Dissertations / Theses on the topic 'Waste of alumina production'
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Beheshti, Reza. "Sustainable Aluminum and Iron Production." Doctoral thesis, KTH, Kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-196547.
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Aluminium recycling requires 95% less energy than primary production with no loss of quality. The Black Dross (BD) produced during secondary aluminium production contains high amounts of water-soluble compounds, therefore it is considered as a toxic waste. In the present work, salt removal from BD by thermal treatment has been investigated in laboratory scale. The optimum conditions for treatment were established, i.e., temperature, gas flow rate, holding time, rotation rate, and sample size. The overall degree of chloride removal was established to increase as a function of time and temperature. Even Pretreated Black Dross (PBD) was evaluated as a possible raw material for the production of a calcium aluminate-based ladle-fluxing agent to be used in the steel industry. The effects of different process parameters on the properties of the produced flux were experimentally investigated, i.e. CaO/Al2O3 ratio, temperature, holding time, and cooling media. The utilization of PBD as the alumina source during the production of a calcium aluminate fluxing agent shows promising results. The iron/steel industry is responsible for 9% of anthropogenic energy and process CO2 emissions. It is believed that the only way to a long-term reduction of the CO2 emissions from the iron/steel industry is commercialization of alternative processes such as Direct Reduction (DR) of iron oxide. Detailed knowledge of the kinetics of the reduction reactions is, however, a prerequisite for the design and optimization of the DR process. To obtain a better understanding of the reduction kinetics, a model was developed step-by-step, from a single pellet to a fixed bed with many pellets. The equations were solved using the commercial software COMSOL Multiphysics®. The final model considers the reaction rate and mass transfer inside the pellet, as well as the mass transfers and heat transfer in the fixed bed. All the models were verified against experimental results, and where found to describe the results in a satisfying way.QC 20161128
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Fridrich, Jakub. "Cihelný recyklát jako surovina pro výrobu pálících pomůcek pro cihlářský průmysl." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401935.
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The focus of this thesis is the study of behavior of brick waste in the mixture with high alumina cement. The result of this research should be a draft of a composition and production process for material that could partly or fully substitute forging accessories in the brick production industry. The aim of this work is to verify the use of brick waste for such purpose. Usage of brick waste for refractories can help the current long-term effort for wasteless production processes.
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Носік, Вікторія Вікторівна. "Модифікований вуглецевмісний сорбент для глибокого вилучення органічних сполук." Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23010.
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Наявність органічних сполук в стічних водах, що надходять у водойми, повинна бути знижена до надзвичайно малих концентрацій для попередження негативних екологічних наслідків. Глибоке очищення води від органічних речовин може бути здійснено шляхом застосування адсорбційної технології.
На сьогоднішній день дослідження можливостей синтезу сорбентів з відходів глиноземних виробництв для очищення стічних вод набувають все більшої популярності.
Метою магістерської роботи є модифікування поверхні активованого вугілля та використання його в технології глибокого очищення стічних вод фармацевтичного виробництва.
Основними завданнями магістерської дисертації є:
вибір методу модифікування та встановлення основних параметрів процесу модифікування;
виявлення типу модифікатору;
встановлення морфології та складу отриманого зразку модифікованого вугілля;
дослідження структурно-сорбційних характеристик поверхні модифікованого активованого вугілля;
виявлення основних параметрів (тривалість процесу, температурний режим, концентрація модифікатору) сорбційного процесу;
дослідження ефективості застосування отриманих зразків модифікованого вугілля для очищення води від левамізолу, норсульфазолу та стрептоциду;
створення технологічної схеми глибокого очищення води від левамізолу, норсульфазолута стрептоциду.
Об’єкт дослідження – процес модифікації вуглецевмісного сорбенту, дослідження закономірностей його застосування для глибокого вилучення органічних сполук.
Предмет дослідження – активоване вугілля, «червоний шлам» Миколаївського глиноземного заводу, модельні розчини фармацевтичних стічних вод (левамізолу, норсульфазолу та стрептоциду).
Синтезовано сорбент з використанням відходів глиноземного виробництв та перевірено його ефективністі в порівнянні з торговою маркою активованого вугілля. Встановлено, що ефективнішим є модифіковане активоване вугілля. Модифікування поверхні АВ призводить до збільшення сорбційної ємності сорбенту.
Результати досліджень відображено у матеріалах міжнародних конференцій.To prevent negative environmental effects the presence of synthetic organic compounds in sewage that enters into ponds should be reduced to extremely low concentrations. Deep water purification from toxic organic substances can be done by applying adsorption technology. Today research opportunities synthesis of sorbents from waste alumina production for wastewater treatment are becoming more popular. The purpose of the master's work is to modify the surface of activated carbon and use it in the technology of deep sewage treatment of pharmaceutical production. The main tasks of the master's thesis are: the choice of the modification method and the establishment of the main parameters of the modification process; detection of modifier type; establishment of morphology and composition of the obtained sample of modified coal; research of structural–sorption characteristics of the surface of modified activated carbon; establishment of the basic parameters (duration of the process, temperature mode, concentration of the modifier) of the sorption process; checking the effectiveness of the application of the obtained samples of modified coal for water purification from levamisole, norsulfazolum and streptocide; creation of a technological scheme of deep water purification from levamisole, norsulfazolum, streptocide. The object of the study – the process of modification of carbon-containing sorbent, the study of the laws of its application for the deep removal of organic compounds. The subject of research - activated carbon, "red mud" of Mykolayiv Alumina Factory, model solutions of pharmaceutical wastewater (levamisole, norsulfazole and streptocide) The sorbent was synthesized using waste from alumina production and its efficiency compared to the trademark of activated carbon was checked. Found that the modified activated carbon is more efficient. Modification of the AC surface leads to an increase sorbent capacity of the sorbent. The results of the research were made public at international conferences.
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KerherveÌ, Gwilherm. "Production and properties of metal clusters on alumina." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288300.
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Lucas, Carlos Krus Galvão. "Biogas production from potato peel waste." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/12337.
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Uncu, Oya Nihan. "Optimization Of Bioethanol Production From Kitchen Waste." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611373/index.pdf.
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Kitchen waste, which is collected in large amounts from cafeterias, restaurants, dining halls, food processing plants, and household kitchens, have become a valuable material for bioprocess engineering. Due to the high carbohydrate fraction, kitchen waste has great potential to be used as a potential substrate for ethanol production. Utilization of it as a raw material in ethanol fermentation would also contribute to reduction of costs. In the first part of this study, the effect of pretreatment method and enzymatic hydrolysis on glucose production was evaluated. Dry baker&rsquos yeast, Saccharomyces cerevisiae, was used in fermentation experiments conducted with and without fermentation medium at pH 4.5 and 30oC for 48 hours. Close values of glucose concentration were obtained from no pretreated and hot water treated samples. The fermentation results indicated that ethanol can be produced at similar concentrations in bioreactors with and without fermentation medium addition (p >
0.05). Thus, it is concluded that use of kitchen wastes as is disposed and without fermentation medium in ethanol fermentation could lower the cost to a large extent. In the second part of this study, the effects of solid load, which is proportional to the glucose concentration (10% to 20% (w/w)), inoculum level of Saccharomyces cerevisiae (5% to 15% (v/v)), and fermentation time (48 to 96 h) on production of bioethanol from kitchen waste were studied using Response Surface Methodology (RSM). A three-factor Box Behnken design was used. Ethanol concentration was used as a response in the resulting experimental design. High Pressure Liquid Chromatography (HPLC) method was used to determine ethanol and glucose concentrations. The statistical analysis of the constructed model developed by RSM suggested that linear effects of solid load, inoculum level, and fermentation time and quadratic effects of inoculum level and fermentation time were all significant (p <
0.05) on bioethanol production. The model was verified by additional runs, which were not present in the design matrix. It was found that the constructed model could be used to determine successfully the bioethanol concentration with >
90% precision. An optimum ethanol concentration of 32.16 g/L was suggested by the model with 20% (w/w) solid load, 8.85% (v/v) inoculum level and 58.8 hours of fermentation. Further study is needed to evaluate the optimal fermentation conditions in a large scale fermentation
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Rajendran, Karthik, and Gopinath Balasubramanian. "High rate biogas production from waste textiles." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20787.
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Textile is a global product used by all people in the world. These textiles after the use are thrown into the trash for incineration or land filling. However an efficient way that can be used to produce more energy, in an environmentally friendly process is anaerobic digestion. Waste textiles which contain cellulosic fibers (e.g. Cotton and viscose) can be converted to biogas. In this study, the performance of a two-stage anaerobic digestion process for biogas production from four different materials, including untreated jeans, treated jeans, cotton, and starch was studied. Starch was used as an easy-to-digest material to compare its digestion with that of cellulosic materials.The two-stage processes were composed of a CSTR (for hydrolysis) and a UASB (for methanogenisis) which were investigated in two different configurations, namely (closed and open systems). In the closed system, the outlet of UASB was completely returned back to the CSTR, while in the open system the UASB outlet was sent to sewage. In a stepwise progress, the OLR was aimed to increase from 2 to 20 g Vs per L per day along with reduction in hydraulic retention time from 10 days to 1 day.The results showed that the closed system was more stable when compared to the open system. The pre-treatment of jeans by NMMO helped to produce methane as that of cotton. The hydraulic retention time was decreased to less than 9 days for treated jeans and less than 5 days for starch. The overall methane yield at OLR of 4 gVS per L per day for starch and treated jeans was 98.5% and 97.4% in the closed system, whereas in the open system the yield was 77.0% and 35.5%, respectively.Another experiment was conducted to compare the performance of two-stage process with that of a single stage process of anaerobic digestion of textiles containing polyester and cotton or viscose. Viscose textiles produced more gas compared to the cotton textile; it may be due to the higher crystalline of cotton which makes it hard to be degraded by the microorganisms. Furthermore, two-stage process could able to produce more methane than the single stage process.The parameters like total solids, volatile solids, pH, gas production, gas composition, concentration of nutrients, and COD were also analyzed for both of the experiments.
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Chhiba, Chetan. "Titanium alloy powder production from waste metal." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/11989.
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Includes abstract.Includes bibliographical references.
Titanium and its alloys are among the most important advanced materials in use today due to attractive properties such as high strength to weight ratio and excellent corrosion resistance. However, the cost of titanium production is high, mostly due to the high cost of extraction. This has led to investigations of potentially lower cost methods such as near-net shape powder metallurgy techniques. One approach, which has the potential of producing the lowest cost powder available, involves converting titanium waste machine turnings to powder using the hydride-dehydride (HDH) process. The focus of this project is directed at this approach where a ball milling process is used to simultaneously hydrogenate and crush the titanium turnings into titanium hydride powder.
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Бурлакова, Ірина Михайлівна, Ирина Михайловна Бурлакова, Iryna Mykhailivna Burlakova, Тетяна Миколаївна Руденко, Татьяна Николаевна Руденко, and Tetiana Mykolaivna Rudenko. "Systemic approach to the waste-free production." Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/31064.
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The issue of the environment has become central, which is where it belongs, in the vicissitudes of human life. It certainly was not discovered yesterday, but the pressure of humans on natural resources in the last half-century has become more intensive and widespread than ever.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31064
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Winzer, Jami Susan [Verfasser]. "Production and Characterisation of Alumina-Copper Interpenetrating Composites / Jami Susan Winzer." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2011. http://d-nb.info/1106453069/34.
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Sawyer, John E. "The oxidation of volatile organic compounds on a platinum-alumina catalyst /." Access abstract and link to full text, 1995. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9529031.
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Junges, Rodrigo Santos. "Automação de reator de hidrogênio para alimentação de motogerador em geração distribuida /." Ilha Solteira, 2019. http://hdl.handle.net/11449/183430.
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Isha, Ruzinah. "Hydrogen production from the gasification of agricultural waste." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545695.
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Shi, Chen. "Potential Biogas Production from Fish Waste and Sludge." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171807.
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In order to decrease the pollution of the marine environment from dumping fish waste and by-catch, alternative use for co-digestion with sludge in anaerobic condition was studied. The purpose of this project is to optimize the methane potential from adjustment of the proportion among mixed substrates. Ten groups of different proportions among fish waste, by-catch and sludge were conducted with AMPTS II instrument under mesophilic condition (37 ± 0.5 ºC), by means of the principle of BMP test. The ratio of inoculums and mixed substrate was set as 3:2. The optimal MP obtained after an experiment with 13 days digestion was 0.533 Nm3 CH4/kg VS from the composition of sludge, by-catch and fish waste as 33 %, 45 % and 22 %. It was improved by 6 % and 25.6 %, to compare with the previous studies by Almkvist (2012) and Tomczak-Wandzel (personal communication, February 2012) respectively.
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Stamouli, Konstantina. "Fuel production and optimisation from mixed plastic waste." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8268/.
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Increasing plastic consumption has created an alerting problem with waste disposal of the mixed waste plastics once the recyclable fractions have been recovered. The percentage sent to landfill of the generated mixed plastic waste amounts to one third of the total. Liquid fuel recovery from mixed plastic waste is possible using pyrolysis as a tertiary recycling process. The focus of this study was to obtain useful liquid product recovered from the pyrolysis of a variety of commercial mixed plastic waste utilising a pilot scale fluidised bed reactor of 1kg/hr processing capacity. The influence of residence time (1.78 to 2.74s), feedstock variation and reaction temperature (500 – 550oC) were investigated to optimise the quality of the wax products. Characterisation of the mixed plastic feedstocks through TGA, DSC and FTIR analysis was carried out to lay the foundation of the pyrolysis conditions. Understanding the fuel quality and product distribution was essential in assessing the key properties such as melting point and viscosity in the optimisation process. Key findings of the research concluded that increasing residence time has the strongest effect on reducing the melting point (up to 14oC) of the liquid product across all studied feedstocks although the magnitude of the effect greatly depends upon the initial feedstock composition. Changes is the average melting point correspond to a shift in the average carbon number distribution of the product. Feedstock and process parameters variability were also found to greatly affect the final product quality resulting in a versatile product composition as well as the product yields that varied between 27 and 60% w.t.
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Rodriguez, Christina. "Enhanced methane production from mixed waste organic materials." Thesis, University of the West of Scotland, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.736952.
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Campos, Joana Coutinho. "SCFA production through acidogenic fermentation of industrial waste." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12486.
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Mestrado em Biotecnologia - Biotecnologia Industrial e AmbientalPolyhydroxyalkanoates (PHA) production from industrial wastes and open mixed cultures (OMC) is a way to reduce process costs. OMC produce PHA from short-chain fatty acids (SCFA), which composition determines the final composition of the polymer and consequently its characteristics. So it is important to understand which operational conditions influence SCFA production during acidogenic fermentation of industrial wastes such as hardwood sulphite spent liquor (HSSL) and cheese whey. This work began with the evaluation of the acidogenic fermentation capacity of HSSL in a continuously stirred tank reactor (CSTR), with emphasis on the influence of the organic loading rate (OLR) and temperature on the process. In the end of the fermentation it was possible to produce a stream with acetic, lactic, propionic and butyric acids and ethanol. The profile of SCFA changed with the OLR, with hydraulic retention time (HRT) and with the age of the culture. A PHA accumulation test was performed with the effluent of the end of the fermentation. With this batch experiment was possible to achieve 32% PHA on dry cell weight, with a 75:25 proportion on 3-hydroxybutyrate and 3-hydroxyvalerate, respectively. In the second part of this work, the acidogenic fermentation of cheese whey in a moving-bed biofilm reactor (MBBR) was studied in order to explore the process in a reactor for biomass retention. The influence of the available surface area, associated with biomass concentration, was studied. The carriers with the largest surface area allowed more biomass growth and consequently more SCFA production. However, an increase in the number of carriers in the reactor does not translate into higher yields possibly due to various limitations of the system. A model based on Michaelis-Menten equation was conceived to evaluate other MBBR designs for fermentation of cheese whey. These results demonstrate the potential of reactors for biomass retention for the acidogenesis of industrial residues.
A produção de polihidroxialcanoatos (PHA) a partir de resíduos industriais e a utilização de culturas mistas microbianas (OMC) constitui-se como hipóteses para diminuir os custos de produção desta classe de bioplásticos. As OMC produzem PHA a partir de ácidos orgânicos voláteis (AOV) cuja composição permite manipular a composição final do polímero e consequentemente as suas características. Neste sentido, é importante compreender quais as condições operacionais que influenciam a produção de AOV por fermentação acidogénica a partir de subprodutos industriais como o licor de cozimento ao sulfito ácido (HSSL) e o permeado do soro de leite. Este trabalho iniciou-se com os testes à capacidade fermentativa do HSSL num reactor contínuo perfeitamente agitado, com ênfase no estudo da influência da carga orgânica (OLR) e da temperatura no processo. No fim da fermentação foi possível produzir um efluente contendo os ácidos acético, láctico, propiónico e butírico e etanol. O perfil dos AOV mudou com a OLR, o tempo de retenção hidráulico (HRT) e com a idade da cultura. O efluente final a fermentação foi utilizado num teste de acumulação de PHA. Com este teste em reactor descontínuo foi possível obter 32% de PHA em peso seco, com uma proporção de 75:25 em 3-hidroxibutirato e 3-hidroxivalerato, respectivamente. Na segunda parte deste trabalho estudou-se a fermentação acidogénica de permeado de queijo num reactor de biofilme, de maneira a explorar a potencialidade do processo num reactor para retenção de biomassa. Estudouse a influência da área superficial, associada à concentração de biomassa. Concluiu-se que os carriers com maior área superficial permitiram maior crescimento de biomassa, e consequentemente a maior produção de AOV. No entanto, maior número de carriers não permitiu um maior rendimento possivelmente devido a limitações do sistema. Foi concebido um modelo baseado na equação de Michaelis-Menten para avaliar outros desenhos de MBBR para fermentação de permeado de queijo. Assim, os resultados obtidos demonstram a potencialidade dos sistemas para retenção de biomassa para a acidogénese de resíduos industriais.
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Papp, Carolle. "Controlling food waste – Home composting or biofuel production?" Thesis, Malmö högskola, Fakulteten för kultur och samhälle (KS), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-22698.
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Ettsyfte med denna uppsats är jämförelsen mellan två behandlingsalternativ för matavfall, hemkompostering eller biogasproducering sett från klimatperspektivet. Koldioxidekvivalenter har beräknats för de två alternativen. Ett annat syfte har varit att studera den politiska processen för att förstå varför det först under 90-talet uppmuntras till att hushållen ska hemkompostera för att sen under början av 2000-talet förespråka rötning av matavfallet. Mina uträkningar och jämförelser visar att det är mer fördelaktigt för klimatet att röta matavfallet, koldioxidutsläppet blir mindre än vid hemkompostering. Mitt andra syfte visar att det kan finnas en klimatvinst genom att låta politiken fatta besluten men det kan även finnas en risk att det egentliga syftet med hemkompostering glöms bort och att hushållen måste betala för något som de egentligen inte behöver (matkärl) eller som inte kanske finns (tillsynen).One purpose of this study is to compare two treatment options for food waste. Home composting or biofuel production, seen from the climate perspective. The carbon dioxide equivalent has been calculated for the two options. The second purpose was to study the political process with regard to food waste to understand why Swedish households were encouraged to home compost food waste during the nineties only to early twenties advocate biofuel production. My calculations and comparisons shows that it is more beneficial for the climate to digest the food waste then composting since the carbon dioxide emissions is less. My second analysis indicates that while the political reorientation has led to environmental improvements, the effect has also been that to gain control of the food waste stream, waste management organisations effectively provide customers with no choice and economically punish households that have no food waste to collect since they have effective home composting.
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Lin, Zhongye. "Microalgal Growth and Lipid Production from Organic Waste." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1385429109.
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Voigt, Paul George. "Bioethanol production from waste paper through fungal biotechnology." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1013447.
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Bioethanol is likely to be a large contributor to the fuel sector of industry in the near future. Current research trends are geared towards utilizing food crops as substrate for bioethanol fermentation; however, this is the source of much controversy. Utilizing food crops for fuel purposes is anticipated to cause massive food shortages worldwide. Cellulose is the most abundant renewable resource on earth and is subject to a wide array of scientific study in order to utilize the glucose contained within it. Waste paper has a high degree of cellulose associated with it, which makes it an ideal target for cellulose biotechnology with the ultimate end goal of bioethanol production. This study focussed on producing the necessary enzymes to hydrolyse the cellulose found in waste paper and using the sugars produced to produce ethanol. The effects of various printing inks had on the production of sugars and the total envirorunental impact of the effluents produced during the production line were also examined. It was found that the fungus Trichoderma longibrachiatum DSM 769 grown in Mandel's medium with waste newspaper as the sole carbon source at 28 °C for 6 days produced extracellular cellulase enzymes with an activity of 0.203 ± 0.009 FPU.ml⁻¹, significantly higher activity as compared to other paper sources. This extracellular cellulase was used to hydrolyse waste newspaper and office paper, with office paper yielding the highest degree of sugar production with an end concentration of 5.80 ± 0.19 g/1 at 40 °C. Analysis by HPLC showed that although glucose was the major product at 4.35 ± 0.12 g/1, cellobiose was also produced in appreciable amounts (1.97 ± 0.71 g/1). The sugar solution was used as a substrate for Saccharomyces cerevisiae DSM 1333 and ethanol was produced at a level of 1.79 ± 0.26 g/1, the presence of which was confirmed by a 600 MHz NMR spectrum. It was found that cellobiose was not fermented by this strain of S. cerevisiae. Certain components of inks (the PAHs phenanthrene and naphthalene) were found to have a slight inhibitory effect (approximately 15% decrease) on the cellulase enzymes at very high concentrations (approximately 600 μg/1 in aqueous medium), while anthracene had no effect. Whole newsprint ink was shown not to sorb glucose. The environmental analysis of the effluents produced showed that in order for the effluents to be discharged into an aqueous ecosystem they would have to be diluted up to 200 times. They were also shown to have the potential to cause severe machinery damage if reused without proper treatment.
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Eriksson, L. Gunnar. "Combustion of solid waste from wood-based ethanol production /." Luleå, 2005. http://epubl.luth.se/1402-1757/2005/22.
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ARAUJO, VICTOR KRAEMER WERMELINGER S. "COST EVALUATION FOR BIODIESEL PRODUCTION FROM WASTE COOKING OIL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11873@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFUNDAÇÃO DE APOIO A PESQUISA DA BAHIA
A busca pelo desenvolvimento sustentável tem como importante fator diferencial as fontes de energia renováveis. O biodiesel desponta como uma das alternativas mais relevantes, mas suas formas de obtenção no Rio de Janeiro não foram suficientemente investigadas. Este trabalho identifica a oportunidade da produção de biodiesel a partir de óleos residuais de fritura neste cenário, enfatizando os custos de transporte do óleo desde os principais produtores comerciais até a obtenção do biocombustível. O objetivo é avaliar os custos de forma a verificar a viabilidade do emprego desta alternativa. Para tanto, foram estudadas as diversas ferramentas de resolução do Problema de Roteamento de Veículos e foi proposto um algoritmo que visa à otimização dos custos. A formulação matemática utilizada baseia-se numa extensão de algoritmos clássicos, como o apresentado por Arenales et al. (2007), e nas equações desenvolvidas em Kallehauge (2006). Os resultados do modelo de roteamento, atrelados aos custos de produção, impostos e insumos, foram comparados com informações sobre a comercialização do biodiesel, comprovando sua viabilidade econômica. A consolidação dos dados obtidos aponta a produção de biodiesel a partir de óleo residual de fritura como viável, com custos logísticos equivalentes a R/tmp/aaaUFg8ya,19 por litro e custo final de R,22 por litro.
The search for a sustainable development has in renewable energy sources an important differential factor. Biodiesel is one of the most important alternatives, but its obtainment forms in Rio de Janeiro have not been investigated enough. This work identifies the opportunity of biodiesel production from waste cooking oil in this scenery, emphasizing oil`s transport costs until factories, where it is possible to obtain biodiesel in its final form. The objective is to evaluate costs in order to verify viability of this alternative source of energy. Hence, this research analysed several tools for solving Vehicle Routing Problem and it proposes an algorithm that results in cost optimization. The adapted mathematic formulation is based in an extension of classic algorithms, like those presented by Arenales (2007), and in equations developed by Kallehauge (2006). The routing model results, linked to production, tributes and input costs, have been compared with information about biodiesel commercialization, verifying its economic viability. The data consolidation obtained indicates that the biodiesel production from waste cooking oil is viable, with logistic costs equal to R/tmp/aaaPLIh7a,19 per liter and final cost equal to R,22 per liter.
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Aslanzadeh, Solmaz. "Pretreatment of cellulosic waste and high rate biogas production." Doctoral thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-3684.
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The application of anaerobic digestion technology is growing worldwide, mainly because of its environmental benefits. Nevertheless, anaerobic degradation is a rather slow and sensitive process. One of the reasons is the recalcitrance nature of certain fractions of the substrate (e.g., lignocelluloses) used for microbial degradation; thus, the hydrolysis becomes the rate-limiting step. The other reason is that the degradation of organic matter is based on a highly dynamic, multi-step process of physicochemical and biochemical reactions. The reactions take place in a sequential and parallel way under symbiotic interrelation of a variety of anaerobic microorganisms, which all together make the process sensitive. The first stage of the decomposition of the organic matter is performed by fast growing (hydrolytic and acid forming) microorganisms, while in the second stage the organic acids produced are metabolized by the slow growing methanogens, which are more sensitive than the acidogens; thus, methanogenesis becomes the rate-limiting step. The first part of this work evaluates the effects of a pretreatment using an organic solvent, N-methylmorpholine-N-oxide (NMMO), on cellulose-based materials in order to overcome the challenge of biomass recalcitrance and to increase the rate of the hydrolysis. NMMO-pretreatment of straw separated from the cattle and horse manure resulted in increased methane yields, by 53% and 51%, respectively, in batch digestion tests. The same kind of pretreatment of the forest residues led to an increase by 141% in the methane production during the following batch digestion assays. The second part of this work evaluates the efficacy of a two-stage process to overcome the second challenge with methanogenesis as the rate-limiting step, by using CSTR (continuous stirred tank reactors) and UASB (up flow anaerobic sludge blanket) on a wide variety of different waste fractions in order to decrease the time needed for the digestion process. In the two-stage semi-continuous process, the NMMO-pretreatment of jeans increased the biogas yield due to a more efficient hydrolysis compared to that of the untreated jeans. The results indicated that a higher organic loading rate (OLR) and a lower retention time could be achieved if the material was easily degradable. Comparing the two-stage and the single-stage process, treating the municipal solid waste (MSW) and waste from several food processing industries (FPW), showed that the OLR could be increased from 2 gVS/l/d to 10 gVS/l /d, and at the same time the HRT could be decreased from 10 to 3 days, which is a significant improvement that could be beneficial from an industrial point of view. The conventional single stage, on the other hand, could only handle an OLR of 3 gVS/l/d and HRT of 7 days.
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Makanyire, Terence. "Reclamation of metal values from TiO2 production waste residues." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/17108/.
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A novel process for recovery of niobium, vanadium and scandium from TiO2 residues in three stages consisting of acid leaching, selective precipitation and oxidative alkali leaching has been developed using a batch leach test rig. While technologies for recovering these valuable metals from various minerals as co-products or by-products are commercially available, they are not currently used for recovering them in combination. An integrated process for reclamation of the metals could increase the total values recovered while reducing the objectives to their subsequent disposal. Three batches of TiO2 filter cake were obtained from Huntsman Pigments and Additives between 2012 and 2014, and were analysed using ICP-OES, TGA, XRD, SEM-EDX and XRF. The samples contained different amounts of unreacted ore and coke, together with hydrated oxides of a wide spectrum of metals such as vanadium, scandium, iron and niobium. Initially, Pourbaix diagrams were utilised for mapping out when the metals would precipitate or be in solution depending on their concentration, solution pH and electrochemical potential. The information was compared with established metal recovery processes to determine the recovery route. This study showed that the metals could be separated by selectively precipitating and filtering niobium from acidic media at pH ≈ 1 followed by controlled co-precipitation of vanadium and iron at pH ≈ 2 and scandium at pH ≈ 4. It was also determined that further concentration enhancement could be achieved by oxidative alkali leaching after the selective precipitation steps. Following establishment of the metal recovery route, experiments were carried out to sequentially study the effects of temperature, lixiviant concentration, reaction time, pH, stirring speed, solid-liquid ratio and oxidant concentration on dissolution and precipitation of the metals. The chloride process of TiO2 production is operated under reducing conditions therefore most hydroxides in the filter cake are in a reduced state. NaNO3 was used as an oxidant for improving metal recovery and selectivity during Na2CO3 leaching. Vanadium purification by salt roasting was investigated and the conventional NH4VO3 precipitation route was utilised for vanadium precipitation from pregnant solutions. Recoveries of over 80 % were achieved for vanadium and niobium, with grades of 99.5 % and 16 % respectively. Zirconium, titanium and thorium were the key impurities in the niobium-rich precipitates. Nearly all the scandium was recovered with a grade of at least 50 % in an alkali solution where rare earths were the main impurities. Adding NaNO3 to the alkali leaching systems significantly improved the extraction of vanadium and scandium, while niobium’s selective precipitation at pH 1 was catalysed by sulphate ions. The random pore model governs the dissolution processes, with all acid leaching kinetics being controlled by pore diffusion and alkali by surface reaction. The developed process opens up opportunities for recovery of other metals, particularly titanium, iron and REE and can be employed for recovery of the metals from filter cake already landfilled.
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Blomstrand, Erica, and Hagström Theresia Silander. "Waste management and production systems; The case of Zanzibar." Thesis, KTH, Industriell produktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173477.
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Denna studie utfördes som ett kandidatexamensarbete vid Kungliga Tekniska Högskolan i Stockholm, Sverige, under våren 2014. Projektet genomfördes som en fältstudie på Zanzibar,Tanzania, finansierad av SIDA och i samarbete med Zanrec. Ögruppen Zanzibar genererar över 92,000 ton avfall varje år vilket är jämförbart med vikten av en Boeing 747 per dag. Avfallet kontaminerar miljön och påverkar såväl folkhälsan som Zanzibars ekonomi negativt. Mängden producerat avfall på en ö är begränsat liksom möjligheten för avfallet att transporteras fritt över landgränser. Traditionella avfallshanteringsföretag saknar ekonomiska incitament för att etablera sig på små marknader likt denna och därmed saknar många öar i utvecklingsländer ett hållbart system föravfallshantering. Zanrec har identifierat detta som en affärsmöjlighet och har utvecklat en affärsmodell för att arbeta med avfallshantering i geografiskt begränsade landområden. Det främsta målet med denna studie var att undersöka hur Zanrec kan möta kundkrav genom en hållbar supply chain samt undersöka hur Zanrec kan öka värdet i specifika avfallsfraktioner för att kunna skala upp verksamheten. För att uppnå ett tillfredsställande resultat grundades studien i att: (i) ge en inblick i avfallshantering i utvecklingsländer, (ii) kartlägga Zanrecs nuvarande supply chain, (iii) definiera vad som är värdeskapande aktiviteter enligt såväl hotell- som slutkunder, (iv) identifiera Zanrecs möjligheter och begränsningar baserat på nuvarande förutsättningar. Slutresultaten av denna studie kommer att ligga till grund för effektivisering av Zanrecs berörda affärsområden och kan användas som riktlinjer i framtagandet av policys gällandes avfallshanteringssystem i andra utvecklingsländer.This study was performed as a bachelor thesis at the Royal Institute of Technology in Stockholm, Sweden, in the spring of 2014, and was carried out as a Minor Field Study funded by SIDA. It was conducted as a literature study complemented by a field study on Zanzibar, in collaboration with Zanrec. Zanzibar as an archipelago, with its 495 000 inhabitants, generates over 92,000 metric tons of waste a year, which is equivalent of the weight of a Boeing 747 per day, contaminating the environment and causing implications to both public health and the island’s economy due to it’s effects on the important tourism industry. The amount of produced waste on an island is limited as well as the possibility for waste to be spread over island boundaries. Traditional waste management companies lack economical incentives to establish on such a small market, therefore many islands in developing countries lack a sustainable system for waste management. Zanrec has identified this as a business opportunity and has developed a business model to deal with waste management on limited geographical areas. The main objective of this study was to investigate how Zanrec can meet customer demands by developing a sustainable supply chain, and to investigate how Zanrec can increase value of specific goods in order to scale the business. In order to achieve a satisfying result, the study was aimed to: (i) give insights into waste management in developing countries, (ii) map Zanrec’s supply chain of today, (iii) define what the value-adding activities are in the eyes of the customers, both hotels and plastic buyers, (iv) identify limitations/possibilities based on Zanrec’s prerequisites. The results of this thesis will work as a foundation to make Zanrec’s business areas of concern more efficient and will work as a benchmark in policy making when working with waste management systems in other developing areas.
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Md, Saad Juniza. "Dry reforming of waste plastics for synthesis gas production." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15698/.
Full textAbstract:
Thermal processing is an effective technique for recycling waste plastics in a sustainable way. The pyrolysis of waste plastics, followed by reforming reactions of the pyrolysis products generates syngas (hydrogen and carbon monoxide) that has a vast array of applications. To date, the steam reforming process has been the most researched technology for syngas production from waste plastics. However, this process produces a large amount of carbon dioxide. Due to the concern related to global warming associated with the emissions of carbon dioxide into the atmosphere, the recycling of carbon dioxide through the pyrolysis-reforming of waste plastic, (dry reforming) is environmentally attractive. The dry reforming process was the focus of this research. A preliminary thermogravimetric and kinetic analysis was conducted in order to have a general understanding on the effect of CO2 in a waste plastics pyrolysis. The results show that most plastics required lower activation energy with the presence of CO2 in the pyrolysis atmosphere (N2:CO2 ratio of 7:3). A two-stage pyrolysis-catalytic dry reforming reactor was used to investigate various process conditions and types of catalyst to maximise syngas production. The two-stage fixed bed reaction systems increased the H2 in both a N2 or CO2 atmosphere. Ni/Al2O3 based catalysts with different metal promoters (Mg, Cu and Co) were selected for the investigation of pyrolysis-dry reforming of waste plastics. Among the catalysts tested, the Ni-Co/Al2O3 catalyst presented the highest catalyst activity resulting in a syngas production of 149.42 mmolsygas g-1plastic with 58% carbon dioxide conversion, also no detectable carbon formation on the catalyst surface was observed. The dry reforming reaction was also favoured with the Ni-Co/Al2O3 catalyst with high cobalt content. Various process parameters such as catalyst preparation method, reforming temperature, CO2 feed input rate and catalyst to plastic ratio were tested. It was found that the addition of steam in the catalytic-dry reforming process manipulated the H2/CO molar ratio, based on the type of catalyst used and the CO2/steam feed ratio. Better catalyst activity in relation to H2 production was observed for the Ni-Mg/Al2O3 catalyst and Ni-Co/Al2O3 catalyst favoured CO production. Different types of plastics; individual and mixed plastics from different waste treatment plants were also processed through the catalytic-dry reforming process to determine the syngas production and catalyst activity of Ni-Co/Al2O3 catalyst. This research has suggested that the use of carbon dioxide as the reforming agent in the dry reforming process of waste plastics was comparable to the current reforming technology with an optimum syngas production of 148.6 mmol g-1SWP.
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Tanriverdi, Senem. "Production Of Alumina Borosilicate Ceramic Nanofibers By Using Electrospinning Technique And Its Characterization." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607378/index.pdf.
Full textAbstract:
Today, ceramic, polymer, and composite nanofibers are among the most charming materials for nanotechnology. Because of their small characteristic dimension, high surface area, and microstructural features, they provide unique mechanical, optical, electronic, magnetic, and chemical properties for an extensive variety of materials applications.
Electrospinning provides an effective way of the nanofiber production in a nanometer scale. This technique utilizes a high voltage DC to create a strong electric field and a certain charge density in a viscous solution contained in a pipette. As a result, fibers with diameters ranging from the micrometer to nanometer are formed from this charged solution.
This study deals with, the fabrication of alumina borosilicate ceramic nanofibers using electrospinning technique. Alumina borosilicates contain important components having intriguing characteristics for many applications and have been widely studied with different compositions.
In this study, alumina borosilicate/PVA solution was prepared using the conventional sol-gel method. Polyvinyl alcohol (PVA) was added into this solution to increase the viscosity for electrospinning. After the alumina borosilicate/PVA solution was electrospun into fibers, high temperature sintering was carried to obtain ceramic alumina borosilicate fibers. The products were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform-infrared spectroscopy (FT-IR), and thermogravimetric/differential thermal analysis (TG-DTA) techniques.
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Keles, Ozgur. "Production And Characterization Of Alumina Fiber Reinforced Squeeze Cast Aluminum Alloy Matrix Composites." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609726/index.pdf.
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The aim of the present study was to investigate the effects of different levels of Saffil alumina fiber addition, magnesium content in aluminum alloy matrix and casting temperature on the mechanical behavior, microstructure and physical properties of short fiber reinforced aluminum matrix composites. The main alloying element silicon was kept constant at 10 wt%. Magnesium contents were selected as 0.3 wt% and 1 wt%. Saffil alumina fiber preforms varied from 10 to 30 vol%. The casting temperatures were fixed at 750 °C and 800 °
C. Micro porosity was present at the fiber-fiber interactions. Closed porosity of the composites increased when fiber vol% increased, however, variation in casting temperature and magnesium content in matrix did not have influence on porosity. Hardness of the composites was enhanced with increasing fiber vol%, magnesium content in matrix and decreasing casting temperature. Alignment of fibers within the composite had an influence on hardness
when fibers were aligned perpendicular to the surface, composites exhibited higher hardness. The highest hardness values obtained from surfaces parallel and vertical to fiber orientation were 155.6 Brinell hardness and 180.2 Brinell hardness for AlSi10Mg1 matrix 30 vol% alumina fiber reinforced composite cast at 800 °
C and at 750 °
C, respectively. 30 vol% Saffil alumina fiber reinforced AlSi10Mg0.3 matrix composite cast at 750 °
C showed the highest flexural strength which is 548 MPa. Critical fiber content was found as 20 vol% for all composites.
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Dyrøy, Are. "Quantification and mitigation of segregation in the handling of alumina in aluminium production." Thesis, University of Greenwich, 2006. http://gala.gre.ac.uk/6154/.
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This thesis addresses the development, evaluation and modelling of an anti-segregation system ("AS-System") for.use in larger silos handling alumina in the aluminium smelting industry. This work is unlike much of what has gone before because it is much more grounded in the technical and economic consequences of segregation for a particular manufacturing process. Segregation of particulates, i.e. separation of components due to differences in properties such as size, density etc., has an extensive literature going back as far as 1915, but this focuses mainly on the segregation process itself and largely ignores the context and the consequences. The consequence of segregation is loss of homogeneity; the impact that has on any given process, is generally not addressed very deeply. Surveying the literature on segregation, and studying the total processes of aluminium production, creates a basis for understanding the importance of segregation for aluminium production, as well as the importance of powder technology in general for this industry. A method for quantification of segregation in this production process, based on sampling, has been established. This was intended to give the fundamental information necessary for measuring the extent of the problem and the degree of improvement achieved. By placing sampling points along the logistic chain for the alumina, and by sampling these points for a long enough period, information about the influence of the various handling steps on the bulk solids can be identified. Segregation by particle size is the main type of influence, although the work has shown that attrition is another. Standardised statistical expressions have been used for analysing the bottlenecks of the logistic loops, and study of the results has led to a useful way of expressing the level of segregation, the change of segregation level in a handling step (silo filling and discharge), and improvements in this change. The degree of segregation when handling alumina has proven to be quite considerable in terms of effects on the production process. The effects on the efficiency of the aluminium smelting process, and the environment, have both been evaluated. Variations in the alumina due to segregation have been found to correlate with both dust concentration in the smelter pot room, and anode effects (an unwanted upset in the smelting process). An economical evaluation of an investment in anti segregation systems has been made. This evaluation has shown significant economic consequences, clearly justifying both the investigations of segregation, and the implementation of anti segregation measures. To remedy the effects of air current segregation in the aluminium industry, a complete Anti Segregation System (AS-System) based around Anti Segregation Tubes (AST) utilising a special inlet configuration has been developed. In a number of full size installations, this solution has proved itself capable of handling the variations and transients of process conditions which occur in the industry, with a large operational capacity range, due to the special inlet configuration. The effect of the full scale installed anti segregation systems have been measured, and compared to other systems. The AS-System clearly demonstrated a homogenising effect no matter how low the ingoing variations in particle size were. Other commercial systems which have been evaluated have turned out to be no more than Segregation Effect Damping Systems, since they only seem to reduce the segregation effect after it has happened, instead of trying to eliminate the problem by directly attacking the segregation mechanism itself which is what the AS-System does. A new scaled down test rig for the AS-System was developed, consisting of three ASTs fed from a central distributor. To test the potential effect of the AS-System, to determine its efficiency in countering segregation, tests with repeated filling and emptying of a scale silo were carried out. The results clearly showed that the AS-System very much reduced segregation, compared to conventional filling, even in a small-scale silo. Improved models have been developed for the function of the AST and these have been verified against measurements from the new test rig. The early version of the test rig for the AST used only one centre-mounted tube, with one pressure measurement in the top of the tube. The first models were based on the assumption of the pressure being linear, and assumed full dispersion of the falling material inside the tube; and calibrated from the single pressure measurement inside at the top of the tube. Although this simple model calculated very conservative values of the negative pressure, the model was used for the initial development and design of the AST, and later the ASSystem (Anti Segregation System). A second model was derived, where the material velocity was calculated based on free fall. This model was also based on the idea of full dispersion, but was in better agreement with measured values during further tests, which showed a considerable deviation from the original assumption of a linear pressure distribution once intermediate pressure measurements were available. When using the multi-phase-flow-simulation-program-code FLUENT to simulate the pressure distribution of the AST, the results were quite disappointing, however the FLUENT program was able to identify an initial positive pressure generated by the flow from the inlet box to the tube. Implementing this initial pressure into the simple non-linear model above, both the trend and values correspond quite well with the measured values. A single particle drag model was tried, but dismissed after calculating the maximum possible capacity for known tubes and finding the predictions to be unrealistically low. A new approach was introduced, modelling the fall of the powder in a continuous layer along the inner wall of the tube on one side, creating skin drag along the surface between the falling solid powder and the air. The length of the tube and the width of the chosen AST profile define this surface. This approach assumes that the powder falls like a layer along the tube wall. Previous theory for pressure drop in pneumatic conveying inspired this approach, but it had not previously been used for gravity flow in vertical tubes, and as a result the novel Solid Surface Body Drag Model (SSBDM) was developed. This analytical model gives very good correspondence with the measured data for the pressure distribution inside the AST, yet is extremely simple to use. When comparing the model with measured data, the SSBDM was able to predict the pressure distribution within the error boundaries of the test measurements. A method for design of the AST was derived from the SSBDM, using a dimensionless parameter function determined for the pressure drop model. The models giving the design indicate that the capacity is more than proportional to the cross sectional area of a chosen tube profile, which is in agreement with observations. The model suggests that the capacity is proportional to the cross sectional area in the power of 1.25. This model allowed the study of the effect of tube shape, which revealed that a square profile for the AST does not seem to be the optimum design; rather, a rectangular profile should be chosen for maximum capacity. The model suggests that the capacity is proportional to the width of the side of the tube along which the powder layer is falling, but proportional to the perpendicular side in a rectangular profile in the power of 1.5. The model gives an equation for pressure drop which can also be utilised to place the first valve on the tube. It also shows that for high capacities, and large silos, a system consisting of several ASTs should be chosen (AS-System). Predictions from the model have been tested against the measured capacities of full scale installed systems and give good agreement. Overall, the AS-System has been shown to be cost-effective in reducing segregation; results measured from the full scale installations show a homogenising factor (reduction in variation of the material being handled) of 1-1.5. As a result of these verifications and the simplicity of the model presented in this thesis, the plant engineer can confidently design a system which will function correctly and make a positive, predictable improvement in the homogeneity of the alumina in his plant.
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Strydom, Riki. "Enhanced waste tyre pyrolysis for the production of hydrocarbons and petrochemicals." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2511.
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Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017.Energy security, environmental and economic issues have spurred the interest in pyrolysis of scrap tyres for the production of fuels and energy in South Africa. However, the application of the process on a commercial scale is being hampered by the high cost required to upgrade the comparatively low quality pyrolytic products as well as the high energy input. Further insights into the mechanisms of thermal degradation of rubber will assist to improve on the process economics for production of liquid hydrocarbons fractions suitable for use as transportation fuels and chemicals. This study developed a correlation to predict the contents of waste tyres that will be converted into hydrocarbons during pyrolysis from the proximate analysis data. The mechanism/kinetics of thermal degradation behaviour of waste tyres is also studied, in order to locate the optimal temperature that will maximize the yield of liquid hydrocarbons and other recoverable materials. Data from thermogravimetric analysis is used to determine the kinetic constants for the pyrolysis reaction over a temperature range of 500 °C - 750 °C. A relationship between the optimal temperatures and the volatile mater content depending on the desired products was obtained. This is necessary to eliminate thermal cracking of the pyrolytic oil into the non-condensable gas that will result from excessive temperature and the associated energy cost. Relationship to determine the kinetic equation constants is presented as a function of the volatile matter content. An inductor furnace batch reactor system is used to carried out the pyrolysis reaction, using Argon as the inert gas to provide the oxygen free environment required. The products are sent through a 2-stage condensers, the first operated at room temperature to collect the pyrolytic oil, and the second maintained at -5 oC to collect the condensable pyrolytic gases.
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Wong, Aidan Marc Yew Fai. "'Waste', value and informal labour : the regional e-waste recycling production network in Malaysia and Singapore." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/9068.
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This thesis examines the regional electronic and electrical waste (e-waste) recycling network in Malaysia and Singapore, with a secondary focus on the articulations of informal labour within the network. I argue that there is a need to theorise production networks post-consumption; i.e. to focus on the activities and processes that occur after a commodity is consumed and subsequently discarded. I argue that discarded e-waste are not ‘value-less’ waste, but instead embody value (specifically latent use value), and have the potential to be re-inserted as ‘raw materials’ into production networks through the processes of recycling. Also, key to the processes of value (re)creation, enhancement and capture is the labour process. I examine informal labour by focusing on karung guni (a local term for the rag-and-bone man) – analysing their critical role in value (re)creation in this regional e-waste recycling production network through the lens of petty commodity production. I argue that karung guni are constitutive of this production network through their collection and primary processing of e-waste, which forms the basis for subsequent value creation, enhancement and capture by downstream actors. Conceptualising karung guni as petty commodity producers – who own both the means of production and their own labour power – is significant in problematising as not so straightforward the separation of capital and labour into discreet categories as normally presented in global value chains (GVC)/global production networks (GPN) approaches. This thesis makes four significant contributions to the GVC/GPN literature. First, it recognises activities beyond the point of consumption (which has been the focus of present GVC/GPN research). Second, it conceptualises the constitutive role of informal labour in the development and structure of production networks. Third, it emphasises the continued relevance of the state. Fourth, by adopting a multi-sited case study method, it contributes to debates on how to carry out GVC/GPN research.
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Assefa, Getachew. "Environmental Systems Analysis of Waste Management : Prospects of Hydrogen Production from Waste for use in FCVs." Thesis, KTH, Industriell ekologi, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32426.
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ORWARE, an evolving systems analysis based computer model is used to assess the performance of different waste management options from a life cycle perspective. The present version of the model consists of different submodels for transport, treatment, and disposal of different types of liquid and solid wastes and recycling of materials. Flows between submodels are described by a vector of several substances of different relevance to the system. The model calculates emissions to water and air, amount of residues returned to arable land and energy flows using the tools of life cycle analysis (LCA) and substance flow analysis (SFA). In going in the direction of stringent environmental standards and policies, there is a need for maximizing energy recovery from waste for both environmental and economic benefits. Sweden has already experience of recovering energy from waste for district heating. Recovering energy not only of high value but also of higher quality from waste would be of interest. Hydrogen is one carrier of such energy. The possibility of using hydrogen from waste as a fuel in the transport sector would contribute in heading for creating a clean environment. In this thesis a new submodel for steam reforming of biogas recovered from an anaerobic digester is developed and used with other submodels within the ORWARE framework. Four scenarios representing alternative ways of energy recovery from the organic waste in Stockholm have been simulated to compare the associated energy turnover and different environmental impacts. Digestion of the organic waste and using the biogas to fuel cars is compared against steam reforming of biogas to hydrogen or thermal gasification of the waste and processing the product gases to hydrogen. In the latter two cases hydrogen produced is used in fuel cell cars. Avoided impacts of using the biogas and hydrogen are analyzed using the fourth scenario where the waste is incinerated to generate heat and electricity. Functional equivalence between scenarios is achieved by external supply of heat, electricity and petrol. While recognizing the uncertainties during modelling and simulation, it is possible to conclude that the results indicate that there is advantage of reduced environmental impact and high energy turnover in introducing the technologies of producing hydrogen from waste into the waste management system. Further and thorough investigation is recommended to come up with a sound and firm conclusion. Key words: Systems analysis, Life cycle analysis, Substance flow analysis, Waste management, Environmental impact, Steam reforming, Thermal gasification, Fuel cell vehicles, Hydrogen 
www.ima.kth.se
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Poe, Nicholas Edward. "Acetone, Butanol, and Ethanol (ABE) Production from Food Waste via Clostridium beijerinckii." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/96601.
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Annually, approximately 150 million metric tonnes of food goes to waste in the U.S., potentially causing economic loss and environmental pollution. Fermentation of food waste to produce acetone, butanol and ethanol (ABE) via fermentation has the potential to valorize food waste by producing value-added chemicals. However, the composition of food wastes from different sources vary, which affects ABE fermentation performance and hinders the commercialization of food waste fermentation. The objective of this study is to investigate the compositional variation of food waste collected weekly for 16 weeks (a total of sixteen samples) and determine how this variation affects ABE fermentation performance. Samples collected from Southgate Center, a food processing facility operated by Virginia Tech Dining Services, was characterized for use as a feedstock for ABE fermentation. Water, sugar, starch, fiber, protein, fat and ash concentrations in each of food waste samples were determined. ABE fermentation of these wastes was performed using Clostridium beijerinckii via batch fermentations. Correlations of ABE and butanol yields with the individual components of food waste composition were performed to better understand which components are key to ABE fermentation.
Overall, this study demonstrated the feasibility of using food waste as a viable feedstock for ABE fermentation and investigated the effect of variation of food waste composition on the ABE fermentation performance. In the 16 collected samples, each major compositional attribute exhibited high variability. The concentration of total soluble sugar, defined as glucose, fructose, sucrose for the purposes of this experiment, ranged from 0.5 to 53.5% (dry basis) among different food waste samples. The concentration ranges of total starch, neutral detergent fiber (NDF), crude protein, crude fat and ash were 0 to 23.4% (dry basis), 0.6 to 25.8%, 5.5 to 21.2%, 0.1 to 37.9%, 1.4 to 13.7%, respectively. The high variation of food waste composition resulted in a high variation of ABE yield when these food wastes were subjected to fermentation by C. beijerinckii. The total ABE concentration following fermentation ranged between 6.9 to 17.0 g/L with an average value of 13.2 g/L. ABE and butanol concentrations are positively correlated with starch and equivalent glucose, i.e., the sum of initial free glucose and glucose that could be theoretically hydrolyzed from starch and sucrose during fermentation, but is negatively correlated with NDF concentrations.Master of Science in Life Sciences
Nearly 40% of food in the U.S. goes to waste, causing a huge amount of economic loss and environmental pollution. Use of microorganisms to ferment food waste is a viable way to mitigate many of the issues associated with food waste. Put simply, fermentation is a biological process in which an organic substrate, such as food waste, is consumed and a more valuable product is produced. In this study, different food wastes were collected from the campus food processing center weekly for 16 weeks. Water, sugars, starch, fiber, protein, fat and ash contents of the collected food wastes were determined. Fermentation of these food wastes were conducted using a microorganism called Clostridium beijerinckii. The results showed that there was a high variation amongst the composition of the food waste samples. The concentration of total soluble sugar (glucose, fructose, sucrose) ranged from 0.5 to 53.5% (dry basis) among different food waste samples. The concentration ranges of total starch, neutral detergent fiber (NDF), crude protein, crude fat and ash were 0 to 23.4% (dry basis), 0.6 to 25.8%, 5.5 to 21.2%, 0.1 to 37.9%, 1.4 to 13.7%, respectively. The variation of food waste composition also led to different fermentation yields. It was also found that a higher glucose content in food waste results in a higher fermentation product yield; however, a higher fiber content in food waste results in a lower fermentation product yield.
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Hill, Damon J. "The production and extraction of landfill gas." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335797.
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Van, Dyk Lizelle Doreen. "The production of granular activated carbon from agricultural waste products." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/52003.
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Thesis (MEng)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: Peach and apricot shells are agricultural waste products. These waste products accumulate around canneries and food-processing plants in South Africa. No effort is being made to utilise these waste products. This study is the first part of the product development from these products i.e. peach shell activated carbon and apricot shell activated carbon. By producing activated carbon from peach and apricot shells the solid waste problem is addressed, but most of all a profit can be made. But why activated carbon? Activated carbons are unique and versatile adsorbent with a vast amount of adsorption applications. It can be produced via a simple oxidation reaction with steam and the nature of peach and apricot shells are such that it is expected that activated carbons with good adsorption properties can be produced from it. The single largest consumer of activated carbon in South Africa is the gold mining industry that uses imported coconut shell activated carbon for gold adsorption in the gold recovery process. Activated carbon is also used as water purification adsorbents. During this study activated carbons were produced in a fluidized bed reactor at various activation conditions: 700 - 900°C, 0.0425 - 0.0629 g steamlg char.min and 30 - 60 min. This was done in order to find the optimum activation conditions within the activation parameter range. The optimal activated carbons were defined as peach and apricot shell activated carbons that showed good microporous as well as mesoporous character. The optimal activated carbons produced are: peach shell activated at 875°C, 0.0533 g stearnlg char. min, 60 min and apricot shell activated carbon at 850°C, 0.0533 g steamlg char.min, 60min. The possible use of these optimal activated carbons and two other activated carbons produced (Peach shell activated carbon 900°C, 0.0425 g steamlg char. min, 60 min and apricot shell activated carbon 900°C, 0.0425 g steamlg char.min, 60min) were tested in gold recovery and water purification. The gold adsorption properties of peach and apricot shell activated carbons were found to be better than two commercial coconut shell activated carbons (Chemquest 650 and GRC 22). No definite conclusions could, however, be drawn about the replacement of coconut shell activated carbon with peach or apricot shell activated carbon, because abrasion test work and thermal regeneration of the experimental carbons still have to be performed. The experimental activated carbons displayed good phenol adsorption characteristic, although further test work is required.
AFRIKAANSE OPSOMMING: Perske- en appelkoospitte is landbouafvalprodukte. Hierdie afvalprodukte versamel rondom inmaakfabrieke en voedselververkingsaanlegte. Tans word daar geen poging in Suid-Afrika aangewend om hierdie afvalprodukte te benut nie. Hierdie studie is die eerste deel van die ontwikkeling van die produkte: Perskepitdop-geaktiveerde koolstof en appelkoospitdop-geaktiveerde koolstof. Deur geaktiveerde koolstof van die perske- en appelkoospitdoppe te maak, word nie net 'n antwoord op die vastestofafvalsprobleem gevind nie, maar daar kan ook geld gemaak word. Hoekom geaktiveerde koolstof? Aktiveerde koolstowwe is veelsydige en unieke adsorbente met 'n groot verskeidenheid adsorpsie toepassings. Dit kan vervaardig word via 'n eenvoudige oksidasie reaksie met stoom en die aard van die perske- en appelkoospitdoppe is sodanig, dat verwag kan word om geaktiveerde koolstowwe met goeie adsorpsie eienskappe daarvan te kry. Die grootste enkelverbruiker van geaktiveerde koolstof in Suid-Afrika is die goudmynbedryf, wat kokosneutdop geaktiveerde koolstof invoer om goud te herwin. Geaktiveerde koolstof word ook gebruik vir watersuiwering. Tydens hierdie studie IS geaktiveerde koolstowwe by verskillende aktiveeringskondisies in 'n gevloeïdiseerde bed vervaardig: 700 - 900oe, 0.0425 - 0.0629g stoornlg gepiroliseerde pitdoppe.min en 30 - 60 mm. Die aktiveringskondisies is gevarieer om sodoende die optimale aktiveringskondisies binne die aktiveringsparameterreeks te kry. 'n Geaktiveerde koolstof is as optimaal geklassifiseer as dit 'n goeie mikro- sowel as mesostruktuur getoon het. Die optimaal geaktiveerde koolstowwe is: geaktiveerde koolstof vervaardig van perskepitdoppe by 875°e, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60 mm en geaktiveerde koolstof vervaardig van appelkoospitdoppe by 850oe, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60min. Die gebruik van die twee optimale geaktiveerde koolstowwe sowel as twee ander geaktiveerde koolstowwe (perskepitdop-geaktiveerde koolstof, 900oe, 0.0425 g stoornlg gepiroliseerde pitdoppe.min, 60 min en appelkoospitdop-geaktiveerde koolstof, 850°C, 0.0533 g stoom/g gepiroliseerde pitdoppe.min, 60min) is VIr goudadsorpsie en watersuiwering ondersoek. Die goudadsorpsie eienskappe van die perske-en appelkoospitdop-geaktiveerde koolstowwe was beter as die van twee kommersiële kokosneutdop-geaktiveerde koolstowwe (Chemquest 650 and GRC 22). Daar kan egter geen definitiewe gevolgtrekkings gemaak word oor die vervanging van kokosneutdop geaktiveerde koolstowwe met dié van perske of appelkoospitdoppe nie, aangesien daar nog toetsresultate oor die slytweerstand en reaktiverings eienskappe van die eksperimentele geaktiveerde koolstowwe uitstaande is. Die eksperimentele geaktiveerde koolstowwe toon goeie adsorpie ten opsigte van fenol, maar verdere toetswerk is egter nodig.
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Malavolti, Anastasia. "Cost Efficiency and Waste Reduction in Completely Knocked Down Production." Thesis, Högskolan i Jönköping, Tekniska Högskolan, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-45421.
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Purpose – To provide a framework for the improvement of the supply chain of Completely Knocked Down Products with a focus on waste reduction and cost-efficiency. Method– A case study at a company dealing with CKD assembly, based on observations and interviews. Triangulation of several sources from scholarly articles, examples from the automotive industries and researches. This investigation has been designed to provide logic and coherent structure backing the purpose following the red-thread of answering the research questions. The objective of the study is achieved combining literature review and a case study mainly based on observations and interviews. Results – CKD production can be beneficial depending on the specific content and market conditions. This thesis focuses on value creation throughout each stage of the production of CKD, from design to final assembly. The study found some guidelines that should be followed in managing the supply chain of CKD products. It fills a vacuum of knowledge on the topic. Implications – The frameworks resulting from the research, highlight the actions to be taken to implement CKD efficiently, with minimum waste and cost, leading to an overall improvement of the entire supply chain. Limitations – There have been found limited resources on the topic. Developing a framework without thorough examples from different industries contexts was a limitation due to the absence of available information. Observations and interviews limited to one company that locally assembles globally sourced parts.
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Yousuf, Rawa. "Novel polyhydroxybutyrate (PHB) production using a waste date seed feedstock." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/novel-polyhydroxybutyrate-phb-production-using-a-waste-date-seed-feedstock(70246fcd-0c95-4a31-a0be-0d337c22aefe).html.
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Polyhydroxybutyrate (PHB) is a biodegradable, linear polyester that has potential as a promising alternative to petrochemical derived plastics as it possesses the same properties as several current and widely used synthetic, non-biodegradable petrochemical-based plastics. PHB is a natural polyester which is accumulated by many bacteria as an intracellular store of energy and carbon, under stress conditions; limited in one or more essential nutrient, with the carbon source in excess. Currently the PHB production cost is far greater than that of petroleum based plastics. Recent research, therefore, has focused on improving the cost- effective synthesis of PHB from different substrates and microorganisms. The improvement of fermentation processes and strains allowing for PHB to be produced from an inexpensive carbon source is required to compete with synthetic plastics and to mimic their desired properties. The goal of the work reported in this thesis is to assess the suitability of using waste date seed as a feedstock for PHB production under various stress conditions. Date seeds have The novelty of this study The results include fructose hydrolysis from date seeds and the development of a mass transfer model to describe the process, demonstrating that the high nutrient content of date seeds makes them a promising raw material for microbial growth and that a meaningful amount of PHB can be produced. Using fructose rich waste date seed derived medium, with an initial fructose concentration of 10.8 g/l, maximum dry cell weight and PHB concentrations of 6.3 g/l and 4.6 g/l, respectively, were obtained, giving a PHB content of 73%. An investigation into the suitability of using waste date seed oil extract as an alternative carbon source for PHB synthesis was also carried out. This date seed oil was used as the sole carbon source in a series of microbial fermentation experiments, and the results demonstrate that date seed oil is a feasible substrate for PHB production. A maximum dry cell weight (DCW) of 14.35 g/l was obtained, with a PHB content of 82%, using 20 g/l of date seed oil. Subsequently, the effect of using mixed-substrate (date seed hydrolysate media and date seed extracted oil) on PHB synthesis was investigated using various ratios of substrate feeding. A ratio of 1:1 fructose to oil produced the highest biomass and PHB concentrations of 15.22 g/l and 12.36 g/l, with PHB content 84.1%, respectively. Solid state fermentation using polyurethane foam (PUF) as inert solid support also proved to be a successful alternative for traditional SSF method for PHB production with ease. The maximum PHB production was 0.169±0.03 g/g PUF and biomass was 0.4±0.003 g/g PUF. This work results demonstrate that the use of a generic waste date seed medium as a feedstock for PHB synthesis is technically feasible. It is shown that waste date seed provides a novel approach to produce value added products, in this case biopolymer (PHB). The specific studies carried out lead to the wider outlook that a general feedstock derived from date palm by-product, seeds, has potential to be utilised to synthesise a wide range of products based on the microorganism used. More improvement of this process to develop the efficient production of nutrients as well as improve product yields and subsequently, integration of the process into a broader biorefining process would be an essential contribution in the improvement of the sustainable bio-products industries. ï¿1⁄4 a high nutrient content, are available in large quantities and are relatively cheap. lies in the fact that waste date seed can be used as the feedstock for biopolymer production, based on the development of various techniques to make these nutrients bioavailable for the bacterium, Cupriavidus necator for PHB accumulation.
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Awosolu, Mary. "Anaerobic digestion of ethanol distillery waste-stillage for biogas production." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19072.
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Dependence on oil imported from foreign countries affect the National Energy securitiesand Energy security of global economies has become one of the most challenging problemthat needs to be resolved as the fossil sources are fast diminishing and irreplaceable. Thealarming energy demand and consumption rate of the present global status is currentlyexponentially exceeding the rate of local supply sources, becoming an issue of concern. Alook beyond the fossils is crucial for long tern economic growth and energy security asthere are numerous uncertainties about the fossil supplies coupled with the greaterenvironmental risks encountered during exploitation. Thus the new concept for treatingethanol distillery waste anaerobically to produce Biogas- a clean renewable alternativeenergy with many applications projects sustainable and more realistic option.The research project focuses on Comparison of the Potentials and Efficacy of AnaerobicDigestion of Stillage (Wheat Stillage and Lignocellulose Stillage) from Ethanol Distilleryplants for Biogas Production. It also investigates better alternative temperature dependentStillage Anaerobic Digestion that will enhance a higher Biogas yield.Anaerobic digestions were performed in triplicate batch systems, during both mesophilic(35 °C) and thermophilic (55 °C) conditions at a period of 50-days. The reactors contained2.73g of Wheat Stillage and 5.2g of Lignocellulose Stillage samples, respectively,corresponding to 2% VS in each reactor. The inoculum was taken from either a mesophilicBiogas Plant (Gässlosa., Borås), or from a thermophilic Biogas Plant (Sobacken, Borås). AGas Chromatographic method (GC) was employed for determination of the obtained biogascomposition.The theoretical CH4 Potential for Wheat Stillage and Lignocellulose Stillage is 0.473m3CH4/kg VS and 0.407 m3CH4/kg VS, respectively. The results obtained from this studyindicated, however, that the Wheat Stillage performed better under thermophilic conditionswith a peak of 575ml CH4 / 0.5g VS; while the Lignocellulosic Stillage gave the bestperformance under mesophilic conditions leading to a methane production of 436ml CH4/0.5g VS after 4 weeks of digestion period.Uppsatsnivå: D
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Kvillborn, Carin. "Enzymatic Pretreatment of Lignocellulose Rich Waste for Improved Biogas Production." Thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104974.
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The present study aimed to investigate the methane yield from anaerobic digestion of a lignocellulosic substrate subjected to different pretreatments. The lignocellulosic forest residues materials were milled and then pretreated with the organic solvent NMMO (N-Methylmorpholine N-oxide) and/or the lignolytic enzymes laccase and versatile peroxidase at a dosage of 60 U g-1 total solids (TS) substrate. The amount of methane produced was studied in a biomethane potential assay with inocula from a thermophilic biogas reactor treating municipal waste. All samples were run in triplicates. Due to the large amount of samples, two biomethane potential assays were conducted: series 10 & 20 and series 30 & 40. The gas production results show that NMMO-treated forest residues yielded 130 NmL CH4 g-1 volatile solids (VS) substrate and the untreated forest residues yielded 95 NmL CH4 g-1 VS substrate for series 10 & 20. For series 30 & 40, both untreated and NMMO-treated forest residues yielded 140 NmL CH4 g-1 VS substrate. NMMO-treatment appears to be favourable and no advantages from the enzyme pretreatment could be seen in terms of gas yield. An analysis of the reaction fluid after the enzymatic treatment showed presence of phenols, an indication of successful lignin hydrolysis.Studien avsåg att undersöka metanutbytet från anaerob nedbrytning med förbehandlad lignocellulosa som substrat. Lignocellulosamaterialet, i form av skogsavfall, maldes och förbehandlades därefter med det organiska lösningsmedlet NMMO (N-metylmorfolin-N-oxid) och/eller de lignolytiska enzymerna laccase och versatile peroxidas med dosen 60 U g-1 torrsubstanshalt (TS). Mängden producerad metan undersöktes i en biometanpotentialanalys med inocula från en termofil biogasreaktor, som behandlade hushållsavfall. Triplikat av varje prov användes för att öka den statistiska stabiliteten. På grund av det stora antalet prover genomfördes studien i två omgångar: Serie 10 & 20 samt serie 30 & 40. Resultaten visade att det NMMO-behandlade skogsavfallet gav 130 NmL CH4 g-1 organisk substans (VS) och det obehandlade skogsavfallet gav 95 NmL CH4 g-1 VS i serie 10 & 20. Både obehandlat och NMMO- behandlat skogsavfall gav 140 NmL CH4 g-1 VS i serie 30 & 40. Förbehandling med NMMO verkar vara fördelaktig medan enzymbehandling endast resulterade i en smärre ökning av gasproduktionen. En analys av vätskan efter enzymbehandlingen visade förekomst av fenoler, vilket visar på en lyckad ligninnedbrytning.
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Gee, Ivan L. "Production and application of activated carbons derived from waste materials." Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/56249.
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The development of waste management legislation in the 1990's has placed great importance on the sustainability of waste disposal/treatment options. Landfill of wastes is increasingly seen as a last resort and reduction, re-use and recovery of wastes is encouraged. The wastes investigated in this study (caustic tar and sewage sludges) are often disposed of by non-sustainable methods. In addition production of sewage sludge will have doubled by 2005 and disposal options are increasingly limited. Alternative treatment options are required for both these waste types that offer re-use potential. In this study the carbonisation and activation of these wastes has been demonstrated to be an effective means of treatment that also produces adsorbents that can be safely and usefully applied to treatment of aqueous waste streams. Previous studies have examined the production of clay-carbon adsorbents from spent bleaching earth and limited studies have been conducted on producing adsorbents from sewage sludges. However, the majority of these have limited investigations to production of oils from sludge and no previous studies of caustic tar carbonisation have been conducted. Treatment of caustic tar involved neutralisation with HCl and absorption of the organic content of the waste by Fullers or Acid Activated Earth. The clay-waste mix was subsequently carbonised (375°C for 2 hours) and activated using an optimised ZnClj activation procedure (600°C for 1 hour). Activated carbons were produced from sewage sludges using carbonisation (500°C for 2 hours), CO^ activation (700°C for I hour) and ZnCl^ activation (450°C for 2 hours and 600°C for 1 hour). The adsorbents produced had well developed porosity and large surface areas (up to 225mVg for caustic tar derived carbons and up to 995mVg for sewage sludge based carbons) and were adsorptive of a range of organic pollutants common in effluents. ZnC^ activated, un-digested sewage sludges proved to be the most effective adsorbents. COj activated sewage sludges and caustic tar derived carbons had similar adsorption capacities for the organic pollutants studied. Leaching tests demonstrated that metals present in the adsorbents other than the ZnClj activated carbons were not readily leachable and would not prevent re-use of the carbons in the treatment of aqueous effluents.
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Hallbäck, Sofia, and Ellen Paulsson. "Reducing waste with an optimized trimming model in production planning." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-173253.
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In which ways can the process of trimming dispersion coated board products be optimized so as to reduce material waste and increase production efficiency? This is the question that this master thesis report seeks to answer. In paper production, alot of waste is generated when cutting production reels into customer reels. Some material waste are necessary in order to ensure good quality, however a large amount of the wastecould be reduced if the cutting process was to be optimized. During this project, carried out at a forest company, a mathematical optimization model was developed in order to reduce waste and save costs. This model is based on a cutting stock problem using column generation approach. It provides as its output cutting patterns and an optimal allocation of rolls for production purposes, which implies minimizing the number production rolls needed.The visualization of the results could also be used to achieve optimal stock levels, and easier keep track on how to use the material available in stock. Findings show that there are potential savings to be done. Simulations suggest an implementation of this model could result in material savings of around 7 %. This could also translateto environmental savings in CO2, where every decrease of one tonne material equals to adecrease in CO2emissions of 500 kg
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Yang, Yang. "Energy production from biomass and waste derived intermediate pyrolysis oils." Thesis, Aston University, 2015. http://publications.aston.ac.uk/25356/.
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This study investigates the use of Pyroformer intermediate pyrolysis system to produce alternative diesel engines fuels (pyrolysis oil) from various biomass and waste feedstocks and the application of these pyrolysis oils in a diesel engine generating system for Combined Heat and Power (CHP) production. The pyrolysis oils were produced in a pilot-scale (20 kg/h) intermediate pyrolysis system. Comprehensive characterisations, with a view to use as engine fuels, were carried out on the sewage sludge and de-inking sludge derived pyrolysis oils. They were both found to be able to provide sufficient heat for fuelling a diesel engine. The pyrolysis oils also presented poor combustibility and high carbon deposition, but these problems could be mitigated by means of blending the pyrolysis oils with biodiesel (derived from waste cooking oil). The blends of SSPO (sewage sludge pyrolysis oil) and biodiesel (30/70 and 50/50 in volumetric ratios) were tested in a 15 kWe Lister type stationary generating system for up to 10 hours. There was no apparent deterioration observed in engine operation. With 30% SSPO blended into biodiesel, the engine presents better overall performance (electric efficiency), fuel consumption, and overall exhaust emissions than with 50% SSPO blend. An overall system analysis was carried out on a proposed integrated Pyroformer-CHP system. Combined with real experimental results, this was used for evaluating the costs for producing heat and power and char from wood pellets and sewage sludge. It is concluded that the overall system efficiencies for both types of plant can be over 40%; however the integrated CHP system is not economically viable. This is due to extraordinary project capital investment required.
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Emmett, Robyn Angela. "Glycerol production by Dunaliella species in saline waste water treatment." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1004079.
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In recent years, much research has focused on Algal High Rate Oxidation Ponds as both an economic means for wastewater treatment and as a system for the mass production of algae. With the advent of these systems for the treatment of saline organic effluents, the extreme halophile, Dunaliella salina was considered. In this study, the growth and productivity of a number of Dunaliella species (and strains thereof) was evaluated in hide soak liquor tannery effluent. Hide soak liquor, diluted to 20% with water, proved to be highly suitable as a growth medium for the majority of the Dunaliella species under study and in some instances, resulted in enhanced growth rates and higher biomass yields compared to those obtained in defined inorganic medium. A few Dunaliella species failed to grow in this effluent. A correlation was observed between the lack of growth displayed by these species in this organio-rich medium and their failure to utilise organic compounds. Glycine, a major component of this effluent, possibly stimulates the growth of Dunaliella. Studies on the mechanism of growth stimulation by glycine revealed that an algal-bacterial relationship existed whereby the bacteria mineralised the amino acid, releasing ammonia which was then utilised by the alga. Results of this work revealed significant variations in the intracellular glycerol content amongst the Dunaliella species under study. Large differences were also observed between the glycerol contents of effluent-grown and control Dunaliella cells, where the effluent-grown cells were characterised by greatly reduced intracellular glycerol content. These reduced glycerol levels are assumed to have arisen from the glycine-induced stimulation of glycerol release which was observed in this study, where the high glycine content of the hide soak liquor is proposed to have induced glycerol release. This enhanced glycerol release in tatmery effluent could play a central role in the fimction of Dunaliella-based High Rate Oxidation Ponding systems, by stimulating bacterial activity. Observed glycerol productivities were therefore proposed to be a fimction of the type and concentration of the organic constituents of the medium. A similar medium-induced phenomenon was observed in the starch content of Dunaliella cells.
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Dalila, Augusto MUSSENGUE SAN. "Biodiesel Production from Jatropha and Waste Cooking Oils in Mozambique." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216984.
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Bethani, Sofia. "Production of lightweight aggregates from 'energy from waste' combustion ashes." Thesis, Imperial College London, 2004. http://hdl.handle.net/10044/1/7932.
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Zheng, Sheng. "Biodiesel production from waste frying oil: Conversion monitoring and modeling." Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/26416.
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Biodiesel is a clean-burning substitute for petroleum-based diesel produced from virgin or waste vegetable oils and animal fats. One obstacle to the development of biodiesel is its high cost compared to petroleum diesel. Using waste frying oil instead of virgin oil can significantly reduce the high production cost. In our lab, promising preliminary results have indicated that transesterification of waste frying oil catalyzed by sulphuric acid has sufficient commercial feasibility to warrant further investigation.
In order to better understand the acid-catalyzed transesterification process and to optimize the process yield, an empirical study of the reaction kinetics was carried out. A mixture design for feed compositions at various temperatures was used to determine their effects on conversion rates and yields. Empirical models were built to describe the relationships of interest. Rate of mixing, feed composition and temperature were chosen as independent factors in this study. Intensity of mixing was found to have no significant effect on the yield over 100 rpm. The methanol to oil ratio and temperature were the most significant factors affecting the yield. Finally, a region of optimum operating conditions was determined from the models.
Analytical methods played an important role in our study. The extent of the reaction was followed off-line by gel permeation chromatography (GPC) and compared to results using an off-line infrared sensor based on attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The development, use and evaluation of the off-line method were discussed. The reproducibility of both methods was found to be excellent (≤1%); data obtained from both methods were found to be reliable. Finally, a comparison of the two methods showed good agreement (within 2%) in the monitoring of the transesterification reaction.
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Elliston, Adam. "The exploitation of municipal solid waste (MSW) and related waste paper streams in the production of bioalcohol." Thesis, University of East Anglia, 2012. https://ueaeprints.uea.ac.uk/42366/.
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An organic fraction from municipal solid waste (MSW) comprised 38.9% (w/w) glucose (cellulose and starch) indicating its potential as a substrate for bioalcohol production. Microscopy indicated that the fraction was rich in waste paper fibres. Much paper waste comes from shredded office paper (50.4% w/w glucose) which is unrecyclable because of poor fibre length. This, and microbiological hazards associated with the use of MSW led to its choice as model substrate for study. Saccharification of shredded paper waste was optimised by selection of Accellerase® and additional beta-glucosidase enabling digestion of 99.27% of cellulose. Sequential batch-addition of substrate permitted substrate “concentrations” equivalent to 25-30% (w/v). Saccharification was enhanced by detergent, but reduced by the presence of alcohols at over 3-4% (v/v). Steam explosion of paper slightly enhanced saccharification. However, the approach was rejected due to high energy cost, production of fermentation inhibitors at high severities, and lack of clear benefit regarding ethanol yield. Interestingly, levels of inhibitors were low compared to other pre-treated substrates and addition of paper to other substrates greatly reduced their own production of inhibitors during pre-treatment (wheat straw 60%, filter paper 95%). Larger pilot-scale (1.5-5 L) operations involved developing the batch-addition regime with a high-shear stirring capacity vessel. Additions equating to final substrate concentrations of ~65% (w/v) were achieved (from an initial 5% w/v) and facilitated high ethanol concentrations (11.6% v/v) with minimal enzyme input (3.7 FPU/g substrate). Thermal tolerance of a range of yeast strains was investigated by developing a rapid screening approach with liquid-handling robotics. This identified strains able to endure temperatures up to 40°C. Evolutionary engineering may improve tolerances to temperatures nearer to enzyme optimums (50°C). Some previously unused strains exhibited superior growth to referenced industrial strains. The above findings were integrated into a process design along with recommendations for further enhancement.
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BRASILEIRO, Maria Isabel. "Síntese de mulita por microondas utilizando composições contendo resíduo de caulim." Universidade Federal de Campina Grande, 2010. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1738.
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A mulita 3Al2O3∙2SiO2 é uma das fases cristalinas mais extensivamente estudadas do sistema binário Al2O3 - SiO2, sendo promissora em cerâmica devido suas ótimas propriedades químicas, mecânicas e elétricas. O caulim é a fonte principal para sintetizar mulita e o resíduo de caulim, obtido a partir de uma segunda etapa do beneficiamento de caulins primários, pode apresentar teores de SiO2 e Al2O3 que permitem a sua incorporação em massas cerâmicas para a produção da mulita. Como a temperatura de reação da mulita é elevada aumentando assim seus custos, o uso da energia de microondas no processamento e obtenção de materiais, tem despertado interesse especial por parte de diversas áreas do conhecimento como a engenharia de materiais. Este interesse estar diretamente ligado ao seu simples uso, além de reduzir o número de etapas em muitas sínteses, melhorar propriedades físicas em cerâmicas tecnológicas e ter como aliado a economia de energia/tempo alcançada no processamento de muitos materiais. Neste trabalho foi feito um estudo sobre a fabricação de corpos cerâmicos de mulita a partir da mistura de resíduo de caulim e alumina, por sinterização convencional e em microondas, para efeito de comparação. Os corpos de prova foram produzidos por prensagem uniaxial na pressão de 35 MPa e sinterizados em potências de 80% (1,44 kW) e 90% (1,62 kW) com tempos de 10, 15, 20 e 25 min em forno de microondas de freqüência de 2,45GHz e no forno convencional em temperaturas de 1400 a 1600°C, com taxa de aquecimento de 5°C/min e patamar de queima de 2h. Por fim os corpos de prova foram submetidos à determinação das propriedades físico-mecânicas, caracterização de fases cristalinas por DRX e análise microestrutural por MEV. Os resultados obtidos mostraram que a mulita obtida a partir do forno de microondas apresenta estrutura das agulhas mais alongadas quando comparadas ao do forno convencional. O aumento do tempo de sinterização e da potência utilizada, no caso do forno de microondas, e que o aumento da temperatura, no forno convencional, são fatores essenciais a serem considerados para se alcançar um alto teor de mulitização.
Mullite (3Al2O3∙2SiO2) is one of the crystalline phases most extensively studied from the binary system Al2O3 - SiO2, and promising ceramic due to their excellent chemical, mechanical and electrical properties. Kaolin is the main source to synthesize mullite and kaolin waste, obtained from a second stage of processing of primary kaolin, can has contents of SiO2 and Al2O3 which allows its incorporation in ceramic bodies for the production of mullite. As the temperature of the reaction of mullite is high thus increasing their costs, the use of microwave energy for processing and obtaining materials, has attracted special interest by a number of areas as engineering materials. This interest is directly linked to its simple use, and reduce the number of steps in many synthesis, improved physical properties in ceramic technology and have the combined savings energy / time achieved in the processing of many materials. The fabrication of mullite ceramic bodies from the mixture of residual kaolin and alumina, in conventional oven and microwave, for comparison. The samples were produced by uniaxial pressure of 35 MPa and sintered in powers of 80% (1,44kW) and 90% (1,62kW) with times of 10, 15, 20 and 25 min in the microwave at frequency 2,45GHz, and conventional oven at temperatures from 1400 to 1600°C with heating rate of 5°C/min and 2h. Finally the specimens were submitted to determination of physic-mechanical characterization of crystalline phases by XRD and microstructural analysis by SEM. The results showed that the mullite obtained from the microwave oven has more elongated structure of the needles when compared to the conventional oven. The sintering time and power used in the case of microwave ovens, and that the increase of temperature in a conventional oven, are key factors to consider in achieving a high level of mullitization.
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Chokazinga, Davlin. "Coordination studies of inositols with aluminium and related cations." Curtin University of Technology, School of Applied Chemistry, 2003. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=14424.
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In this work cis-inositol, epi-inositol and myo-inositol carbonate were successfully synthesised and used for coordination studies. The preparation of cis-inositol was achieved by reduction of tetrahydroxybenzoquinone via hydrogenation with palladium hydroxide as the catalyst and was purified by chromatographic separation using Dowex resin. The synthesis of epi-inositol was achieved by the nitric acid oxidation of myo-inositol to form epi-inosose which was subsequently reduced by hydrogenation using palladium hydroxide as the catalyst. myo-Inositol was converted into its mono-orthoformate derivative and the equatorial hydroxy group was then protected as a tertiary-butyldimethylsilyl ether. The carbonate group was introduced onto this protected inositol and then the protecting groups were removed by acid hydrolysis. The coordination characteristics of four inositols, viz cis-inositol, epi-inositol, myo-inositol and myo-inositol carbonate with calcium, aluminium, gallium, lanthanum and samarium ions have been investigated. Interactions of the aluminate anion with epi-inositol and myo-inositol in deuterated sodium hydroxide were also investigated. Three methods were used in the study of complexation behaviour of these systems. namely, [superscript]13C NMR spectroscopy, HPLC and ion exchange chromatography. [superscript]13C NMR spectroscopy was found to be most useful for determining possible complexation behaviour of the inositols. Chemical shift changes of the resonance signals in the [superscript]13C NMR spectra on sequential addition of cations to solutions of the inositols at near neutral pH, have led to determination of possible coordination sites of the inositols. In general, large induced chemical shift changes have been interpreted to signify strong cation-inositol interaction at specific hydroxy groups.Triaxial sites of the inositols have shown a preference to coordinate small ions with ionic size of at least 60 pin, smaller ions than this displayed very weak interactions. Likewise large ions (90-100 pm) imparted weak interactions on triaxial sites of the inositols. These large ions coordinated well with the axial-equatorial-axial sites of the inositols although it was observed that calcium ions appeared to form a 2:1 ligand:cation complex with cis-inositol at the triaxial site despite being a large cation (100 pm). The detection of complex formation by HPLC showed a possible formation of very stable complexes of epi-inositol complexes with calcium ions. However, a change of refractive index of the solution on sequential addition of the cation may have caused an interference in the results such that direct interpretation was not possible. Ion exchange chromatography provided the quickest guide on how strongly the inositols interact with a particular cation. However, determination of complex stoichiometry and or structure was not possible using this technique.
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Bennen, Wilroy. "The evaluation of waste minimization/waste treatment strategies for a commercial production process of 4-methyl-3-thiosemicarbazide." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/97.
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Chemical synthesis is closely related to waste minimization. There is no chemical process that does not produce waste. The methods used by industry to deal with this waste is a major environmental concern. This thesis describes the laboratory scale waste minimization and waste treatment strategies for the commercial production process of 4-methyl-3-thiosemicarbazide (MTSC). The production process of 4-methyl-3-thiosemicarbazide was investigated with the aim of increasing the isolated yield of MTSC and at the same time decrease the amount and toxicity of effluent obtained. During this study, parameters were investigated such as the use of excess DIPEA and the temperature of the reaction. Preliminary studies clearly showed that both factors have a significant influence on the final yield of the product. The next part of the investigation was to optimize the two parameters influencing the isolated yield of the MTSC. For this investigation, a multi factorial design was used to determine the optimum conditions in the MTSC yield response. From the results obtained, it was clear that the excess of DIPEA and the temperature of the reaction both need to be high to obtain high yields. These theoretical results were confirmed by results obtained practically, where yields of up 82 % were obtained, but it became clear that even higher yields could be obtained since chromatographic results showed yeilds as high as 90 %. The mass balance of the MTSC synthesis showed a loss of approximately 30 grams per reaction. This loss may have an influence on the final yield. The effluent obtained during the synthesis of MTSC was investigated and a waste treatment protocol was established to reduce the high COD value of the MTSC effluent. The protocol consists of two steps used for the clean up of the effluent. The first being a cooling step; the effluent was cooled at 0oC to induce precipitation of a solid, consisting mostly of MTSC. The second step is a high pressure wet oxidation of the effluent with oxygen in a high pressure reactor. The remaining compounds in the effluent were oxidized, resulting in another precipitate, consisting mostly of sulphur. After the oxidation the COD value of the effluent was decreased by 98 % to a value of 0.4 %. The MTSC present in the precipitate obtained after cooling could be isolated and purified, to add to the yield of the synthesis. The sulphur obtained during the oxidation could also be isolated and reused, or sold to prevent it from contaminating the environment.