuel (Biomass) Energy.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Thondhlana, Gladman. "Land acquisition for and local livelihood implications of biofuel development in Zimbabwe." Rhodes University, 2016. http://hdl.handle.net/10962/49940.
Full textAbstract:
In recent years, proponents of 'green and clean fuel' have argued that the costs of overreliance on fossil fuels could be reduced through transition to biofuels such as bio-ethanol. Global biofuel discourses suggest that any transition to biofuel invariably results in significant benefits, including energy independence, job creation, development of agro-industrial centres at local level and high revenue generations for the state with minimum negative impacts on the environment. With many risks and costs associated with traditional 'dirty' fuels, it is likely that many countries, particularly African countries, will move towards the 'green and clean fuel' alternative. However, until recently research has arguably paid limited attention to the local livelihood impacts related to land acquisition for biofuel development or the policy frameworks required to maximise biofuel benefits. With regards to biofuel benefits, some recent studies suggest that the much bandied potential for greater tax revenue, lowered fuel costs and wealth distribution from biofuel production have all been perverted with relatively little payoff in wage labour opportunities in return (e.g. Richardson, 2010; Wilkinson and Herrera, 2010). Based on work done in Chisumbanje communal lands of Zimbabwe (Thondhlana, 2015), this policy brief highlights the local livelihood impacts of biofuel development and discusses policy implications of the findings. By highlighting the justifications of biofuel development at any cost by the state, the study sheds some light on the conflicts between state interests and local livelihood needs.
2
Anfinrud, Robynn Elizabeth. "Nitrogen Uptake and Biomass and Ethanol Yield of Biomass Crops as Feedstock for Biofuel." Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26524.
Full textAbstract:
Nitrogen fertilizers are extensively used to enhance the growth of biomass crops. This study was conducted to determine the effect of N rates on the biomass yield and quality, and N uptake of several crops. The experiment was conducted at Fargo and Prosper, ND, in 2010 and 2011. The crops studied were forage sweet sorghum [Sorghum bicolor L. Moench], sorghum x sudangrass [Sorghum bicolor var. sudanense (Piper) Stapf.], kenaf [Hibiscus cannabinus L.], and reed canarygrass [Phalaris arundinacea L.]. The different crops constituted the main plots and the nitrogen rates were regarded as subplots. The five N rates were 0, 75, 100, 150, and 200 kg N ha-1.
Forage sweet sorghum and sorghum x sudangrass had the greatest dry matter biomass yield. Nitrogen fertilization increased biomass yield for each of the crops. The results indicate that forage sorghum and sorghum x sudangrass have the greatest potential as a feedstock.
3
Inglesby, Alister Edward. "Biochemical and bioelectrochemical technology for third generation biofuel production." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648335.
Full text
4
Adebayo, Adebola B. "Pretreatments and energy potentials of Appalachian hardwood residues for biofuel production." Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/10928.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2010.Title from document title page. Document formatted into pages; contains viii, 98 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references.
5
Kazamia, Elena. "Synthetic ecology : a way forward for sustainable algal biofuel production." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607904.
Full text
6
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.
Full text
7
Matakala, Litiya. "Biofuel policies : what can Zambia learn from leading biofuel producers." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/5748.
Full textAbstract:
Thesis (MDF (Development Finance))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: Price volatility and high dependency on imported petroleum fuel has prompted the Zambian government to look into renewable fuels as part of an energy diversification program. With growing global interest in biofuels as a transportation fuel, the Zambian government intends to introduce bioethanol and biodiesel as renewable fuels in the transportation sector. While it seems feasible to produce both the feedstocks and biofuels to meet local demand, a regulatory framework and industry support mechanisms have not yet been formulated. The policy and regulatory frameworks encompass a multitude of actors, networks and institutions all playing distinct and important roles. Incorporating the differing interests of all these stakeholders is an involving process that requires detailed analysis of agriculture, environmental, energy, socioeconomic and taxation policies. This study attempts to contribute to the biofuels policy formulation process in Zambia. It analyses biofuel policies in leading biofuels producing countries and identifies aspects that the Zambian government should consider incorporating in its own policies to ensure a viable biofuels industry. Biofuel policies in Brazil, Germany and the United States of America were analysed using a detailed case study and extensive literature review. Furthermore, a detailed analysis of the Zambian agriculture sector and the demand for petroleum fuel puts into context the potential demand and challenges likely to be faced. By understanding the history and development of biofuels in the case study countries, best practices, problems faced, policy innovations and industry support mechanisms were identified to inform policy formulation in Zambia. This does not only provide valuable insights and lessons but also ensures that time and resources are not wasted by reinventing the wheel. The comparative analysis of policies and support mechanisms in the three case study countries showed that articulating a clear policy objective, government support in the form of subsidies, wide stakeholder involvement and industry regulation have all played a critical role in the development of the industry. However, the extent to which all these factors have helped to shape the industry in Brazil, Germany and the USA is neither equal nor static. Countries are continuously adapting their policies and support mechanisms to environmental, energy and economic conditions.
AFRIKAANSE OPSOMMING: Die onbestendigheid van pryse en die groot mate van afhanklikheid van ingevoerde petroleumbrandstof het die Zambiese regering aangespoor om ondersoek in te stel na hernubare brandstof as deel van 'n energiediversifiseringsprogram. In die lig van die groeiende globale belangstelling in biobrandstof as vervoerbrandstof, beplan die Zambiese regering om bioetanol en biodiesel as hernubare brandstof in die vervoersektor te begin gebruik. Al lyk dit prakties uitvoerbaar om sowel die voerstof as die biobrandstof te vervaardig om in die plaaslike aanvraag te voorsien, is 'n reguleringsraamwerk en ondersteuningsmeganismes vir die industrie nog nie geskep nie. 'n Menigte rolspelers, netwerke en instellings, wat almal verskillende en belangrike rolle speel, sal betrokke wees by die beleidsformulering en reguleringsraamwerk. Om die uiteenlopende belange van al die betrokke partye in ag te neem is 'n ingewikkelde proses wat sal vereis dat 'n uitvoerige analise gemaak word van landbou-, omgewings-, energie-, sosio-ekonomiese en belastingbeleidsrigtings. Die doelwit van hierdie studie is om 'n bydrae te lewer tot die formuleringsproses van die biobrandstofbeleid in Zambie. Dit analiseer die biobrandstofbeleid van die vooraanstaande lande wat biobrandstof vervaardig, en identifiseer aspekte wat die Zambiese regering in sy beleid behoort in te sluit om 'n lewensvatbare biobrandstofindustrie te verseker. Die biobrandstofbeleid van Brasilie, Duitsland en die Verenigde State van Amerika (VSA) is geanaliseer met behulp van uitvoerige gevallestudies en 'n grondige literatuurstudie. Verder plaas 'n noukeurige analise van die Zambiese landbousektor en die aanvraag na petroleumbrandstof die potensiele aanvraag en uitdagings wat waarskynlik hanteer sal meet word in konteks. Deur insig te verkry in die geskiedenis en ontwikkeling van biobrandstof in die lande waar die gevallestudies gedoen is, kon die beste gebruike, moontlike probleme, nuwe beleidsrigtings en ondersteuningsmeganismes in die bedryf geidentifiseer word om die beleid in Zambie te help formuleer. Dit bied nie slegs waardevolle insig en leergeleenthede nie, maar verseker ook dat tyd en hulpbronne nie vermors word deur die wiel van voor af uit te vind nie. Die vergelykende analise van die beleidsrigtings en ondersteuningsmeganismes in die drie lande waar die gevallestudies gedoen is, het getoon dat 'n duidelik geformuleerde beleidsdoelwit, ondersteuning van die regering in die vorm van subsidies, die algemene betrokkenheid van belanghebbendes en die regulering van die industrie alles 'n uiters belangrike rol gespeel het in die ontwikkeling van hierdie industrie. Die mate waarin al hierdie faktore die industrie in Brasilie, Duitsland en die VSA help vorm het, het egter gewissel en was nooit staties nie. Lande pas voortdurend hulle beleid en ondersteuningsmeganismes aan by omgewings-, energie- en ekonomiese toestande.
8
Görling, Martin. "Turbomachinery in Biofuel Production." Licentiate thesis, KTH, Energiprocesser, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-28901.
Full textAbstract:
The aim for this study has been to evaluate the integration potential of turbo-machinery into the production processes of biofuels. The focus has been on bio-fuel produced via biomass gasification; mainly methanol and synthetic natural gas. The research has been divided into two parts; gas and steam turbine applications. Steam power generation has a given role within the fuel production process due to the large amounts of excess chemical reaction heat. However, large amounts of the steam produced are used within the production process and is thus not available for power production. Therefore, this study has been focused on lowering the steam demand in the production process, in order to increase the power production. One possibility that has been evaluated is humidification of the gasification agent in order to lower the demand for high quality steam in the gasifier and replace it with waste heat. The results show that the power penalty for the gasification process could be lowered by 18-25%, in the specific cases that have been studied. Another step in the process that requires a significant amount of steam is the CO2-removal. This step can be avoided by adding hydrogen in order to convert all carbon into biofuel. This is also a way to store hydrogen (e.g. from wind energy) together with green carbon. The results imply that a larger amount of sustainable fuels can be produced from the same quantity of biomass. The applications for gas turbines within the biofuel production process are less obvious. There are large differences between the bio-syngas and natural gas in energy content and combustion properties which are technical problems when using high efficient modern gas turbines. This study therefore proposes the integration of a natural gas fired gas turbine; a hybrid plant. The heat from the fuel production and the heat recovery from the gas turbine flue gas are used in a joint steam cycle. Simulations of the hybrid cycle in methanol production have shown good improvements. The total electrical efficiency is increased by 1.4-2.4 percentage points, depending on the fuel mix. The electrical efficiency for the natural gas used in the hybrid plant is 56-58%, which is in the same range as in large-scale combined cycle plants. A bio-methanol plant with a hybrid power cycle is consequently a competitive production route for both biomass and natural gas.QC 20110128
9
Luo, Dexin. "Design of highly distributed biofuel production systems." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45878.
Full textAbstract:
This thesis develops quantitative methods for evaluation and design of large-scale biofuel production systems with a particular focus on bioreactor-based fuel systems. In Chapter 2, a lifecycle assessment (LCA) method is integrated with chemical process modeling to select from different process designs the one that maximizes the energy efficiency and minimizes the environmental impact of a production system. An algae-based ethanol production technology, which is in the process of commercialization, is used as a case study. Motivated by this case study, Chapter 3 studies the selection of process designs and production capacity of highly distributed bioreactor-based fuel system from an economic perspective. Nonlinear optimization models based on net present value maximization are developed that aim at selecting the optimal capacities of production equipment for both integrated and distributed-centralized process designs on symmetric production layouts. Global sensitivity analysis based on Monte Carlo estimates is performed to show the impact of different parameters on the optimal capacity decision and the corresponding net present value. Conditional Value at Risk optimization is used to compare the optimal capacity for a risk-neutral planner versus a risk-averse decision maker. Chapter 4 studies mobile distributed processing in biofuel industry as vehicle routing problem and production equipment location with an underlying pipeline network as facility location problem with a focus on general production costs. Formulations and algorithms are developed to explore how fixed cost and concavity in the production cost increases the theoretical complexity of these problems.
10
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.
Full text
11
Orr, Kyla Kathleen. "Predicting the ecosystem effects of harvesting beach-cast kelp for biofuel." Thesis, University of the Highlands and Islands, 2013. https://pure.uhi.ac.uk/portal/en/studentthesis/predicting-the-ecosystem-effects-of-harvesting-beachcast-kelp-for-biofuel(82d8913a-164a-4e21-b61b-9f83b462b079).html.
Full textAbstract:
Beach‐cast kelp (principally Laminaria spp.), known as macroalgal wrack, has been suggested as a feedstock for biofuel. However, to be extracted sustainably it is necessary to understand its ecological role and predict the impacts of its removal. Field‐based observations combined with food web modelling were used to predict the ecosystem effects of removing wrack from beaches of the Uists, western Scotland. Beaches with wrack were associated with enriched benthic infauna (polychaetes) on the lower shore, and wrack mounds supported abundant macroinvertebrates (mainly Diptera larvae and oligochaetes); with some of the highest biomasses reported globally for beaches. These fauna are valuable prey to shorebirds, as demonstrated by a strong positive relationship (R2 = 0.82) between wader abundances and the percentage cover of wrack on beaches. Inshore, drifting macroalgae was associated with elevated abundances of detritivorous hyperbenthic fauna (mysids, isopods and gammarid amphipods). In addition, the volume of drifting macroalgae inshore was a significant predictor (along with physical beach characteristics) for the abundance of decapods and fish. Food web models and network analysis indicated that beaches which accumulate wrack had a greater diversity of trophic links and more functional redundancy, making their food webs more resilient to perturbations. Such perturbations may include stressors induced by climate change, such as increased erosion of sediments during storms, elevated atmospheric and sea surface temperatures and elevated CO2 concentrations. Model simulations of wrack harvesting predicted an immediate decline in primary consumers in direct proportion to the quantity of wrack removed, and a slow decline in shorebirds in response to reduced prey. Primary consumers were predicted to recover to their pre‐harvest biomasses within 1 to 2 years regardless of harvesting intensity, but recovery times for shorebirds were an order of magnitude longer, and increased with harvesting intensity. Harvesting more than 50% wrack predicted a ‘collapse’ in wader populations within 25 years, and recovery times of 45‐60 years were estimated if >70% wrack was removed. The findings of this thesis suggest wrack provides essential food and shelter to coastal fauna, and its large‐scale removal would have significant negative impacts to the ecosystem functioning.
12
Fischback, Michael Bryant. "Introduction and characterization of an innovative biofuel cell platform with improved stability through novel enzyme immobilization techniques." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Fall2006/m_fischback_121206.pdf.
Full text
13
Wong, Ka In. "Machine-learning-based modeling of biofuel engine systems with applications to optimization and control of engine performance." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691886.
Full text
14
Chan, Jin Hooi. "Evolution of biofuel value chain governance and government policy : the cases of China, Thailand, the Philippines and Vietnam." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610635.
Full text
15
Berger, Elena M. "Dynamics of innovation of biofuel ethanol. three decades of experience in the U.S. and in Brazil." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37315.
Full textAbstract:
This dissertation draws on the burgeoning field of innovation of low carbon technologies. Using the functions of innovation systems, this study explores the process of innovation of biofuel ethanol in the U.S. and in Brazil. It uses "process theory" to build a narrative of historical events that represent the innovation trajectory of ethanol biofuel in the U.S. and in Brazil over a period of thirty years. The data is drawn from newspaper articles from the New York Times, Washington Post, and O Estado de Sao Paulo published between 1975 and 2008. Results of this research confirm findings published previously that innovation performs better when the main actors in the innovation process act under clear and well defined policy targets, and when the innovation environment contributes to building positive expectations about the technology. The empirical findings build upon the literature and validate early claims that the alignment of goals between technology producers and users is an inducer of innovation. Moreover, the analysis presented shows that by developing new capabilities, technology users in the downstream market broaden the innovation environment and facilitate the adoption of the emerging technology by new users and markets. For example, the automobile sector has been participating actively in the ethanol technological innovation system in Brazil, facilitating the innovation flow between upstream and the downstream market. This has not been the case in the U.S., where the automobile sector has not found incentives to participate in the ethanol technological innovation systems.
16
Ndimande, Sandile. "Increasing cellulosic biomass in sugarcane." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86296.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Increased demand of petroleum, declining fossil fuel reserves, geopolitical instability and the environmentally detrimental effects of fossil fuels have stimulated research to search for alternative sources of energy such as plant derived biofuels. The main feedstocks for production of first generation biofuels (bioethanol) are currently sucrose and starch, produced by crops such as sugarcane, sugarbeet, maize, and cassava. The use of food crop carbohydrates to produce biofuels is viewed as competing for limited agronomic resources and jeopardizing food security. Plants are also capable of storing sugars in their cell walls in the form of polysaccharides such as cellulose, hemicelluloses and pectin, however those are usually cross-linked with lignin, making their fermentation problematic, and are consequently referred to as lignocellulosics. Current technologies are not sufficient to degrade these cell wall sugars without large energy inputs, therefore making lignocellulosic biomass commercially unviable as a source of sugars for biofuel production. In the present study genes encoding for enzymes for cellulosic, hemicellulosic and starch-like polysaccharides biosynthesis were heterologously expressed to increase the amount of fermentable sugars in sugarcane. Transgenic lines heterologously expressing CsCesA, encoding a cellulose synthase from the marine invertebrate Ciona savignyi showed significant increases in their total cellulose synthase enzyme activity as well as the total cellulose content in internodal tissues. Elevation in cellulose contents was accompanied by a rise in hemicellulosic glucose content and uronic acid amounts, while total lignin was reduced in internodal tissues. Enzymatic saccharification of untreated lignocellulosic biomass of transgenic sugarcane lines had improved glucose release when exposed to cellulose hydrolyzing enzymes. Calli derived from transgenic sugarcane lines ectopically expressing galactomannan biosynthetic sequences ManS and GMGT from the cluster bean (Cyamopsis tetragonoloba) were observed to be capable of producing a galactomannan polysaccharide. However, after regeneration, transgenic sugarcane plants derived from those calli were unable to produce the polymer although the inserted genes were transcribed at the mRNA level. While the ectopic expression of Deinococcus radiodurans amylosucrase protein in the cytosol had a detrimental effect on the growth of transgenic lines (plants showed stunted growth through the 18 months growth period in greenhouse), contrastingly targeting the amylosucrase protein into the vacuole resulted in 3 months old transgenic lines which were having high maltooligosaccharide and soluble sugar (sucrose, glucose and fructose) levels in leaves. After 18 months growing in the greenhouse, the mature transgenic lines were morphologically similar to the untransformed lines and also contained comparable maltooligosaccharide and soluble sugar and starch amounts. The non-biosynthesis of galactomannan and amylose polysaccharides in the matured transgenic plants may be due to post-transcriptional protein processing and or protein instability, possibly explainable by other epigenetic mechanisms taking place to regulate gene expression in the at least allo-octaploid species of sugarcane under investigation in this study.
17
Von, Maltitz Graham Paul. "Biofuel, land-use tradeoffs and livelihoods in Southern Africa." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1021005.
Full textAbstract:
The rapid expansion of biofuel projects in southern Africa creates an opportune issue against which to examine land-use tradeoffs within the areas of customary land tenure. For this an ecosystems services approach is used. Jatropha curcas (L), a perennial oilseed plant which has been the key focus of most of the region’s biofuel expansion to date is used as the focus biofuel crop for which case study data were obtained from Malawi, Mozambique, Zambia and South Africa. Despite the initial enthusiasm for jatropha, most projects have proven less successful than hoped, and many have collapsed. A few are, however, still showing signs of possible success and it is two of these that form the basis of the case studies. Hugely complex tradeoffs are involved when considering biofuel as a land-use option for communal areas. They range from global impacts such as biodiversity and global climate forcing, through national concerns of rural development, national food security and national fuel security, to local household concerns around improving livelihoods. Land that is converted to biofuel needs to be removed from some previous use, and in the southern African case it is typically woodlands and the multitude of services they provide, that suffer. The nature of the tradeoffs and the people affected change over the scale under consideration. For the local farmer it is only the local issues that are of concern, but national and global forces will change the policy environment and lead to new types of development such as biofuels. Change is inevitable, and in all developments there are likely to be both winners and losers. It is clear that the impacts arising from biofuel are situation dependent, and each community and location has unique social and environmental considerations that need to be taken into account. In the case of jatropha the final realised yield and the economic returns that this can generate, will be of critical importance and remain one of the main uncertainties. There are promising signs that under certain circumstances the balance of benefits from jatropha biofuel may be positive, but if implemented incorrectly or in the wrong place, there is extensive evidence of total project failure. It is clear that evidence-based data and assessment tools are needed to assist communities, developers and government departments to make sound decisions around biofuel (or other land-use based) development. A number of such tools are suggested in the thesis. Both the use of large-scale plantations or small-scale farmer centred projects have their advantages and disadvantages. It is probable that in the correct circumstances either can work. However, large-scale plantations can have huge negative social and environmental consequences if poorly implemented. Small-scale projects, though improving livelihoods, are unlikely to take the farmers out of poverty. Tradeoffs from any land-use change are inevitable. Empirical data on biofuel impacts on the environment and society are needed for the development of sound policy. A favourable policy environment can ensure that positive benefits from biofuel are obtained, whilst minimising negative impacts. To develop this policy means that southern African countries will have to clearly understand what they wish to achieve from biofuel, as well as having a clear understanding of impacts from biofuel implementation. Sound scientific knowledge needs to underpin this process. For instance governments may wish to increase the ratio of small-scale to large-scale plantation to increase the developmental benefits, ensure biofuel is used to promote national fuel security rather than being exported, or develop a medium-scale farming sector which can help move farmers out of poverty and assist in developing a market surplus of agricultural commodities. Analysing impacts from biofuel expansion is a complex and multi-dimensional problem and as such will require multi-criteria analysis tools to develop solutions. Global, national and local tradeoffs must all be considered. In addition a wide range of stakeholders are involved and participatory processes may be needed to capture their inputs. Tools to better analyse impacts, specifically at the local level are needed. These local results need to feed into national level economic assessments. The cost of biofuel introduction should be considered against the costs of not implementing biofuel, realising that doing nothing also has a cost and long-term impact. Third-party certification provides a useful tool for shifting costs of ensuring compliance with social and environmental legislation, from the state to biofuel companies. In addition ongoing monitoring and evaluation of existing projects is needed to learn from successes and failures, to identify unintended consequences, and to increase the resilience of projects, community livelihoods and the national economy. This will have to be supplemented with additional focused and ongoing research.
18
Nguyen, Thi Hong Minh, and Van Hanh Vu. "Bioethanol production from marine algae biomass: prospect and troubles." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99282.
Full textAbstract:
The increase of petroleum cost as well as global warming and climate change result in investigation to discover new renewable energy resources. Bioenergy is one of the most important sources that is concerning the scientists and industrial sector. Although bioethanol had to be known as one of the most important renewable energy sources in order to reduce greenhouse gases and global warming, there is a limited number of publications reporting on them. In this review, a brief overview is offered about bioethanol production from algae. It can be given a deeper insight in dificulties and promising potential of bioethanol from algaeSự gia tăng giá nhiên liệu hóa thạch cùng với cảnh báo toàn cầu về biến đổi khí hậu hướng đến việc nghiên cứu tìm ra những nguồn năng lượng có thể tái tạo. Năng lượng sinh học là một trong những nguồn quan trọng được các nhà khoa học và doanh nghiệp quan tâm. Mặc dù ethanol sinh học đã được biết đến như là một trong những dạng năng lượng tái tạo quan trọng nhất để giảm thiểu các khí nhà kính và cảnh báo toàn cầu, nhưng chỉ có một số ít bài báo về nó. Trong bài tổng quan này, chúng tôi giới thiệu vắn tắt việc sản xuất ethanol sinh học từ tảo. Nó đưa ra cái nhìn sâu hơn về những khó khăn và tiềm năng hứa hẹn của sản xuất ethanol sinh học từ tảo
19
Hu, Zhoujian. "Utilization of switchgrass as a biofuel feedstock." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44088.
Full textAbstract:
Secondary generation biofuels such as cellulosic biofuels rely on large portions of cellulosic bioresources, which may include forests, perennial grasses, wood and agricultural residues. Switchgrass is one promising feedstock for biofuel production. In the present study, thesis work focused on the chemical and structural profiles and hydrothermal pretreatment of switchgrass. Four populations of switchgrass were investigated for their chemical properties among populations and morphological portions, including the compositions of lignin and carbohydrates, extractives content, higher heating value (HHV), and syringyl:guaiacyl (S:G) ratio. The results demonstrate similar chemical profiles and lignin structure among the four populations of switchgrass. Morphological fractions of switchgrass including leaves, internodes, and nodes differ significantly in chemical profiles and S:G ratios of lignin. The structure of isolated cellulose from switchgrass SW9 is similar between leaves and internodes. The structure of isolated lignin from leaves and internodes of switchgrass SW9 differs in S:G ratio and molecular weight. Hydrothermal pretreatment of leaves and internodes indicates that a similar chemical composition and chemical structure for pretreated leaves and internodes. The degree of polymerization (DP) for cellulose of the pretreated internodes is 23.4% greater than that of the pretreated leaves. The accessibility of pretreated leaves measured by Simons' Staining technique is greater than that of pretreated internodes. Pretreated leaves have a 32.5-33.8% greater cellulose-to-glucose conversion yield than do pretreated internodes.
20
Archbold, Brad. "Using algae to capture CO₂ and as a feedstock for biofuel." Online pdf file accessible through the World Wide Web, 2007. http://archives.evergreen.edu/masterstheses/Accession86-10MES/Archbold_%20B%20MESThesis%202007.pdf.
Full text
21
Bojler, Görling Martin. "Energy system evaluation of thermo-chemical biofuel production : Process development by integration of power cycles and sustainable electricity." Doctoral thesis, KTH, Energiprocesser, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105814.
Full textAbstract:
Fossil fuels dominate the world energy supply today and the transport sector is no exception. Renewable alternatives must therefore be introduced to replace fossil fuels and their emissions, without sacrificing our standard of living. There is a good potential for biofuels but process improvements are essential, to ensure efficient use of a limited amount of biomass and better compete with fossil alternatives. The general aim of this research is therefore to investigate how to improve efficiency in biofuel production by process development and co-generation of heat and electricity. The work has been divided into three parts; power cycles in biofuel production, methane production via pyrolysis and biofuels from renewable electricity. The studies of bio-based methanol plants showed that steam power generation has a key role in the large-scale biofuel production process. However, a large portion of the steam from the recovered reaction heat is needed in the fuel production process. One measure to increase steam power generation, evaluated in this thesis, is to lower the steam demand by humidification of the gasification agent. Pinch analysis indicated synergies from gas turbine integration and our studies concluded that the electrical efficiency for natural gas fired gas turbines amounts to 56-58%, in the same range as for large combined cycle plants. The use of the off-gas from the biofuel production is also a potential integration option but difficult for modern high-efficient gas turbines. Furthermore, gasification with oxygen and extensive syngas cleaning might be too energy-consuming for efficient power generation. Methane production via pyrolysis showed improved efficiency compared with the competing route via gasification. The total biomass to methane efficiency, including additional biomass to fulfil the power demand, was calculated to 73-74%. The process benefits from lower thermal losses and less reaction heat when syngas is avoided as an intermediate step and can handle high-alkali fuels such as annual crops. Several synergies were discovered when integrating conventional biofuel production with addition of hydrogen. Introducing hydrogen would also greatly increase the biofuel production potential for regions with limited biomass resources. It was also concluded that methane produced from electrolysis of water could be economically feasible if the product was priced in parity with petrol.QC 20121127
22
Danje, Stephen. "Fast pyrolysis of corn residues for energy production." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17822.
Full textAbstract:
Thesis (MScEng)--Stellenbosch University, 2011.ENGLISH ABSTRACT: Increasing oil prices along with the climate change threat have forced governments, society and the energy sector to consider alternative fuels. Biofuel presents itself as a suitable replacement and has received much attention over recent years. Thermochemical conversion processes such as pyrolysis is a topic of interest for conversion of cheap agricultural wastes into clean energy and valuable products. Fast pyrolysis of biomass is one of the promising technologies for converting biomass into liquid fuels and regarded as a promising feedstock to replace petroleum fuels. Corn residues, corn cob and corn stover, are some of the largest agricultural waste types in South Africa amounting to 8 900 thousand metric tonnes annually (1.7% of world corn production) (Nation Master, 2005). This study looked at the pyrolysis kinetics, the characterisation and quality of by-products from fast pyrolysis of the corn residues and the upgrading of bio-oil. The first objective was to characterise the physical and chemical properties of corn residues in order to determine the suitability of these feedstocks for pyrolytic purposes. Secondly, a study was carried out to obtain the reaction kinetic information and to characterise the behaviour of corn residues during thermal decomposition. The knowledge of biomass pyrolysis kinetics is of importance in the design and optimisation of pyrolytic reactors. Fast pyrolysis experiments were carried out in 2 different reactors: a Lurgi twin screw reactor and a bubbling fluidised bed reactor. The product yields and quality were compared for different types of reactors and biomasses. Finally, a preliminary study on the upgrading of bio-oil to remove the excess water and organics inorder to improve the quality of this liquid fuel was performed. Corn residues biomass are potential thermochemical feedstocks, with the following properties (carbon 50.2 wt. %, hydrogen 5.9 wt. % and Higher heating value 19.14 MJ/kg) for corn cob and (carbon 48.9 wt. %, hydrogen 6.01 wt. % and Higher heating value 18.06 MJ/kg) for corn stover. Corn cobs and corn stover contained very low amounts of nitrogen (0.41-0.57 wt. %) and sulphur (0.03-0.05 wt. %) compared with coal (nitrogen 0.8-1.9 wt. % and sulphur 0.7-1.2 wt. %), making them emit less sulphur oxides than when burning fossil fuels. The corn residues showed three distinct stages in the thermal decomposition process, with peak temperature of pyrolysis shifting to a higher value as the heating rate increased. The activation energies (E) for corn residues, obtained by the application of an iso-conversional method from thermogravimetric tests were in the range of 220 to 270 kJ/mol. The products obtained from fast pyrolysis of corn residues were bio-oil, biochar, water and gas. Higher bio-oil yields were produced from fast pyrolysis of corn residues in a bubbling fluidised bed reactor (47.8 to 51.2 wt. %, dry ash-free) than in a Lurgi twin screw reactor (35.5 to 37 wt. %, dry ash-free). Corn cobs produced higher bio-oil yields than corn stover in both types of reactors. At the optimised operating temperature of 500-530 °C, higher biochar yields were obtained from corn stover than corn cobs in both types of reactors. There were no major differences in the chemical and physical properties of bio-oil produced from the two types of reactors. The biochar properties showed some variation in heating values, carbon content and ash content for the different biomasses. The fast pyrolysis of corn residues produced energy products, bio-oil (Higher heating value = 18.7-25.3 MJ/kg) and biochar (Higher heating value = 19.8-29.3 MJ/kg) comparable with coal (Higher heating value = 16.2-25.9 MJ/kg). The bio-oils produced had some undesirable properties for its application such as acidic (pH 3.8 to 4.3) and high water content (21.3 to 30.5 wt. %). The bio-oil upgrading method (evaporation) increased the heating value and viscosity by removal of light hydrocarbons and water. The corn residues biochar produced had a BET Brynauer-Emmet-Teller (BET) surface area of 96.7 to 158.8 m2/g making it suitable for upgrading for the manufacture of adsorbents. The gas products from fast pyrolysis were analysed by gas chromatography (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ hydrocarbons. The gases had CO2 and CO of more than 80% (v/V) and low heating values (8.82-8.86 MJ/kg).
AFRIKAANSE OPSOMMING: Die styging in olie pryse asook dreigende klimaatsveranderinge het daartoe gelei dat regerings, die samelewing asook die energie sektor alternatiewe energiebronne oorweeg. Biobrandstof as alternatiewe energiebron het in die afgope paar jaar redelik aftrek gekry. Termochemiese omskakelingsprosesse soos pirolise word oorweeg vir die omskakeling van goedkoop landbou afval na groen energie en waardevolle produkte. Snel piroliese van biomassa is een van die mees belowende tegnologië vir die omskakeling van biomassa na vloeibare brandstof en word tans gereken as ’n belowende kandidaat om petroleum brandstof te vervang. Mielieafval, stronke en strooi vorm ’n reuse deel van die Suid Afrikaanse landbou afval. Ongeveer 8900 duisend metrieke ton afval word jaarliks geproduseer wat optel na ongeveer 1.7% van die wêreld se mielie produksie uitmaak (Nation Master, 2005). Hierdie studie het gekk na die kinetika van piroliese, die karakterisering en kwaliteit van by-produkte van snel piroliese afkomstig van mielie-afval asook die opgradering van biobrandstof. Die eerste mikpunt was om die fisiese en chemiese karakteristieke van mielie-afval te bepaal om sodoende die geskiktheid van hierdie afval vir die gebruik tydens piroliese te bepaal. Tweendens is ’n kinetiese studie onderneem om reaksie parameters te bepaal asook die gedrag tydens termiese ontbinding waar te neem. Kennis van die piroliese kinetika van biomassa is van belang juis tydens die ontwerp en optimering van piroliese reaktore. Snel piroliese ekspermente is uitgevoer met behulp van twee verskillende reaktore: ’n Lurgi twee skroef reaktor en ’n borrelende gefluidiseerde-bed reaktor. Die produk opbrengs en kwaliteit is vergelyk. Eindelik is ’n voorlopige studie oor die opgradering van bio-olie uitgevoer deur te kyk na die verwydering van oortollige water en organiese materiaal om die kwaliteit van hierdie vloeibare brandstof te verbeter. Biomassa afkomstig van mielie-afval is ’n potensiële termochemiese voerbron met die volgende kenmerke: mielie stronke- (C - 50.21 massa %, H – 5.9 massa %, HHV – 19.14 MJ/kg); mielie strooi – (C – 48.9 massa %, H – 6.01 massa %, HHV – 18.06 MJ/kg). Beide van hierdie materiale bevat lae hoeveelhede N (0.41-0.57 massa %) and S (0.03-0.05 massa %) in vergelyking met steenkool N (0.8-1.9 massa %) and S (0.7-1.2 massa %). Dit beteken dat hieride bronne van biomassa laer konsentrasies van swael oksiedes vrystel in vergelyking met fossielbrandstowwe. Drie kenmerkende stadia is waargeneem tydens die termiese afbraak van mielie-afval, met die temperatuur piek van piroliese wat skuif na ’n hoër temperatuur soos die verhittingswaarde toeneem. Die waargenome aktiveringsenergie (E) van mielie-afval bereken met behulp van die iso-omskakelings metode van TGA toetse was in die bestek: 220 tot 270 kJ/mol. Die produkte verkry deur Snel Piroliese van mielie-afval was bio-olie, bio-kool en gas. ’n Hoër opbrengs van bio-olie is behaal tydens Snel Piroliese van mielie-afval in die borrelende gefluidiseerde-bed reakctor (47.8 na 51.2 massa %, droog as-vry) in vergelyking met die Lurgi twee skroef reakctor (35.5 na 37 massa %, droog as-vry). Mielie stronke sorg vir ’n hoër opbrengs van bio-olie as mielie strooi in beide reaktore. By die optimum bedryfskondisies is daar in beide reaktor ’n hoër bio-kool opbrengs verkry van mielie stingels teenoor mielie stronke. Geen aansienlike verskille is gevind in die chemise en fisiese kenmerke van van die bio-olie wat geproduseer is in die twee reaktore nie. Daar is wel variasie getoon in die bio-kool kenmerkte van die verskillende Snel Piroliese prosesse. Snel piroliese van mielie-afval lewer energie produkte, bio-olie (HVW = 18.7-25.3MJ/kg) en bio-kool (HVW = 19.8-29.3 MJ/kg) vergelykbaar met steenkool (HVW = 16.2-25.9 MJ/kg). Die bio-olies geproduseer het sommige ongewenste kenmerke getoon byvoorbeeld suurheid (pH 3.8-4.3) asook hoë water inhoud (21.3 – 30.5 massa %). Die metode (indamping) wat gebruik is vir die opgradering van bio-olie het gelei tot die verbetering van die verhittingswaarde asook die toename in viskositeit deur die verwydering van ligte koolwaterstowwe en water. Die mielie-afval bio-kool toon ’n BET (Brunauer-Emmet-Teller) oppervlakte area van 96.7-158.8 m2/g wat dit toepaslik maak as grondstof vir absorbante. The gas geproduseer tydens Snel Piroliese is geanaliseer met behulp van gas chromotografie (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ koolwaterstowwe. Die vlak van CO2 en CO het 80% (v/V) oorskry en met lae verhittingswaardes (8.82-8.86 MJ/kg).
23
Bartle, Samantha. "Establishing a new biofuel crop using System Thinking." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86519.
Full textAbstract:
Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The complexity of adopting a new crop-based biodiesel feedstock into South Africa given the prevailing environmental, economic and social concerns facing the country are addressed in this study by utilising a Systems Thinking approach. Solaris is a new variety of Tobacco developed specifically as an energy crop over the last twelve years by Italian companies Plantechno and Sunchem. Small-scale trials have been underway over the last year in the Loskop Valley farming community in the Limpopo Province of South Africa. These trials have been managed by the newly-formed local entity, Toboil (Pty) Ltd. In order to assess the viability of introducing Solaris into Loskop in terms of addressing the current diesel and electricity needs of the community and larger over-arching biofuel goals of South Africa, the full System Dynamic Modelling process was employed. This included significant research, stakeholder engagement, a Systems Thinking workshop as well as model development and simulation using the System Dynamics programming tool, Vensim. Following the simulation of various scenarios, it was determined that in order for Solaris implementation to have the greatest impact on the diesel and electricity independence desires of the community, as well as maximising job creation and avoided greenhouse gas emissions, the first five to ten years of implementation may only achieve low to moderate profitability. It was further concluded that if crop-based biofuels are to help meet the rural development goals of South Africa then significant investment and skills transfer is required. In order to address both of these, a modular development process is advocated and should be aided and mentored by members of the commercial farming industry.
AFRIKAANSE OPSOMMING: Die kompleksiteit van die aanvaarding van ‘n nuwe oes-gebaseerde bio diesel roumateriaal in Suid-Afrika in die heersende omgewings-, ekonomiese- en sosiale kommer wat die land ervaar, word in hierdie studie aangespreek deur gebruik te maak van ‘n Sistemiese Denke Benadering (Systems Thinking approach) Solaris is ‘n nuwe variasie Tabak wat deur twee Italiaanse maatskappye Plantechno en Sunchem oor die afgelope twaalf jaar spesifiek as ‘n bron van energie ontwikkel is. Kleinskaalse proewe is gedurende die afgelope jaar in die Loskop Vallei Landbougemeenskap in die Limpopo-provinsie van Suid-Afrika gedoen. Hierdie proewe word onder die toesig van die nuut gevormde plaaslike entiteit, Toboil (Pty) Ltd uitgevoer. Aansienlike navorsing, die aktiewe deelname van die onderskeie belanghebbende partye, ‘n Sistemiese Denke werkswinkel sowel as die ontwerp van ‘n simulasie model deur die gebruik van Sisteem Dinamieke Programerings program, naamlik Vensim, is ingespan om die lewensvatbaarheid van die moontlike aanplanting van Solaris te beoordeel. Die spesifieke gemeenskap se huidige behoeftes aan diesel en elektrisiteit sowel as Suid-Afrika se breër doelwitte aangaande bio-brandstowwe was as die grondslag gebruik waarop die volle Sistemiese Denke Benadering toegepas is. In Loskop omgewing was verskeie moontlike scenarios beproef en daar is op grond daarvan vasgestel dat ten einde die grootste moontlike inpak te maak op die afhanlikheid van diesel en elektrisiteit behoeftes van die gemeenskap, sowel as om die grootste moontlik werkskepping potensiaal te verwesenlik – terwyl die afskeiding van kweekhuis gasse verhoed word - die eerste vyf tot tien jaar van implementering baie lae winsgrens tot gevolg sal hê. Daar is ook verder afgelei dat afsienbare beleggings en opleiding benodig gaan word indien aangeplante bio-brandstowwe aangewend sou word om die landelike ontwikkelingsdoelwitte in Suid-Afrika te verwesenlik. Ten einde beide hierdie doelwitte aan te spreek, word ‘n modulêre ontwikkelings proses aanbeveel waar gevestigde lede van die kommersiële lanbou industrie, bystand en leierskap voorsien.
24
Pang, Bairen. "Effect of irrigation on grain sorghum ethanol yield and sorghum mutants on biomass composition." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38194.
Full textAbstract:
Master of ScienceDepartment of Biological & Agricultural Engineering
Donghai Wang
Bioprocessing is widely involved in our daily life and significantly relative to the general public because bio-products are widely used in eating, clothing, and living as well as transportation. Due to the public concern of the environmental deterioration, limited fossil fuel resources, and energy price volatility, biofuel as a clean, safe and sustainable energy needs to be developed in response to this growing concern. Sorghum, an important dryland crop, represents a renewable resource currently grown on 8 million acres throughout the United States. Due to climate variability and the continuous decline of water resources, utilization of dryland to grow sorghum and forage sorghum is critically important in order to ensure available energy resources and sustainable economic development. The objectives of this research were 1) to study the impact of deficit irrigation strategies on sorghum grain attributes and bioethanol production, and 2) to evaluate the potential fermentable sugar yield of pedigreed sorghum mutants. Results showed that average kernel weight and test weight of grain sorghum increased as irrigation capacity increased, whereas kernel hardness index decreased as irrigation capacity increased. Starch content increased as irrigation level increased and protein contents decreased as irrigation level increased. Irrigation also had a significant effect on starch properties and bioethanol yield. Sorghum mutants had a significant effect on chemical composition and physical properties such as glucan content, glucan mass yield, ash content, and high heating value, and also had a significant effect on fermentable sugars yield and enzymatic conversion efficiency.
25
Veiga, João Paulo Soto. "Biomass to energy: mass and exergy assessment of carbon mitigation and triple bottom line assessment." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-09112016-154413/.
Full textAbstract:
Earth is exposed to an amount of energy that is fixed organically via photosynthesis and stored as fossil fuels, which are currently the major energy sources of humanity. Since Arrhenius concluded that carbon dioxide emissions from fossil fuels could lead to a climate warming, studies have sought ways to reduce human contribution on the environment to mitigate possible negative impacts on climate. The increasing world population is an obstacle for the efforts to reduce CO2 emissions and other greenhouse gases (GHG), because it demands more energy for transportation, electricity and heating. Among several renewable energy sources, biomass for fuels stands out, such as sugarcane ethanol in Brazil. Using biomass for fuels may help reducing the pressure on fossil fuels, besides, fixing organic carbon already emitted, contributing to mitigate problems of climate change and global warming. Thus, this study aims to analyse carbon cycles of mitigating emissions from fossil fuels with biofuel based on useful energy (exergy) content to determine the equivalent area required. Previous studies of life cycle assessment in sugarcane and eucalyptus were used to obtain carbon- and energy-flow data. These data were applied to estimate the available exergy to the final user through different routes of biofuel production, including current and evolving technologies. Exergy assessment demonstrated that on average, each Mg of biomass produced, led to a change of 3.02 GJ on sugarcane scenarios and 5.93 GJ on eucalyptus scenarios. Reducing sugarcane straw moisture from 50% to 30% increased the exergy output in 13.32 GJ ha-1, an increase of 0.67 GJ ha-1 for each 1% of moisture reduce. Eucalyptus to firewood, reducing moisture from 20% to 15% had an increase of 7.52 GJ ha-1 in the exergy output, representing 1.50 GJ ha-1 of increase for each 1%. This kind of assessment brings a new point of view in carbon mitigation, looking for its functionality. Biofuel use implications in environmental, social and economic aspects were also studied through a hybrid input-output life cycle assessment (IO-LCA) showing differences between the occupation of land use and two different ways of sugarcane production. The IO-LCA showed, in areas of land use change from pasture to sugarcane, energy consumption is increased by 3.7 times, employment is reduced by 5.4 times, and GHG emissions are reduced to only 2% of original emissions for each unit of R$ of final demand changed Most of the employment is generated by the sugarcane supply chain sector. Comparing sugarcane produced by the mills, it originates more direct full time jobs and probably in a more formal job market than sugarcane produced by farm suppliers. Farm suppliers use less energy and release less GHG than mills sugarcane production.A energia à qual o planeta é exposto é fixada organicamente via fotossíntese e estocado na forma de combustíveis fósseis, atualmente, as maiores fontes energéticas da humanidade. Desde que Arrhenius concluiu que emissões de CO2 decorrentes de combustíveis fósseis, poderiam levar a um aquecimento do clima, até os dias atuais, estudos buscam formas de reduzir os impactos antrópicos de forma a atenuar possíveis problemas climáticos. Os esforços para a redução de emissões de CO2 e outros gases de efeito estufa (GEE) têm como obstáculo uma população mundial crescente, que demanda cada vez mais energia para transporte, eletricidade e calor. Dentre as possibilidades de uso de fontes renováveis de energia, a biomassa é uma que se destaca em alguns países, como no caso do uso de etanol de cana-de-açúcar no Brasil. O uso de biomassa para a produção de combustíveis auxilia na redução da pressão para o uso de mais combustíveis fósseis e fixa organicamente o carbono emitido, contribuindo duplamente para a mitigação de problemas com mudanças climáticas e aquecimento global. O presente trabalho analisa os ciclos de carbono em biocombustível, correlacionando-os com sua energia útil (exergia) valorando a equivalência em área para a produção da exergia equivalente de combustíveis fósseis através de uma nova metodologia de avaliação de mitigação. Foram utilizados trabalhos existentes de análise de ciclo de vida em cana-de-açúcar e eucalipto para obtenção dos dados de inventário e fluxos de carbono e energia. Realizaram-se cálculos de exergia disponível ao usuário final com diferentes rotas de produção de biocombustível, abrangendo tecnologias atuais e em desenvolvimento. Na avaliação exergética, reduzir a humidade da palha da cana de 50% a 30% aumentou a exergia disponível em 13,32 GJ ha-1, 0,67 GJ ha-1 para cada 1% de redução na humidade. No caso do eucalipto para combustão, reduzindo-se a umidade de 20% a 15% houve um aumento de 7,52 GJ ha-1, 1,50 GJ ha-1 para cada 1% de umidade. Em média, cada Mg de biomassa produzida aumentou 3,02 GJ em cenários de cana de açúcar e 5,93 GJ em cenários de eucalipto. Este conceito traz uma nova perspectiva na mitigação de carbono, avaliando-o por sua funcionalidade. Também foram estudadas as implicações do uso de biocombustíveis em aspectos ambientais, sociais e econômicos em uma análise híbrida de ciclo de vida e insumo-produto (ACV-IP) evidenciando diferenças entre ocupação do uso de solo e duas maneiras de produção de cana-de-açúcar. A ACV-IP demonstrou que, em áreas de mudança do uso do solo de pastagem para cana de açúcar, o consumo de energia aumenta em 3,7 vezes, o emprego é reduzido em 5,4 vezes, e as emissões de GEE são reduzidas à apenas 2% das emissões originais para cada unidade de R$ de alteração na demanda final. A maior parte do emprego é gerado pelo setor da cadeia de suprimentos de produção de cana. A cana produzida pelas usinas origina mais empregos diretos do que a cana produzida por fornecedores agrícolas. Fornecedores usam menos energia e emitem menos GEE do que a produção de cana por usinas.
26
Malta, Nuno Vital Serrador. "Plano de negócios - "Bio Wood Energy"." Master's thesis, Universidade de Évora, 2011. http://hdl.handle.net/10174/15208.
Full textAbstract:
Este projecto consiste na realização de um Plano de Negócios para criação de
uma empresa a laborar no ramo das madeiras.
Esta empresa, de tratamento de biomassa, será concebida com alguns objectivos
fundamentais como: produzir, consumir e comercializar energias “limpas” e ecológicas;
ter o máximo de autonomia possível; aproveitar ao máximo os recursos disponíveis,
dando o melhor uso possível aos produtos recebidos e produzidos; e, contribuir para um
aumento do número de postos de trabalho e desenvolvimento da zona onde irá ser
instalada.
Os produtos finais a comercializar serão: estilha calibrada; combustível sólido
(cascas, ramas, cepos e desbastes); e, biocombustivel refinado (pellets) e estilha
calibrada.
A empresa irá, também, produzir energia, através da minigeração de energia a
partir de painéis fotovoltaicos, de forma ter o máximo de auto-suficiência, e dessa forma
ser mais “amiga” do ambiente e conseguir redução de despesas.
O projecto demonstra ter grande probabilidade de sucesso, pois apresenta
elevada viabilidade económico-financeira; ABSTRACT: This project consist of a business plan for starting a woods business.
This company, of biomass processing, will be designed with some fundamental
objectives such as: producing, consuming and transact "clean" energy and
environmentally friendly; have as much autonomy as possible; make the most of
available resources, making the best use of the received and produced products; and
contribute to an increase in the number of jobs and development within the area where it
will be installed.
The transacted final products will be: chips calibrated, solid fuel (bark, branches,
stumps and thinning), and refined biofuels (pellets) and calibrated chips.
The company will also produce energy through microgeneration from
photovoltaic panels in order to have as much self-sufficiency as possible, and thus be
more "friendly" of the environment and also reduce expenses.
This project demonstrates a high probability of success, because it has high
economic and financial viability.
27
Adamovska, Jana. "A larger laboratory scale investigation into the thermal liquefaction of high potential 2nd and 3rd generation biofuel feedstocks." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/95783/1/Jana_Adamovska_Thesis.pdf.
Full textAbstract:
This thesis contributes to the development of thermochemical liquefaction as a process for biofuel production. This study investigated residues from sugarcane, energy crops and algae. The potential amount of energy from biomass resources were investigated for each region in Australia. The work was at a larger laboratory scale than other workers which allowed more detailed characterisation of each sample and more thorough investigation of the fuels. Importantly, various bio-crude oils were successfully generated which were comparable with heavy fossil fuel based oils by changing only the processing conditions and without catalytic upgrading.
28
McFadden, Kathrine D. "Reverse-selective zeolite/polymer nanocomposite hollow fiber membranes for pervaporative biofuel/water separation." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39538.
Full textAbstract:
Pervaporation with a "reverse-selective" (hydrophobic) membrane is a promising technology for the energy-efficient separation of alcohols from dilute alcohol-water streams, such as those formed in the production of biofuels. Pervaporation depends on the selectivity and throughput of the membrane, which in turn is highly dependent on the membrane material. A nanocomposite approach to membrane design is desirable in order to combine the advantages and eliminate the individual limitations of previously-reported polymeric and zeolitic membranes. In this work, a hollow-fiber membrane composed of a thin layer of polymer/zeolite nanocomposite material on a porous polymeric hollow fiber support is developed. The hollow fiber geometry offers considerable advantages in membrane surface area per unit volume, allowing for easier scaling and higher throughput than flat-film membranes.
Poly(dimethyl siloxane) (PDMS) and pure-silica MFI zeolite (silicalite-1) were investigated for these membranes. Iso-octane was used to dilute the dope solution to provide thinner coatings. Previously-spun non-selective Torlon hollow fibers were used as the support layer for the nanocomposite coatings. To determine an acceptable method for coating fibers with uniform, defect-free coatings, flat-film membranes (0 to 60 wt% MFI on a solvent-free basis) and hollow-fiber membranes (0 and 20 wt% MFI) were fabricated using different procedures. Pervaporation experiments were run for all membranes at 65C with a 5 wt% ethanol feed. The effects of membrane thickness, fiber pretreatment, coating method, zeolite loading, and zeolite surface treatment on membrane pervaporation performance were investigated.
29
Walker, Devin Mason. "Catalytic Tri-reforming of Biomass-Derived Syngas to Produce Desired H2:CO Ratios for Fuel Applications." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4250.
Full textAbstract:
This study focuses on upgrading biomass derived syngas for the synthesis of liquid fuels using Fischer-Tropsch synthesis (FTS). The process includes novel gasification of biomass via a tri-reforming process which involves a synergetic combination of CO2 reforming, steam reforming, and partial oxidation of methane. Typical biomass-derived syngas H2:CO is 1:1 and contains tars that deactivate FT catalyst. This innovation allows for cost-effective one-step production of syngas in the required H2:CO of 2:1 with reduction of tars for use in the FTS. To maximize the performance of the tri-reforming catalyst, an attempt to control oxygen mobility, thermal stability, dispersion of metal, resistance to coke formation, and strength of metal interaction with support is investigated by varying catalyst synthesis parameters. These synthesis variables include Ce and Zr mixed oxide support ratios, amount Mg and Ni loading, and the preparation of the catalyst. Reaction conditions were also varied to determine the influences reaction temperature, gas composition, and GHSV have on the catalyst performance. Testing under controlled reaction conditions and the use of several catalyst characterization techniques (BET, XRD, TPR, XAFS, SEM-EDS, XPS) were employed to better explain the effects of the synthesis parameters. Applications of the resulting data were used to design proof of concept solar powered BTL plant. This paper highlights the performance of the tri-reforming catalyst under various reaction conditions and explains results using catalyst characterization.
30
Nakashima, Gabriela Tami. "Use of sugarcane trash for solid biofuel production: physicochemical characterization and influence of storage time." Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/8955.
Full textAbstract:
Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:03Z
No. of bitstreams: 1
NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5)Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:12Z (GMT) No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5)
Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:18Z (GMT) No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5)
Made available in DSpace on 2017-08-09T12:48:26Z (GMT). No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5) Previous issue date: 2016-04-29
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
In the sugarcane plantation it was common to use fire to facilitate the cutting and harvesting of sugarcane. However, Law 11,241 / 02 in São Paulo State provides the gradual elimination of this straw burning of sugarcane. The largest producer of sugarcane in Brazil is the São Paulo State, which has about 4.7 million hectares of planted area. It is estimated that one hectare produces about 14 tons of trash. Therefore, the mills have been trying to incorporate this trash in burning with the bagasse for power generation. However, high concentrations of mineral impurities are impossible its use for energy purposes. The aim of the study was to investigate the influence of storage time and particle size in the physicochemical characterization of the sugarcane trash. It was used the sugarcane trash inside and outside of the bale collected at different storage time (0, 1 and 2 years). The collected material was separated into four different particle sizes (> 0.420mm, 0.250-0.420mm, < 0.250mm and mix). The analyzes involved particle size distribution, proximate analysis, the high heating value (HHV), the chemical analysis of the components of the ashes, the images in the Scanning Electron Microscope (SEM), the Klason lignin content, the holocellulose content and extractives. There were variations in the results of the ash content with different particle sizes. It was observed a higher concentration of mineral impurities in smaller particles (< 0.250mm). The HHV varied from 15.9 to 18.3 MJ.kg-1 and showed no statistical difference for the treatments. The results indicate that the sugarcane trash presents problems related to mineral impurities which constrain its use as a solid fuel in the industry. The particle size interferes in their physicochemical characteristics. The trash can be stored in field and the time storage did not affect the quality for use as solid biofuel.
No manejo da cana-de-açúcar era comum a utilização do fogo para facilitar o corte e colheita da cana. No entanto, a Lei 11.241/02 do estado de São Paulo prevê a eliminação gradual da queima da palha da cana-de-açúcar. O maior produtor de cana-de-açúcar do Brasil é o estado de São Paulo, que possui aproximadamente 4,7 milhões de hectares de área plantada. É estimado que 1 hectare produza cerca de 14 toneladas de palha. Logo, as usinas vêm tentando incorporar esta palha na queima para geração de energia, juntamente com o bagaço. Porém, as altas concentrações de impurezas minerais estão impossibilitando seu uso para fins energéticos. O trabalho teve como objetivo o estudo da influência do tempo de estocagem e da granulometria na caracterização físico-química do palhiço da cana-de-açúcar. Foi utilizado o palhiço de canade-açúcar da superfície e do interior do fardo coletados em diferentes períodos de estocagem, 0, 1 e 2 anos. O material coletado foi separado em 4 granulometrias diferentes (> 0,420mm, 0,250-0,420mm, < 0,250mm e mix). As análises realizadas foram a distribuição granulométrica, a análise imediata, o poder calorífico superior (PCS), a análise química dos componentes das cinzas, as imagens no Microscópio Eletrônico de Varredura (MEV), o teor de lignina Klason, a holocelulose e os extrativos. Houve variações nos resultados do teor de cinzas com as diferentes granulometrias. Observou-se maior concentração de impurezas minerais nas partículas mais finas (< 0,250mm). O PCS variou entre 15,9 a 18,3 MJ.kg-1 e não apresentou diferença estatística para os tratamentos. Os resultados indicam que a palha de cana-de-açúcar apresenta problemas relacionados às impurezas minerais, que dificultam e restringem seu uso como combustível sólido na indústria. A granulometria da palha interferiu nas suas características físico-químicas. O palhiço pode ser estocado no campo e o tempo de estocagem não interferiu na qualidade para o uso como combustível sólido.
31
Olarte, Mariefel Valenzuela. "Base-catalyzed depolymerization of lignin and hydrodeoxygenation of lignin model compounds for alternative fuel production." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39613.
Full textAbstract:
This study considered the potential use of lignin as possible renewable fuel and chemical feedstock source. Among the various polymers present in lignocellulosic biomass, the polyaromatic lignin is the one component that is most chemically similar to petroleum. However, it still contains a much larger amount of oxygen compared to crude oil. As such, two strategies were employed in this study: (1) studying the lignin depolymerization in the presence of high temperature and base catalysts; and, (2) employing hydrodeoxygenation as a means to decrease the O/C ratio in lignin-derived model compounds.
The base-catalyzed depolymerization (BCD) of organosolv lignin was done in a 500-mL Monel Parr reactor at temperatures ranging from 165°C to 350°C. Complete solubilization of lignin derivatives was possible in the presence of NaOH and KOH, except at 350°C. NMR experiments revealed formation of oxidized groups (carboxylic and hydroxyl groups) as well as alkyl groups. On the other hand, the use of NH4OH showed N incorporation. Identified and quantified DCM-soluble monomeric compounds were at most 6% of the starting material and are mainly phenolic. This study revealed the apparent susceptibility of syringyl units over guaiacyl units in BCD. This could in turn guide the choice of substrate on which base-catalyzed depolymerization could be applied.
Syringaldehyde was used as the starting material to study batch hydrodeoxygenation (HDO) using several non-cobalt/molybdenum based catalysts. A 50-ml Parr reactor was used, pressurized by 1000 psig of H2 and heated to 300°C. Nickel based catalysts (nickel phosphide, nickel oxide and nickel phosphate) as well as supported precious metals (Pt and Pd) were tested as HDO catalysts. Of the three O-containing functional groups of syringaldehyde, the aldehydic group was found to be the most susceptible. In the presence of the Al2O3-supported catalysts, the methyl groups liberated were found to be incorporated back into the aromatic ring, forming alkylated compounds.
In the last section of this dissertation, hydrothermally synthesized supported Ni on mesoporous silica (MCF) and acid catalysts (HY and H-Al-MCF) were used for probing the effect of bifunctional metal-acid catalysis on phenol hydrodeoxygenation/hydrogenation. Catalyst configurations were varied from the previously studied wet-impregnated Pt/HY catalyst. Based on a hypothesis that coking catalyzed by the acidic zeolite in the wet impregnated Pt/HY catalyst was the main cause of catalyst deactivation and decreased phenol conversion, separately synthesized metal and acid catalyst systems were tested. Complete phenol conversion was sustained for at least three times longer in a continuous flow reactor operated at 200°C and 0.79 MPa of flowing H2. The separation of the metal and acid sites generated a tunable system capable of producing cyclohexanol, cyclohexane or cyclohexene at very high selectivities, even achieving 99% selectivities for cyclohexane.
32
Vadlamani, Agasteswar. "Enhanced Biomass and Lipid Productivities of Outdoor Alkaliphilic Microalgae Cultures through Increased Media Alkalinity." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1481307126330107.
Full text
33
Setter, Cassandra Marie. "Weed Control Effects on Native Species, Soil Seedbank Change, and Biofuel Production." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29318.
Full textAbstract:
Aphthona spp. flea beetles were released in the Little Missouri National Grasslands
(LMNG) in western North Dakota in 1999 to control leafy spurge (Euphorbia esula L.). The
changes in soil seed bank composition and leafy spurge density were evaluated on two
ecological sites five (2004) and ten years (2009) after Aphthona spp. release to monitor
the effectiveness of the insects on weed control and associated change in plant
communities. In 2009, leafy spurge stem density averaged 2 and 9 stems m-2 in the loamy
overflow and loamy sites, respectively, compared to 110 and 78 stems m-2, respectively, in
1999 and 7 and 10 stems m-2, respectively, in 2004. Leafy spurge constituted nearly 67%
of the loamy overflow seed bank in 1999 compared to 17% in 2004 and 2% in 2009. In the
loamy seedbank, the weed represented nearly 70% in 1999 compared to approximately
11% in 2004 and 15% in 2009. As leafy spurge was reduced, native species diversity and
seed count increased ten years following Aphthona spp. release. High-seral species
represented 17% of the loamy overflow seedbank in 2009, an increase from 5% in 1999.
However, Kentucky bluegrass, a non-target weedy species, increased over 250% in the
loamy overflow seedbank from 2004 to 2009. The reestablishment of native plant species
has often been slow in areas where leafy spurge was controlled using Aphthona spp. A
bioassay was completed to evaluate native grass establishment when grown in soil from
Aphthona spp. release and non-release sites throughout North Dakota. Native grass
production was not affected when grown in soil collected from established Aphthona spp. sites (1.5 g per pot) compared to soil without insects (1.6 g per pot). The cause of reduced
native grass production in sites with Aphthono spp. previously observed is unknown but
may have been due to a chemical inhibition caused by the insects within the soil that no
longer exists. The native warm-season switchgrass (Ponicum virgotum L.) may be an
alternative to corn for efficient biofuel production; however, control of cool-season grassy
weeds has been a problem in switchgrass production. Various herbicides were evaluated
for smooth bromegrass (Bromus inermis Leyss.) and quackgrass [Elymus repens (L.) Gould]
control in an established switchgrass stand near Streeter, ND and a weed-infested field in
Fargo, ND. Switchgrass yield was higher than the control 14 mo after treatment (MAT)
when aminocyclopyrachlor or sulfometuron were applied early in the growing season, but
no treatment provided satisfactory long-term grassy weed control. Herbicides were
reevaluated at increased rates for smooth bromegrass or quackgrass control in Fargo.
Sulfometuron provided 99% smooth bromegrass control when applied at 280 g ha-1 in the
fall but injured other grass and forb species as well. Sulfometuron would likely be
injurious to switchgrass and could not be used for biofuel production.
Aminocyclopyrachlor did not injure other grass species but only reduced smooth
bromegrass control by 76% when applied at 280 g ha-1 in the fall. No treatment provided
satisfactory long-term quackgrass control.
34
Lindfeldt, Erik G. "A trinity of sense : Using biomass in the transport sector for climate change mitigation." Doctoral thesis, KTH, Energiprocesser, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9292.
Full textAbstract:
This thesis analyses two strategies for decreasing anthropogenic carbon dioxide (CO2) emissions: to capture and store CO2, and to increase the use of biomass. First, two concepts for CO2 capture with low capture penalties are evaluated. The concepts are an integrated gasification combined cycle where the oxygen is supplied by a membrane reactor, and a hybrid cycle where the CO2 is captured at elevated pressure. Although the cycles have comparatively high efficiencies and low penalties, they illustrate the inevitable fact that capturing CO2 will always induce significant efficiency penalties. Other strategies are also needed if CO2 emissions are to be forcefully decreased. An alternative is increased use of biomass, which partially could be used for production of motor fuels (biofuels). This work examines arguments for directing biomass to the transport sector, analyses how biofuels (and also some other means) may be used to reduce CO2 emissions and increase security of motor fuel supply. The thesis also explores the possibility of reducing CO2 emissions by comparatively easy and cost-efficient CO2 capture from concentrated CO2 streams available in some types of biofuel plants. Many conclusions of the thesis could be associated with either of three meanings of the word sense: First, there is reason in biofuel production – since it e.g. reduces oil dependence. From a climate change mitigation perspective, however, motor fuel production is often a CO2-inefficient use of biomass, but the thesis explores how biofuels’ climate change mitigation effects may be increased by introducing low-cost CO2 capture. Second, the Swedish promotion of biofuels appears to have been governed more by a feeling for attaining other goals than striving for curbing climate change. Third, it seems to have been the prevalent opinion among politicians that the advantages of biofuels – among them their climate change mitigation benefits – are far greater than the disadvantages and that they should be promoted. Another conclusion of the thesis is that biofuels alone are not enough to drastically decrease transport CO2 emissions; a variety of measures are needed such as fuels from renewable electricity and improvements of vehicle fuel economy.QC 20100823
35
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.
Full textAbstract:
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.
36
Okwo, Adaora. "Next-generation biofuels: the supply chain approach to estimating potential land-use change." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47603.
Full textAbstract:
Biofuels, including ethanol and biodiesel, are important components of energy policy in the U.S. and abroad. There is a long history of ethanol production from corn (maize) in the United States and from sugarcane in Brazil. However, there has been a push for greater use of next-generation biofuels (including those derived from cellulosic feedstocks) to mitigate many of the environmental and potential food system impacts of large scale biofuel production.
Farmer willingness to grow biomass crops and ensuring adequate feedstock supply are two important challenges impeding large scale commercialization of next-generation biofuels. The costs of transporting bulky, low density biomass will be substantial. Consequently, in the near term, the economic success of next-generation biofuels will hinge on the supply of locally available biomass. As such, agricultural contracts are expected to be an important tool in overcoming the feedstock acquisition challenge. The broad objective of this study is to understand the effect of contracting for non-food energy crops (cellulosic feedstocks) on the agricultural landscape via the displacement of commodity (food) crops on productive cropland.
We develop an analytical framework for evaluating the design and use of two different contract structures for securing cellulosic feedstock in a representative supply chain with a biorefinery and farmer. We study the dynamics of scarce land and indirect competition from commodity market production on a biorefinery's equilibrium pricing strategy and the resultant supply of cellulosic biomass. And we consider its sensitivity to various production characteristics and market conditions.
We develop a method for quantifying the biorefinery's tradeoff between profit margins and competing for land in order to secure the requisite feedstock for biofuel production. And we characterize the loss of efficiency in the decentralized system, relative to a vertically integrated system, that can be attributed to the need to compete for the farmer's scarce land resource versus that which results from the biorefinery's desire to make a profit.
Then we extend our framework to consider multi-year contracts for biomass production and evaluate the importance of land quality, yield variability and contract structure on a farmer's willingness to accept a contract to produce cellulosic feedstock as well as the resulting impact on the agricultural landscape through the displacement of commodity crops. Using switchgrass production in Tennessee as a case study, we develop feedstock supply curves for each contract structure considered and evaluate the conditions and contract prices at which land devoted to various field crops would be displaced by switchgrass based on field trials of switchgrass production in Tennessee and recent USDA data on crop prices and production.
37
Swart, Wessel Johannes. "The economic feasibility of commercial biodiesel production in South Africa including analyses of important production and related parameters." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/19998.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2012.ENGLISH ABSTRACT: In the developed and developing world, the use of lipids for the production of alkyl esters, also known as biodiesel, showed phenomenal growth during the ten year period up to the end of 2007. The main sources for these lipids are the oils extracted from oil seeds such as soya-, palm-, and rape seed, but other products in the food chain such as waste cooking oil (yellow grease) and animal fats are also used. In Africa and Asia vast tracks of land not previously tilled, are now being cultivated to yield oils which are not edible and in a number of countries intensive research is focused on lipid producing species such as algae. Meanwhile more evidence is coming to the fore pronouncing biodiesel and other first generation biofuels not to be the panacea for the predicament the world is facing on unbridled population growth, energy security concerns and environmental issues such as indirect land use changes, global warming and climate changes. The acceptance of the National Biofuels Industrial Strategy at Cabinet level has not yet resulted in significant commensurate activity in South Africa. The availability, other uses and volumes of selected feed stocks for biodiesel production invite debate on the choice between food- and energy security and the appropriateness of some identified socio-economical and socio-political drivers for a viable industry. Somehow the unique characteristics of South Africa and its resources seem not to feature in debate and constraints on the production of biodiesel, as described in this dissertation. The conventional process routes for commercial biodiesel production are based on a mature technology which has inherent pollution and economical limitations. This called for a detailed critical evaluation on process routes more environmentally friendly or involving fewer unit processes generating more desirable products, albeit with more severe process conditions. By comparison, the homogeneous alkali catalyst alcoholysis (HACA), the enzymatic catalyst alcoholysis (ECA) and the super critical alcoholysis (SCA) process routes as developed in this study, are found to be competitive on total manucturing costs as assessed, if results emanating from selected sensitivity analyses and optimisation studies, are accepted. The total manufacturing and operating costs in the selected process routes as estimated, assuming the same capacities for commercial biodiesel production, are dominated by feed stock costs. Incentives on depreciation and fuel levies are deemed not effective, if costs are compared to the price of fossil diesel at the retail level – October 2011. It is concluded that using the feed stocks indicated in the Strategy, commercial biodiesel production is not economically feasible in South Africa at present. In this study process routes and feed stocks were identified that can change this position. Note should be taken of the intensive research activities being conducted on second generation technologies and biorefineries in the developed world, as discussed in this dissertation.
AFRIKAANSE OPSOMMING: In die ontwikkelde en ontwikkelende wêreld het die gebruik van vette vir die produksie van alkielesters, ook bekend as biodiesel, in die tienjaarperiode tot die einde van 2007 fenomenale groei getoon. Die hoofbronne vir hierdie lipiede is die olies onttrek van oliesade soos soja-, palm-, en raapsaad, maar ander produkte in die voedselketting soos gebruikte kookolie en dierevette word ook gebruik. In Afrika en Asië word uitgestrekte stukke grond voorheen onbewerk, nou bewerk om olies wat nie eetbaar is nie, op te lewer, en in verskeie lande word intensiewe navorsing op vetproduserende spesies soos alge gedoen. Intussen kom meer bewyse na vore wat verklaar dat biodiesel en ander eerste-generasie biobrandstowwe nie die wondermiddel is vir die moeilike posisie wat die wêreld in die gesig staar oor onbeteuelde bevolkingsaanwas, kwellings oor energiesekuriteit en omgewingskwessies soos indirekte grondverbruike, aardverwarming en klimaatsveranderings nie . Die aanvaarding van die Nasionale Biobrandstowwe Industriële Strategie op kabinetsvlak het nog nie verhoogde soortgelyke aktiwiteite in Suid-Afrika tot gevolg gehad nie. Die beskikbaarheid, gebruike en volumes van gekose grondstowwe, lok debatte uit oor die keuse tussen voedsel- en energiesekuriteit en die toepaslikheid van sekere geïndentifiseerde sosio-ekonomiese en sosio-politieke stimulante vir ‘n lewensvatbare nywerheid. Op een of ander manier is die unieke kenmerke van Suid- Afrika en sy bronne nog nie in die debat op die knelpunte van biodiesel nie, soos beskryf in hierdie proefskrif. Die gewone prosesroetes vir kommersiële produksie van biodiesel is gebaseer op ‘n beproefde tegnologie met inherente besoedelings- en ekonomiese beperkings. Dit het gevra vir ‘n uitvoerige kritiese evaluasie van meer omgewingsvriendelike- en minder eenheidsprosesse wat meer gewensde produkte genereer, al is dit met erger prosesbepalings. By vergelyking, is dit bevind dat die homogene alkali-katalisator- alkoholisis (HAKA), ensiem-katalisator-alkoholisis (EKA) en die superkritiese-alkoholisis (SKA) prosesroetes soos in hierdie studie ontwikkel, mededingend is op ‘n totale vervaardigingskoste-vlak, as die resultate wat spruit uit geselekteerde sensiwiteitsanalises en optimiseringsstudies, aanvaar word. Die totale vervaardigings- en bedryfskostes soos beraam vir die gekose prosesroetes vir kommersiële biodieselvervaardiging vir dieselfde deursette, word oorheers deur grondstofkostes. Aansporings op afskrywings en brandstofheffings word gesien as nie effektief nie, as kostes vergelyk word met die prys van fossieldiesel op kleinhandelsvlak – Oktober 2011. Die gevolgtrekking word gemaak dat met die grondstowwe aangedui in die Strategie, kommersiële biodieselvervaardiging tans nie ekonomies gangbaar is vir Suid-Afrika nie. In hierdie studie is prosesroetes en grondstowwe geïdentifiseer wat die posisie kan verander. Kennis moet geneem word van die intensiewe navorsingsaktiwiteite op tweede-geslag tegnologieë en bioraffinaderye in die ontwikkelde wereld, soos in hierdie proefskrif bespreek.
38
Rismani-Yazdi, Hamid. "Bioconversion of cellulose into electrical energy in microbial fuel cells." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1211313869.
Full text
39
Vice, President Research Office of the. "Pellet Power." Office of the Vice President Research, The University of British Columbia, 2009. http://hdl.handle.net/2429/9507.
Full text
40
Mehlitz, Thomas Hagen. "Temperature Influence and Heat Management Requirements of Microalgae Cultivation in Photobioreactors." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/54.
Full textAbstract:
Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In addition, a dynamic mathematical model was developed to simulate heating and cooling energy requirements of tubular PBRs for any desired location. Operating the model with hourly weather data as input, heating and cooling loads can be calculated early in the planning stage of a project. Furthermore, the model makes it possible to compare the operation inside a greenhouse to the outdoor operations, and consequently provides fundamental information for an economic feasibility study. The best configuration for a specific location can be evaluated easily. The model was exemplary tested for a hypothetical 100,000 l photobioreactor located in San Luis Obispo, California, U.S.A. Average algae productivity rates of 23% and 67% for outdoor and indoor PBR operations, respectively, were obtained. Actual energy loads (heating and cooling) needed to maintain the PBR at optimal temperature were determined and compared. Sensitivity analyses had been performed for abrupt temperature and solar radiation steps, PBR row distances, ground reflectivities, and ventilation rates of the greenhouse. An optimal row distance of 0.75 m was determined for the specific PBR. The least amount of energy was needed for a ground reflectivity of 20%. The ventilation rate had no major influence on the productivity rate of the system. Results demonstrated the importance of a simulation model as well as the economic impact of a sophisticated heat management system. Energy savings due to an optimized heat management system will eventually increase proficiency of the systems, which will support a new sustainable industry and future developmental potential.
41
Fogdal, Hanna, and Adrian Baars. "Utilization of Forest Residue through Combined Heat and Power or Biorefinery for Applications in the Swedish Transportation Sector : a comparison in efficiency, emissions, economics and end usage." Thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215767.
Full textAbstract:
Sweden has the goal of reaching a fossil independent transportation sector by 2030. Two ways to reach the goal is to increase the use of electric vehicles or produce more biofuels. Both alternatives could be powered by forest residue, which is an underutilized resource in the country. Electricity could be produced in a biomass fired Combined Heat and Power (CHP) plant, and biofuel could be produced in a biorefinery through gasification of biomass and Fischer-Tropsch process. When located in Stockholm County, both system can also distribute heat to the district heating system. It is however important to use the biomass in an energy-efficient way. The scope of this work has been to analyze the efficiency together with environmental and economic aspects of the two systems. To assess the efficiency and environmental impact of the two systems a forest to wheel study was made of the systems where the product was studied from harvesting of forest residue to driving the vehicle. The studied functional units were: kilometers driven by vehicle, kWh of district heating, CO2-equivalents of greenhouse gases and MWh of forest residue. The system using CHP technology and electric vehicles outperformed the biorefinery system on the two first functional units. Using the same amount of forest residue more than twice as much district heating and almost twice as many driven kilometers were produced in this system. The study also showed that both systems avoids significant greenhouse gas emissions and can be part of the solution to decrease emissions from road transportation. The profitability of investing in a CHP plant or a biorefinery was calculated through the net present value method. It showed that the expected energy prices are too low for the investments to be profitable. The CHP plant investment has a net present value of -1.6 billion SEK and the biorefinery investment has a net present value of -4.6 billion SEK. Furthermore, the biorefinery investment entails higher risk due to the high investment cost and uncommercialized technology. Both systems face barriers for implementation, these barriers have been studied qualitatively.Sverige har som mål att skapa en fossiloberoende fordonsflotta till år 2030. Två vägar som pekats ut för att nå målet är att öka användningen av eldrivna fordon eller att producera mer biobränsle. Båda alternativen kan drivas av skogsavfall, en råvara som det finns gott om i Sverige. Elektricitet kan produceras av skogsavfallet i ett kraftvärmeverk, och biobränsle i ett bioraffinaderi genom användning av förgasning och Fischer-Tropschmetoden. I Stockholms län skulle båda systemen dessutom kunna producera värme till Stockholms fjärrvärmesystem. Det är dock viktigt att använda skogsavfallet på ett resurseffektivt sätt. Därför undersöker detta arbete effektiviteten av de två olika systemen tillsammans med en analys av växthusgasutsläpp och ekonomiska förutsättningar. För att kunna utvärdera effektiviteten och klimatpåverkan av de två olika systemen utfördes en ”skog-till-hjul”-analys där produkten undersöktes från ursprunget, till drivandet av ett fordon. För att utföra studien definierades fyra funktionella enheter. De funktionella enheterna var: körsträcka med bil mätt i kilometer, kWh fjärrvärmeproduktion, CO2 ekvivalenter av växthusgasutsläpp och MWh skogsavfall. Studien visade att systemet där skogsavfallet används i ett kraftvärmeverk för att producera elektricitet och ladda elbilar hade bättre resultat i de två första funktionella enheterna. Systemet producerade nästan dubbelt så lång körsträcka och mer än dubbelt så mycket fjärrvärme som systemet där skogsavfallet används i ett bioraffinaderi och biobränslet används i dieselbilar. Studien visade även att båda system kan bidra till att sänka växthusgasutsläppen från transportsektorn. Lönsamheten att investera i ett kraftvärmeverk eller bioraffinaderi beräknades med nuvärdesmetoden. Studien visade att de förväntade framtida energipriserna är för låga för att investeringarna ska bli lönsamma. Kraftvärmeanläggningen hade ett nuvärde på -1.6 miljarder kronor, och bioraffinaderiet ett nuvärde på -4.6 miljarder kronor. Dessutom ansågs investeringen i ett bioraffinaderi vara en hög risk på grund av den höga investeringskostnaden och att tekniken idag inte är kommersialiserad. Det finns även en rad andra barriär för att genomföra de två olika systemen, dessa barriärer har studerats kvalitativt i arbetet.
42
Alkadee, Dareen. "Techniques de réduction et de traitement des émissions polluantes dans une machine thermique." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2011. http://tel.archives-ouvertes.fr/tel-01005123.
Full textAbstract:
Cette thèse de doctorat, a consisté, dans une première partie, à introduire d'une part, la notion de l'analyse du cycle de vie " ACV " et celle des biocarburants. D'autre part, à présenter l'intérêt d'appliquer une ACV sur des biocarburants afin de valoriser leurs bilans énergétiques et analyser leurs impacts environnementaux face aux carburants conventionnels. Dans une deuxième partie, nous avons comparé, d'un point de vue énergétique et environnemental, 3 scénarios de production d'électricité : 2 scénarios de cogénération (turbine à vapeur et ORC) pour la production d'énergie électrique et thermique à partir de biomasse, et un scénario de cogénération par moteur diesel. Ces scénarios sont comparés à l'aide de deux méthodes orientées " analyse des dommages ": Eco-indicateur 99 (E) et IMPACT2002+Dans une troisième partie, on a abordé la valorisation du biogaz sous forme de carburant dans des moteurs "dual fuel" pour des engins agricoles dans le but de déterminer l'impact environnemental lié à l'utilisation de ce carburant alternatif au diesel par rapport aux autres biocarburants. Les méthodes Eco-indicateur 99 (E) et CML ont été utilisées ici. On a pu ainsi identifier les principaux polluants générés à chaque étape du cycle de vie de l'agrocarburant et les étapes qui ont les plus grands impacts environnementaux et on a identifié, selon nos critères et par rapport au contexte, le scénario énergétique le plus compatible avec le principe de développement durable.
43
Nduli, Mbalenhle B. "Thermophysical properties of biofuel components derived from biomass." Thesis, 2016. http://hdl.handle.net/10321/1732.
Full textAbstract:
Submitted in fulfillment of the academic requirements of the degree of Master of Technology, Durban University of Technology, Durban, South Africa, 2016.The thermophysical properties of the binary mixtures containing biofuel components derived from biomass were determined. Experimental densities, speed of sound, and refractive indices for the binary mixtures (methanol or 1-ethyl-3-methylimidazolium acetate [EMIM][OAc] + furfural or furfuryl alcohol ) were measured at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. From the experimental data, excess molar volume, E m V , isentropic compressibility, s , molar refractions, R, and deviation in refractive index, Δn, were calculated. The excess molar volumes were found to be negative for all systems studied. The isentropic compressibility were found to be both positive for the whole composition and temperature range and increases slightly with increasing temperature. The deviation in refractive index was positive over the whole composition range. The obtained values of excess molar volumes and changes of refractive index on mixing were satisfactorily correlated by the Redlich–Kister equation. The Lorentz–Lorenz equation was applied to predict the density and calculate the excess molar volume of the binary mixtures.
M
44
Singh, Shikhar. "Development of Water Requirement Factors for Biomass Conversion Pathways." Master's thesis, 2009. http://hdl.handle.net/10048/768.
Full textAbstract:
This study develops the water requirement factors for different thermo-chemical and biochemical biomass conversion pathways for production of biofuels and biopower. Twelve biomass conversion pathways based on six biomass feedstocks are assessed. For all these pathways integrated water and energy requirement factors are developed. The biomass feedstocks considered for bioethanol production are corn, wheat, corn stover, wheat straw, and switchgrass. The biomass feedstock considered for biodiesel production is canola seed. Three biomass feedstocks are considered for biopower generation using direct combustion of biomass and bio-oil produced from the feedstocks through fast pyrolysis. These three feedstocks are corn stover, wheat straw and switchgrass. The water requirement is also evaluated for biofuels production based on wheat, wheat straw and canola seed in Alberta. Agriculture residues based ethanol production pathways are water and energy efficient, consuming only 0.3 liters of water per MJ of net energy value (NEV), whereas biopower pathways consume about 1.2 1.5 liters of water per MJ of NEV due to their lower energy efficiency. The pathway for producing ethanol from switchgrass is the most energy efficient, but consumes 117 liters of water per MJ of NEV. Producing biopower through the direct combustion of switchgrass and from combustion of switchgrass based bio-oil consumes 278 and 344 liters of water per MJ of NEV, respectively. Wheat and corn based ethanol production pathways consume 653 and 409 liters of water per MJ of NEV, respectively. Canola seed based biodiesel production pathway consumes 176 liters of water per MJ of NEV. Water demand in Alberta due to biofuels production will be 12.7% higher than the projected demand in 2025, but it can be met using existing resources.Engineering Management
45
Yenerall, Jacqueline Nicole Ready Richard C. "The effects of climate change and biofuel policy on agricultural land use in Pennsylvania." 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4023/index.html.
Full text
46
James, Gabriel. "Algae and cyanobacteria platforms for engineering biofuel production." Phd thesis, 2013. http://hdl.handle.net/1885/155923.
Full textAbstract:
This thesis investigated the capacity of a model microalga and two cyanobacteria species to provide the feedstock for sustainable liquid biofuel production. In particular, genetic manipulations in conjunction with nutritional triggers were used to redirect carbon into lipid biosynthesis. Wild-type and starch mutants of Chlamydomonas reinhardtii, a well-established model green alga, were subjected to nitrogen starvation to examine carbon storage and partitioning between starch and lipid synthesis. The starch-less mutant, BAF-J5, was found to store up to 75% of dry cell weight as fatty acid when grown photoheterotrophically under nitrogen starvation. Fourier transform infrared spectroscopy was used as a high-throughput method for semi-quantitative measurements of protein, carbohydrate and lipid content. Fluorescent spectroscopy was used for semi-quantitative measurements of neutral lipid storage in lipid droplets stained with Nile Red. Oleosin-like and caleosin-like genes, which are associated with lipid droplets in plants were identified in the genome. However, proteomic analysis of isolated lipid droplets only identified a key lipid droplet associated protein. The fatty acids were identified and quantified by gas chromatography mass spectrometry. Long-chain saturated, mono- and polyunsaturated fatty acids were found. This study demonstrates it is possible to manipulate algal biosynthetic pathways to produce high levels of lipid that may be suitable for conversion to liquid biofuels. Nutrient availability and temperature were used to improve the fatty acid profile for biodiesel, thereby, potentially reducing the requirement for costly refining. Two cyanobacterial model organisms; a wild-type and glycogen mutant of the mesophile Synechococcus sp. PCC 7942, and the thermophile wild-type Thermosynechococcus sp. BP-1 isolated from different environments and therefore likely to have different lipid metabolism and responses to nutritional triggers were selected for study. Synechococcus sp. PCC 7942 was grown phototrophically and subjected to nitrogen starvation to examine the effect of nutrient limitation on the fatty acid content and composition. Carbon was not found to be stored as fatty acid or hydrocarbons in either the wild-type or glycogen deficient mutant under nitrogen starvation. Thermosynechococcus sp. BP-1 was also grown phototrophically and subjected to nitrogen and phosphorus starvation. Again, nitrogen starvation did not result in carbon storage as fatty acids or hydrocarbons. Only trace levels of organic compounds were found in the culture medium under nitrogen sufficient and deficient conditions. These studies indicate that metabolic engineering would be required to enhance lipid production in these species. The experimentally determined fatty acid profiles from these organisms were used to calculate fuel properties and to determine if any of the strains or environmental treatments would produce a fuel that would meet the biodiesel specifications for either the EU or the USA. In conclusion, it was found that disruption of starch biosynthesis and nitrogen starvation, in conjunction with an optimised growth temperature, greatly improved the likely quality of a biodiesel fuel derived from Chlamydomonas reinhardtii.
47
Beal, Colin McCartney. "Constraints on algal biofuel production." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-2775.
Full textAbstract:
The aspiration for producing algal biofuel is motivated by the desire to replace conventional petroleum fuels, produce fuels domestically, and reduce greenhouse gas emissions. Although, in theory, algae have the potential to produce a large amount of petroleum fuel substitutes and capture carbon emissions, in practice, profitable algal biofuel production has proven quite challenging. This dissertation characterizes the production pathways for producing petroleum fuel substitutes from algae and evaluates constraints on algal biofuel production. Chapter 8 provides a summary of the entire dissertation.
The first chapter provides a framework for reporting the production of renewable diesel from algae in a consistent way by using data that are specific and by presenting information with relevant metrics. The second chapter presents a review of analytical tools (i.e., microscopy, spectroscopy, and chromatography) that can be used to analyze the structure and composition of intermediate products in an algal biofuel production pathway.
In chapters 3 through 6, the energy return on investment, water intensity, and financial return on investment are presented for three cases: 1) an Experimental Case in which data were measured during five batches of algal biocrude production with a combined processed volume of about 7600 L, 2) a hypothetical Reduced Case that assumes the same energy output as the Experimental Case, with reduced energy and material inputs, and 3) a Highly Productive Case that assumes higher energy outputs than the Experimental Case, with reduced energy and material inputs, similar to the Reduced Case.
For all three cases, the second-order energy return on investment was determined to be significantly less than 1, which means that all three cases are energy negative. The water intensity (consumption and withdrawal) for all cases was determined to be much greater than that of conventional petroleum fuels and biofuels produced from non-irrigated crops. The financial return on investment was also found to be significantly less than 1 for all cases, indicating production would be unprofitable. Additionally, it was determined that large-scale algal biofuel production would be constrained by the availability of critical energy and material inputs (e.g., nitrogen and carbon dioxide).
The final part of this dissertation presents a first-principles thermodynamic analysis that represents an initial attempt at characterizing the thermodynamic limits for algal biofuel production. In that analysis, the energy, entropy, and exergy is calculated for each intermediate product in the algal biofuel production pathway considered here.
Based on the results presented in this body of work, game-changing technology and biotechnology developments are needed for sustainable and profitable algal biofuel production.text
48
Obidike, Lawrence Ikechukwu. "Biofuel production from waste animal fat using pyrolysis (thermal cracking)." Thesis, 2016. http://hdl.handle.net/10539/21141.
Full textAbstract:
Submitted to
School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa
June, 2016The main objective of this study is to produce biofuel from waste animal fat (collected from abattoirs) using the pyrolysis (thermal cracking) method. To achieve this goal, the study investigated the effects of temperature and heating rate on the yield and quality of the bio-oil produced. Also investigated was the effect of zeolite nano-catalyst(s) on the quality of the bio-oil produced. Animal waste fat (tallow) was pyrolyzed in a laboratory fixed bed reactor of volume 2200 cm3 at final temperatures (FT), 450oC, 500oC, 530oC and 580oC using heating rates (HR) of 4oC/min, 5oC/min and 6oC/min. The properties of the resultant bio-oils were tested and analyzed. The maximum bio-oil yield of 82.78 % was achieved at 530oC FT and 6oC /min HR while the highest calorific value, 52.41 MJ/kg, was recorded from the bio-oil produced at the FT of 580oC and 6oC/min HR. The molecular components of each of the bio-oil samples was analyzed using the Gas Chromatography – Molecular Spectrograph (GC-MS) which indicated the predominant presence of alkanes, alkenes, carboxylic acids and alkyl esters in the bio-oils produced without a catalyst. The introduction of zeolites in nano-form yielded relatively more cyclo-alkanes and aromatics. A maximum yield of 58% was recorded when 1% of the zeolite nano-catalyst was used to pyrolyse the tallow at 530oC FT and 6oC/min HR but with lots of coking and gas formation. The viscosity improved with a 35% reduction for the samples produced with 1% zeolites (C1 and C2). The viscosity of the bio-oil produced with 2% zeolites improved with a resultant 34% reduction in value. For pyrolysis done at 530oC FT and 6oC/min HR, the bio-oils with 1% (C1) and 2% zeolite (C3) resulted in a reduction in acid value of 32% and 30%, respectively. Acid value is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance.
MT2016
49
"Production of biofuel from microalgae cultivated in treated sewage." 2013. http://library.cuhk.edu.hk/record=b5549306.
Full textAbstract:
從微藻提煉的生物燃料，是化石燃料和其他生物燃料的優良替代品。藻類生物燃料屬碳中性，因為微藻為光自養生物，能經光合作用吸收二氧化碳，並將之轉化成碳氫化合物和脂肪。碳氫化合物和脂肪可用以提煉生物燃料。此外，微藻可以吸收廢水中的污染物作生長的營養，同時作污水處理。本研究項目的目的為透過下述方法，降低藻類生物燃料的生產成本，並提高藻株的脂肪含量： (1) 篩選可以在污水自養培育，並有高產油量的微藻菌株，(2) 以兩階段培養方法，用處理過的污水作培養，從而提高油脂產，(3) 透過微藻毒理測試，和水質化學分析，研究處理後的污水中影響微藻生長的污染物和有毒物質。
這個研究中使用從沙田污水處理廠收集的二級處理污水，其水質亦被研究。幾種微藻菌株分別為小球藻 (Chlorella pyrenoidosa)，叢粒藻 (Botryococcus braunii) 和微綠球藻 (Nannochloropsis oculata)，從鰂魚池水分離出的小球藻 (Chlorella sp.1)，及兩種從處理污水中分離出的小球藻(Chlorella sp. 2, Chlorella sp. 3)。微藻菌株分別在培養基和處理污水中培養，並比較在兩種情況下的脂肪，脂肪酸，碳水化合物，蛋白質含量，生物質量和總有機碳。結果發現，雖然經處理的污水中營養成分非常低 (<0.11 mg / L活性磷，<9.68 mg / L硝酸根，<0.5 mg / L鉀離子)，所有研究的微藻菌株都能存活。在兩階段培養法下，首先以「氮含量充足階段」(培養基)提高生物質量，然後以「氮含量不足階段」(經處理污水) 培養，培養成本可以降低，同時提高脂肪生產率。在兩階段培養法下，叢粒藻的脂肪生產率比在人工培養基和經處理污水高2.6倍和7.13倍。
沙田污水處理廠處理的污水水質良好，並無驗出有害重金屬，雙酚A(BPA)，四溴雙酚A(TBBPA)和2,3,7,8-四氯二苯並二噁英(TCDD)。從藻類產生的生物燃料將不含有重金屬。
在這個研究中的叢粒藻 (Botryococcus braunii)，微綠球藻 (Nannochloropsis oculata)和小球藻 (Chlorella sp.1)都可以容忍雙酚A(BPA)，四溴雙酚A(TBBPA)，二氯苯氧氯酚 (TCS)和2,3,7,8-四氯二苯並二噁英(TCDD)。他們可以培育在其他來源的經處理污水。
利用經處理污水於兩階段培養法，是一種新的、更經濟的增加微藻油脂產量方法，亦可以配合任何其他方法，以減低藻類生物燃料的製造成本。
Biofuel from microalgae can be an excellent substitute of fossil fuel and other biofuels. Algal biofuel is carbon neutral as microalgae are photoautotrophic. Through photosynthesis, microalgae can capture and convert carbon dioxide to hydrocarbons or lipids which can be used for biofuel production. Besides, microalgae can use pollutants from wastewater as nutrients for growth, which can serve as a wastewater treatment process.
The aims of the project are to lower the cost of algal biofuel production and boost up lipid content of algal strains by (1) screen a microalgal strain that can be cultivated in treated sewage autotrophically and give high oil yield, (2) use two phase cultivation, with treated sewage as medium, to boost up lipid productivity, (3) investigate heavy metals and some organic pollutants that may exist in treated sewage and can affect algal growth by performing algal toxicity test and chemical analysis of treated sewage.
The secondarily treated sewage used in this project was collected from the Sha Tin Sewage Treatment Works. The quality of the secondarily treated sewage was monitored. Chlorella pyrenoidosa, Botryococcus braunii and Nannochloropsis oculata from commercial source, and Chlorella sp. 1 isolated from tilapia fish pond water, and two species of algae, Chlorella sp. 2 and Chlorella sp. 3, isolated from treated sewage were investigated. Microalgal strains are compared by investigating the content of lipid, fatty acid, carbohydrate, protein, biomass and total organic carbon when cultivated in culture medium and treated sewage. Results found that although nutrients in treated sewage were very low (<0.11 mg/L reactive phosphorus, <9.68 mg/L nitrate and <0.5 mg/L potassium ion), all the microalgae investigated could grow reasonably well. Using two phase cultivation, with an initial nitrogen sufficient phase (artificial media) for biomass production, followed by nitrogen limitation phase (treated sewage), cost of cultivation could be reduced and the overall lipid productivity could be increased. Under the two phase cultivation, the lipid productivity of Botryococcus braunii was 2.6 and 7.13 fold higher than cultivated in artificial medium and treated sewage respectively.
Treated sewage from the Sha Tin Sewage Treatment Works was in good quality without harmful concentrations of heavy metal and BPA, TBBPA and TCDD. The microalgae could not absorb or adsorb significant amount of the harmful substances and the algal biofuel produced would not contain heavy metals. All the microalgae investigated in this project could tolerate BPA, TBBPA, TCS and TCDD. They could be cultivated in treated sewage from other sources.
Two phase cultivation using treated sewage is a new way for increasing lipid productivity from microalgae economically and can be combined with any other means for producing algal biofuel with lowest cost.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Kwan, Ka Ki.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 104-113).
Abstracts also in Chinese.
Acknowledgements --- p.i
Abstract --- p.iii
摘要 --- p.Vi
Table of Contents --- p.viii
List of Figures --- p.Xii
List of Plates --- p.Xvi
List of Tables --- p.xviii
Abbreviations --- p.xx
Chapter 1. --- General introduction
Chapter 1.1 --- Fossil fuel, the major energy source nowadays --- p.1
Chapter 1.2 --- Disadvantages of using fossil fuel --- p.3
Chapter 1.3 --- Biofuel --- p.5
Chapter 1.4 --- Disadvantages of traditional biofuel production --- p.8
Chapter 1.5 --- Characteristics of microalgae --- p.9
Chapter 1.6 --- Biofuel from microalgae --- p.14
Chapter 1.7 --- Nutrients for microalgae related to lipid production --- p.18
Chapter 1.8 --- Current research on algal biofuel --- p.19
Chapter 1.9 --- Two phase cultivation as a new way for lipid production --- p.24
Chapter 1.10 --- Objectives --- p.24
Chapter 2. --- Biofuel production under two phase cultivation with artificial medium and treated sewage
Chapter 2.1 --- Introduction --- p.26
Chapter 2.2 --- Materials and Methods --- p.28
Chapter 2.2.1 --- Algal strains collection and isolation --- p.28
Chapter 2.2.2 --- Artificial culture media --- p.29
Chapter 2.2.2.1 --- Bristol’s Medium (BM) --- p.29
Chapter 2.2.2.2 --- Modified Bold 3N medium (MBM) --- p.31
Chapter 2.2.3.3 --- F/2 medium (F/2) --- p.33
Chapter 2.2.3 --- Water quality of treated sewage --- p.33
Chapter 2.2.3.1 --- Chemical and biological condition --- p.34
Chapter 2.2.3.2 --- Total organic carbon and total nitrogen (TOC/TN) --- p.35
Chapter 2.2.3.3 --- Reactive phosphate --- p.35
Chapter 2.2.3.4 --- Nitrate --- p.37
Chapter 2.2.3.5 --- Ammonia --- p.39
Chapter 2.2.3.6 --- Metal elements --- p.40
Chapter 2.2.4 --- Cultivation conditions --- p.40
Chapter 2.2.5 --- Growth monitor of microalgae in artificial medium and treated sewage --- p.41
Chapter 2.2.6 --- Comparison of microalgae cultivated in artificial media and treated sewage --- p.42
Chapter 2.2.6.1 --- Large scale cultivation --- p.42
Chapter 2.2.6.2 --- Cell morphology --- p.43
Chapter 2.2.6.3 --- Cell harvesting --- p.44
Chapter 2.2.6.4 --- Dried biomass --- p.44
Chapter 2.2.6.5 --- Lipid content --- p.45
Chapter 2.2.6.6 --- Fatty acid profile --- p.46
Chapter 2.2.6.7 --- Extraction of carbohydrates and protein --- p.48
Chapter 2.2.6.8 --- Carbohydrate content --- p.48
Chapter 2.2.6.9 --- Protein content --- p.49
Chapter 2.2.7 --- Two phase cultivation --- p.50
Chapter 2.2.8 --- Statistical analysis --- p.50
Chapter 2.3 --- Results --- p.51
Chapter 2.3.1 --- Water quality of treated sewage --- p.51
Chapter 2.3.2 --- Nutrient contents in artificial medium --- p.54
Chapter 2.3.3 --- Growth of microalgae in artificial medium and treated sewage --- p.54
Chapter 2.3.3.1 --- Cell morphology and cell size --- p.57
Chapter 2.3.3.2 --- Biomass --- p.59
Chapter 2.3.3.3 --- Lipid content --- p.61
Chapter 2.3.3.4 --- Fatty acid profile --- p.63
Chapter 2.3.3.5 --- Carbohydrates content --- p.66
Chapter 2.3.3.6 --- Protein content --- p.67
Chapter 2.3.4 --- Two phase cultivation --- p.69
Chapter 2.4 --- Discussion --- p.74
Chapter 2.4.1 --- Water quality of treated sewage and nutrients in artificial medium --- p.74
Chapter 2.4.2 --- Growth of microalgae in artificial medium and filtered treated sewage --- p.75
Chapter 2.4.3 --- Microalgae cultivated in artificial media and treated sewage --- p.76
Chapter 2.4.4 --- Two phase cultivation --- p.81
Chapter 3. --- Possible toxic effect on algal growth from chemicals in sewage
Chapter 3.1 --- Introduction --- p.84
Chapter 3.2 --- Materials and methods --- p.85
Chapter 3.2.1 --- Analysis of dissolved metals by ICP --- p.85
Chapter 3.2.2 --- Organic compounds --- p.86
Chapter 3.2.3 --- Algal bioassay --- p.87
Chapter 3.3 --- Results --- p.88
Chapter 3.3.1 --- Dissolved metals and metalloids --- p.88
Chapter 3.3.2 --- Organic compounds --- p.88
Chapter 3.3.3 --- Algal bioassay --- p.91
Chapter 3.4 --- Discussion --- p.97
Chapter 4. --- Conclusion and future prospectives --- p.99
Chapter 4.1 --- Summary --- p.99
Chapter 4.2 --- Genetic engineering --- p.100
Chapter 4.3 --- Further study --- p.102
Chapter 4.4 --- Conclusion --- p.102
Chapter 5. --- References --- p.104
50
Murphy, Thomas Eugene. "Radiant and thermal energy transport in planktonic and benthic algae systems for sustainable biofuel production." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-2756.
Full textAbstract:
Biofuel production from microalgal biomass offers a clean and sustainable liquid fuel alternative to fossil fuels. In addition, algae cultivation is advantageous over traditional biofuel feedstocks as (i) it does not compete with food production, (ii) it potentially has a much greater areal productivity, (iii) it does not require arable land, and (iv) it can use marginal sources of water not suitable for irrigation or drinking. However, current algae cultivation technologies suffer from (i) low solar energy conversion effiencies, (ii) large thermal fluctuations which negatively affect the productivity, and (iii) large evaporative losses which make the process highly water intensive. This thesis reports a numerical study that address these key issues of planktonic as well as benthic algal photobioreactor technologies.
First, radiant energy transfer in planktonic algal photobioreactors containing cells with different levels of pigmentation was studied. Chlamydomonas reinhardtii and its truncated chlorophyll antenna transformant tla1 were used as model organisms. Based on these simulations guidelines are derived for scaling the size and microorganism concentration of photobioreactors cultivating cells with different levels of pigmentation to achieve maximum photosynthetic productivity. To achieve this, the local irradiance obtained from the solution of the radiative transport equation (RTE) was coupled with the specific photosynthetic rates of the microorganisms to predict both the local and total photosynthetic rates in a photobioreactor. For irradiances less than 50 W/m2,
the use of genetically modified strains with reduced pigmentation was shown to have negligible effect on increasing photobioreactor productivity. However,
at irradiances up to 1000 W/m2, improvements of up to 30% were possible with cells having 63% less pigment concentration. It was determined that the ability of tla1 to transmit light deeper into the photobioreactor was the primary mechanism by which a photobioreactor using the modified strain can achieve greater productivity. Furthermore, it was determined photobioreactors using each strain have dead zones in which the local photosynthetic rate is negligible due to nearly complete light attenuation. These dead zones occur at local optical thicknesses greater than 169 and 275 in photobioreactors using the wild strain and the genetically modified strain, respectively.
In addition, a thermal model of an algae biofilm photobioreactor was developed to assess the thermal fluctuations and evaporative loss rate of these novel photobioreactors under varying outdoor conditions. The model took into account air temperature, irradiance, relative humidity, and wind speed as inputs and computed the temperature and evaporative loss rate as a function of time and location in the photobioreactor. The model was run for a week-long period in each season using weather data from Memphis, TN. The range of the daily algae temperature variation was observed to be 13.2C, 12.4C, 12.8C, and 9.4C in the spring, summer, winter, and fall, respectively. Furthermore, without active cooling, the characteristic evaporative water loss from the system is approximately 6.3 L/m2-day, 7.0 L/m2-day, 4.9 L/m2-day, and 1.5 L/m2-day in the spring, summer, fall, and winter, respectively.text