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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

The Effects of Nitrogen Fertilization on Bioenergy Sorghum Yield and Quality

Zilahi-Sebess, Szilvia 2012 May 1900 (has links)
Forage sorghum (Sorghum bicolor L. Moench) is one of the prospective crops that may be used to produce biofuels in the future. Therefore, it is of interest to find management practices that improve both the production of biomass yield and quality. This study presents observations of the effects different rates of nitrogen fertilization have on yield, tissue nitrogen content, and tissue quality measures such as ash, lignin, sucrose, xylans, cellulose and starch content, based on three years of field trials from the Brazos Bottom and one year of field trials from near China, Texas. Data for the quality components were obtained using near infrared spectroscopy, with the exception of tissue nitrogen which was determined by using the dry combustion method. This study has showed fertilizer nitrogen had a strong positive correlation with the tissue nitrogen of sorghum biomass. Changes in tissue quality in relationship with fertilizer nitrogen levels and tissue nitrogen concentration were also observed. Ash showed a strong positive and sucrose showed a strong negative correlation to both tissue nitrogen concentration and fertilizer nitrogen application. Similarly to sucrose, starch also decreased with higher nitrogen levels and lignin was found to increase slightly. The concentration of cellulose and xylans were very weakly affected by nitrogen application and nitrogen concentration.
72

A review and analysis of sustainable issues related to liquid biofuels.

Islam, M Munirul January 2015 (has links)
Most of the time when developing policies for the promotion of future biofuel, the social dimension of sustainable development is neglected. But it is important to incorporate both social and economic issues along with environmental issues for a successful sustainability strategy because sustainable development depends on all three aspects of sustainability. This paper focuses on the sustainable development of liquid biofuel for the transport sector.The global transport sector is booming as is the need for energy. With the growing concern about climate change, governments of developed countries have been implementing different policy directives to promote biofuel as an alternative source of energy. But strategies implemented to fulfill the target of mitigating effects of climate change have exposed negative effects of liquid biofuels on both environment and society. This paper reviewed information on liquid biofuels and their effects on environment, society and economy and analyzed them from a sustainable development point of view. Although scientists have developed biofuels through advanced technology that seem to have less negative effects than traditional biofuels, they are still on a trial basis. In addition to this the effects of these biofuels are also need to be tested on a commercial basis in order to ensure their sustainability. Due to these considerations the process of switching from traditional biofuel to advanced biofuels will require time. It is imperative to develop sustainable ways of production and use of available biofuels which do not harm nature or exploit vulnerable communities. Biofuel policies also need to be studied thoroughly in order to find weaknesses and pitfalls. Although numerous studies related to specific issue like indirect land use change, GHG emission, biofuel policies or the biofuel market etc. have been conducted, it is rare to find a study that takes into consideration of all three aspects (economy, society and environment) of sustainable development. After reviewing and analyzing the literature, this thesis has come to a conclusion that the potential of liquid biofuel in the future transport sector is unlimited. But due to the negative effects on environment and society it has not achieved sustainability. Moreover the expense of production and lack of investment in the sector has made it economically unsustainable. But, it is possible to change the scenario by implementing proper policies in a way that the social and environmental issues that happened in the past do not happen again and the sector can achieve sustainability.
73

A Study on the Technical and Economic Feasibility for Arable Agriculture and Biofuel Production on Landfill Covers in Southern Ontario

Battiston, Lee Anthony 14 February 2013 (has links)
There are over 3,700 active and decommissioned municipal solid waste (MSW) landfill sites located in Ontario (MOE, 1991). Under current legislation, these landfill sites must be rehabilitated to a defined end use when decommissioned. In Ontario, the primary prescribed end use of closed landfills is typically agriculture, and that end use can lead to food-consumer concerns, due to the perceived risk of potential contamination from legacy materials found in landfills. Converting these sites to produce biomass-energy crops instead of food crops could mitigate that concern and also help to avoid the current controversy with bioenergy-crop production on high-capability agricultural land. In this study, a 3.5-year field program with subsequent verification and analysis investigated and developed rehabilitation prescriptions using locally obtained topsoil and soil-forming materials (subsoil) to develop anthropogenic soil profiles on top of a sealed landfill cover (clay cap). These prescriptions provided crop productivity at least as good as, and generally better than, local agricultural soils. Mixed forages and biomass-specific crops (warm season grasses) were grown on these soils in replicated plot trials to evaluate the efficacy of a range of soil treatments. Following establishment of technical feasibility for site rehabilitation, economic modeling was conducted to determine the feasibility of using these anthropogenic soils for the production of forage crops, biofuel feedstock, and simple energy products at a scale consistent with typical landfill sites in Ontario. An economic model was developed to aid proponents in selecting appropriate rehabilitation methods and to assess potential bioenergy-crop outputs for their site. This study demonstrated that while it is technically feasible to rehabilitate these waste sites to produce agricultural crops and/or biofuel feedstock, the scale of typical landfill sites makes it very difficult to compete, from an economic perspective, with conventional energy sources. However, the diverted incoming materials, such as leaf and yard waste, compostable biosolids, and paper mill waste, can be used in the development of manufactured soil profiles for rehabilitation, significantly reducing rehabilitation costs and facilitating more cost-competitive production of agricultural and biomass feedstock crops. / Niagara Waste Systems Limited, a division of Walker Industries Holdings Limited, MITACS
74

NANOSCALE BIOCATALYSTS FOR BIOELECTROCHEMCIAL APPLICATIONS

Zhao, Xueyan January 2006 (has links)
No description available.
75

An industry analysis of the South African biofuels industry

Cilliers, Bronwyn Lee January 2012 (has links)
Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
76

An industry analysis of the South African biofuels industry

Cilliers, Bronwyn Lee January 2012 (has links)
Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
77

Biodrivmedelsproduktion i Sverige: Utvecklingen av svenska styrmedel och politiska mål / Biofuel production in Sweden: The development of Swedish policy instruments and political goals

Kjellvertz, Viktor January 2023 (has links)
I det här examensarbetet har utvecklingen av den svenska politiken kring biodrivmedel under perioden 1975–2020 undersökts. Detta i syfte att öka förståelsen för de politiska motiv som legat till grund vid utformningen av politiska styrmedel samt hur sambanden mellan styrmedel och biodrivmedelsproduktion utvecklats. I rapporten ingår granskningen av de propositioner och underlagsrapporter som varit grund till svenska styrmedel riktade mot biodrivmedel. Styrmedelsförslagen har beskrivits och vissa skillnader mellan underlagsrapporter och slutgiltigt förslag har diskuterats. De motiveringar och politiska mål som hänvisas till i styrmedelsförslagen har satts i en bredare kontext för att beskriva hur utvecklingen sett ut. Utvecklingen av biodrivmedelsmarknaden har samtidigt undersökts med hjälp av Energimyndighetens årliga rapporter samt årsredovisningar och offentliga uttalanden från de största biodrivmedelsproducenterna. Vad denna genomgång visat är att biodrivmedel använts som ett medel för att minska användningen av fossilbaserad bensin och diesel för att nå målen inom ett flertal olika politikområden. I början av tidsperioden var det främsta målet att öka den svenska energiförsörjningstryggheten, det målet kompletterades sedan med mål om att minska hälso- och miljöskadliga utsläpp. Att minska utsläppen av växthusgaser började sedan bli allt mer prioriterat och har under de senaste 20–30 åren varit det främsta målet. Vilka målsättningar som biodrivmedel kopplats till har skiftat under tidperioden och det har även funnits skillnader mellan olika styrmedel under samma tidsperiod. Forsknings- och utvecklingsstöd har varit fokuserade på att omvandla inhemska råvaror till biodrivmedel. Finansiella- och administrativa styrmedel har i stället främst varit utformade för att öka andelen biodrivmedel i den totala mängden drivmedel och inte för att öka den inhemska produktionen. Efter Sveriges inträde i EU har en stor del av den svenska biodrivmedelspolitiken varit utformad till att uppfylla de EU-direktiv som funnits. De styrmedel som existerat har haft en tydlig koppling till hur den svenska biodrivmedelsmarknaden utvecklats men sambandet är komplext och det har även funnits andra faktorer så som oljepriset som också haft en påverkan på utvecklingen. / In this thesis, the development of Swedish biofuel policy during the period 1975–2020 were investigated. The goal was to increase the understanding of the political motives behind the formulation of policy instruments and how the links between policy instruments and biofuel production have developed. A review of policy instruments targeting biofuels were conducted and presented in the report. The basis for the policy proposals has been summarized and some differences between the suggested policy and the final proposal have been discussed. The justifications and policy objectives referred to in the proposals have been put in a broader context to describe the development. The development of the biofuel market was investigated using the reports compiled annually by the Swedish Energy Agency, as well as previous compilations from several journals. What these reviews have shown is that biofuels have been used as a means of reducing the use of fossil-based petrol and diesel to achieve the targets in several different policy areas. At the beginning of the period, the main goal was to increase Swedish energy security, which was then supplemented by the goal of reducing harmful emissions. Reducing greenhouse gas emissions then became an increasing priority and has over the past 20–30 years been the main goal. The objectives to which biofuels have been linked have both changed during the period, and there have also been d¬ifferences between different policy instruments during the same period. Research and development support have been focused on converting domestic raw materials into biofuels, while financial and administrative instruments have mainly been designed to increase the share of biofuel use within the total use of transportation fuels and not to increase domestic production. Since Sweden's entry into the EU, a large part of the Swedish biofuels policy has been designed to comply with the EU directives that have existed. The policy instruments that have existed have had a clear connection to how the Swedish biofuels market has developed, but the relationship is complex and there have also been other factors that have affected the development, such as the oil price.
78

Sorghum improvement as biofuel feedstock: juice yield, sugar content and lignocellulosic biomass.

Godoy, Jayfred Gaham Villegas January 1900 (has links)
Master of Science / Department of Agronomy / Tesfaye Tesso / Sorghum [Sorghum bicolor (L.) Moench] is listed as one of the potential feedstock sources for biofuel production. While sorghum grain can be fermented into ethanol in a similar way as maize, the greatest potential of the crop is based on its massive biomass and sugar rich juices. Thus development of the crop as alternative energy source requires improvement of these traits. The objectives of this study were (1) to determine the mode of inheritance of traits related to ethanol production and identify suitable genetic sources for use in breeding programs, and (2) to evaluate the potential of low lignin mutations for biomass feedstock production and assess biotic stress risks associated with deployment of the mutations. The study consisted of three related experiments: (i) estimating the combining ability of selected sweet and high biomass sorghum genotypes for biofuel traits and resistance to stalk lodging, (ii) determine the impact of brown mid-rib mutations on biofuel production and their reaction to infection by Macrophomina phaseolina and Fusarium thapsinum, and (iii) assess the reaction of low lignin mutants to green bug feeding. In the first experiment six sorghum genotypes of variable characteristics (PI193073, PI257602, PI185672, PI195754, SC382 and SC373) were crossed to three standard seed parent lines ATx3042, ATx623 and ATx399. The resulting hybrids and the parents were evaluated at four locations, three replications during 2009 and 2010 seasons. Data were collected on phenology, plant height, juice yield, °brix score and biomass production. In the second experiment, two brown mid-rib mutations (bmr6 and bmr12) and their normal versions were studied in four forage sorghum backgrounds (Atlas, Early Hegari, Kansas Collier and Rox Orange). The experiment was planted in four replications and at 14 d after flowering five plants in a plot were artificially infected with F. thapsinum and another five with M. phaseolina. The plants were harvested and rated for disease severity (lesion length and nodes crossed). Another five normal plants in each plot were harvested and used to determine biofuel traits (juice yield, ºbrix score and biomass). In the third experiment, a subset of entries evaluated in experiment II and three tolerant and susceptible checks were tested for greenbug feeding damage. Biotype K greenbug colony was inoculated to each genotype using double sticky foam cages. Feeding damage was assessed as percent chlorophyll loss using SPAD meter. There was significant general combining ability (GCA) effect among the male entries for juice yield, stem obrix and biomass production indicating that these traits are controlled by additive genes. Lines PI257602 and PI185672 in particular, had the highest GCA for all the traits and should serve as excellent breeding materials. There was no significant difference among the bmr mutants and between the bmr and normal genotypes for both stalk rot and greenbug damage. In conclusion, juice yield, °brix and biomass are largely controlled by additive genes and hence are amenable to genetic manipulation. The bmr mutations despite their impact on lignin content do not increase risk of attack by stalk rot pathogens and greenbugs and thus can be deployed for biofuel production without incurring losses to these factors.
79

Ultrasonic vibration - assisted pelleting and dilute acid pretreatment of cellulosic biomass for biofuel manufacturing

Song, Xiaoxu January 1900 (has links)
Doctor of Philosophy / Department of Industrial & Manufacturing Systems Engineering / Zhijian Pei / Donghai Wang / In the U.S. and many other countries, the transportation sector is almost entirely dependent on petroleum-based fuels. In 2011, half of the petroleum used in the U.S. was imported. The dependence on foreign petroleum is a real threat to national energy security. Furthermore, the transportation sector is responsible for about 30% of U.S. greenhouse gas emissions and is growing faster than any other major economic sector. National energy security, economy, environment sustainability are all driving the U.S. to develop alternative liquid transportation fuels that are domestically produced and environmentally friendly. Promoting biofuel is one of the efforts to reduce the use of petroleum-based fuels in the transportation sector. Cellulosic biomass are abundant and diverse. Thus, the ability to produce biofuel from cellulosic biomass will be a key to making ethanol competitive with petroleum-based fuels. Ultrasonic vibration- assisted (UV-A) pelleting can increase not only the density of cellulosic biomass but also the sugar yield. This PhD dissertation consists of fourteen chapters. Firstly, an introduction of the research is given in Chapter 1. Chapters 2, 3, 4, and 5 present experimental investigations on effects of input variables in UV-A pelleting on pellet quality. Chapter 6 investigates effects of input variables on energy consumption in UV-A pelleting. Chapter 7 develops a predictive model for energy consumption in UV-A pelleting using the response surface method. Chapter 8 investigates effects of input variables on energy consumption, water usage, sugar yield, and pretreatment energy efficiency in dilute acid pretreatment. Chapter 9 develops a predictive model for energy consumption in dilute acid pretreatment using the response surface method. Chapter 10 studies ultrasonic vibration-assisted (UV-A) dilute acid pretreatment of poplar wood for biofuel manufacturing. Chapter 11 compares sugar yields in terms of total sugar yield and enzymatic hydrolysis sugar yield between two kinds of materials: pellets processed by UV-A pelleting and biomass not processed by UV-A pelleting in terms of total sugar yield and enzymatic hydrolysis sugar yield. Chapter 12 develops a physics-based temperature model to predict temperature in UV-A pelleting. Chapter 13 develops a physics-based density model to predict pellet density in UV-A pelleting. Finally, conclusions and contributions of this research are summarized in Chapter 14.
80

Management of biofuel sorghums in Kansas

Dooley, Scott J. January 1900 (has links)
Master of Science / Department of Agronomy / Scott A. Staggenborg / Current demand for ethanol production is stressing feedstock production. Previous research has shown sweet sorghum and photoperiod sensitive sorghum [Sorghum bicolor (L.) Moench] as viable feedstocks which may supplement or replace current feedstocks. Studies were conducted at two dryland locations in north central and northeast Kansas in 2008 and 2009 to determine the effects of cultivar, nitrogen fertilizer rate, plant density, and harvest date on sweet sorghum juice and biomass yields. The cultivar study indicated the cultivar ‘M81E’ generally had the greatest yield. Other cultivars were not well suited for this region. No significant results were found in the nitrogen rate trial, indicating sweet sorghum may be insensitive to nitrogen fertilizer applications. The plant density trial results indicated that sweet sorghum possess a great ability to compensate for plant spacing. No differences were found in juice yields across densities, and the only difference found in total dry biomass was at the highest plant density. Results from the harvest date study indicate that sweet sorghum harvest should be delayed until at least the grain soft dough stage and can be continued for at least 10 days after a killing freeze without a yield penalty. Delaying harvest allowed for an increase in total dry matter and fermentable carbohydrates without a decrease in juice yield. Two studies were conducted at two dryland locations in northcentral and northeast Kansas in 2008 and 2009 to determine the effects of plant density on photoperiod sensitive sorghum yields, with an additional study to determine the effects of winter weathering. Photoperiod sensitive sorghum was found to be similarly insensitive to plant density, with few differences found in total dry biomass yield. Yields were found to decrease significantly due to winter weathering. A final study was conducted to examine a variety of sorghums as biofuel feedstocks. Photoperiod sensitive sorghum yielded the greatest in 2008 while sweet sorghum yielded less. In 2009, sweet and photoperiod sensitive sorghum yielded less than the cultivar TAMUXH08001. Sweet sorghum yields are generally the greatest with ‘M81E’ and when harvested after soft dough. Yields of both sorghums are occasionally influenced by plant density.

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