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.

Le colture energetiche su larga scala, cosi come l’utilizzo di biomassa forestale non residuale, impattano notevolvente i cicli di nutrienti, la biodiversità e l’occupazione di suolo (i tre limiti del pianeta già oltrepassati, oltre al cambiamento climatico) risultando non riconciliabili con uno spazio di operazione sicuro per l’umanità. Occorre piuttosto perseguire fonti di energia rinnovabile che consentano di disaccoppiare il sistema energetico dall’emissione di gas climalteranti ed al contempo richiedano un uso minimo del suolo e limitati impatti sui cicli dei nutrienti e sulla biodiversità.La biomassa forestale residua, la biomassa coltivata in terreni marginali / abbandonati con un basso apporto di nutrienti e la biomass residual proveniente da altri settori dell'economia possono fornire una fonte temporanea di energia per quei settori più difficili da dissociare dai combustibili fossili, in un percorso che porti verso una società in meno dipendente dalle tecnologie di combustione. / Large scale dedicated cultivation of bioenergy on fertile arable land or the large scale deployment of biomass from standing forest, with their impact on nutrient cycles, biodiversity and land occupation (the three planet boundaries which are already overtaken beside climate change) is difficult to reconcile with a safe operating space for humanity. Renewable energy sources allowing the decoupling of energy systems from GHG emission requiring a minimal land use, and therefore limited impacts on nutrient cycles and biodiversity, are to be pursued. Residual biomass such as forest harvest residues, biomass cultivated in marginal/abandoned land with low nutrients input, and biowaste from other sectors of the economy may provide a temporary source of energy for those sectors more difficult to decouple from fossil fuels, towards a society less dependent on combustion technologies.

Since the beginning of farming, and even before, humans have been actively modifying our environment in order to harvest biomass. With the ‘Great Acceleration’ of the industrial age, the global system of biomass harvest for food production has become a major driver of Earth system processes, and caused multi-dimensional sustainability issues which must be addressed in order to meet continued increases in demand for food and other biomass. In addition, bioenergy generation, with the subsequent storage of some or all of the carbon content of the feedstock (known as bioenergy with carbon storage or BECS), is now seen as an important tool for rebalancing the carbon cycle. This thesis has used a biomass flows modelling approach to examine possible trajectories for the socio-ecological metabolism of humanity, with a focus on fluxes of carbon contained in biomass. This approach connects social and economic drivers of biomass harvest with physical Earth systems processes such as the global carbon cycle. Meeting growing food demand in the years 2000-2050 is likely to be a significant challenge in its own right, necessitating the harvest of over 30% of terrestrial biomass. This can only be done without significant damage to natural ecosystems if large increases in efficiency and intensity of food production are achieved, or diets are altered. The production of livestock products is shown to be a major cause of inefficiency in biomass harvest, and changes to livestock demand or production are particularly powerful in ensuring a less damaging relationship with Earth system processes. If increases in efficiency are achieved, it may be possible to grow dedicated bioenergy crops, which, combined with the biomass available in waste and residue streams can be used to generate significant carbon dioxide removal (CDR) fluxes via BECS. Following this strategy it is possible to have a non-trivial effect on atmospheric CO2 concentration by 2050. Increasing the intensity of biomass harvest, particularly when low intensity pasture is replaced with intense bioenergy cropping, also has significant implications for ecological energy flows, and the potential trade-off between protecting biodiversity and growing bioenergy crops to mitigate climate change is also discussed. This body of work presents several interesting areas of potential conflict in different drivers of biomass harvest, and suggestions are made for ways in which to develop the approach in order to explore them.

This thesis applies concepts and techniques in geography in order to contribute to our understanding of the opportunities and challenges associated with the transition toward renewable energy. The work is best understood as the sum of two parts. In the first part, the methodological and philosophical underpinnings of the field of energy geography are explored in order to situate the research in the broader constellation of geographical practices surrounding energy. I make the case that energy transitions are not merely shifts in energy supply but are also simultaneously fundamental shifts in prevailing spatial relations, so that energy transition management is best conceived as a spatial strategy with emphasis on regional level land-energy planning. In the second part of the thesis, I aim to provide decision support in favour of this spatial strategy. This begins in Chapter 4 with a comprehensive critical review of how GIScience and remote sensing has been applied in RE assessments and spatial planning. The next three chapters engage key gaps in this literature and are the analytical contributions of the thesis. The focus of the research is on biomass and solar energy in (eastern) Ontario. In Chapter 5 I develop geographically explicit supply-cost curves for forestry and agricultural biomass and assess the relative merits of a mixed biomass feedstock stream. In Chapter 6 I recognize and address the issue that developers of dedicated bioenergy crops and ground-mount solar PV systems prefer the same type of land. Land-energy trade-offs are modeled and their implications in the context of incentivizing RE development are discussed. In Chapter 7 I explore ways in which targeted facility siting can capture ancillary benefits related to RE production. I argue that focusing on the benefits as well as the costs of system siting is critical to linking developer and public interests. Ontario’s feed-in tariff program is evaluated in the light of this claim. Chapter 8 concludes with a summary of key findings and describes the ways in which this thesis can be used as a platform upon which a broader research program can be raised. / Thesis (Ph.D, Geography) -- Queen's University, 2013-07-03 00:36:53.142

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.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Donghai Wang / Sweet sorghum accumulates high concentrations of fermentable sugars in the stem, produces significant amount of starch in the grain (panicle) and has shown to be a promising energy feedstock. Sweet sorghum has a short growing season so adding it to the sugar cane system would be good. The overall goal of this dissertation is to enhance the attractiveness of biofuel production from sweet sorghum to fully utilize fermentable sugars in the juice, starch in the panicle and structural carbohydrates in the stalk for high efficiency and low-cost ethanol production. Sweet sorghum juice was incorporated into the dry-grind process which achieved 28% increase of ethanol yield compared to the conventional ethanol method and decreased enzymatic hydrolysis time by 30 minutes. A very high gravity fermentation technique was applied using sweet sorghum juice and sorghum grain yielded 20.25% (v/v) of ethanol and 96% fermentation efficiency. Response surface methodology was applied in order to optimize diffusion conditions and to explore effects of diffusion time, diffusion temperature, and ratio of sweet sorghum biomass to grain on starch-to-sugar efficiency and total sugar recovery from sweet sorghum. Starch hydrolysis efficiency and sugar recovery efficiency of 96 and 98.5% were achieved, respectively, at an optimized diffusion condition of 115 minutes, 95 °C, and 22% grain loading. Extraction kinetics based on the optimized diffusion parameters were developed to describe the mass transfer of sugars in sweet sorghum biomass during the diffusion process. Ethanol obtained from fermented extracted sugars treated with granular starch hydrolyzing enzyme and those with traditional enzymes were comparable (14.5 – 14.6% v/v). Ethanol efficiencies also ranged from 88.92 –92.02%.

Master of Science / Department of Agronomy / Humberto Blanco / DeAnn Presley / The U.S. agricultural sector is in a prime position to provide crop residues such as corn (Zea mays L.) stover as feedstock for large-scale bioenergy production. While producing renewable energy from biomass resources is a worthy initiative, excessive removal of corn stover from agricultural fields has the potential to increase soil erosion, degrade soil properties, and reduce corn yields. A need exists to objectively assess stover removal impacts on agriculture and the environment on regional scales. This project assessed the effects of removing various rates of corn stover on runoff and erosion and changes in soil physical properties and corn yields on a regional scale across three soils at Colby, Hugoton, and Ottawa in Kansas, USA. The soils were Ulysses silt loam (Fine-silty, mixed, superactive, mesic Aridic Haplustolls) at Colby, Hugoton loam (Fine-silty, mixed, superactive, mesic Aridic Argiustolls) at Hugoton, and Woodson silt loam (Fine, smectitic, thermic Abruptic Argiaquolls) at Ottawa, all with slopes [less than or equal to] 1%. Five stover treatments were studied that consisted of removing 0, 25, 50, 75, and 100% of stover after harvest from no-till and strip-till continuous corn plots. Simulated rainfall was applied in spring 2010 at rates representing 5 yr return intervals at each site and included a dry and wet run. Runoff increased with an increase in stover removal at Colby and Hugoton, but not at Ottawa. At Colby, stover removal rates as low as 25% caused runoff to occur 16 min sooner and increased sediment loss. At this site, runoff and sediment-carbon (C) loss increased as removal rates exceeded 25%. At Hugoton, complete stover removal increased loss by total N by 0.34, total P loss by 0.07, PO[subscript]4-P by 0.003 and NO[subscript]3-N by 0.007 kg ha-[superscript]1. At Ottawa, PO[subscript]4-P loss decreased by 0.001 kg ha-[superscript]1 with 25% removal and by 0.003 kg ha-[superscript]1 with 50% removal. Mean weight diameter (MWD) of wet aggregates decreased with an increase in stover removal on all soils. At Ottawa, stover removal at 75% reduced soil C in the top 5 cm by 1.57 Mg ha-[superscript]1. Soil volumetric water content decreased with stover removal at Colby and Ottawa, but was variable at Hugoton. Soil temperature tended to increase with stover removal during summer months and decrease during winter months. Soil temperature also fluctuated much more widely with stover removal, resulting in more freeze-thaw events compared to no stover removal. No effect of stover removal on soil water retention was observed on any of the soils. In 2009, removal rates [greater than or equal to]50% resulted in greater grain yield at Colby, while removal rates [greater than or equal to]75% resulted in greater grain yields at Ottawa in 2009 and 2010. Results from the first two years of stover management suggest that stover removal at rates above 25% for bioenergy production increased water erosion, degraded soil structural properties, and altered soil water and temperature regimes. Higher rates of removal ([greater than or equal to]75%) can also reduce soil C concentration in the short-term in rainfed regions. However, grain yields may be enhanced by stover removal from irrigated soils and from rainfed soils with adequate moisture. Overall, the increase in water erosion and alteration in soil properties in the short-term suggest that stover removal can detrimentally affect water quality and soil productivity in Kansas. Further long-term monitoring is warranted to conclusively discern stover removal implications.

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.

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.

<p>In the U.S., bioenergy accounts for about 50% of the total renewable energy that is generated. Every stage in the life cycle of using bioenergy (e.g., growing biomass, harvesting biomass, transporting biomass, and converting to fuels or materials) has consequences in terms of the three dimensions of sustainability: economy, environment, and society. An integrated sustainability model (ISM) using system dynamics is developed for a bioenergy system to understand how changes in a bioenergy system influence environmental measures, economic development, and social impacts.<br></p><p><br></p><p>Biomass may be used as a source of energy in a variety of ways. The U.S. corn ethanol system forest residue system for electricity generation, and cellulosic ethanol system have been investigated. Predictions, such as greenhouse gas (GHG) savings, soil carbon sequestration, monetary gain, employment, and social cost of carbon are made for a given temporal scale. For the corn ethanol system, the annual tax revenue created by the ethanol industry can offer a significant benefit to society. For the forest residue system for electricity generation, different policy scenarios varying the bioenergy share of the total electricity generation were identified and examined via the ISM. The results of the scenario analysis indicate that an increase in the bioenergy contribution toward meeting the total electricity demand will stimulate the bioenergy market for electricity generation. For the cellulosic ethanol system, the compliance of cellulosic ethanol can be achieved under the advanced bioconversion technologies and the expansion of energy crops. However, nitrate leaching and biodiversity change should be considered when expanding energy crops on marginal land, pasture, and cropland. Moreover, three bioenergy systems reduce GHG emissions significantly, relative to fossil fuel sources that are displaced, and create economic benefits (e.g., GDP and employment). Additionally, a spatial agent-based modeling is developed to understand farmers’ behaviors of energy crop adoption and the viability of cellulosic biofuel commercialization.<br></p>