The project focus on combustion of softwood pellets and pellets in a 40 kW grate fire reactor at TEC-Lab. Dept Applied Physics and Electronics at Umeå University. Experiments were performed at four primary airs to fuel ratios (0.7 to 1.3), where aspects such as temperature profile, levels of gases (CO and NO), sintering-/-slagging and unburned fraction of the ashes were studied. Four different fuel loads were used for wood pellets (10, 20 and 30 kW) and one fuel load for straw (10 kW). Combustion of straw proved very difficult to ignite, and also led to other combustion-related technical problem such as slag formation due to the relatively low melting temperature-/-slag temperature of the straw.

AbstractThis degree thesis was made in cooperation with Chematur Engineering in Karlskoga.Many of the environmental issues of today are a result of the motor traffic. Consumption of fossil fuels harms our environmental through formation of carbon dioxide and other greenhouse gases. To get under control with our environmental issues it?s important to find substitutes for oil that are both cheap and environmentally friendly. Ethanol has a long history as a motor fuel and is both enviromentally friendly has a high efficiency.According to the EU commissions directives for motor fuels, 5, 75 % of all the fuels in Sweden should be renewable in 2010.

The aim of this study was to develop a simple model for calculating stock costs for bio fuel at Billerud Karlsborg and subsequently recommending a suitable stock level of bio fuel. The stock components considered in the model are GROT (branches and tops), bark, dry wood chips, raw wood chips from barking and sawdust. The calculations are based on a probability distribution of historical deviations between ordered and delivered volumes. The model presents two different ways to manage the supply in case of irregular deliveries. The first way is to stock enough volume to cover the deviations and the second way is to compensate with a quick purchase from the spot market (at extra high purchase prices).

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing Fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in Fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.

This final thesis is initiated by the wood fuel department at the Swedish forest company Sveaskog as part of a project which also involves two other final thesises. The overall goal of the project is to investigate Sveaskog´s possibilities to produce and sell different wood fuel assortments in Västerbotten and the southern parts of Norrland. The aim of this thesis is to investigate how much wood fuel Sveaskog can produce in the area during the next five years and what that would cost. Furthermore the thesis will investigate the total possible supply of wood fuel from all other possible producers in the area. Treated assortments are forest residues from final fellings, whole trees from direct wood fuel thinnings, non industrial wood and industrial by-products from sawmills. The main effort to investigate Sveaskog´s production possibilities has been made to calculate the possible annual amount of forest residues and fuel from wood fuel thinnings that can be produced.

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing Fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in Fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.

Several technical solutions are ready to step forward as the new generation of propellant, and this report aims to explore the possibility of commercializing fuel cell cars. The report is based on current research and data from today's technology and engineering solutions that are estimated to be commercially realized before 2020.A mapping of today?s different fuel cell options has shown that the most suitable fuel cell option is the Proton Exchange Membrane Fuel Cell, which uses hydrogen as fuel. The report is focusing on a techno-economic well-to-wheel analysis of hydrogen and the energy balance and costs in a system perspective. The basis for this analysis consists of two centralized methods of production, steam methane reforming (SMR), and alkaline water electrolysis.

Ethanol fuel is a biofuel, which been widely reported in the public debate and on the fuel market the last years. Ethanol is sold as both E85 and as a five percent admixture of all petrol sold in Sweden. Research studies on ethanol fuel often focus on environmental issues surrounding the production and utilization of ethanol as a fuel, and omits the private and business aspects of the subject. The purpose of this study is to illustrate the economics of ethanol as a fuel. How the Swedish market for ethanol is and how it evolved over time and what the future prospects are.

Stands where pre commercial thinning has been ignored or inadequate often tend to have high stem density and low average diameter when they reach heights of thinning. In such stands, it can often be expensive to do a conventional pulpwood harvest as a first thinning. This study investigates the development of the stands and the economic outcome of forest fuel extraction, or a combined harvest as alternatives to the ordinary pulpwood harvest. Simulations in Heureka StandWise were performed for two thin and dense stands, which were constructed by data from the Swedish National Forest Inventory. The simulations show that the extraction of forest fuel in first thinning at an early stage can provide higher net revenue compared to conventional pulpwood harvest at the same time or later.

In the world we live in today the environmental issues has become increasingly important, and we have begun to realize that we can not continue to use fossil fuels at the rate we do. When it comes to generating electricity we are constantly trying to come up with cleaner and more efficient solutions. The fuel celltechnology is one such alternative and has been around for over 100 years. Yet, it is not until now that the world has started to notice this great technology. The fuel cell has been developed in several areas and can today be used for handheld electronics, vehicles and small settlements.

A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.

The consumption levels in Sweden, Denmark, Finland and Norway have been rising fo r the last decade. Even after the financial crisis of 2008, consumption levels continued their upward trend, regardless of the recession. The explanation seems to be, at least partly, that households tends to increase their debt ratio in order to continue the same standard of living as before in terms of consumption. It is clear, based of our results, that there is a connection between increased consumption and debt ratio for households. And the consequences of allowing loans to finance a sustained or increasing consumption may ultimately be difficult to manage.

This study concerns the energy future of the county of Stockholm up until 2050 and describes how the energy consumption can be compared to today with the use of scenario methodology. Within energy future studies the backcasting approach is well known and has been put to use in this study. Due to the characteristics of backcasting the study is self-fulfilling, i.e. the future energy scenarios presented in this study satisfy the targets set up in this study. In the light of what may be the largest challenge of our time ? the climate change - the aim of this study is to describe how the energy consumption in a fossil fuel free Stockholm county in the year of 2050 may be.

Denna studie handlar om den fartförlust och därmed den ökade energiförbrukningen som drabbar fartyg på grunt vatten. Syftet var att ta reda på hur mycket kortare en grund passage behöver vara för att den ska vara ett bättre alternativ än en lång och djup rutt med hänsyn till bränsleförbrukning och tidsåtgång. Resultatet av detta blev att det inte går att dra några generella slutsatser som gäller för alla fartygstyper men att det går att se tydliga tendenser. Studien hade även som målsättning att skapa ett underlag som skulle kunna användas av nautiker vid planering av resor, detta presenterades i form av en sammanställning av de resultat som erhållits vid beräkning av fartförlust i öppet vatten. Någon sammanställning gjordes inte för begränsat vatten eftersom exempelfartygen där fick likadana resultat vilket skulle ha gjort en sådan överflödig.

 With the increases in fuel costs due to the depletion of the world oil reserves and the increase of greenhouse gasses as a consequence to using oil as a fuel many companies are looking to new and innovative ways to power their aircraft. One of these new ways to power an aircraft is using fuel cells powered using hydrogen and oxygen, thus producing nothing but water vapour and small amounts of nitrogen dioxide as well as trace amounts of other emissions. Both Boeing (1) and Politecnico di Torino (2) have shown that it is possible to build an all-electric aircraft powered by fuel cells. Both flights used small, two-seater aircraft and a constant between them was the loss of the co-pilot seat due to weight and lack of space. As this paper will deal with a commercial aircraft a primary concern is the cargo and passenger capacity and whatever impact switching propulsion system has on these.