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Nordlander, Eva. "System studies of Anaerobic Co-digestion Processes." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-36515.
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Production of biogas through anaerobic digestion is one pathway to achieving the European Union (EU) goals of reducing greenhouse gas emissions, increasing the share of renewable energy, and improving energy efficiency. In this thesis, two different models (Anaerobic Digestion Model No. 1 and an artificial neural network) are used to simulate a full-scale co-digester in order to evaluate the feasibility of such models. This thesis also includes models of two systems to study the inclusion of microalgae in biogas plants and wastewater treatment plants. One of the studies is a life-cycle assessment in which replacement of the ley crop with microalgae is evaluated. The other study concerns the inclusion of microalgae in case studies of biological treatment in three wastewater treatment plants. Finally, the co-digestion between microalgae and sewage sludge has been simulated to evaluate the effect on biogas and methane yield. The results showed that Anaerobic Digestion Model No.1 and the artificial neural network are suitable for replicating the dynamics of a full-scale co-digestion plant. For the tested period, the artificial neural network showed a better fit for biogas and methane content than the Anaerobic Digestion Model No. 1. Simulations showed that co-digestion with microalgae tended to reduce biomethane production. However, this depended on the species and biodegradability of the microalgae. The results also showed that inclusion of microalgae could decrease carbon dioxide emissions in both types of plants and decrease the energy demand of the studied wastewater treatment plants. The extent of the decrease in the wastewater treatment plants depended on surface volume. In the biogas plant, the inclusion of microalgae led to a lower net energy ratio for the methane compared to when using ley crop silage. Both studies show that microalgae cultivation is best suited for use in summer in the northern climate.
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Niklasson, Johanna, and Skogfors Linnea Bergquist. "Can organic waste fuel the buses in Johannesburg? : A study of potential, feasibility, costs and environmental performance of a biomethane solution for public transport." Thesis, Linköpings universitet, Industriell miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149268.
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Like many large cities, Johannesburg faces several sustainability challenges such as unsustainable use of natural resources, emissions contributing to environmental- and waste related problems. The city is a provincial transport centre, and the transport sector is responsible for a large share of the city’s energy demand and emissions. To approach several of these challenges simultaneously the City of Johannesburg considers the possibilities to use renewable, waste-based, fuel for public transport and has shown a great interest in how Sweden produce and use biogas. In this study an early assessment of the potential, feasibility, economic costs and environmental performance of a waste-based biomethane solution in Johannesburg is performed, with the purpose to fuel a public transport bus fleet. This has been done by developing and using a multi-criteria analysis (MCA). The MCA consists of four categories: potential, feasibility, economic costs and environmental performance. These categories consist of 17 key areas with corresponding key questions and indicators with relating scales used for scoring the indicators. The indicators and scales help identify what information is necessary to collect for the assessment. Furthermore, an Excel tool and a questionnaire are provided to serve as a help when performing the assessment. The feasibility assessment is conducted both for the city as a whole as well as for individual feedstocks. Information for the studied case was gathered from a literature study and interviews in Johannesburg with local experts and potential stakeholders. The identified feedstocks in Johannesburg are landfill gas, waste from a fruit and vegetable market, organic household waste, abattoir waste, waste from the food industry, waste management companies and sewage sludge from the wastewater treatment plants (WWTP). The identified biomass potential is 230,000 tonnes of dry matter/year, generating a total biomethane potential of 91,600,000 Nm3/year, which is enough to fuel almost 2700 buses. In the process of producing biogas, digestate is created. The digestate can be used as biofertilizer and recycle nutrients when used in agriculture. The complete biomass potential in Johannesburg was not identified meaning there is additional potential, from e.g. other food industries, than examined in this study. Assuming that all feedstocks except for landfill gas and WWTP sludge are processed in one biogas plant, the investment cost for this biogas plant is 28 million USD and the total operation and maintenance cost is 1.4 million USD per year. The investment cost and yearly operating cost for the upgrading plant is 43 million USD and 2.4 million USD respectively. Finally, the distribution costs were calculated, including compression and investment in vessels. The investment and operational costs for compression is 7.4 million USD and 220,000 USD/year respectively. The investment cost for the vessels was calculated to 15 million USD and the operational costs of the distribution 16 million USD/year. Consideration should be given to the fact that the numbers used when calculating these costs comes with uncertainties. Most indicators in the feasibility assessment of the city as a whole were given the score Poor, but some indicators were scored Satisfactory or Good. The assessment of the individual feedstocks led to a ranking of the most to the least feasible feedstocks where the waste from the fruit and vegetable market and the municipal household waste are considered being in the top. This assessment also shows the feedstocks are in general quite suitable for biomethane production. The issue is the lack of economic and legislative support and strategies not working in favour of biomethane. These are areas that can be improved by the local or national government to give better conditions for production of biomethane in the future. Some examples of this are a proposed landfill tax or landfill ban as well as a closing of the landfills due to the lack of new land. This could all contribute to better conditions for biomethane solutions in the future. Main identified hinders are electricity generation from biogas as a competitor with biomethane, and a general lack of knowledge about biogas and biomethane, from the high-level decision makers to a workforce lacking skills about construction and operation of biogas plants.
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Bergström, Maria. "Pyrolysolja som bränsle för fjärrvärmeproduktion samt råvara till biodrivmedel : Egenskaper och prestanda vid lagring, förbränning och uppgradering." Thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-85314.
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För att Sverige ska nå klimatmålet om noll nettoutsläpp av växthusgaser till år 2045 behöver bland annat mer biobränslen fasas in och fossila bränslen fasas ut och därför behövs större produktion och fler alternativ av biobränslen. Pyrolysolja är ett alternativ till biobränsle som har forskats på sedan 1970-talet men som först för några år sedan börjat produceras i större skala för användning till värmeproduktion. Först i år startades även en byggnation för produktion av pyrolysolja som ska uppgraderas till biodrivmedel av Pyrocell. Pyrolysoljan har annorlunda egenskaper och sammansättning mot andra biooljor och fossila oljor. Till exempel har pyrolysolja högt vatteninnehåll, hög viskositet och högt innehåll av syresatta komponenter vilket gör att pyrolysoljan har lågt värmevärde, är svårare att hantera och är ostabil. Karlstad Energi AB har påbörjat ett projekt för att utvärdera en integrerad pyrolysreaktor vid en befintlig kraftvärmepanna med målsättningen att i framtiden producera pyrolysolja. De är intresserade av att använda pyrolysoljan som bränsle i två av deras reservpannor för fjärrvärmeproduktion och för att få produktionen lönsam är de dessutom intresserade av att sälja pyrolysoljan som råvara till drivmedelsindustrin. Syftet med arbetet är att undersöka pyrolysoljans användbarhet i Karlstad Energis system utifrån pyrolysoljans egenskaper, åldring, förbränning och uppgradering till biodrivmedel samt jämföra pyrolysoljans egenskaper och förbränning med biobränslet de använder idag, bio100. Målen är att; (1) kartlägga och jämföra pyrolysoljans egenskaper med bio100 utifrån litteratur, (2) beräkna och bedöma viskositetsförändring samt varmhållnings och förvärmningstemperaturer av färsk och lagrad pyrolysolja utifrån litteratur, (3) beräkna förbränningsegenskaper och förbränningsprestanda vid en uttagen effekt på 30 MW i reservpannan genom simulering i Chemcad tillsammans med en uppbyggd värmeöverföringsmodell i Excel och (4) undersöka möjligheten att uppgradera pyrolysolja till biodrivmedel genom teoretisk beräkning av vätgasbehov och oljeutbyte. Pyrolysoljan undersöks med 25, 15 och 8 vikt % vatten och tillsats av 5 och 10 vikt % metanol och etanol för att stabilisera pyrolysoljan samt förbättra förbränningen. Resultaten visar på att en pyrolysolja med 8 % vatteninnehåll kan ha alltför hög viskositet för att kunna pumpas och förbrännas i rimliga varmhållnings- och förvärmningstemperaturer, medan 26 och 15 % klarar det med rimliga temperaturer, med och utan tillsats av alkohol. Vid förbränning med en uttagen effekt på 30 MW krävs ca 1,9-2,6 gånger så högt oljeflöde och ca 1,05-1,21 gånger så högt rökgasflöde för pyrolysoljorna mot bio100 (3250 kg/h respektive 42900 m3/h). Det innebär att anläggningen skulle kunna vara underdimensionerad för att få ut 30 MW vid förbränning av pyrolysolja där oljeflödet förmodligen är det begränsande flödet. Detta kräver ytterligare utredning av utrustningen. Luft-bränsle förhållandet för att uppnå 4 % syreöverskott är ca dubbelt så stort för bio100 mot pyrolysoljorna (16 mot 6,7-8,6 kg luft/kg olja). Utsläpp av stoft och NOx kan bli väldigt högt på grund av det höga ask- och kväveinnehållet och kommer förmodligen inte klara de framtida utsläppsbegränsningarna varav åtgärder kommer behövas. Verkningsgraden (baserat på det högre värmevärdet) för 8 % vatteninnehåll med 10 % etanol kommer upp i samma verkningsgrad som bio100 (91 %) mot 26 och 15 % vatteninnehåll som kommer upp i ca 84 respektive 88 %. Det teoretiskt beräknade vätgasbehovet och oljeutbytet ligger mellan ca 575-775 liter vätgas/kg pyrolysolja respektive ca 45-62 %. Överlag är tillsats av metanol det bättre alternativet för viskositeten men etanol är bättre vid förbränning och uppgradering till biodrivmedel.For Sweden to reach the goal of zero net emissions of greenhouse gases by the year 2045, more use of biofuels and less use of fossil fuels is needed and for this we need higher production and more options of biofuels. One option is pyrolysis oil which has been in research since the 1970’s but was only recently introduced to large-scale heat production. Also, this year Pyrocell have started the construction of a pyrolysis plant where the pyrolysis oil is going to be upgraded to biofuels. The pyrolysis oil has different properties and composition compared to other biooils and fossil oils. For example, it has high water content, high viscosity and high content of oxygenated compounds which makes the oil more difficult to handle, unstable and gives the oil a low heating value. Karlstads Energi AB has started a project to evaluate an integrated pyrolysis reactor to one of their existing combined heat and power plants with the objective to produce pyrolysis oil in the future. They are interested in using the pyrolysis oil as a fuel in two of their reserve boilers for district heating production and to sell as raw material to the fuel industry. The object of this study is to investigate the possibility of using the pyrolysis oil at Karlstads Energi in the meaning of properties, aging, combustion and upgrading to biofuel and to compare the properties and combustion performance with the fuel they are using today, bio100. The goals are to; (1) map and compare the properties and composition of pyrolysis oil with bio100 from literature, (2) calculate and estimate changes of viscosity and storage- and atomization temperatures of fresh and stored pyrolysis oil using data from literature, (3) calculate combustion properties and combustion performance at 30 MW power outlet from the boiler through simulation in Chemcad and a heat transfer-model in Excel and (4) investigate the possibility to upgrade pyrolysis oil to biofuel through theoretical calculation of hydrogen consumption and biofuel yield. The pyrolysis oil is investigated with 25, 15 and 8 wt% water and addition of 5 and 10 wt% methanol and ethanol to stabilize the oil and to improve the combustion. The results shows that a pyrolysis oil with 8 wt% water could have too high viscosity to be able to be pumped and combusted in reasonable temperatures while 26 and 15 wt% water have lower viscosity and can be used in reasonable temperatures, both with and without addition of alcohol. At combustion with 30 MW power output the flow of pyrolysis oil and flue gases is 1,9-2,6 times and 1,05-1,21 times higher than bio100, respectively (3250 kg/h and 42900 m3/h, respectively for bio100). This means that the facility could be undersized to be able to get 30 MW power output with pyrolysis oil, where the oil flow probably is the limiting factor. This requires further investigation of the equipment. The air-fuel-ratio to receive 4% excess oxygen in the flue gases for the pyrolysis oils is about half of that of bio100 (6,7-8,6 compared to 16 kg air/kg oil, respectively). The emissions of dust and NOx are high for the pyrolysis oils because of high content of ash and nitrogen and will probably exceed the future limitations of which measures will be needed. The efficiency (based on higher heating value) for pyrolysis oil with 8 wt% water and 10 wt% ethanol can reach the same efficiency as bio100 (91%), while 26 and 15 wt% water content reach 84 and 88%, respectively. The theoretical hydrogen consumption and biofuel yield were calculated to 575-775 L hydrogen/kg pyrolysis oil and 45-62%, respectively. Overall, addition of methanol is a better choice for the viscosity, but ethanol performs better in combustion and upgrading to biofuels.
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Persson, Andreas. "Utvärdering av hur mekanisk avvattning påverkar termisk torkning av sågspån : Försök med olika partikelstorlekar och temperaturer i en konvektiv tork." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-74310.
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Hansson, Sara. "Approaches to the Bioenergy Potential in 2050 : An assessment of bioenergy projections." Thesis, Uppsala universitet, Naturresurser och hållbar utveckling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314983.
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There is an abundance of reports and articles on the extent of future bioenergy usage. Decision-makers might turn to bioenergy projections in hopes of making informed decisions for policies or investments. This report aims to highlight irregularities and differences regarding calculations and results in 15 global bioenergy projection studies for the year 2050, and to find underlying connections by applying a metaanalysis with a methodological focus. Statistical distributions were made for the projected global bioenergy potentials. A growth rate study based on the projected global bioenergy potentials was made and used as a simple “reality check”. Regarding Sweden and the EU, it was investigated whether decisions has been made based on estimated bioenergy potentials. The final aim was to make recommendations for bioenergy decision-makers and policy-makers. There are many statistical distributions fitting the projections for 2050. The distribution functions showed that with a 95 % confidence level, the bioenergy projections in 2050 is 151.3 EJ. The interquartile range of all studies included in this report for primary bioenergy in the year 2050 was shown to be 120-400 EJ, with minimum value of 30 EJ and maximum of 1600 EJ. A mere third of the projection values were in the vicinity of a linear or exponential trendline based on historical values. The historical annual average growth rate for bioenergy from 1971 to 2011 was found to be 1.9 percent. A higher growth rate is required to achieve the larger quantities that are projected in most studies, the most extreme rate was 7.6 percent, which is far above the average. The EU has adopted a biomass action plan partly based on bioenergy projections by the European Energy Agency in 2006. National and international energy projection reports influence Swedish politics, albeit not directly in propositions. The difference between individual reports and articles projected bioenergy level in 2050 is significant. It is recommended to read more than one. Most forecasting models and estimates will likely perform poorly numerically, so it is recommended to look for underlying factors, connected longterm trends, or behavioral consequences.
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Llavero, Pasquina Marcel. "Engineered light controlled cell development for enhanced hydrogen production in Nostoc punctiforme ATCC 29133." Thesis, Uppsala universitet, Mikrobiell kemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-294854.
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The aim of this thesis is to enhance heterocyst-based hydrogen production inNostoc punctiforme ATCC 29133. We envision to do so by finely regulatingthe ratio of heterocyst in order to optimize the filament energy balance. Wehereby report the development of an optogenetic synthetic switch basedon the native PcpeC promoter. The optogenetic switch featured a 24-folddynamic range when measuring reporter sfGFP fluorescence. Such a geneticgate was conceived to artificially drive the expression of hetR, the masterregulator of heterocyst development. We achieved to induce enhancedheterocyst differentiation in the presence of ammonia only by changing thechromatic properties of the light source. Thus, the natural cell developmentregulation was substituted by effectively introducing a full person-drivencontrol over the process.
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Olofsson, Jonny. "Sojaprotein, oxiderad majsstärkelse, vetestärkelse & ärtstärkelse som additiv i träpellets : Effekter på pelletsens kvalitet, CO2ekv utsläpp & energianvändning." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-64753.
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Currently, only 2.8% of total energy use in the world is renewable energy. As a climate target in 2020, the European Union has set a goal of increasing the renewable energy to 20%. Renewable energy includes biofuel such as pellets. Pellets use has already increased significantly and several large production units have been built in recent years. To achieve a competitive pellet, production must be improved in terms of quality, environmental impact, and electricity consumption. Adding additives can improve pellets strength, reduce CO2eq emissions and reduce energy consumption. The purpose is to investigate how different percentages of additive affect pellets to achieve a more sustainable and competitive biofuel. In the quality analysis where sustainability and hardness were investigated, oxidized corn starch showed the best result where sustainability increased from 94.8% to 97.86%. The hardness varied greatly from pellets to pellets from the same sample. Since the hardness varied so widely, it was impossible to say which sample who had the highest hardness. On the other hand, it is concluded that the oxidized cornstarch samples received higher hardness than the zero sample. In the environmental section, CO2equivalents for pellet production were investigated in Sweden, OECD member countries and non-OECD member countries in Europe. In Sweden and in OECD member countries, pellets production did not reduce the CO2eq emissions with any added additive. In non-OECD member countries, wheat starch was the best additive and reduced CO2eq emissions by 2.4%. The energy consumption in the pellet press was also analyzed and the results showed that all additives reduced energy consumption. The best additive in this study was wheat starch, which reduced electricity consumption by 3.9%.
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Leijen, Sebastian. "Semi-kontinuerlig samrötning av ensilerat våtmarksgräs och matavfall : En studie av metan utbyte." Thesis, Karlstads universitet, Avdelningen för energi-, miljö- och byggteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-62559.
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Världens ökande energibehov och önskan om att minimera konsekvenserna av klimatförändringen har gjort att flera miljömål tagits fram både på nationella och internationella nivåer. Mycket resurser läggs ner på att utveckla nuvarande förnyelsebara energikällor och hitta nya alternativ till de fossila bränslena. En förnyelsebar energiresurs är biogas. Biogas bildas vid nedbrytning av organiskt material och bildar koldioxid och energirik metangas. Detta examensarbete har fokuserat på två områden, det första att undersöka metanproduktionen i en samrötningsprocess med ensilage av våtmarksgräs och substrat från Mosseruds biogasanläggning. Mosserud ligger några km väster om Karlskoga och idag behandlas i huvudsak insamlat matavfall, nötflytgödsel och vallgröda. Våtmarksgräset kommer från Brosjö området utanför Säffle. Under 2010-2014 ingick Brosjö i ett EU projekt som främjar mångfaldignatur och utsatta djurarter, vilket bland annat har gett ett ekonomisk stöd i att skörda gräset. Det skördade gräset har idag ingen användning, men skulle kunna passa i en rötprocess. Det andra området var att jämföra resultaten med tidigare rapporter inom rötning samt användandet av våtmarksgräs. Arbetet av Neldorin (2015) där en studie om substratmixen vid Mosserud gjordes, låg som grund för hur biogasproduktionen ser ut på Mosseruds anläggning idag och jämfördes med metanproduktionen i denna studie. Den andra rapporten studerade våtmarksgräs som additiv i pellets. Där Henriksson (2016) hade fokus på energiåtgången av pelleteringen när våtmarksgräs från Brosjö användes. Rötningsförsöken skedde på Karlstads universitet, där rötningen var en semi- kontinuerlig våt process med mesofila förhållanden. Där inmatning och uttag av gas gjordes en gång om dagen, vilket var samma uppställning som Neldorin (2015) använde. Försöket varade under 10 veckors tid och 2 olika substratblandningar användes; en med 30 % gräs 70 % matavfall och en med 15 % gräs 85 % matavfall. Resultatet gav att rötningen med substratblandningen 30 % gräs 70 % substrat från Mosserud var att föredra. Den specifika metanproduktionen var 0,300 och 0,350 Nm3/kg VS/dag, vilket var mindre än de värde som kommit fram från Mosserud 0,352 Nm3/kg VS/dag. Den totala produktionen av metangas kunde ökas mellan 1,5 - 2,6 % då mer substrat fanns tillgängligt. Våtmarksgräset var bättre att använda till rötning än till pelletering då rötning kunde öka den totala metanproduktionen, medans pelleten som tillverkades inte uppfyllde kraven på hållfasthet, bulkdensitet och andel finfraktion. De problem som är kopplade till att använda gräs i rötning är slambildning i reaktortanken och processen stabilitet under en längre tid, då pH värdet sjönk av ansamling av VFA.The worlds increasing need for energy and the desire to minimize the consequences of climate change have led to several environmental goals at both national and international levels. Many resources are spent on developing the current renewable energy sources and to find new alternatives. One of the renewable energy resources is biogas. Biogas is formed when organic matter is decomposed which forms carbon dioxide and energy rich methane gas. This master's thesis has focused on two areas, the first to examine methane production in a co- digestion process with silage of wetlands grass and food waste from Mosserud biogas plant. Mosserud is located a couple of kilometers west of Karlskoga city. Today the plant mainly uses food waste, manure and ley crops. The wetland grass originates from an area outside of Säffle called Brosjö. In 2010-2014 the Brosjö area was a part of an EU project that promotes bio diversity and threaten animal species, which . Due to this project the harvesting of grass has been made easier and has no use today, but could fit in an anaerobic digestion process. The second area was to compare the results with earlier reports on anaerobic digestion and the use of wetland grass. Neldorin (2015),vconducted a study of the substrate mix at Mosserud, whihc lays as a basis for biogas production from Mosserud today compared to the results of this study. The second report studied wetland grass as an additive in pellets. Where Henriksson (2016) had focus on energy consumptions during production of pellets when using wetland grass from Brosjö. The laboratory study was made at Karlstad University, the study was a semi continuous wet anaerobic process with mesophilic conditions. Feeding and withdrawal of gas was made once a day, using the same lab line up as Neldorin (2015) did. The experiment lasted 10 weeks and 2 different substrate mixtures were used; one with 30% grass 70% food waste and one with 15% grass 85% food waste. The result showed that digestion with 30 % grass mix was preferred. The specific methane production was 0.300 and 0.350 Nm3 / kg VS / day, which was less than those obtained from Mosserud at 0,352 Nm3 / kg VS / day. The total production of methane gas could be increased between 1.5 - 2.6% as there was access to more substrates. Wetland grass was better used for digestion than pelleting as it could increase the total methane production, while the pellets produced did not meet the requirements of strength, bulk density and fractional fineness. The problems associated with using grass in digestion are sludge formation in the reactor tank and process stability for a long time, when the pH value fell by the accumulation of VFA.
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Zetterholm, Jonas. "Forest based biorefinery supply chains - Identification and evaluation of economic, CO2, and resource efficiency." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67924.
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Biorefineries for production of fuels, chemicals, or materials, can bean important contribution to reach a fossil-free economy. Large-scaleforest-based biorefineries are not yet cost competitive with their fossil counterparts and it is important to identify biorefinery supply chain configurations with good economic, CO2, and biomass performance if biorefineries are to be a viable alternative to the fossil refineries. Several factors influence the performance of biorefinery supply chains,e.g. type of conversion process, geographical localisation, and produc-tion capacity. These aspects needs to be analysed in conjunction to identify biorefineries with good supply chain performance. There ares everal approaches to improve the performance of biorefineries, wheree.g. integration with other industries can improve the economic perfor-mance by utilisation of excess heat and by-products. From a Swedish perspective the traditional forest industry is of interest as potential host industries, due to factors such as by-product availability, opportunity for heat integration, proximity to other biomass resources, and their experience in operating large-scale biomass supply chains. The objectives of this work were to investigate how different supply chain configurations influence the economic, biomass, and CO2 perfor-mance of thermochemical biorefineries integrated with forest industries,as well as methods for evaluating those supply chains. This work shows that there is an economic benefit for integration with the traditional forest industry for thermochemical biorefineries.This is especially true when the biorefinery concept can replace cur-rent old industrial equipment on site which can significantly improvethe economic performance of the biorefinery, highlighting the role the Swedish forest industry could play to reach a cost efficient large-scale implementation of lignocellulosic biorefineries. The cost for biomass is a large contributor to the total cost of biore-fineries and for traditional techno-economic evaluations, the biomass prices are considered as static variables. A large-scale biorefinery will likely have an impact on the biomass market, which could lead to both changes in the biomass price, as well as changed biomass demand for other industries. A framework where this is accounted for was intro-duced, combining a techno-economic perspective for evaluating the sup-ply chain performance, with a market model which identifies changes in biomass price and allocation due to the increased biomass competition. The biorefinery performance can be determined from several per-spectives and system boundaries, both from a plant-level and a national perspective. To facilitate a large-scale introduction of biorefineries and maximise the benefit from their implementations, there is a need to identify biorefinery concepts with high performance considering severa system boundaries, which has been explored in this work.
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Mishra, Navin. "Analysis of fault ride through disturbances in wind energy." Thesis, Högskolan i Halmstad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-40474.
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Sönefors, Adam. "Kylningens inverkan på pelletskvalitén : En studie om kylning av träpellets med olika kylningsmetoder." Thesis, Karlstads universitet, Avdelningen för energi-, miljö- och byggteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67478.
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Det blir allt viktigare med fler hållbara och miljövänliga lösningar för att kunna ta itu med dagens miljökris och för att kunna ersätta de fossila bränslena. Pelletseldning är en lösning som anses vara koldioxid neutralt och går att elda året runt. För att pelleten ska vara lätthanterlig och tålig så är de b.la. viktigt med en bra bulkdensitet och hållfasthet. Där spelar kylning av pellets roll och därför skall detta examensarbete undersöka hur olika kylningsmetoder påverkar pelletsen kvalité. Ett antal prover av pellets tillverkades på Karlstad universitetet med en pelletsmaskin under två olika labbsessioner. Tre av dessa prover kyldes sedan på olika effekt på en fläkt i en mindre kylanläggning. Två andra prover kyldes i en hink och utspridda i en stor låda/plåt. Dessa stod under natten och kyldes till omgivningstemperaturen. Efter att proverna hade kylts så gjordes olika kvalitétstester på varje kylt prov; bulkdensitet, hållfasthet, hårdhet, fukthalt och andel fabriksmul mättes. En analys av insamlad data gjordes, efter det så kunde en slutsats dras. En fältundersökning gjordes även för att utröna hur olika pelletsföretag går tillväga med deras kylningsprocess och hur tekniken på deras kylning ser ut. Den kylningsmetod från första sessionen som hade bäst resultat i alla kvalitétstester var pelletsen som kyldes naturligt och utspridda i en låda, med en bulkdensitet på 646 kg/m3 och en hållfasthet på 96,6% samt minimalt fabrikssmul. Pelletsen som kyldes på lägsta effekt på kylanläggningen visade också bra resultat på testerna. De mindre bra kylningsmetoderna var pellets som kyldes i hink under natten samt pellets som kyldes på maxeffekt på kylanläggningen. Från andra sessionen så fick pelletsen som kyldes med 30Hz bäst hållfasthet på 98,6% men lägst bulkvikt på 693 kg/m3. Pelletsen som kyldes med max effekt fick sämre hållfasthet och lägst hårdhet. Högst bulkvikt på 737 kg/m3 fick det provet som var utspritt på en plåt och kyldes naturligt. Inget tydligt samband kunde ses mellan resultaten från de olika labsessionerna.
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Michel, Johannes. "The Sustainability of Decentralized Bioenergy Production : Case Study: The 'Bioenergy Village' Bollewick." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-194437.
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The concept of Sustainable Development is an interdisciplinary science. Transcending various academic fields the concept shows paths how the needs of present and future generations can be met through economic development on a finite natural resource base. Global warming and rising sea levels are just two of a series of phenomena that are directly attributable to human-induced increasing greenhouse gas levels in the atmosphere as consequence of the combustion of fossil fuels. Therefore, reducing greenhouse gas emissions through the use of renewable resources such as bioenergy are of vital importance if detrimental environmental effects are to be mitigated. The production of biogas in a decentralized context is receiving much attention in Germany as a means to reduce greenhouse gases and to counteract correlated negative environmental effects, respectively. In addition, socio-economic benefits such as local employment creation have the potential to empower rural communities. Subsidised by the German Renewable Sources Act and its various remuneration schemes, two 500kWel CHP biogas plants are producing through anaerobic digestion of maize silage and manure electricity and heat in the East German village Bollewick, which is the case study. The sustainability of this decentralized system is analyzed by applying a set of indicators. Socio-economic benefits for the population, economic efficiency of the digestion process and impacts of substrate costs on the profitability, greenhouse gas emissions due to land use change and biodiversity loss being some of these indicators. The thesis concludes that none of the sustainability indicators are sufficiently fulfilled in Bollewick. Especially the cultivation of the energy crop maize has despite crop rotations immense negative environmental effects. Therefore, the decentralized biogas production in the rurally coined village Bollewick is not sustainable.
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Kimani, Duane. "Biodiesel and Hydrogen Production : A Study of Nostoc sp. in Pulp and Paper Wastewater." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-125085.
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The modernized world is over-consuming low-cost energy sources that strongly contributes to environmental stress. As a consequence, the interest for environmentally friendly alternatives has increased immensely. One such alternative is utilizing the diazotrophic nature of the heterocystous filamentous cyanobacteria Nostoc sp. as feedstock for biodiesel and hydrogen production using pulp and paper wastewater – a phosphorous and nitrogen deficient medium. In this work, biodiesel and hydrogen production was studied with respect to three main aspects: biodiesel quality properties, lipid content and hydrogen production coupled with a preliminary study investigating the luminous effects on the biomass and biodiesel quality properties when exposed to low (50 μEm-2s-1), medium (150 μEm-2s-1) and high light (300 μEm-2s- 1). The preliminary study showed that an increase of light intensity was associated with parabolic results for biomass following the 10-day cultivation period, with the medium light intensity showing an average dried weight of at the most 203% greater than the two other light intensities. When analysing the FAME- composition, similar results were demonstrated for the fatty acid constituents preferred for biofuel applications, C18:1 and C18:2 fatty acids, where the low, medium and high light showed an accumulative 34.65, 43.1 and 31.6 dwt % respectively. The strain could be of interest as feedstock for biodiesel when cultivated in pulp and paper wastewater, due to the positive results pertaining to the lipid content and biodiesel quality properties. Following the 10-day cultivation period the lipid content obtained was 35.9 dwt %. The biodiesel quality properties were tested to assess the strains suitability for biodiesel and were tested to ensure its accordance to the standards on commercial biodiesel quality; European Standard for Biodiesel as heating oil (EN 14213) and European Biodiesel Standard (EN 14214). The critical parameters tested were the regulated (iodine value, cetane number, density, viscosity, pour point, cold filter plugging point, oxidative stability) and unregulated (FAME-composition) fuel properties. Results obtained showed values within the regulated values set by the different standards. However, due to a high saturated fatty acid content, the strain showed inadequate low temperature flow properties (cloud point, pour point and the cold filter plugging point). This study shows that this strain has a low potential for hydrogen production, with a hydrogen production of 0.13 nmol/mg dry wt/h following the 10-day cultivation period. This low hydrogen production could be attributed to the among other things the current growth phase of the cyanobacteria. Chemical analyses were conducted for revealing the total nitrogen, total phosphorus and chemical oxygen demand (COD) content. Following the 10-day cultivation period, the samples showed a 22% decrease in phosphorous concentration, 11% decrease in COD concentration and 51% increase of nitrogen concentration. The probable causes for this increase is the Nostoc’s diazotrophic nature and the ammonium excretion nitrogen fixation entails, as well as the nitrogen release following the final algal growth phase – the death phase. In conclusion, the results showed great potential, however, further studies are recommended investigating the changes that occurs during cultivation period to further assess the strains potential as well as assessing the continuity of the results with a greater initial cellular concentration. Nonetheless, due to the positive results obtained regarding the nutrient uptake, biodiesel and hydrogen production, this study shows potential for further optimization for the use of Nostoc grown in pulp and paper wastewater for wastewater treatment, biodiesel and/or hydrogen production.
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Isaksson, Simon. "Biogas production at high ammonia levels : The importance of temperature and trace element supplementation on microbial communities." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-350087.
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Andersson, Simon. "Pellet production of Sicklebush, Pigeon Pea, and Pine in Zambia : Pilot Study and Full Scale Tests to Evaluate Pellet Quality and Press Configurations." Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-55393.
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More deaths are caused every year by indoor air pollution than malaria, HIV/AIDS and tuberculosis combined. Cooking with traditional fuels such as charcoal and fuelwood with poor ventilation causes the single most important environmental health risk factor worldwide. It also contributes to environmental issues such as deforestation as traditional biomass fuels and cooking stoves are inefficient and requires large quantities of wood. This is especially critical in Africa where the largest regional population growth in the world is expected to occur. A solution to these issues was realized through fuel pellets and modern cooking stoves by Emerging Cooking Solutions, a company started by two Swedes and based in Zambia. The production of fuel pellets in Zambia is dependent on pine sawdust from small sawmills and is a declining source of raw material. However, other sources of biomass are available in Zambia such as pigeon pea stalk, an agricultural waste product, and sicklebush, an invasive tree species. If these species are viable for pelletization, the production of pellets can increase while reducing issues with sicklebush and promoting cultivation of pigeon pea. The aim of this work is to evaluate if pigeon pea stalk and sicklebush are viable to pelletize in Zambia and how the press is affected by the different raw materials. A pilot study is done at Karlstad University with a single unit press, hardness tester and soxhlet extractor to evaluate how the material constituents correlate to friction in the press channel and hardness of the pellets. The results of the pilot study provide support for full scale tests done in a pellet plant in Zambia. The normal production of pellets from pine sawdust is used as quality and production reference for the tests with pigeon pea stalk, sicklebush, and different mixes of the raw materials. The properties used to evaluate the quality of the pellets are hardness, durability, moisture content, bulk density, and fines. The press configuration is evaluated by logging the electricity consumption by the press motor, calculating the power and specific energy consumption from the logs, and observations during the tests. The results show that sicklebush, and mixes of sicklebush with pigeon pea stalk can produce pellets with better quality than the reference pine pellets. An interesting composition is a mix of 80% pigeon pea and 20% sicklebush that produces pellets with the best quality of all the tests. However, pellets produced from sicklebush and pigeon pea show a larger variation in hardness as compared to the reference pellets from pine sawdust. Mixing pigeon pea with pine reduces these variations but reduces the hardness of the pellets below the reference. The press struggles to process sicklebush and pigeon pea stalk with fluctuating power consumption that causes the motor to trip. The inhomogeneity of the materials in sicklebush and pigeon pea are identified to cause the issues in the press. Production improvements are discussed to facilitate the production of pigeon pea stalk and sicklebush pellets.
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Horn, Svein Jarle. "Bioenergy from brown seaweeds." Doctoral thesis, Norwegian University of Science and Technology, Department of Biotechnology, 2000. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-547.
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Brown seaweeds lack lignin and have a low cellulose content. Thus, seaweeds should be an easier material for biological degradation than land plants. However, seaweeds have a complex composition, and complete degradation of the material necessitates the presence of microorganisms with a broad substrate range. During anaerobic degradation of organic material, energy carriers such as methane and ethanol may be produced. This is a study of two particular species of brown seaweeds; Laminaria hyperborea and Ascophyllum nodosum, which are the most abundant Norwegian species and also the two species that are commercially harvested in Norway.
Most of the degradation studies were carried out in batch systems at pH 7 and at 35 °C. The digestion pattern of the seaweeds were studied by measuring gas production, alginate lyase activity, remaining alginate, the concentrations of uronic acids, VS, COD, mannitol, organic acids and polyphenols. NIR spectroscopy was applied as a new method for alginate quantification. Ethanol production was carried out at 30 °C at different pH, both in batch and continuous cultures. Gas production and concentrations of mannitol, laminaran, ethanol and organic acids were measured.
Methane is the end product of a mixed microbial community. However, it is the initial steps of hydrolysis and acidogenesis that are specific for the raw material. Alginate forms the major structural component of brown algae, and its degradation is catalysed by alginate lyases. Polyphenols proved to be the most important limiting factor in the biodegradation: the content of polyphenols was much higher in A. nodosum than L. hyperborea, and this led to a reduced biodegradability of A. nodosum. However, when the polyphenols were fixed with formaldehyde, this seaweed was also readily degraded. Manipulation of the content of polyphenols in L. hyperborea gave similar results. This toxic effect was probably caused by direct inhibition of the microbes, especially the methanogenic bacteria, and complexation reactions with algal material and enzymes. Generally, the guluronate content of the remaining alginate increased during biodegradation, probably due to the Ca-linked guluronate junction zones less accessible for alginate lyase. The main organic product of the acidogenesis was acetate, which was easily converted to methane. In this study, it was not attempted to optimise the methane yield.
Ethanol is an intermediate in the complete digestion of organic material and is produced by specific microbial strains. Thus, ethanol production should take place under controlled conditions to prevent contamination problems. The complex composition of seaweeds makes it a difficult substrate to ferment to ethanol by one or a few strains of microbes. In this work, laminaran and mannitol extracted from L hyperborea fronds were used as substrate for ethanol production. A bacterium, Zymobacter palmae, was able to produce ethanol from mannitol, but could not utilise laminaran. However, the yeast Pichia angophorae was able to produce ethanol from both substrates simultaneously. Some supply of oxygen was necessary for the fermentation of mannitol, while a too high aeration resulted in the production of organic acids.
Thus, it has been shown that both methane and ethanol can be produced from brown seaweeds. However, an optimisation of the processes will be necessary. Energy production from seaweeds will only be economic if the harvesting costs are low. It may be noted that wastes from the alginate industry may be considered a non-cost raw material for energy production.
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Lerkkasemsan, Nuttapol. "Modeling of Bioenergy Production." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/48591.
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In this dissertation we address three different sustainability concepts: [1] modeling of biodiesel production via heterogeneous catalysis, [2] life cycle analysis for pyrolysis of switchgrass for using in power plant, and [3] modeling of pyrolysis of biomass. Thus we deal with Specific Aim 1, 2 and 3.
In Specific Aim 1, the models for esterification in biodiesel production via heterogeneous catalysis were developed. The models of the reaction over the catalysts were developed in two parts. First, a kinetic study was performed using a deterministic model to develop a suitable kinetic expression; the related parameters were subsequently estimated by numerical techniques. Second, a stochastic model was developed to further confirm the nature of the reaction at the molecular level. The deterministic and stochastic models were in good agreement.
In Specific Aim 2, life cycle analysis and life cycle cost for pyrolysis of switchgrass for using in power plant model were developed. The greenhouse gas (GHG) emission for power generation was investigated through life cycle assessment. The process consists of cultivation, harvesting, transportation, storage, pyrolysis, transportation and power generation. Here pyrolysis oil is converted to electric power through co- combustion in conventional fossil fuel power plants. The conventional power plants which are considered in this work are diesel engine power plant, natural gas turbine power plant, coal-fired steam-cycle power plant and oil-fired steam-cycle power plant. Several scenarios are conducted to determine the effect of selected design variables on the production of pyrolysis oil and type of conventional power plants.
In Specific Aim 3, pyrolysis of biomass models were developed. Since modeling of pyrolysis of biomass is complex and challenging because of short reaction times, temperatures as high as a thousand degrees Celsius, and biomass of varying or unknown chemical compositions. As such a deterministic model is not capable of representing the pyrolysis reaction system. We propose a new kinetic reaction model, which would account for significant uncertainty. Specifically we have employed fuzzy modeling using the adaptive neuro-fuzzy inference system (ANFIS) in order to describe the pyrolysis of biomass. The resulting model is in better agreement with experimental data than known deterministic models.Ph. D.
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Chen, Binbin. "Pyrolytic biochar stability assessed by chemical accelerating aging method." Thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277933.
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Now that the EU and Sweden have adopted a new climate policy framework to regulate net carbon emission. A new concept, negative CO2 emission, has been considered to neutralize the CO2 generated from necessary consumption of fossil fuel. Biochar, as a pyrolytic product from biomass, can store carbon in a relatively stable way. Therefore, it is one of the most promising and outstanding tools for carbon sink. Biochar stability, defined as the ratio of remaining carbon in biochar after 100 years, is the most crucial factor when using biochar for carbon storage. So far, various approaches have been proposed to measure and predict biochar stability, such as elemental analysis, proximate analysis, accelerating aging methods. Each method has its pros and cons. The reliability of these methods still needs to be verified. In this project, the chemical accelerating aging method has been selected for assessing biochar stability, because this method captures both chemical and physical properties of biochar. Besides, the gas, liquid, and solid products generalized during the chemical treatment are collected and analyzed separately in order to study the oxidation mechanism. Biochar in this project is produced from miscanthus and seaweed at various pyrolysis temperature. It is found that biochar stability can be increased by enhancing pyrolysis temperature, and miscanthus biochar is more sensitive to pyrolysis temperature within the pyrolysis temperature range of 350-600℃. The highest biochar stability (73%) has been achieved with miscanthus-derived biochar produced at 550 ℃, which demonstrates high potential as carbon sequestration tool.Nu när EU och Sverige har antagit en ny klimatpolitisk ram för att reglera nettokoldioxidutsläppen. Ett nytt koncept, negativt koldioxidutsläpp, har ansetts neutralisera den koldioxid som genereras av nödvändig förbrukning av fossila bränslen. Biokol, som en pyrolytisk produkt från biomassa, kan lagra kol på ett relativt stabilt sätt. Därför är det en av de mest lovande och enastående verktyg för kolsänka. Biokolsstabilitet, definierad som förhållandet mellan återstående kol i biokol efter 100 år, är den viktigaste faktorn vid användning av biokol för kollagring. Hittills har olika metoder föreslagits för att mäta och förutsäga biokolsstabilitet, såsom elementär analys, proximate analys, accelererande åldrande metoder. Varje metod har sina för-och nackdelar. Tillförlitligheten hos dessa metoder måste fortfarande kontrolleras. I detta projekt har den kemiska accelererande åldrandemetoden valts ut för att bedöma biokolsstabilitet, eftersom denna metod fångar upp både kemiska och fysikaliska egenskaper hos biokol. Förutom, gasen, flytande, och fasta produkter generaliserade under den kemiska behandlingen samlas in och analyseras separat för att studera oxidation mekanism. Biokol i detta projekt framställs av miscanthus och tång vid olika pyrolystemperatur. Det visar sig att biokolsstabiliteten kan ökas genom att öka pyrolystemperaturen, och miscanthusbiokol är mer känsligt för pyrolystemperatur inom pyrolystemperaturområdet 350-600°C. Den högsta biokolsstabiliteten (73%) har uppnåtts medbiokol som framställts vid 550°C och som visar stor potential som kolbindningsverktyg.
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Karlsson, Jonas. "Modeling and simulation of existing biogas plants with SIMBA#Biogas." Thesis, Linköpings universitet, Teknisk biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138638.
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The main purpose of this project was an attempt to modulate and simulate two existing biogas plant, situated in Lidköping and Katrineholm, Sweden and evaluate how the process reacts to certain conditions regarding feeding, layout and substrate mixture. The main goal was to optimize the existing processes to better performance. Both the modeling and simulation were executed in SIMBA#Biogas with accordance to the real conditions at the plant in question. The simulation of each model was validated against data containing measurements of, CH4 yield, CH4 production, TS, VS, NH4-N concentration and N-total concentration. The data was obtained from each plant in accordance with scheduled follow ups. Both models were statistically validated for several predictions. Predictions of N-total and NH4-N concentration failed for some cases. Both plants were tested with new process lay outs, where promising results were obtained. The Lidköping model was provided with a post-hygienization step to handle ABPs. The Katrineholm model was provided with a dewatering unit, where 35% of the centrate was recirculated back to the system. Both setups was configured to yield the highest CH4 production. This study suggests that SIMBA#Biogas can be a tool for predictions and optimizations of the biogas process.
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Ankarhem, Mattias. "Bioenergy, pollution, and economic growth." Doctoral thesis, Umeå : Umeå University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-530.
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Wells, Tyrone. "Lignin for bioenergy & biomaterials." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53575.
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Sustainable waste treatment and lignin development strategies targeted for biorefineries will benefit industry, consumers, and the environment. This dissertation demonstrates the feasibility of a novel biochemical pathway capable of converting sugars and lignin sourced from biorefinery waste streams into microbial oils suitable for biodiesel, cosmetic, and biopharmaceutical applications. This biochemical pathway also presents interesting avenues for the commercial production of higher-value intermediate metabolites such as catechol, protocatechuate, pyruvate, and succinate. Alternatively, this dissertation also demonstrates a unique polymerization strategy for lignin that can be adopted towards the production of green polymeric biomaterials. Overall, these strategies jointly present intriguing routes for lignin valorization.
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Akgul, O. "Optimisation of bioenergy supply chains." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1418184/.
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This thesis aims to address the optimal strategic design of bioenergy supply chains and provide insight into the future implications of these systems. Among the bioenergy supply chains, biomass-to-biofuel (as the main focus), biomass-to-bioelectricity and biomass-to-hydrogen routes are studied within the context of this thesis. To solve these problems, mathematical programming, especially mixed integer linear programming (MILP), models and solution approaches are developed. Regarding the biofuel supply chains, deterministic, spatially-explicit, static optimisation models are developed first based on single economic objective considering first and hybrid generation systems. A “neighbourhood” flow approach is also proposed for the solution of these models. This approach provides significant computational savings when compared to similar models in literature. The single objective modelling framework is then extended to a multi-objective optimisation model which considers economic and environmental objectives simultaneously. The multi-objective model can provide insight into the trade-offs between the two conflicting objectives. Finally, the single objective static model is further developed into deterministic and stochastic multi-period modelling frameworks to incorporate temporal effects such as change of demand and biomass availability with time as well as uncertainty related to different aspects such as biomass availability. Regarding the bioelectricity supply chains, a deterministic, spatially-explicit, static, multi-objective mathematical programming model is developed based on mixed integer nonlinear optimisation. This considers electricity generation through biomass enhanced carbon capture and storage (BECCS) systems. The model aims to address issues such as carbon tax levels required to incentivise decarbonisation in the power sector as well as the potential impacts of biomass availability and commodity (carbon and coal) prices. The biomass-to-hydrogen route is considered as one of the possible conversion pathways within a deterministic, spatially-explicit, multi-period model developed for the optimal strategic design of future hydrogen supply chains. A two-step hierarchical solution approach is also proposed to increase computational efficiency during the solution of the large scale problem. The model results provide insight into the optimal evolution of a hydrogen supply chain through time.
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Wang, Shule. "Catalytic fast pyrolysis of softwood under N2 and H2 atmosphere." Thesis, KTH, Energi- och ugnsteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216995.
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Bio-oil generated from biomass is becoming one of the most promising alternatives as potential energy sources to replace fossil fuels in the transportation sector. Fast pyrolysis of biomass is one of the most economically feasible ways to produce bio-oil according to recent research on thermochemical conversion of biomass. Upgrading of oils derived from to hydrocarbon fuels requires oxygen removal and molecular weight reduction. Catalytic cracking and hydrotreating are two efficient processes to upgrade bio-oil. Hydrotreating requires that hydrogen is added in the process to increase the H/C ratio of the product. Normally, catalytic fast pyrolysis and hydrotreating are two separated processes. In order to increase the energy efficiency of the process, exploring the fast pyrolysis of biomass with in-situ catalyst under the hydrogen atmosphere, i.e. catalytic hydropyrolysis shall be very interesting, and this is the objective of this work. In this work, biomass pyrolysis experiments using softwood have been performed in hydrogen and nitrogen atmospheres with/without catalyst. It was found that in the case of the H2 atmosphere, a higher yield on oil phase and a reduced water production is found. More oxygen was removed as CO and CO2. The catalytic fast pyrolysis (CFP) under H2 atmosphere also produce relatively more PAH (polymer aromatic hydrocarbon) and less MAH (monomer aromatic hydrocarbon) than under N2 atmosphere.
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Parsland, Charlotte. "Study of the activity of catalysts for the production of high quality biomass gasification gas : with emphasis on Ni-substituted Ba-hexaaluminates." Licentiate thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-55702.
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The fossil hydrocarbons are not inexhaustible, and their use is not without impact in our need of energy, fuels and hydrocarbons as building blocks for organic materials. The quest for renewable, environmentally more friendly technologies are in need and woody biomass is a promising candidate, well provided in the boreal parts of the world. To convert the constituents of wood into valuable gaseous products, suitable for the end use required, we need a reliable gasification technology. But to become an industrial application on full scale there are still a few issues to take into account since the presence of contaminants in the process gas will pose several issues, both technical and operational, for instance by corrosion, fouling and catalyst deactivation. Furthermore the downstream applications may have very stringent needs for syngas cleanliness depending on its use. Therefore, the levels of contaminants must be decreased by gas cleanup to fulfil the requirements of the downstream applications. One of the most prominent problems in biomass gasification is the formation of tars – an organic byproduct in the degradation of larger hydrocarbons. So, tar degrading catalysts are needed in order to avoid tar related operational problems such as fouling but also reduced conversion efficiency. Deactivation of catalysts is generally inevitable, but the process may be slowed or even prevented. Catalysts are often very sensitive to poisonous compounds in the process gas, but also to the harsh conditions in the gasifier, risking problems as coke formation and attrition. Alongside with having to be resistant to any physical and chemical damage, the catalyst also needs to have high selectivity and conversion rate, which would result in a more or less tar-free gas. Commercial tar reforming catalysts of today often contain nickel as the active element, but also often display a moderate to rapid deactivation due to the causes mentioned.
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Lopes, Merwyn. "Feasibility study: Biogas in Sonderborg." Thesis, KTH, Industriell ekologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-33068.
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The purpose of this feasibility study has been to guide decision makers in the implementation of abiogas project for the region of Sønderborg, Denmark. The project has been part of Feasibility studies envisioned in the Master Plan for Sønderborg to go carbon neutral by 2029. The study tried to evolve abest alternative for the city and gives a ready document to refer all aspects of biogas. The intensive industrial farming in Sønderborg needs to evolve to compare favorably with the situationin other regions of Denmark. The interests of various stakeholders in the waste cycle should be alignedwith that of farming. Interesting developments in the Bioenergy space hold promise for farmers to usetheir capacities for additional or alternative livelihood in energy. The focus to promote biogas as part ofDanish energy strategy and multiply capacity over the next 3 years has attracted numerous biogas proposals all over Denmark. This study had started off with identifying and estimating very obvious substrate sources. At verymoderate assumptions the value of methane in these sources has been estimated at 9 million m3. Thispotential could easily be increased if economically feasible substrates like energy crops and algae areadded. The SWOT analysis of pig farming in the region brings out the perspectives of farming direction in the near future. The 5 scenarios developed help the decision maker understand the various aspects thatneed to be carefully considered when planning the plant. The best case scenario for the city would bethe energy mosaic scenario which would integrate the high tech focus of local industry, a renewable energy source and a showcase project to make the region stand out among the other regions focused inthe climate change debate. The technological system analysis should help decision makers understand the stakeholders and the various dimensions in biogas that although complicated are manageable. The business case approach to identify utilization of energy and its costs gives a clear picture on the need for using the energy in CHP.The present focus by potential investors on government subsidies to calculate profitability needs to be understood in the context of other similar plants accepting present subsidy levels and the societal benefits, which unfortunately cannot be valued in money terms. At the center of all this is the need for proper stakeholder management within a bound timeframe asidentified by the “Create acceptance process”. The various tools and data are all present in this study,that only need to be arranged and presented by the company eventually handling the strict Projectmanagement goals of this project.www.ima.kth.se
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Reuterswärd, Caspar. "Exploring the repurposing of cross laminated timber spillage." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-161026.
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Forestry is one of Sweden’s largest natural resources and a largeand important foundation for the country’s economic stability.There is a significant opportunity to evaluate material efficiencyand values in the supply chain of industrialised wood-basedproducts. This thesis comprises on handling a spill-product of amodern wood-based building material: cross-laminated timber(CLT). With the aim to increase value of this spill product throughpractical design iteration, material exploration and theoreticalanalysis. The material exploration leads to a collection of furnitureand interior products which are evaluated based on commercialinterest and production feasibility.
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Plews, Ian Kenneth. "Sorghum bioenergy genotypes, genes and pathways." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2432.
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Haney, Paul E. "Corn stalk as a bioenergy resource /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115551.
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Pietracci, Breno <1977>. "Essays on the microeconomics of bioenergy." Doctoral thesis, Università Ca' Foscari Venezia, 2013. http://hdl.handle.net/10579/3016.
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This thesis explores the microeconomics of bioenergy with focus on Brazil. The three chapters are interconnected by this thread. The first chapter investigates empirically land use patterns for liquid biofuels production in Brazil using the neoclassical land use model. It analyzes the determinants of sugarcane and soybean production location. The second chapter inquire empirically, using regional variables, location and capacity decision drivers for ethanol and biodiesel mills in Brazil. The third chapter proposes a microeconomic framework for modeling several types of bioenergy production. It provides a definition of bioenergy clusters and tests it employing statistical cluster analysis considering three different bioenergy production chains.Questa tesi esplora la microeconomia della bioenergia con un focus nel Brasile. I tre capitoli sono interconnessi da questo filo. Il primo capitolo analizza empiricamente i modelli di uso del suolo per la produzione di biocarburanti liquidi in Brasile utilizzando il modello neoclassico d'uso del suolo, analizzando le determinanti di localizzazione della produzione di canna da zucchero e soia. Il secondo capitolo investiga empiricamente i meccanismi alla base delle decisioni di localizzazione e di capacità per impianti d'etanolo e biodiesel in Brasile utilizzando variabili regionali. Il terzo capitolo propone un quadro microeconomico per modellare diversi tipi di produzione di bioenergia e fornisce una definizione di cluster bioenergetico validata usando l'analisi statistica di cluster considerando tre differenti catene di produzione di bioenergia.
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Lerin, Tommy. "Förutsättningar och Avsättningar för Biogas för Gröna Vessigebro : Version 1.0." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25745.
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The community Vessigebro, in Falkenberg and its surrounding areas housing one percent of all dairy cattle and two percent of all pigs in Sweden. This means that there is a large amount of manure as a basis for producing biogas in the area. A number of farmers have therefore formed a cooperative named Vessigebro biogas and started the project Green Vessigebro, with the goal of creating the conditions for a more profitable and more sustainable agriculture production. The study deals with the conditions and sale opportunities of the feasibility study Green Vessigebro. The study has looked at the work that was previously carried out for the biogas that could be produced on the farms in Vessigebro, The main pipeline for natural gas on the Swedish west coast and its operators, the Swedish Competition Act , Electricity Act , Natural Gas Act, the District Heating Act , Sustainability Act , previously proposed measures, municipality interest in biogas from Vessigebro , possible collaborations, possible sale opportunities and perform calculations with data from the municipality Ljungby for a suggested transportation of biogas between Vessigebro and Ljungby. The study shows that there are several interesting sale opportunities for biogas from Vessigebro. The production and use of biogas in Sweden is increasing and the trend seems set to continue. Six gas retailers can buy gas, which EON is the most established around Vessigebro with a distribution network. EON: s distribution network runs only a few kilometers from the planned upgrading plant , in Vessigebro. An already built upgrading facility is one mil from Vessigebro. Swedegas is the only main pipeline network owner with storing and balancing responsibility on the main line that is closer than EON distribution network. A number of suppliers and industries have shown interest in purchasing the biogas and the interest from potential buyers are likely to increase when the biogas production starts. A collaboration with, for example, "Arena Bioenergy Halland" increases business intelligence and can provide an increased influence with policy proposals. The use of gas and the interest is too low for the moment for tractors, boats, trains, buses and taxis to be a possible outlet specifically for Vessigebro biogas. The conditions make it interesting for Vessigebro biogas to look at five different options for sale opportunities of the biogas. Three options are based on a pipeline to either the pipeline, owned by Swedegas or EON distribution line alternatively a pipeline to EON upgrading facility. One possibility is to replace vehicles that run on fossil fuels with gas-powered vehicles providing a local use and purpose and the aims of the project Green Vessigebro. The calculations made by the study with different conditions shows that a very interesting and possible sale opportunity is a transportation of biogas between Vessigebro and Ljungby. The conclusion from the study shows that conditions and sale opportunities are good for the planned biogas production of Green Vessigebro to become reality.
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Xu, Vita. "The POTENTIAL OF MICROALGAE TECHNOLOGY AT THE CEMENT INDUSTRY ON GOTLAND." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445509.
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Due to the increasing climate change concerns, biofuels have attracted more attention in the energy field as potential alternative energy sources. Particularly, microalgal biofuel has stood out because of its higher fuel yield potential and lower water and land demand than terrestrial biomass. Because of its outstanding photosynthetic efficiency, the microalgal technology is also investigated by researchers around the world as a potential biological solution for carbon capturing in the industrial sector. To explore the prospects of microalgal technology in a local context, this research lays it focus on investigating the potentiality of microalgal biofuel in the cement industry on Gotland, which is the largest emitter of greenhouse gases on the island. For this purpose, the thesis implements a series of estimations based on the emission data of Cementa AB, Slite, a picture of the potential production of algal biomass and biofuel was created, followed by comparisons to the energy situation on Gotland. While practical data of the selected microalgae species are presented, the results indicate a high potential of microalgae in the production of algal biofuel and the possibility for algal biofuel to power the industrial sector of Gotland, or even the island entirely. Although the estimations are made based on an assumption where all controlling parameters are assumed to be perfectly manipulated, the results still indicate the significance of microalgal technologies in the near-future bioeconomy and global energy system.
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Helgesson, Per Otto Ragnar, and Gustaf Elias Båberg. "Biogasframställning på kryssningsfartyg." Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-74557.
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Bränsle är en av det största kostnaden för sjöfart och ny teknik tas fram för att spara bränsle. Men det finns potential att tillverka bränsle på kryssningsfartyg. En av de största utgifterna för att tillverka biogas iland är uppvärmning av substratet, denna kostnad kan elimineras på fartyg genom att använda spillvärme från motorer och ångsystem. Detta arbete undersöker möjligheten att producera biogas av toalett- och matavfall som dagligen skapas på kryssningsfartyg, vilka komponenter som behövs samt beräkningar av utrymme de skulle ta och hur stor mängd gas som kan tänkas produceras. Rapporten utfördes genom att undersöka hur biogas produceras i land, vilka är de vanligaste teknikerna som används idag och om de är teknisk möjliga att ha på kryssningsfartyg. För att räkna ut gaspotential samt volym för tankar och reaktor har data samlat in från fyra kryssningsfartyg, data för toalettavfall har tagit från land. Resultatet av beräkningarna blev att potential att tillverka biogas finns men att mängden gas inte kan motivera kostnaden för att installera en biogasanläggning på ett kryssningsfartyg.Fuel is one of the biggest costs in shipping today, and new technologies are being developed to save fuel. But there is potential to make fuel today aboard cruise ships. One of the biggest expenses in making biogas on land is the heating of the substrate, this cost can be eliminated on ships by using waste heat from engines and steam systems. This report explores the possibility of producing biogas by using toilet and food waste that is created daily aboard cruise ships. What components are needed, calculations of the space they would take and how much gas could be produced. The report was conducted by examining how biogas is produced on land, what are the most common technologies used today? And if they are technically possible aboard a cruise ship? To calculate gas potential, tank and reactor volume. Data has been collected from four cruise ships. The results show that it is possible to create biogas. But that the amount of gas could not justify the cost of building a biogas plant aboard cruise ships.
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Grandis, Adriana. "Respostas fotossintéticas e de crescimento da espécie amazônica Senna reticulata sob elevada concentração de CO2." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-18012011-171004/.
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Processos fisiológicos que modulam a aclimatação fotossintética e o crescimento de plantas ao aumento da concentração de CO2 atmosférico são desconhecidos para a maioria das espécies da região amazônica. Neste sentido, este estudo buscou compreender o comportamento fotossintético e a alocação de carbono em Senna reticulata. Esta espécie ocorre em regiões amazônicas que passam por períodos de seca e alagamento e como estratégia de estabelecimento possui crescimento rápido e alta capacidade fotossintética. O objetivo deste estudo foi comparar os parâmetros de trocas gasosas e de crescimento de plantas cultivadas em câmaras de topo aberto sob diferentes concentrações de CO2 (380ppm-ambiente e 760ppm-elevado). Foram realizadas 6 coletas a cada 15 dias, nas quais foram mensurados pontos relativos as curvas AxPAR e AxCi, calculando-se os parâmetros fotossintéticos de cada curva. Os parâmetros de crescimento foram medidos em coletas destrutivas (biomassa) e não destrutivas (área foliar, altura e nº de folhas). As plantas do tratamento elevado apresentaram maior assimilação fotossintética aos 30 e 45 dias de experimento. Após este período foi observada uma mudança no padrão de alocação (de folha para raízes) e as plantas do elevado apresentaram aclimatação na fotossíntese. A aclimatação foi caracterizada primeiramente por uma redução na velocidade de carboxilação da Rubisco, que foi concomitante com a redução na concentração de N e C foliar. A partir disso ocorreu aumento na senescência das folhas, redução na área foliar e redução na concentração de clorofilas. Somente aos 90 dias é que houve um aumento de 30% na biomassa total das plantas submetidas ao tratamento elevado, resultante do aumento de massa principalmente das raízes e folhas. A transpiração e a respiração das plantas do elevado tenderam a ser menores ao longo de todo o tempo, sendo esta diferença significativa apenas aos 75 dias. Apesar das folhas possuírem menor área foliar e número de folhas, foi observado pela análise de massa especifica das folhas que as plantas do tratamento elevado possuem maior massa em relação às do ambiente, possivelmente pelo maior acúmulo de amido. A eficiência no uso da água foi maior nas plantas do elevado aos 30, 75 e 90 dias. A partir desses dados é possível concluir que S. reticulata submetida ao dobro da concentração atual de CO2, desenvolve processos de aclimatação fotossintética sob longa exposição ao elevado CO2, porém consegue produzir mais biomassa.Physiological processes that modulate growth and photosynthetic acclimation of plants to increased atmospheric CO2 concentration are unknown for most species in the Amazon region. This study aimed to understand the photosynthesis and carbon allocation in Senna reticulata. This species occurs in the Amazonian regions that experience periods of drought and flooding and it has a fast growth and a high photosynthetic capacity as a strategy for its establishment. S. reticulata plants were grown in open top chambers under different concentrations of CO2 (380ppm Ambient - 760ppm Elevated) and their gas exchange and growth were compared. The harvests were performed at 15, 30, 45, 60, 75 and 90 days of experiment. At each date, AxPAR and AxCi curves were carried out to calculate the photosynthetic parameters. Growth parameters included biomass, leaf area, height and number of leaves. The plants of elevated CO2 presented higher photosynthetic assimilation at 30 and 45 days of experiment. After this period was observed a change in the carbon allocation (e.g. root to leaf) and the plants at elevated CO2 demonstrated a photosynthetic acclimation. This acclimation was characterized primarily by a reduction in velocity of carboxylation of Rubisco, which was concomitant with the reduction in N and C concentration in leaves. Also, the plants at elevated CO2 showed an increase in leaf senescence and a reduction in leaf area and chlorophyll concentration. After 90 days there was an increase (i.e. 30%) in total biomass of plants growing under elevated CO2, due to increase of roots and leaves biomass. The transpiration and respiration rates of plants at elevated CO2 tended to be lower throughout the experiment and the significant difference was found at 75 days. Although the leaves have less leaf area and leaf number, it was observed that specific leaf area from elevated CO2 treatment showed higher biomass when compared to ambient CO2. That difference possibly occurred due to greater starch accumulation. The water use efficiency was greater in plants from the elevated CO2 at 30, 75 and 90 days. From these data we conclude that S. reticulata grown at the elevated CO2 produces more biomass despite occurs the photosynthetic acclimation under long exposure to high CO2.
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Olsson, Olle. "European bioenergy markets : integration and price convergence /." Uppsala : Dept. of Energy and Technology, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/11701267.pdf.
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Welfle, Andrew James. "Biomass resource analyses & future bioenergy scenarios." Thesis, University of Manchester, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.644461.
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The United Kingdom has committed itself to ambitious and legally-binding Greenhouse Gas emission reduction, and renewable energy contribution targets. Energy production from biomass is expected to play a significant role in achieving these targets. The PhD Research Project as presented in this Thesis provides an analysis of the UK’s indigenous biomass resources, and the potential they offer in servicing domestic bioenergy requirements. The biomass resource supply chain dynamics within the UK, govern the availability of these indigenous resources. By modelling these supply chain dynamics, an assessment has been undertaken; the principle aim of which was to evaluate the potential contribution that indigenous biomass resources can make towards the UK’s future energy mix. This Research finds that the United Kingdom has considerable indigenous biomass resources that could potentially be made available, if the UK were able to develop its supply chains to appropriately mobilise these resources. However, the specific demands and the direction of development of the UK’s future bioenergy sector, as driven by the UK Government’s current strategies and policies; demonstrate degrees of incompatibility with the forecast potential of biomass resource availability. The consequence of this disparity is likely to result in rising biomass resource imports to balance the UK’s future energy demands. Further analysis highlights the potential impacts, inherent uncertainties, and risks to the United Kingdom’s bioenergy sector; associated with trade within future global biomass resource markets. The concluding themes are based on analyses and discussions that indicate that the UK should implement strategies to develop its indigenous resources, and develop its supply chains to optimise these resources; rather than become heavily reliant on imports from the global markets.
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AUDIELLO, DANILO. "Internationalisation and Bioenergy Effects on Economic Growth." Doctoral thesis, Università di Foggia, 2015. http://hdl.handle.net/11369/338336.
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Abstract
Existing literature evidence suggests a strong relationship between internationalisation and
economic growth, as well as a link between biofuel production and economic growth for various
clusters of countries, including the members of the Eurozone. As Eurozone policy is shaped with a
special focus on internationalisation and well defined directives on bioenergy, their actual effect on
economic growth needs to be further investigated.
This dissertation aims firstly to evaluate the impact of internationalisation, as represented by foreign
direct investments (FDI) and trade openness, and secondly to measure the effects of bioenergy
production, as represented by the daily volume of total biofuel production, on the economic growth,
as represented by the growth rate of real gross domestic product (GDP), of the Eurozone.
The analysis is conducted by employing the methods of linear regression, under the exogenous
growth theory. The research methodology implies a quantitative analysis of economic data collected
from the World Bank and OECD, for the period from 1991 to 2013. In addition to this, the model
includes several control variables such as labour force, technology, fixed capital formation and the
savings rate.
The results of the research reject the hypotheses of the significant effects of internationalisation and
biofuel production on economic growth in the Eurozone. The factors that appear to affect economic
growth are the growth of gross fixed capital, inflation, human capital and savings.
Abstract
La letteratura esistente evidenzia una forte relazione tra l'internazionalizzazione e la crescita
economica, oltre che una relazione tra la produzione di bioenergie e la crescita economica per vari
gruppi di paesi, includendo i paesi membri della zona euro. Poiché la politica dell'Eurozona viene
continuamente modificata e modellata con una particolare attenzione all’internazionalizzazione e a
ben definite direttive sulle bioenergie, il loro effetto reale sulla crescita economica ha bisogno di
essere ulteriormente approfondito.
Questa tesi si propone in primo luogo di valutare l'impatto sulla crescita economica
dell’internazionalizzazione, rappresentato dagli investimenti diretti esteri (FDI) e dall'apertura
commerciale, ed in secondo luogo di misurare gli effetti della produzione di bioenergie,
rappresentato dal volume giornaliero della produzione totale di biocarburanti, sulla crescita
economica, quest’ultima rappresentata dal tasso di crescita del prodotto interno lordo (PIL), della
zona euro.
L'analisi viene condotta impiegando i metodi di regressione lineare, secondo la teoria della crescita
esogena. La metodologia di ricerca implica un’analisi quantitativa dei dati economici raccolti dalla
Banca Mondiale e dall’OCSE, nel periodo tra il 1991 ed il 2013. In aggiunta, il modello include
diverse variabili di controllo come la forza lavoro, la tecnologia, gli investimenti fissi lordi ed il
tasso di risparmio.
I risultati della ricerca hanno respinto le ipotesi di effetti significativi dell’internazionalizzazione e
della produzione di biocarburanti sulla crescita economica nella zona euro. I fattori che hanno
inciso in modo significativo sulla crescita economica sono stati la crescita del capitale fisso,
l'inflazione, il capitale umano ed i risparmi.
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GONZALEZ, SALAZAR Miguel Angel. "Strategic planning of biomass and bioenergy technologies." Doctoral thesis, Università degli studi di Ferrara, 2016. http://hdl.handle.net/11392/2395637.
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Il dimensionamento di sistemi energetici sostenibili e rispettosi dell'ambiente è una sfida fondamentale che deve essere affrontata dalle nazioni di tutto il mondo. Questa sfida è particolarmente rilevante nei paesi in via di sviluppo, in quanto vi sono aree remote ancora non elettrificate, vi è una eccessiva dipendenza da fonti convenzionali di energia, si registra una carenza
di risorse finanziarie e non sono sviluppate ed implementate adeguate politiche e regolamentazioni. L'obiettivo di questa tesi è lo sviluppo di una metodologia per la pianificazione strategica delle tecnologie basate su biomasse e bioenergie in genere, nei paesi in via di sviluppo. L'approccio seguito è quello di iniziare da un approccio generale e poi passare ad uno specifico contesto di applicazione, che nel caso in esame è la Colombia. Le metodologie sviluppate ed applicate nella tesi sono relative a quattro aree principali. In primo luogo, viene sviluppato un metodo per stimare l’attuale potenziale energetico della biomassa e la sua incertezza a livello nazionale, per tenere conto del fatto che la disponibilità e la
qualità dei dati possono essere limitati. A questo scopo, si propone un approccio focalizzato sul tipo
di risorsa e bottom-up, con analisi statistica che utilizza un algoritmo Monte Carlo. In secondo luogo, viene sviluppato un metodo per stimare il futuro potenziale energetico della biomassa e il cambiamento di uso del suolo, per paesi il cui mercato nazionale non influenza i mercati internazionali. Il metodo proposto è una combinazione di approcci focalizzati sul tipo di risorsa e guidati dalla domanda, in cui l'energia potenziale della biomassa è influenzato dalla domanda interna, dall’uso del suolo, dall'economia, dalla macroeconomia e dall'uso di biocarburanti globale. In terzo luogo, la tesi propone un metodo per tracciare la roadmap per l’utilizzo di tecnologie energetiche, adattato alle condizioni dei paesi in via di sviluppo, e una nuova strategia per costruire
il consenso sulla base del metodo Delphi. Questi strumenti sono impiegati per la definizione di un piano per implementare tecnologie bioenergetiche sostenibili in Colombia fino al 2030. Il piano è costituito da una serie di obiettivi a lungo termine, di tappe, di barriere e di “azioni” individuate da più di 30 esperti per le diverse aree tecnologiche. In quarto luogo, viene sviluppato un modello generale di simulazione per valutare gli impatti che l’implementazione a lungo termine delle tecnologie bioenergetiche potrebbe causare su domanda e richiesta di energia, emissioni e uso del territorio a livello nazionale. Il metodo combina elementi sia quantitativi sia qualitativi. L'elemento
qualitativo integra i risultati della tecnologia di sviluppo della roadmap con analisi di scenari per indagare varie storie con diverse ipotesi circa le azioni di politica energetica da attuare. L'elemento
quantitativo comprende quattro strumenti integrati, vale a dire il modello di sistema energetico (ESM), l'uso del suolo e un modello di mercato (LUTM), un modello economico e un modello che tiene conto del clima. Questi strumenti servono per quantificare in modo integrato gli impatti conseguenti all’attuazione di diversi scenari sul sistema energetico, le emissioni e l’uso del suolo a
livello nazionale, così come i legami con l'economia e il clima. I risultati dello studio per il caso della Colombia indicano che la diffusione di tecnologie per la produzione di biometano, la generazione di energia e la cogenerazione dovrebbero essere le tecnologie sulle quali investire per il futuro, in quanto permettono di ridurre le emissioni di metano,
la sostituzione dei combustibili fossili, la riduzione delle emissioni di CO2 e la massimizzazione della riduzione di gas serra per suolo incrementale utilizzato per la produzione di bioenergia.The design of sustainable, environmentally friendly energy systems which have adequate capacity is a critical challenge faced by nations across the globe. This challenge is compounded in developing countries, which contain with remote areas yet to be connected to the grid, an over- dependence on conventional sources of energy, a shortage of financial resources, and, limited supporting policies and legislation. The objective of this thesis is to develop methods for strategic planning of biomass and bioenergy technologies in developing countries. The approach followed is to start from the general and move to the specific. After a general formulation of methods, an exemplary case study of Colombia is presented. The formulated methods cover four main areas. Firstly, a method to estimate the current biomass energy potential and its uncertainty at a country level is formulated when availability and quality of data are limited. For this purpose, a bottom-up resource-focused approach with statistical analysis using a Monte Carlo algorithm is proposed. Secondly, a method to estimate the future biomass energy potential and land use change is formulated for countries with domestic markets unable to influence international markets. The proposed method is a combination of resource-focused and demand driven approaches, in which the biomass energy potential is influenced by the internal demand, land use, economics, macroeconomics and global biofuel use. Thirdly, a method for energy technology roadmapping adapted to the conditions of developing countries and a new strategy to build consensus based on the Delphi method are formulated. These tools are employed for defining a plan to deploy sustainable bioenergy technologies in Colombia until 2030. The plan consists of a set of long-term goals, milestones, barriers and action items identified by over 30 experts for different bioenergy technology areas. Fourthly, a modeling framework to evaluate the impacts that long-term deployment of bioenergy technologies might cause on the energy supply and demand, emissions and land use at a country level is proposed. The method combines a quantitative and a qualitative element. The qualitative element integrates outcomes of technology roadmapping with scenario analysis to investigate various storylines with different underlying assumptions on policy measures. The quantitative element comprises four integrated tools, namely the energy system model (ESM), the land use and trade model (LUTM), an economic model, and an external climate model. These tools quantify in an integrated manner the impacts of implementing different scenarios on the energy system, emissions and land-use at a country level as well as the linkages with the economy and climate. Results of the study case of Colombia suggest that the deployment of technologies for biomethane production, power generation & CHP should be prioritized. These technology routes avoid methane release, substitute fossil fuels, reduce CO2 emissions and maximize the GHG reductions per incremental land of bioenergy.
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Catron, Jonathan Franklin. "ECONOMIC AND POLICY IMPLICATIONS OF FOREST-BASED BIOENERGY PRODUCTION IN KENTUCKY." UKnowledge, 2012. http://uknowledge.uky.edu/forestry_etds/4.
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Interest in using woody biomass from forestlands for energy production has reemerged in recent years. In Kentucky, bioenergy has great potential to help reduce reliance on fossil fuels. However, questions still remain about economic and other social effects associated with forest-based bioenergy production. This study investigates some of the economic implications of harvesting woody biomass for bioenergy production alongside traditional forest products in Kentucky. Results show that forest-based bioenergy can increase financial return to nonindustrial private forest owners. This study also investigates social impacts and drivers of forest-based bioenergy in Kentucky. Results indicate that a variety of issues will have to be dealt with in order for bioenergy production from forestlands to be viable in Kentucky.
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Schyllander, Josefin. "Industriell symbios mellan algodling och industri för hållbar biomassaproduktion : Utvärdering av en industriellt integrerat algodling ur miljö-, energi- och kostnadssynpunkt." Thesis, Karlstads universitet, Avdelningen för energi-, miljö- och byggteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-56510.
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Klimatförändringarna har medfört en ökad efterfrågan på biobaserade bränslen. Mikroalger har flera intressanta egenskaper som gör dem till en attraktiv och lovande bioråvara för bränsleproduktion. Algerna har en effektiv fotosyntes vilket bidrar till ett lägre landanspråk jämfört med terrestra energigrödor. Dessutom kan odlingarna placeras på oproduktiv mark vilket gör att produktionen inte konkurrerar med andra areella näringar. Genom att integrera algodlingar med industriell infrastruktur kan restflöden som spillvärme, koldioxid, närsalter och vatten från industri nyttiggöras och därmed bidra till en mer effektiv och hållbar biomassaproduktion. I detta arbete studeras en industriell symbios mellan en algodling, det lokala kraftvärmeverket (Hedenverket) och rötningsanläggningen vid Sjöstadsverket i Karlstads kommun. Symbiosen bygger på att rökgaser från Hedenverket används som kolkälla för algerna, spillvärme används för att upprätthålla en lämplig odlingstemperatur i bassängen, varma rökgaser används för att torka biomassan inför förbränning och algernas näringsbehov tillgodoses genom att cirkulera kväve- och fosforrikt rejektvatten från rötningsanläggningen på Sjöstad. Biomassan som produceras används sedan som bränsle i kraftvärmeverket. På så vis skapas nya kretslopp och ett lokalt biobränsle produceras samtidigt som spillflöden från industrin tas till vara. Två tänkbara scenarion för energiutvinning studerades; rötning (Scenario A) och direkt förbränning (Scenario B). För att belysa fördelarna med symbiosen analyserades även ett referensscenario, vilket bygger på att odlingen sker fristående i en så kallad Stand alone-anläggning. Målet med studien var att konstruera en beräkningsmodell för att simulera biomassaproduktionen utifrån platsspecifika förutsättningar samt utvärdera systemet ur miljö-, energi- och kostnadssynpunkt. Studien utformades som en förstudie med syfte att vara ett övergripande men ändå tydligt kunskaps- och beslutsunderlag för berörda aktörer. Arbetet ska belysa symbiosens styrkor, svagheter, möjligheter och risker. Resultatet från studien visar att det genom industriell symbios går att odla alger över en lång säsong vid Hedenverket i Karlstad med det system som föreslås. Den industriella symbiosen förlänger odlingssäsongen med 75 % jämfört med en Stand alone-anläggning och den årliga produktiviteten ökar från 14 till 18 g m-2 d-1. Miljöanalysen visar att det utifrån de systemförslag som undersöks finns liten eller ingen miljönytta med den industriella symbiosen. Scenario A bidrar till att öka CO2-emsisionerna med 0,2 kg m-2 år-1 medan Scenario B bidrar till en reduktion motsvarande 0,2 kg m-2 år-1. En bidragande faktor till detta resultat är att Karlstad Energis el- och värmeproduktion idag i stort sett redan är fossilfri. Detta medför att det algbaserade bränslet ersätter en redan biobaserad process. En högre miljönytta kan åstadkommas genom att överväga alternativa energiutvinningsprocesser. För att tydliggöra miljöfördelarna med en integrerad algodling bör en fullskalig livscykelbedömning för systemet genomföras. Nettoenergi-ration (NER-värde) för Scenario A och Scenario B beräknades till 2,6 respektive 5,3. De höga NER-värdena pekar på att utvinningen av energi med god marginal överträffar energibehovet i produktionsledet för båda processvägarna. Lönsamhetsbedömningen visade att båda scenariona innebär en återbetalningstid som överstiger den tekniska livslängden för anläggningen, 44 och 56 år för respektive scenario. Sammanfattningsvis visar studien att det finns goda möjligheter för att odla alger och framställa ett lokalproducerat biobränsle vid Hedenverket. Trots att det föreslagna systemet med industriell symbios uppvisar positiva resultat beträffande energiprestanda så finns det inte ekonomiska eller miljömässiga förutsättningar för en algodling vid Hedenverket baserat på den systemutformning som föreslagits. Genom att framställa produkter med högre värde från biomassan kan dock ekonomisk- och miljömässiga vinster uppnås, vilket är något som bör utredas vidare.
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Lee, Eunyoung. "Carbon and Nutrient Balances in Microalgal Bioenergy System." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6885.
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This research investigated life cycle environmental impacts and benefits of an integrated microalgae system with wastewater treatment system using an integrated process modeling approach combined with experimentation. The overall goal of this research is to understand energy, carbon and nutrient balances in the integrated system and to evaluate the environmental impacts and benefits of the integrated system from a carbon, nutrient, and energy perspective. In this study, four major research tasks were designed to contribute to a comprehensive understanding of the environmental and economic sustainability of the integrated system, which included development of an integrated co-limitation kinetic model for microalgae growth (Chapter 2), kinetic parameter estimation models for anaerobic co-digestion (Chapter 3), development of an integrated process model (Chapter 4), and life cycle environmental and economic assessments of the integrated system (Chapter 5).
The integrated co-limitation kinetic model was developed to understand microalgae growth in the centrate from dewatering of anaerobically digested sludge. This growth kinetic model considered four major growth factors, including Nitrogen (N), dissolved carbon dioxide (CO2) concentrations, light intensity, and temperature. The model framework was constructed by combining threshold and multiplicative structures to explain co-limitation among these factors. The model was calibrated and validated using batch studies with anaerobically digested municipal sludge centrate as wastewater source, and the model was shown to have a reasonable growth rate predictor for Chlorella sp. under different nutrient levels of the centrate.
Anaerobic co-digestion was used for energy conversion process in the integrated system. To estimate methane production of anaerobic co-digestion, kinetic models commonly applied. To apply the kinetic model, determining kinetic parameters for anaerobic co-digestion of microalgae and waste activated sludge (WAS) is essential, and this research introduced two potential regression-based parameter estimation models to estimate the kinetic parameters. Using the estimation models presented, the kinetic parameters for co-digestion was able to be determined for different ratios of co-substrates with limited experiments.
In this research, the integrated process model was developed to simulate the dynamic behavior of the integrated system. The model included the microalgae cultivation, harvesting, and anaerobic co-digestion processes in the integrated system to provide a comprehensive understanding of the integrated system. For cultivation, the integrated co-limitation kinetic model was applied to estimate microalgae productivity, while the regression-based parameter estimation model was used to determine the first order kinetic parameter to estimate methane production rates for anaerobic co-digestion. The simulated microalgae productivity results were comparable to typical microalgae productivity in open pond systems. For the integrated system, removal of NH4-N by microalgae was not efficient. In particular, the NH4-N removal was minimal during the winter season due to low microalgae growth. As the microalgae productivity increased, the CH4 and biosolids production increased as a result of the increased amount of the substrates from the harvested microalgae biomass. The increase of CH4 and biosolids productions, however, was minor because of the small amount of microalgae biomass for the co-digestion.
Based on simulated data for integrated process modeling, the life cycle environmental and economic impacts of the integrated system (with different CO2 supply areas) were evaluated and compared to the conventional wastewater treatment system. The integrated systems had a lower carbon footprint, cumulative energy demand, and life cycle cost than the conventional system. The integrated system with 10% CO2 sparging area was able to achieve the lowest carbon footprint. Without CO2 addition during microalgae cultivation, the integrated system had the lowest energy balance and life cycle cost. However, there is no significant difference between the integrated and conventional systems for eutrophication potential because these systems had the same effluent quality. In terms of an energy saving with the integrated systems, the benefit of energy reduction for the wastewater treatment was greater than the energy production from the anaerobic co-digestion, compared to the conventional system. Overall, the integrated system can improve the carbon balance by reducing the life cycle energy required in the conventional system.
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Pang, Xi. "Modelling trade-offs between forest bioenergy and biodiversity." Licentiate thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180333.
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Globally, biodiversity is declining due to loss, fragmentation and degradation of habitat, which undermines ecosystem functioning and therefore threatens also the ability of ecosystems to supply ecosystem services. Moreover, there is a need for adapting to climate change as well as securing the supply of energy, which have led to a shift in energy consumption from fossil fuel to renewables, especially biomass, which in turn put increasing pressure on ecosystems and biodiversity. In Sweden, forest bioenergy has an important role, and high forest biomass production is an important societal objective. Intensified forestry could increase the biomass production through monocultures of native or introduced tree species as well as forest fertilization. However, due to negative effects on natural forest structures and processes, a more intensive forestry could be detrimental to forest biodiversity. The balance between energy demand and the long-term capacity of ecosystems to supply goods and services as well as support biodiversity is therefore crucial. The existing energy models and research have relatively low concerns on land use, landscape and biodiversity, comparing with high enthusiastic on energy economics, climate change and greenhouse gas emission research. Consequently, it would be difficult to provide comprehensive decision support by using only these economy and climate change oriented tools. However, ecological assessment models and multi-criteria approaches exist with great potential for linking with suitable energy models. This will enable the development of more comprehensive decision support tools for assessing future energy scenarios, integrating main policy concerns when assessing renewable energy options. The research was based on a survey on existing energy models and a case study of forest biomass extraction in Kronoberg, a region in southern Sweden. The aim of this project was to develop and test methods for integrated the sustainability assessment of forest biomass extraction for bioenergy purposes by incorporating effects on biodiversity. Forest growth was simulated under two management scenarios: Even-aged-forestry (EAF) and continuous-cover-forestry (CCF), in a time period between 2010-2110. The GIS-based approaches for assessment of biomass impacts on biodiversity involved an ecological network assessment of prioritized ecological profiles across the landscape under the two scenarios.QC 20160111
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Lloyd-Betts, Christine. "Supply chain integration in the UK bioenergy industry." Thesis, Aston University, 2017. http://publications.aston.ac.uk/31761/.
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This study is an investigation on supply chain integration in bioenergy. It takes a different approach from many contemporary studies found in the literature because most research in bioenergy treats technological performance, characteristics of feedstock, impact on energy consumption in relation to the carbon footprint as distinct and separate entities. None of these examples consider bioenergy from supply chain integration and thus, a business performance perspective. The study proposes that bioenergy is defined from the biomass-to-bioenergy, which is from the point of origin to the point of conversion, and that it is a developing industry. It was found that stakeholders play a prominent role throughout the various phases from planning approval to project implementation and are also involved during operational phases of a bioenergy business. In the study this is referred to as stakeholder integration. During handover phases process integration dominates operational activities within the bioenergy firm. By dividing characteristics in a bioenergy business as stakeholder and process integration it is possible to identify constructs that are applicable to bioenergy. These were investigated through secondary research as well as primary research approaches. Inherent within the configuration of bioenergy supply chains are issues and challenges that were different from established energy systems and factors peculiar to conventional supply chain approaches. The research finds bioenergy supply chains tend to be horizontally integrated from B2C, and as yet lack vertical integration, B2B found in mature supply chains. Contributions resulting from this factor, coupled with the research approaches, particularly by using qualitative methods extended knowledge and practice in operations management research as well identifying best practice in a novel and emergent industry.
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Heggenstaller, Andrew Howard. "Productivity and nutrient cycling in bioenergy cropping systems." [Ames, Iowa : Iowa State University], 2008.
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Noshy, Rafeek <1976>. "Optimization of bioenergy solutions at different farm scales." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5650/1/THESIS.pdf.
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RAF is a bio-energetic descriptive model integrates with MAD model to support Integrated Farm Management. RAF model aimed to enhancing economical, social and environmental sustainability of farm production in terms of energy via convert energy crops and animal manure to biogas and digestate (bio-fertilizers) by anaerobic digestion technologies, growing and breeding practices. The user defines farm structure in terms of present crops, livestock and market prices and RAF model investigates the possibilities of establish on-farm biogas system (different anaerobic digestion technologies proposed for different scales of farms in terms of energy requirements) according to budget and sustainability constraints to reduce the dependence on fossil fuels. The objective function of RAF (Z) is optimizing the total net income of farm (maximizing income and minimizing costs) for whole period which is considered by the analysis.
The main results of this study refers to the possibility of enhancing the exploitation of the available Italian potentials of biogas production from on-farm production of energy crops and livestock manure feedstock by using the developed mathematical model RAF integrates with MAD to presents reliable reconcile between farm size, farm structure and on-farm biogas systems technologies applied to support selection, applying and operating of appropriate biogas technology at any farm under Italian conditions.RAF è un modello descrittivo bio-energetico che si integra con il modello MAD per supportare la gestione integrata di un’azienda agricola. Il modello RAF è finalizzato alla valorizzazione economica, sostenibilità ambientale e sociale della produzione agricola in termini di energia tramite la conversione di colture energetiche e letame animale in biogas e digestato (bio-fertilizzanti) mediante tecnologie di digestione anaerobica, coltivazione e pratiche di allevamento. L'utente definisce la struttura della fattoria in termini delle presenti colture, bestiame e prezzi di mercato, e il modello RAF indaga le possibilità di installare il sistema di produzione di biogas in azienda (diverse tecnologie di digestione anaerobica sono proposte per diverse scale di aziende agricole in termini di fabbisogno energetico) secondo i vincoli di bilancio e sostenibilità per ridurre la dipendenza da combustibili fossili. La funzione obiettivo della RAF (Z) è ottimizzare il reddito complessivo netto dell'azienda (massimizzare il reddito e minimizzando i costi) per tutto il periodo considerato dall'analisi. I principali risultati di questo studio si riferiscono alla possibilità di migliorare lo sfruttamento delle potenzialità di produzione di biogas in azienda mediante la produzione di colture energetiche italiane disponibili e letame come materia prima, utilizzando il modello matematico sviluppato RAF che si integra con MAD per presentare un’affidabile equlibrio tra la dimensione dell’azienda agricola, la struttura della fattoria e tecnologie biogas di sistemi applicati in azienda per supportare la selezione, l’applicazione e il funzionamento della tecnologia biogas presso qualsiasi azienda italiana.
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Noshy, Rafeek <1976>. "Optimization of bioenergy solutions at different farm scales." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5650/.
Full textAbstract:
RAF is a bio-energetic descriptive model integrates with MAD model to support Integrated Farm Management. RAF model aimed to enhancing economical, social and environmental sustainability of farm production in terms of energy via convert energy crops and animal manure to biogas and digestate (bio-fertilizers) by anaerobic digestion technologies, growing and breeding practices. The user defines farm structure in terms of present crops, livestock and market prices and RAF model investigates the possibilities of establish on-farm biogas system (different anaerobic digestion technologies proposed for different scales of farms in terms of energy requirements) according to budget and sustainability constraints to reduce the dependence on fossil fuels. The objective function of RAF (Z) is optimizing the total net income of farm (maximizing income and minimizing costs) for whole period which is considered by the analysis.
The main results of this study refers to the possibility of enhancing the exploitation of the available Italian potentials of biogas production from on-farm production of energy crops and livestock manure feedstock by using the developed mathematical model RAF integrates with MAD to presents reliable reconcile between farm size, farm structure and on-farm biogas systems technologies applied to support selection, applying and operating of appropriate biogas technology at any farm under Italian conditions.RAF è un modello descrittivo bio-energetico che si integra con il modello MAD per supportare la gestione integrata di un’azienda agricola. Il modello RAF è finalizzato alla valorizzazione economica, sostenibilità ambientale e sociale della produzione agricola in termini di energia tramite la conversione di colture energetiche e letame animale in biogas e digestato (bio-fertilizzanti) mediante tecnologie di digestione anaerobica, coltivazione e pratiche di allevamento. L'utente definisce la struttura della fattoria in termini delle presenti colture, bestiame e prezzi di mercato, e il modello RAF indaga le possibilità di installare il sistema di produzione di biogas in azienda (diverse tecnologie di digestione anaerobica sono proposte per diverse scale di aziende agricole in termini di fabbisogno energetico) secondo i vincoli di bilancio e sostenibilità per ridurre la dipendenza da combustibili fossili. La funzione obiettivo della RAF (Z) è ottimizzare il reddito complessivo netto dell'azienda (massimizzare il reddito e minimizzando i costi) per tutto il periodo considerato dall'analisi. I principali risultati di questo studio si riferiscono alla possibilità di migliorare lo sfruttamento delle potenzialità di produzione di biogas in azienda mediante la produzione di colture energetiche italiane disponibili e letame come materia prima, utilizzando il modello matematico sviluppato RAF che si integra con MAD per presentare un’affidabile equlibrio tra la dimensione dell’azienda agricola, la struttura della fattoria e tecnologie biogas di sistemi applicati in azienda per supportare la selezione, l’applicazione e il funzionamento della tecnologia biogas presso qualsiasi azienda italiana.
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BOLOGNESI, SILVIA. "Microbial Electrochemical Technologies for Biofuels and Bioenergy Production." Doctoral thesis, Università degli studi di Pavia, 2021. http://hdl.handle.net/11571/1425234.
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Wastewater treatment and energy production are key points to grant the next generations health, economic, and environmental sustainability. The water–energy nexus represents a synergy between water, energy and the environment, leading to complex relationships between stakeholders, authorities, resources and environmental management. Research nowadays is focusing on developing efficient, green technologies based on water responsible use, sustainable energy management and environmental preservation; on the other hand, green energy production processes and resource recovery from waste streams are essential factors in environmental sustainability.
Microbial electrochemistry is a branch of bioelectrochemistry based on the study and application of the interactions between living microbial cells and a solid-state electrode, serving well the purpose of the water-energy nexus. In the last two decades many biologist and microbiologists, chemists, biotechnologists, engineers have focused their interest on the different applications and interaction mechanisms of this new research field. Microbial Electrochemical Technologies (METs) present attractive applications, such as: (i) wastewater treatment, (ii) groundwater pollutants removal, (iii) water desalination and (iv) synthesis of added value carbon chemicals.
In this context, two applications are thereby studied and operated in the present thesis, to investigate potential energy recovery options from waste streams: Microbial Fuel Cells (MFCs) and Microbial Electrosynthesis (MES). MFCs rely on direct conversion of the chemical energy of a substrate into electrical energy, while MES technology focus on electron (energy) utilization for chemical commodities production (for example, biofuels) using a liquid or gaseous waste stream as feedstock.
However, the implementation of METs in scaled-up applications depends upon the optimization of microbial, technological, and economic issues: (i) use of genetically engineered bacteria, (ii) biological or chemical catalysts, (iii) materials, reactors and electrode design. Other strategies rely on integration of METs with different technologies. The present thesis also explores the possibility of combining microalgae and METs, and the possible products that can be recovered from waste streams in the attempt to improve the water-energy nexus balance.
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Ljungberg, Stina. "Drivkrafter och hinder ur ett multifunktionellt perspektiv : Förutsättningar och utvecklingsområden för produktion av biobränsle från våtmarker." Thesis, Södertörns högskola, Miljövetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-31057.
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Då Sverige redan nått flera av de energi- och klimatpolitiska målen kan målet om att skapa ett fossilfritt samhälle stå som ytterligare drivkraft för att fortsätta utvecklingen av de hållbara bränslena. Bidrag finns att få för att anlägga våtmarker, minska klimatpåverkan, förbättra naturmiljön och för utvecklandet av ny teknik samt bygga upp anläggningar för biobränsleproduktion. Trots detta har odling av våtmarksgrödor för energiutvinning ännu inte etablerats på energimarknaden. Denna studie är en del i kartläggningen av vad som kan komma att driva utvecklingen av våtmarker som källa till bioenergi framåt, och vilka delar som saknas i det arbetet. Efter intervjuer med intresserade och kunniga aktörer inom ämnet presenteras här de drivkrafter och hinder som påverkar denna utveckling. Drivkrafterna grundar sig i viljan att komma bort från fossila bränslen, att minska utsläppen av näringsämnen samt ge utrymme för biologisk mångfald, samtidigt som åtgärderna kan göra nytta för samhället och hjälpa till att nå klimat- och miljömålen. De största hindren utgörs av att speciella maskiner kan behövas för behandling av våtmarksgrödorna där terrängen är känslig och att mycket stora ytor skulle behövas för att öka lönsamheten. De ekonomiska stöd som finns att tillgå täcker inte heller alla nödvändiga steg i produktionsledet. Eftersom priserna på el och fossila bränslen är låga finns ännu ingen etablerad marknad för denna typ av energikälla och produktionen leder därför inte till någon större förtjänst. Biobränsleproducenter har även svårt att på ett tillräckligt effektivt sätt utvinna energin från grödorna. Detta gör att efterfrågan på energigrödor från våtmarker idag är mycket låg. Trots detta kan våtmarker bidra med en rad viktiga ekosystemtjänster i samband med produktion av energigrödor. Det rekommenderas därför att ett sådant system präglas av förvaltningsfilosofin mångbruk, där en naturresurs syfte är att nyttjas för flera ändamål samtidigt. Detta multifunktionella synsätt kan hjälpa till att öka våtmarkernas roll i uppfyllandet av flera av de nationella klimat- och miljömålen, om dess ekosystemtjänster vägs in tydligare i kalkylerna vid energiproduktion.Sweden have already reached several of their goals for energy consumption, but the overall goal to become a fossil free society can still be seen as a driving force to keep developing renewable fuels. There is financial support for wetland construction, reduce impact on the climate, improve the natural environment, for developing new techniques and for biomass fuel plants. Still, cultivation of wetland crops for energy extraction are not yet well established on the energy market. After interviews with actors interested and knowledgeable in this field, this study presents driving forces and barriers affecting the development of this energy source. Driving forces comes from the ambition to move away from fossil fuels, decrease emissions of nutrients, make room for biodiversity, and provide services for the society while helping to reach climate and environmental goals. The barriers affecting this development is that special machines might be needed for handling of the crops and also to harvest the sensitive wetlands while large areas would be needed to increase profitability. The financial support available is not enough to cover the costs for production. Also, the prices on electricity and fossil fuels are low, which lowers the profitability for this type of energy source. Bioenergy producers have not yet found an effective way to extract energy from the crops. All of this makes the demand for energy crops from wetlands small. Despite this, wetlands provide several important ecosystem services and it is therefore recommended to use the management philosophy of multiple-use. With a multifunctional view of wetlands, the value of its ecosystem services can be added to the calculations of energy production and increase its role in reaching several national climate and environmental goals.
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Wilhelmsson, Ella. "Investigations of the Effects of Lowering the Temperature in Full Scale Mesophilic Biogas Digesters at a Wastewater Treatment Plant." Thesis, Linköpings universitet, Tema Miljöförändring, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-167059.
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This thesis has investigated the effects of running the two full scale biogas digesters at Slottshagen wastewater treatment plant at 34 °C compared to 37 °C, in terms of process stability, biogas production and energy savings with the aim of saving energy and money by not heating the digesters as much. The main objective was to investigate whether it is at all possible to operate the biogas process at 34 °C or if the process becomes inhibited or otherwise unstable. If the process could be operated at 34 °C it might mean savings of both energy and money, provided that there is still a sufficient production of biogas.The experiment lasted for three months and investigated the short-term effects of the reduction of temperature. The process was monitored closely, and samples from the reactors were collected and analysed twice a week to ensure the stability of the biogas process. Several parameters were monitored online, the biogas production and methane content amongst others. Other parameters were calculated, such as the degree of degradation and specific methane production. This was done to ensure process stability and a sufficient production of biogas. The energy balance was calculated to evaluate if energy was saved by lowering the temperature in the digesters.The results show that the biogas process does remain stable at 34 °C while still producing a satisfactory amount of biogas during the short time of the experiment. Calculations show that both energy and money has been saved during the experiment. However, the system is largely dependent on seasonal variations, therefore further studies over a longer time period would be desirable. During the course of the thesis it has also become evident that the biogas process at Slottshagen is irregular in several aspects, and that it would be beneficial to even the process out, especially with regards to the hydraulic retention time. Making the process more even would enable further improvements to be made and simplify interpretations and comparisons of processstability data.
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Ma, Charlie. "Aspects of Ash Transformations in Pressurised Entrained-Flow Gasification of Woody Biomass : Pilot-scale studies." Doctoral thesis, Luleå tekniska universitet, Energivetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62914.
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Pressurised entrained-flow gasification (PEFG) of woody biomass has the potential to produce high purity syngas for the production of vital chemicals, e.g., biofuels. However, ash-related issues such as reactor blockages and refractory corrosion need to be addressed before this potential can be realised from a technical perspective. These undesirable consequences can be brought about by slag formation involving inorganic ash-forming elements and the chemical transformations that they undergo during fuel conversion. The objective of this study was to elucidate the ash transformations of the major ash-forming elements and the slag formation process. A pilot-scale PEFG reactor was used as the basis of the study, gasifying different woody biomass-based fuels including wood, bark, and a bark/peat mixture. Different ash fractions were collected and chemically analysed. Reactor slags had elemental distributions differing from that of the fuel ash, indicating the occurrence of fractionation of ash material during fuel conversion. Fly ash particles from a bark campaign were also heterogeneous with particles exhibiting differing compositions and physical properties; e.g., molten and crystalline formations. Si was consistently enriched in the reactor slags compared to other major ash-forming elements, while analyses of other ash fractions indicated that K was likely volatilised to a significant extent. In terms of slag behaviour, near-wall temperatures of approximately 1050-1200 °C inside the reactor were insufficient to form flowing ash slag for continuous extraction of ash material during firing the woody biomass fuels alone. However, fuel blending of a bark fuel with a silica-rich peat changed the chemical composition of the reactor slags and bulk slag flow behaviour was evident. Thermochemical equilibrium calculations supported the importance of Si in melt formation and in lowering solidus and liquidus temperatures of Ca-rich slag compositions that are typical from clean wood and bark. Viscosity estimations also showed the impact that solids have upon slag flow behaviour and corresponded qualitatively to the experimental observations. Corrosion of reactor refractory was observed. The mullite-based refractory of the reactor formed a slag with the fuel ash slag, which caused the former to flux away. Reactor blockages were also resultant because of the high viscosity of this slag near the outlet. A preliminary study into the corrosion of different refractories was also carried out, based on firing a bark/peat mixture. Alumina-rich refractories consisting of corundum, hibonite, mullite, and andalusite tended to form anorthite and exhibited varying degrees of degradation. Infiltration of slag was evident for all the samples and was a severe mode of degradation for some refractories. For fused-cast periclase and spinel-based refractories, slag infiltration was limited to voids and no extensive signs of refractory dissolution were found. This is also supported by a thermochemical equilibrium calculations mimicking slag infiltration that incorporated viscosity estimations. The findings from this thesis contribute towards the development of woody biomass PEFG by highlighting issues concerning ash fractionation, slag behaviours and ash\slash refractory interaction that should be investigated further.
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Lindberg, Simon. "Förnybar gas för värmningsugnar i stålindustrin : Tekno-ekonomisk utvärdering av gasproduktion för SSAB Borlänge." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75181.
Full textAbstract:
Sverige strävar efter ett mer hållbart samhälle och har som mål att nå netto nollutsläpp av växthusgaser till atmosfären år 2045. Företag som agerar i Sverige måste därmed göra stora omställningar för att målet ska kunna nås. I detta arbete har möjligheten att ersätta SSAB Borlänges fossila bränslebehov i varmvalsningsprocessen med gas från termisk förgasning undersökts. Genom litteraturstudier, behovsanalys, beräkningar och modellering i Excel har fyra fallstudier med olika förgasningskoncept utvärderats. En stor utmaning har varit att finna lösningar för hantering av de stora värmelasterna i varmvalsningsugnarna. I fallstudierna har olika strategier tillämpats för att hantera dessa; gasmotorer, balansering med gasklocka eller uppgradering till SNG som lagras i kryogena behållare. Ett fall med inköp av biobränslebaserad flytande naturgas (bio-SNG) från externa producenter har också utvärderats. Den tekniska genomförbarheten samt den ekonomiska insatsen och vinningen har utvärderats för att hitta det bästa alternativet. Fallet med gasklockan (Fall 1b) visade på bäst ekonomisk prestanda med en internränta på 1,6%, en återbetalningstid på 21 år och tillverkningskostnad på 518 kr/MWh. Detta är sämre än nuvarande lösning som kostar 470 kr/MWh. De känsligaste faktorerna för kostnaden är biomassans och fossila bränslets priser. Även investeringskostnaden har stor inverkan. En stor fördel med nya lösningen är minskningen av SSAB:s användning av fossila bränslen med cirka 850 GWh som ersätts av förnybar gas.Sweden strives for a more and more sustainable society and aims to reach the net zero emissions of greenhouse gases to the atmosphere by 2045. Companies that operate in Sweden must therefore make major changes to achieve that goal. In this project, the possibility of replacing SSAB Borl¨anges fossil fuel needs in the hot-rolling process with gas from thermal gasification has been investigated. Through literature studies, needs analysis, calculations and modeling in Excel, four case studies with different gasification concepts have been evaluated. One major challenge has been to find solutions for handling the large heat loads in the hot-rolling furnaces. In the case studies, different strategies have been applied to address these; gas engines, balancing with a gasholder or upgrading to SNG that are stored in cryogenic containers. A case of purchasing biofuel-based liquid natural gas (bio-SNG) from external producers has also been evaluated. The technical feasibility as well as the financial stake and profit have been evaluated to find the best option. The case with the gasholder (Case 1b) showed the best economic performance with an IRR of 1.6%, a payback period of 21 years and manufacturing cost of 518 SEK/MWh. This is worse than the current solution, which costs 470 SEK/MWh. The most sensitive factors are the price of biomass and fossil fuels. The investment cost also has a great impact. A major advantage of the new solution is the reduction of SSAB’s use of fossil fuels with about 850 GWh being replaced by renewable gas.